eChapters

8.1 Economic Geology and Ore Mineralogy

8.1.1 Economic geology

Economic Geology deals with the comprehensive study of mineral deposits including their processes of formation and uses. By applying the principles of geology, a mining engineer is able to exploit such deposits profitably for the use of Man.

8.1.2 Ore mineral

An ore is a term applied usually to that part of a metalliferous mineral deposit that can be utilized profitably as a source of one-or-more metals, this term now is widely used for the usable part of many non-metallic (non-metalliferous mineral) deposits, like barite, fluorite, sulphur, etc.

8.1.3 Gangue mineral

An ore is usually a mixture of one or more usable minerals (ore minerals) and one or more unusable minerals (gangue minerals). The usual gangue minerals are quartz and other forms of silica, calcite, dolomite, siderite, barite, feldspars, garnet, chlorite, kaolin, fluorite, apatite, pyrite, pyrrhotite, arsenopyrite, and sometimes the gangue material is the country rock or host rock itself in which the ore minerals occur. Sometimes, the gangue minerals may also be utilized as by-products of the ore deposit. The nature and proportion of the gangue influence the economic value of an ore to a great extent.

Abstract

The dating of fluvial landforms by archaeological, epigraphical, historical, thermo-luminescence, radiocarbon, etc. are of greater significance because it not only provides information on the date of origin of such fluvial landforms but also isostatic, eustatic, climatic histories of the Quaternary period. Hence, the Geoscientists have always been giving greater importance to the dating of the fluvial landforms. In India, the Cauvery is one such river studied for its migratory melodrama with the help of satellite data and inferred that the river Cauvery has earlier flowed along the Hogenekkal-Chennai tract (PCS-1-Palaeo Channel System-1) during 500 thousand to 3000 YBP (years Before Present), then migrated towards southerly and flowed along the present day paths of Thoppurar, Vaniyar and Ponnaiyar rivers (PCS-2) during 2700-2300 YBP and further migrated southerly and entered into Tiruchirappalli-Thanjavur plains after 2300 YBP and finally anticlockwisely migrated in different parts of the present day Cauvery delta and stabilized as river Coleroon during 2100-750 YBP. Such broad chronological history was brought out on the basis of archaeological, epigraphical, historical, literature and few radiocarbon dating. In the present study, more number of radiocarbon dating was done in various palaeochannels of river Cauvery which has over all coincided with above observations and further provided discrete information on (1) the southerly migration of river Cauvery from PCS-1 to PCS-2 after 8000 YBP, (2) tectonic arching and splitting up of channels in Chennai region during above period, (3) gradual younging nature of palaeochannels from PCS-1 of Chennai region to PCS-3 of Tiruchirappalli – Thanjavur region, etc.

Abstract

From amongst various geomorphic features the landforms generated by the river systems are significant as these are not only the records of the life histories of the rivers, but also the various dynamic processes and phenomenon operated during their origin like tectonic movements, sea level changes, flood histories, climate changes etc. In this connection a study has been conducted using the satellite borne multi spectral remote sensing data in mapping the flood plains, particularly their anomalies like symmetrical, asymmetrical, multilevel, offset and meander scrolled flood plains of some selected rivers from Asia viz: Tamirabharani, Cauvery and Brahmaputra from India, Indus river from Pakisthan and Tineg river from Phillipines. The paper discusses about these and their significance in unfurling the ongoing tectonic movements, sea level changes, palaeo – ongoing strom surge / tidal activities, ongoing earth tremors etc.

Introduction

The Rivers are not simply the carriers of water from the mountain ranges to the plains and to the oceans. But they have well defined and characteristic life histories of their own, with youthful stage in the mountains, mature stage in the plains and the old stage in the coastal regions [6] and the life histories of the rivers are often compared with man’s life. Infact, once the rivers are born on the surface of the Earth, their only aim is to attain the Mean Sea Level (MSL) or the base level of erosion as early as possible and as short as possible. So, in the mountains, which are normally their regions of origin, since the rivers occur thousands of meters above the MSL, flow vibrantly taking advantage of the slope as short and straight drainages to cut deeply the terrain so as to attain the MSL easily. Since such vibrant activities of the rivers, appear to be similar to the human youths, the rivers are said to be in youthful stage in the mountain regions and the erosion is the only dominant activity. But, on climbing down the hills and reaching the plains, as they still occur at hundreds of meters above the MSL, continue to flow towards the sea but with meandering, sinuous and oscillatory paths as they have lost their elevations when compared to the mountains and in this process of meandering perform both erosion and deposition. As such stabilized flow or “Watch and walk phase” of the rivers in the plains resembles the matured behavior of the middle aged Men, it is called as mature stage of the rivers. In contrast, when the rivers reach the coastal zones as they have attained the MSL, they don’t have any energy to carry even their own load and hence dump all the sediments as deltas, oscillate here and there and finally somehow reach the sea. Such Brownian movement of the rivers as replicates the activities of the old Men, called as the old stage of the rivers. Thus the erosion, both erosion and deposition and only the deposition are respectively the activities of the rivers in these three stages, accordingly the respective and contrasting landforms are formed in these three different stages of the rivers.

Abstract

Geomorphology not only provides the panorama on the external architecture of the Earth surface, but also it is the record of the past geological events including the climate, especially of the Quaternary period. Detailed geomorphology map was prepared using the IRS LISS IV FCC and SRTM data showing the tectonic, denudational and fluvial landforms of Kollai hill, Eastern Ghats, Tamil Nadu. The geomorphic features showed that the Kollai hill can be divided into two as northern and southern blocks separated by a NE-SW active sinistral fault in the overall N-S rectangular hill. The integration all the geological , structural and geomorphic features show that the Kolli hill is under the grip of uplift in the south west with hinge towards north easterly. Because of this, the northern block/rim of the hill is fragmented into a series of East-West trending fracture/ fault swarms which are sympathetic tectonic grains to the Attur graben rimming the Kollai hill to its north. This phenomenon seems to control the overall resources and environment of the hill.

Introduction

The mountains are not only the store houses of natural resources like minerals, water, geothermal springs, forest & biomass etc., but also possesses unique & self-styled ecosystems drafting the mankind from the plains for comfort and livelihood. Further, the tourists are highly attracted by the mountain regions due to the ecosystems, climate and scenic beauty. Due to all these, the resources of the mountains are exponentially exploited during the recent 6–7 decades thus causing phenomenal depletion of natural resources and initiation of chains of environmental disorders, viz., deforestation triggered soil erosion, landslides, debris dumping along the slopes and foot hills, sedimentation of the downhill reservoirs & drainages, all of which in turn induce haphazard flooding. Hence, the Union and various Federal Governments have started working on the restoration of the ecosystems of their respective mountain regions in several nations. In the Indian sub- continent too, both under the Centrally sponsored schemes and the State funding, number of Hill Area Development Programmes have been initiated and going on especially in Himalayas, Easternghats and Westernghats. The state of Tamil Nadu possesses both Easternghats and Westernghats. While the Westernghats are found along the western part of the state with NNW-SSE orientation, the Easternghats represented by the Kollai- Pachhamalai hills, Shevroy - Chitteri – Kalrayan hills and Javadi hills, aligned in N-S direction, are traversing the Central part of Tamil Nadu. To comprehensively understand the resources, hazards potential, the ecosystems and also the modern geological processes which only control and tutor them, a geomatics based study was carried out in Kollai hills so that it can be used as a reference study to all those who are engaged in eco-restoration and hill area development programmes in India.

Abstract

The coastal zones are very fragile owing to the reason that these form the junction between the continents and the oceans. Further the multivariate tectonic, fluvial, marine and aeolian processes, which vary independently in their degrees and duration in space and time, act in different permutations and combinations with each other and keep on constructing and destroying the landforms along the coasts. Again, as coastal zones are heavily populated; it adds further pressure on the coastal systems. The paper deals about the hierarchy of issues faced by the coastal zones like tectonic emergence and subsidence and it‘s impacts and the ways, means and needs for measuring the rate of such movements; marine regression and the need for the time series models on the land-ocean boundaries for drawing the sea level curve for India, the Quaternary deltas and the essentiality for understanding the mixture of fluvial and marine forces for the possible future forecasting models; back water modifications, the related issues and the demands for the sediment-chemo dynamics modelling; disaster vulnerabilities and mapping methodologies etc; all using the unexplored vistas of Geomatics technology. The concept has been explained by taking Tamilnadu coast as the reference region.

Introduction

The coastal zones are always fragile as these are formed by the tectonic, fluvial, marine and aeolian processes, which act independently in varying degrees and duration and occur cumulatively in different permutations and combinations along the different parts of the coasts. In addition to such inherent fragility, the coastal zones stand vulnerably exposed to various natural and anthropogenic disasters like seismicity and earth movements, tsunamis, floods, sea level rise, cyclones, coastal erosion etc. Further, owing to the enriched land and water resources, enjoyable eco systems and avenues for intra and intercontinental trades, more than 70% of the global population and the related infrastructure are clustered in the coastal zones. Hence the scientists from all over the world have started showing more attention towards the coastal regions (Ahmed, 1972). The advent of Geomatics technology comprising multi spectral and hyper spectral remote sensing, GIS, GPS, Interferometry, etc. have opened up exhaustive newer vistas in unfurling the hidden complexities of the coastal zones and to provide solutions. From amongst many, the remote sensing based studies carried out by Shailesh Nayak and his team (2004) have brought out many first time information to light about the Indian coasts. But still we will have to go a long way, as the global coasts in general and the Indian coasts in particular are confronted with a hierarchy of challenges and the Geomatics technology can provide answers for these challenging issues owing to its unique virtues. The paper narrates the unique issues of the Indian coasts and how effectively the geomatics technology can be used in solving them. This has been done by taking Tamil Nadu coast as the test area.

Abstract

The time-transgressive changes in the landscape architecture of the Rameswaram island located in the semiarid tract of southeastern India, was animated using ARC/INFO GIS. The animation has shown that the Rameswaram island has evolved through an interplay of tectonic. fluvial, marine and aeolian activities and that the Aeolian activity was accentuated during 1921-1990 A.D

Introduction

The state of Tamil Nadu in the southeastern fringe of India has well evolved riverine ecosystem in the east and a 900 km. long coastal ecosytem in the eastern fringe. From Vedaranniyam in the northeast to Cape Comorin in the southwest these fluvial and coastal ecosystems show evidence of Aeolian activity, especially during the Holocene. Several researches1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19 have studied the Quaternary tectonic, fluvial, fluviomarine and marine processes in this part of the semi-arid tract.

Abstract

The Adam bridge, the curvilinear chains of islands linking India (Thanushkodi) with Sri Lanka (Thalaimannar), has been a matter of scientific and mythological debate. While the great epic Ramayana says that Lord Rama built this Adam bridge around 1.5 million years ago to bring back his wife Seetha from Srilanka who was a captive by king Ravana of Srilanka, some reports gave another view that it is coral islands of 1.7 million years of age. Under this backdrop, the author refutes the claim made by NASA that the Adam bridge was located firstly by one of its satellites and cited evidences that the Indian scientists located and mapped it using the IRS satellite data much earlier. Further, on the basis of bundles of beach ridges dated in Tiruthuraipoondi-Vedaranniyam area and as well as some of these continue up to Uchipulli area in Ramanathpuram district, the author assigned an age of 3500 YBP ( Years Before Present) to Uchipulli beach ridges seen in the main land to the west of Rameshwaram and Adam’s bridge and inferred that the Adam’s bridge must be equal to or younger than 3500 YBP. The easterly nosing of Indian mainland in Ramanathapuram – Rameshwaram – Thanushkodi and its further extension in the form of Adam bridge, the author demonstrated that the because of anticlockwisely rotating littoral currents to the north and clockwisely moving littoral currents to the south of Adam bridge, the chains sandy islands namely Adam’s bridge was formed by the segregation of sands in between currents shadow zone after 3500 YBP.

Studies and Findings

There was some coverage in the newspapers some time ago about the discovery of a land bridge (Adam’s Bridge) between Dhanushkodi (India) and Talaimannar (Sri Lanka) by NASA through one of its satellite mission. It was also written in some articles that this land bridge was constructed by Lord Rama 1.7 million years ago to reach Sri Lanka with the aim to bring back his wife Sita from the clutches of Ravana. However, this linkage was refuted by NASA. It accepted that the picture was captured by one of its satellites, but it was unaware of the linkage of the land bridge with the great Indian epic Ramayana. Some reports gave another view and mentioned that the bridge was nothing, but 1.7 million years old coral reefs. Many historians have also come out against linking the Adam’s Bridge with Ramayana.

Abstract

Historically, the tiny island katchatheevu located in between Rameshwaram and Srilanka belongs to Ramnad Kingdom and it was handed over to Britishers and during the British’s rule. During that time both Indian and Srilankan fishermen communities were using this for their fishing related activities. On a goodwill, in 1994, the Government of India donated this island to Srilanka. Since then it has become a major issue and a perpetual problem to Indian fishermen that they could neither do fishing around nor berth their boats for drying their fishing nets. Under this scenario, an attempt was made to evaluate the geological setting of Katchatheevu island using E-Topo data which provides the sea bottom topography/morphology. The study revealed that the Katchatheevu island is the north eastern extension of the Pisasumunai of the Rameshwaram island and such arcuate nature of the land between the Pisasumunai and Katchatheevu is attributed to anticlockwisly spiralling littoral currents which would have dumped the sands and developed the island. Thus the study brings some newer information that the Katchatheevu is geologically a part of Indian land mass.

Studies and Findings

The boundary problems within the nations and amongst the nations, especially amongst the territorial nations, have started emerging as major issues of global concern. Katchatheevu Theevu located between India and Sri Lanka is one such a major issue, as the said island which originally belonged to Ramnad kingdom was handed over to Sri Lanka by India in 1974 and since then, the Indian fishermen community is facing untold miseries in the hands of Sri Lankans and hence it warrents immediate attention.

Abstract

The continental drifting and the movement of Indian plate to the tune of 6500 km in a time frame of 65 million years towards north north-easterly, its collision with Eurasian plate, the rise of mighty Himalayan mountains, the still prevalent northerly directed compressive force which has originally drifted the Indian plate and the disseminated intraplate seismicities have been the proven facts. In this context, a remote sensing based study carried out using IRS satellite images revealed that the whole Indian plate is whirling like a worm with series of alternately arranged E-W trending arches and deeps and N-S extensional/block faulting, NE-SW & NW-SE strike slip faults and E-W trending fracture swarms from Cape Comorin in the South to foot hills of Himalayas in the north. These ongoing tectonic activities have displayed hierarchy of geomorphic anomalies in the fluvial, coastal and hydrological systems and these suggest that the whole Indian subcontinent warrant detailed studies to understand the post drift kinematics and its impacts over the ecosystems, natural resources and natural disasters.

Introduction

Consequent to the continental drifting, the Indian plate has moved towards north northeasterly and collided with Eurasian plate, thus resulting into the rise of Mighty Himalayan Mountains along the junction of these two plate boundaries as demonstrated by many earlier Geoscientists. But the behaviour of the Indian plate, both during the collision and after that, has not been comprehensively studied and understood as to whether it has remained as an inert plate or suffered any mid plate deformations. However, disseminated information has been brought out by many earlier workers on the post trappean arches, deeps, horsts and grabens within the

Indian plate. Some of such tectonic grains from north to south in the Indian Peninsular are:

Abstract

The Indian Peninsula in general and its southern part in particular has been thought to be a stable shield area and hence inert to younger earth movements and seismicities. However, in addition to fast relapsing seismicities, the studies carried out by earlier workers during the past three decades indicate possible pulsatory tectonism, at least since the Jurassics. The present study is a newer attempt to identify, analyse, and spatially amalgamate a large number of anomalies visibly displayed by the tectonic, fluvial, coastal, and hydrological systems in remote sensing and ground based datasets/observations, and to finally paint a fair picture on the active tectonic scenario of South India. The study reveals that the phenomena, viz. extensive soil erosion, reservoir siltation, sediment dump into the ocean, preferential migration of rivers, restricted marine regression, shrinkage of back waters, withdrawal of creeks, fall of groundwater table, etc., indicate two E–W trending ongoing tectonic (Cymatogenic) archings along Mangalore–Chennai in the north and Cochin–Ramanathapuram in the south. Intervening these two arches, a cymatogenic deep along Ponnani–Palghat–Manamelkudi exhibiting phenomena opposite to the above is observed. In addition, the characteristic tectonic, geomorphic, and hydrological anomalies observed in 1B satellite FCC data, as well as in the field, indicate N–S trending extensional, NE–SW sinistral, and NW–SE dextral strike slip faults. These anomalies and the tectonic features deduced there upon, indicate that the southern part of the Indian Peninsula is tectonically active due to the northerly to north– north-easterly directed compressive force related to post collision tectonics. This active tectonic model visualized for South India gives a further clue that the whole Indian plate is whirling like a worm with alternate E–W arching and deepening, along with block and transform faulting from Cape Comorin in the south to the Himalayas in the north.

Introduction

The Indian Peninsular Shield in general and its southern part in particular has always been thought of as being inert to younger earth movements and related seismicities / earthquakes. For this reason, geoscientists have not shown much interest in studying the Neo-active-seismotectonics of the southern part of the Indian Peninsula, mostly restricting themselves to the western (Kutch) and central (Son-Narmada) parts of India (Auden 1949, West 1962, Choubey 1970, Biswas and Deshpande 1973, Kailasam 1975, Ghosh 1976, Pal and Bhimashankaran 1976, Crawford 1978, Dessai and Peshwa 1978, Sharma 1978, Guha and Padale 1981, Kaila et al., 1981, 1985, Murty and Mishra 1981, Powar 1981, 1993, Bhagwandas and Patel 1984, Bakliwal and Ramasamy 1987, Merh 1987, Ravishankar 1987, Amalkar 1988, Ramasamy et al. 1991, Gupta 1992, Sareen et al. 1993, Ramasamy 1995a, 1998, and many others).

Abstract

Drainages have characteristic pattern and life histories with youthful stage in hilly areas, mature stage in plains and old stage in the coastal zones. The deviations from their normal life histories, especially aberrations in their flow pattern in the form of various drainage anomalies have been inferred to be the indications of dominantly the Eustatic and Isostatic changes. This, especially after the advent of Earth Observing Satellites, has attracted the geoscientists from all over the world, for studying such drainage anomalies. In this connection, a study has been undertaken in parts of South India falling south of 14° south latitude to comprehensively map some drainage anomalies like deflected drainages, eyed drainages and compressed meanders and to evolve the tectonic scenario therefrom. The mapping of such mega drainage anomalies and the related lineaments/faults from the satellite digital data and the integration of such lineaments/faults with the overall lineament map of South India showed that the study area is marked by active N–S block faults and NE–SW sinistral and NW–SE dextral strike slip faults. Such an architecture of active tectonic grains indicates that the northerly directed compressive force which has originally drifted the Indian plate towards northerly is still active and deforming the Indian plate.

Introduction

Rivers have characteristic pattern and life histories with (1) short and straight drainages performing only erosion in the hilly catchments, (2) meandering and sinuous paths doing both erosion and deposition in the plains and (3) Brownian pattern of movement doing only dumping of sediments and building up of deltas in the coastal zones. Such characteristic life history of the rivers with youthful stage in the hills, mature stage in the plains and the old stage in the coastal zones in general are controlled by the base level of erosion or Mean Sea Level (Thornbury, 1985). But, the rock types and the geological structures of the terrain related to palaeo, time transgressive and ongoing tectonism too significantly control the drainage pattern and the related river flow dynamics in all these three stages. Hence, geoscientists from all over the world have all along been showing greater interest in understanding the drainage architecture in general and their anomalies in particular. That too, after the advent of Earth Observing Satellite technology, mapping of drainage pattern and their anomalies like dentritic, semi dentritic, trellis, parallel, annular, radial, deflected, pirated, avulted, eyed, compressed, preferentially migrated and other drainage anomalies have gained greater momentum, since, besides lithology, tectonics and sea level changes, these drainage anomalies have the credibility of providing information on the flood histories, seismic vulnerability, past climates and anthropogenic phenomenon too (Chitale, 1970; Chen and Stanley, 1995; Lillesand, 1989; Matmon et al., 1999; Miller, 1937; Reid, 1992; Saintot et al., 1999; Smith et al., 1997; Twidale, 2004; Thornbury, 1985 and many others). In different parts of the Indian sub-continent too, studies have been carried out on the drainage anomalies using topographic sheets, black and white panchromatic aerial photographs and orbital multimode and multispectral satellite data, to elucidate the structural fabric, tectonic processes, climatological and other phenomenon of especially the Quaternary period (Amalkar, 1988; Babu, 1975; Bakliwal and Sharma, 1980; Barooah and Bhattacharya, 1989; Mitra et al., 2005; Murty and Mishra, 1981; Narasimhan, 1990; Oldham et al., 1901; Philip et al., 1989; Rajaguru and Kale, 1985; Ramasamy, 1991, 2006; Ramasamy and Kumanan, 2000; Ramasamy et al., 1987, 1991, 2006; Singh et al., 1996; Sood et al., 1982; Thirunaranan, 1938; Vaidyanadhan, 1971; Yashpal et al., 1980).

Abstract

Visualisation of geological process raises special issues for scientists and animators. The degree of physical movement of a rising arch or along a fault line may be very small compared to the normal terrain variation. Over a long time period the major changes in the environment may come from the more substantial surface manifestations of changing draining regimes. In Tamil Nadu State in South-Eastern India there are continuing tectonic movements arising from the collision of the subcontinent with the greater Asian land mass. Over comparatively recent times (7000 years) these movements have had a major impact on drainage and other hydrological outcomes. The Cauvery River in particular has migrated several hundred kilometers over this period. A mosaic was made from recent satellite imagery and then manipulated to create surface textures for dates between -7000 years and +1000 years. Changes in the terrain surface, such as rising arch structures and descending grabens, have been modelled and animated. The combination of terrain movement and surface change provides a visual history of the period.

Introduction

The continued northward movement (5±6 mm per year) of the subcontinental land mass of India induces substantial tectonic pressures all over India. In the southeast, primarily within Tamil Nadu, there is significant differential movement, both vertical and horizontal, of portions of the existing land mass. This is producing a number of effects:

Abstract

Overall geological histories of the Quaternary deltas of all over the world have been studied considerably, to understand the evolution, eustatic – isostatic changes, land – ocean interactive phenomenon, resources, environment etc. But tectonic signatures of these deltas have been less studied, though these have significance in understanding the natural resources, environment and evaluation of natural disasters. In this context, as the state of Tamil Nadu is a low easterly gradient plain, all the easterly flowing rivers have developed well evolved geomorphic features related to youthful, mature and old stages. Such old stages of the rivers are marked by the spectacular development of deltas. These deltas of Tamil Nadu have been studied in detail for understanding the tectonics with the help of visibly seen tectonic and geomorphic features in satellite based remote sensing and ground based data sets. The study has revealed that the upper age limit / ages of these deltas are probably of Middle to Late Holocene and the various tectonic and geomorphic anomalies observed in these deltas obviously indicate the tectonic processes/ phenomena that prevailed during Middle Holocene - till date. The Proto Cauvery delta of Chennai region is witnessing ongoing NE–SW sinistral, NW–SE dextral and E–W vertical tectonic activities. The streams in Ponnaiyar delta are showing persistent southerly migration due to the probable ongoing land subsidence along NE–SW faults in the southern part of the delta. The Cauvery river which has originally developed a broad bird-foot shaped – arcuate delta, has undergone a phase of anticlockwise rotational migration and stabilized in the northern rim of the delta as Coleroon river during 2300–750 Y.B.P. due to the ongoing tectonic emergence in the south of the delta almost since the last 6000 years or so. The Vellar river, in deltaic regime, shows northerly migration due to E–W grabening in the northern part of the delta. Vaigai and Manimuttar rivers are again migrating northerly in their deltaic regions due to the probable land arching to the south of their present day flow. Thus, the paper discusses the post deltaic / Middle -Late Holocene geological processes of Tamil Nadu deltas which are predominated by tectonic activities.

Abstract

The Cauvery delta is a major bird-foot shaped delta with its apex located east of Tiruchirappalli with the mother channel Cauvery flowing along Thanjavur– Kumbakonam – Kaveripoompattinam. The distributary drainages are radiating over an arc towards east from its apex with a fan shape and finally debouch into the sea from south of Tiruthuraipoondi in the south to Kaveripoompattinam in the north. All these distributary drainages are now seen as palaeochannels including the mother channel Cauvery, which is now called as “Palam Cauvery”. The present day flow of Cauvery river is confined to the northernmost rim of the delta as river Coleroon. On the basis of the archaeological, epigraphic and historical data analysed earlier and the14C dating carried out recently, the present authors infer that the age of the delta may vary from 2300 Y.B.P. ( Years Before Present) to 750 Y.B.P. and the age of the palaeochannels are also younging from 2300 Y.B.P. in the south to 750 Y.B.P. in the north. In the southern part of the Cauvery delta, the Mio-Pliocene Sandstone of Pattukottai-Mannargudi area is undergoing upliftment along N-S faults. On the basis of the rapid land progradation during 6085±233 Y.B.P. - 1020±80 Y.B.P. in Vedaranniyam coast, it is visualized that the Mio-Pliocene Sandstone must be undergoing upliftment significantly since 6100 Y.B.P. onwards. On the basis of the occurrence of older palaeochannels in the south, the gradual younging palaeochannels towards the north and the land emergence in the south of the Cauvery delta in Pattukottai – Mannargudi area, it is concluded that the distributary drainages of river Cauvery would have become sequentially defunct / shifted from south to north and finally the mother channel Cauvery also would have been pushed towards north to reach the present tract of Coleroon river. The thinner palaeochannels in the south and the gradual wider palaeochannels in the north of the delta further indicate that as the land was already undergoing emergence in the south even before river Cauvery has entered into Thanjavur plains, the river could not comfortably spread its distributaries in the south. Hence, the southern distributaries, after a brief flow, would have started drying sequentially from south to north during 2300–750 Y.B.P. thereby the floodwater of each of the southern distributary channel would have been pushed to its successive northern counterpart, i.e. the southern distributary (say 1), pushing its water to its immediate northern counterpart (say 2), then the combined flow of 1 and 2 pushing the water to 3 and so on. The anomalous eyed drainage and its modifications during the last 50–60 years and compressed meanders in Coleroon river, deflected drainages in Palam Cauvery, truncation and punctuation of beach ridges by the E – W faults along the N – S coast and such faults acting as pathways for the sub parallel creeks indicate vibrant Late Holocene geological history predominated by the tectonic movements in Cauvery delta.

Abstract

The drainage pattern and the architecture are the reflections of not only the tectono fabric of a region, but also the active tectonic processes. From amongst many drainage patterns and anomalies, the eyed drainages, deflected drainages and the compressed meanders interpreted from satellite images for Pudukkottai region of Southern Tamil Nadu infer to reflect the active N-S block faults and NE-SW sinistral and NW-SE dextral faults related to post collision tectonic phenomena.

Introduction

The Geoscientists have long back recognized that the drainages are the reflections of the surface and subsurface lithology, structure and tectano fabric and also the active tectonic movements especially of the Quaternary period (Thornbury, 1985). Hence, the Geoscientists have all along been showing greater interest in mapping the drainage patterns. However, the mapping of the drainage patterns and detection of tectonic features there from have gained greater momentum only after the advent of modern Remote Sensing technology. Since the airborne and satellite borne spectral images have the credentials of showing the drainage pattern, the drainage anomalies and the tectonic features related to them all of which were studied in conjunction to bring out information on the geological history of the Quaternary period by many workers (Vaidyanadhan, 1971; Murthy and Sastri, 1981; Agarwal and Mitra, 1991; Ramasamy, 1991; Saravanavel and Ramasamy, 2014).

Abstract

Being the junction between the continental and the oceanic plates, the coastal zones are always tectonically alert and hence vested with number of aults. The study of LANDSAT ETM FCC imagery revealed one such a major fault along NNE-SSW aligned Tamil Nadu coast from Chennai in the North northeast to Cape Comorin in the South southwest. This Precambrian boundary fault shows signs of repetitive reactivation during Gondwana, Tertiary and Late Holocene periods. While in former two periods it shows indications of faulting, in the latter period, it is manifested in the form of drainage deflections indicating sinistral movements of beds. While such sinistral morphology of the fault seems to be related to the Post collision compression, the seismicities in and in its close proximities indicate the seismic significance of this fault. In the context of natural resources and disasters viz: geothermal springs, flooding and seismicities, this fault demands deeper studies.

Introduction

The coastal regions in general form the junction between the continental and oceanic plates. Hence, the coastal regions are always tectonically active and thus vested with coast parallel, tangential and conjugate faults depending upon the tectonic history of the area. In the Indian subcontinent too, all along the 9000 km long east and west coast margins, number of major faults were mapped by the earlier workers. Significantly, Vardarajan and Ganju (1989) have brought out a comprehensive picture on the lineaments of the entire coastal zone of India using Landsat images. Vemban et al. (1977) earlier inferred faults along certain segments of east coast of Tamil Nadu and observed them to be lithological contacts and also seismogenic in nature. Raiverman et al. (1966) have again inferred earlier a N-S curvilinear fault in Thanjavur deltaic region and attributed it to post drift kinematics of the Indian plate. Ramasamy (1989) has brought out the morphotectonic and morphodynamic model of the east and west coasts of India on the basis of tectonic and geomorphic signatures using Landsat satellite images. Ramasamy (2006) developed a first time comprehensive model on the active tectonics of the Indian Peninsular and in which he brought out detailed information on the varied geomorphic, tectonic and hydrological anomalies and inferred them to be related to the whirling and fracturing of the Indian plate due to the still prevailing N–S to NNE – SSw compressive force which originally drifted the Indian plate to the present position after the breakup of the Gondwana land.

Abstract

The frequently recurring earth tremors / Seismicities in parts of Tamil Nadu & Kerala and the earthquakes of higher magnitude in Central India in the recent years have gradually dissolved the concept of shield area stability for the South India and the concept of mid-plate seismicity has emerged in the minds of geoscientists, Hence, the geoscientists have embarked into a number of studies to bringout seismotectonic maps for South India. In this context, a detailed studies have been carried out by the authors in parts of westernghats (Kodaikkanal and Varushanad hills) in Tamil Nadu. In the said study lineaments were interpreted using high resolution IRS satellite data and from the lineament pattern, isofracture, lineament density and lineament interaction intensity the strain maxima axes were drawn. Such strain maximas were observed to fall in N- S, E – W and NE –SW directions. These strain maximas were found to coincide with various drainage anomalies, like radial, compressed meandering and eyed drainages indicating that these lineaments are prone for seismicity/ earth tremors.

Abstract

The coastal regions are always tectonically active since these form the junction between the continental and oceanic plates. These tectonic activities and the resultantly tutored fluvial and marine geomorphic processes and the independent fluvial and marine geomorphic processes carve out the coastal morphology. And if these coastal geomorphic features are studied, it will lead to the understanding of the morphotechtonics. One such a study carried out for a part of Ganjam coast, revealed various geomorphic anomalies viz: presence of high order hill ranges only in the north eastern and south western parts of the area with the central plain, northerly migrating Ganjam river, development of wide beach ridges only along the central plain, all indicating the Late Quaternary upliftment of the central plain.

Introduction

The Indian subcontinent is vested with nearly 9,000km long coastline both in its eastern and the western continental margins. These coasts provide unique configuration with convexities (land protruding into the coast), concavities (vice-versa), deltas of different morphologies, beach ridges and swales, bay mouth bars, peaks, serrations and projections in the shorelines, all indicating the vibrant tectonic, fluvial, marine and aeolian processes. As the coastal zones in general, form the boundaries between the continental and oceanic plate margins, these are inherent weak zones prone to tectonic activities, which in conjunction with other geomorphic processes, provide unique architecture to the coasts with above varied geomorphic features. That too, the Indian coasts were inferred to stand as testimony to the vibrant tectonic activities and other related geodynamic processes of the Quaternary period (Ramasamy, 1989; Ramasamy, 1999).

Abstract

Indian Peninsular shield has been thought as tectonically inert and aseismic for many years by the Geoscientists. But, subsequent to the disastrous earthquakes in Killari, Jabalpur and Kutch, studies have been initiated in multiple directions on various aspects of seismicities. The present study is aimed at bringing out a possible picture on the seismic vulnerability of parts of Westernghats of Tamil Nadu using various tectano geomorphic anomalies like unifrequency lineaments and different levels of dissection of plateaus, denudational geomorphic anomalies like anomalous talus materials and fluvial geomorphic anomalies like radial drainages, compressed meanders, eyed drainages and wider flood plains interpreted from the raw and digitally processed Landsat TM and IRS P6 LISS-III satellite datasets. The subsequent generation of individual GIS layers on these anomalies and their integration revealed that the N-S faults are tectonically active and the NE-SW and NNE-SSW faults are active faults. Many earthquake epicenters were also found to fall along these lineaments / faults.

Introduction

The Indian peninsular shield, exposing the Archaeozoie - Proterozoic piles of rocks, is known for its tectonic inertness and the related land stability. Owing to such shield area character, the geoscientists were also having strong convictions for a long time that seismically the area is safe.

Abstract

Landslides have become a recurring phenomenon in most of the mountainous regions of the world. In Indian peninsular, the landslides which were mostly confined to the tectonically active Himalayan Mountains once, have started spreading over to the other mountain belts of the Peninsula. The Tirumala – Tirupati hills, which is drawing millions of pilgrims from all over the world is facing landslides especially along the newly built southern uphill Ghat Road. The geology of the area, studied using geomatics tools like Remote Sensing, SRTM based Digital Elevation Models, GPS Survey, etc., showed that Tirumala hills is under the grip of upward tectonic movement as evidenced from the N-S and E–W oriented Pleistocene faults, intensely dissected Plateau top Cuddapah Quartzites, retreating escarpments, exhaustive debris slopes, extensive valley fills along the slopes, colluvial fills in lower slopes, palaeo debris flows along the southern and western obsequent slopes of the Tirumala hills etc. All these indicate the inherent landslide vulnerability of the slopes. The E-W trending dykes which are piercing the slopes and standing as ridges add further landslide vulnerability to such fragile slopes. So, the new ghat road laid along such southern slope is obviously facing landslides. However, the detailed geomatics based studies show that the dykes, valley fills and steep slopes are particularly more vulnerable to landslides. Though remedial measures have been broadly evolved, abandoning the southern uphill new ghat road and widening the older northern downhill ghat road seems to be the better and long term feasible alternative to prevent Landslides.

Abstract

Landslides have become a fast spreading epidemic in the mountain belts around the world. As both the natural geosystem and the triggering parameters this phenomenon, the scientists & technocrats from all over the world have started studying it using varying parameters and multivariate advanced scientific tools. In this connection the present study lays an emphasis on the need for giving deserving importance to one of the important geosystem parameters, namely the geomorphology in Landslide Vulnerability Mapping. The same has been accomplished by taking the Nilgiri Mountains of Western Ghats, South India as the test site.

Introduction

Landslides are the most commonly witnessed geohazards in mountainous systems of all over the world causing greater and recurring loss to Man, his properties and to his various developmental programmes. As these landslides mostly occur after heavy rainfalls, it was considered as the most important triggering parameter for the landslides. In indian subcontinent, the landslides of Himalayan region while were inferred to be predominately due to Active tectonics (1,2,3,4,5,6,7,8,9,10) landslides of Westernghats of Maharastra were explained to be the effect of extensive weathering and the rock falls from the cliff and the summit zone (11,12) but in contrast, the landslides of Nilgiri mountains have been attributed to deforestation, direct entry of rain water into the soil system and the resultant pore pressure increase (13,14,15,16,17,18,19,20,21) but the studies carried out (22) in the Nilgiri Mountains indicated that various geosystem parameters viz: Lithology, Structure, Geomorphology, Slope etc., occur in various permutations and combinations and assign different landslide vulnerability grades to the land systems and when such vulnerable zones are interfered by the triggering parameters, the landslides occur.

Abstract

The recent disastrous tsunami of December 26, 2004 has not only alarmed the administrative and the planning machinery to have tsunami mitigation strategies for India. But also signalled the geoscientists to have a deeper look on the phenomenon of tsunami and the vulnerabilities of the Indian coasts. In this context, the authors have conducted a study primarily to evaluate the responses of the coastal Geosystems to the tsunami inundation, as it is a very vital component in f raming strategies for mitigating the effect of tsunami. The study has revealed that the central coastal parts of Tamil Nadu, namely Cuddalore – Nagapattinam districts, which were worst affected by the recent tsunami, expose a combination of landforms of tectonic, fluvial, fluvio – marine and marine processes. These different landforms have responded differently to the recent tsunami viz: as facilitators, carriers, accommodators, absorbers, barriers etc. on the basis of the same, different eco – friendly, cost effective and result oriented methods are suggested to mitigate the effects of tsunamis.

Introduction

Tsunami is an unfamiliar term and also a scantily referred term in the dictionaries in India till December 26, 2004. Even the students of geosciences were all along been taught about the origin and impact of tsunamis by citing examples from the Pacific Ocean. But the term tsunami has now become a widely known and a commonly deliberated phenomenon in India amongst various cross sections of the society irrespective of age and literacy. However, the historical tsunami data (USGS & GSI websites)

Absolute advantage : This is the simplest yardstick of economic performance. If one person, firm or country can produce more of something with the same amount of effort and resources, they have an absolute advantage over other producers. Being the best at something does not mean that doing that thing is the best way to use your scarce economic resources. The question of what to specialise in—and how to maximize the benefits from international trade—is best decided according to comparative advantage. Both absolute and comparative advantage may change significantly over time.

Access to Health Care : 1) The degree to which individuals are inhibited or facilitated in their ability to gain entry to and to receive care and services from the health care system. Factors influencing this ability include geographic, architectural, transportation, and financial considerations, among others. 2) Entry to the health care system is dependent on the wants, resources, and needs that individuals bring to the care-seeking process. Ability to obtain wanted or needed services may be influenced by many factors, including travel distance, waiting time, available financial resources, and availability of a regular source of care.

Acquisition cost : The purchase cost of a drug to an agency, person or institution.

Adaptive expectations : A theory of how people form their views about the future that assumes they do so using past trends and the errors in their own earlier predictions. Contrast with rational expectations.

Backwardation : When a commodity is valued more highly in a spot market (that is, when it is for delivery today) than in a futures market (for delivery at some point in the future). Normally, interest costs mean that futures prices are higher than spot prices, unless the markets expect the price of the commodity to fall over time, perhaps because there is a temporary bottleneck in supply.

Balance of payments : The total of all the money coming into a country from abroad less all of the money going out of the country during the same period. This is usually broken down into the current account and the capital account. The current account includes : *visible trade (known as merchandise trade in the United States), which is the value of exports and imports of physical goods; *invisible trade, which is receipts and payments for services, such as banking or advertising, and other intangible goods, such as copyrights, as well as cross-border dividend and interest payments; *private transfers, such as money sent home by expatriate workers; official transfers, such as international aid. The capital account includes : *long-term capital flows, such as money invested in foreign firms, and profits made by selling those investments and bringing the money home; *short-term capital flows, such as money invested in foreign currencies by international speculators, and funds moved around the world for business purposes by multinational companies. These short-term flows can lead to sharp movements in exchange rates, which bear little relation to what currencies should be worth judging by fundamental measures of value such as purchasing power parity. As bills must be paid, ultimately a country’s accounts must balance (although because real life is never that neat a balancing item is usually inserted to cover up the inconsistencies).

Balanced budget : When total public-sector spending equals total government income during the same period from taxes and charges for public services. Politicians in some countries, such as the United States, have argued that government should be required to run a balanced budget in order to have sound public finances. However, there is no economic reason why public borrowing need necessarily be bad. For instance, if the debt is used to invest in things that will increase the growth rate of the economy—infrastructure, say, or education—it may be justified. It may also make more economic sense to try to balance the budget on average over an entire economic cycle, with public-sector deficits boosting the economy during recession and surpluses stopping it overheating during booms, than to balance it every year.

Capacity : The amount a company or an economy can produce using its current equipment, workers, capital and other resources at full tilt. Judging how close an economy is to operating at full capacity is an important ingredient of monetary policy, for if there is not enough spare capacity to absorb an increase in demand, price are likely to rise instead. Measuring an economy’s output gap – how far current output is above or below what it would be at full capacity – is difficult, if not impossible, which is why even the best-intentioned central bank can struggle to keep down inflation. When there is too much spare capacity, however, the result can be deflation, as firms and employees cut their prices and wage demands to compete for whatever demand there may be.

Capital adequacy ratio : The ratio of a banks’s capital to its total assets, required by regulators to be above a minimum (“adequate”) level so that there is little risk of the bank going bust. How high this minimum level is may vary according to how risky a bank’s activities are.

Capital Asset Pricing Model : A method of valuing assets and calculating the cost of capital (for an alternative, see arbitrage pricing theory). The capital asset pricing model (CAPM) has come to dominate modern finance. The rationale of the CAPM can be simplified as follows. Investors can eliminate some sorts of risk, known as residual risk or alpha, by holding a diversified portfolio of assets (see modern portfolio theory). These alpha risks are specific to an individual asset, for example, the risk that a company’s managers will turn out to be no good. Some risks, such as that of a global recession, cannot be eliminated through diversification. So even a basket of all of the shares in a stock market will still be risky. People must be rewarded for investing in such a risky basket by earning returns on average above those that they can get on safer assets, such as treasury bills . Assuming investors diversify away alpha risks, how an investor values any particular asset should depend crucially on how much the asset’s price is affected by the risk of the market as a whole. The market’s risk contribution is captured by a measure of relative volatility, beta, which indicates how much an asset’s price is expected to change when the overall market changes. Safe investments have a beta close to zero : economists call these assets risk free. Riskier investments, such as a share, should earn a premium over the risk-free rate. How much is calculated by the average premium for all assets of that type, multiplied by the particular asset’s beta. But does the CAPM work ? It all comes down to beta, which some economists have found of dubious use. They think the CAPM may be an elegant theory that is no good in practice. Yet it is probably the best and certainly the most widely used method for calculating the cost of capital.

Deadweight cost/loss : The extent to which the value and impact of a tax, tax relief or subsidy is reduced because of its side-effects. For instance, increasing the amount of tax levied on workers’ pay will lead some workers to stop working or work less, so reducing the amount of extra tax to be collected. However, creating a tax relief or subsidy to encourage people to buy life insurance would have a deadweight cost because people who would have bought insurance anyway would benefit.

Death-to-case ratio : The number of deaths attributed to a particular disease during a specified time period divided by the number of new cases of that disease identified during the same time period.

Debt forgiveness : Cancelling or rescheduling a borrower’s debts to lessen the pain of the debt burden. Debt forgiveness is increasingly viewed as the best way to relieve the financial problems facing poorer countries. Some of these countries have to pay so much in interest each year to foreign lenders that they have little money left to spend on the long-term solutions to their poverty, such as educating their workers and building a modern infrastructure. In 1998 the world Bank calculated that around 40 of the world’s poorest countries had an “unsustainably high” debt burden : the present value of their total debts was more than 220% of their exports. Debt forgiveness has potential drawbacks. For instance, there is a risk of moral hazard. If countries that borrow too much are let off their financial obligations, poor countries may feel they have nothing to lose by borrowing as much as they can. This is why policymakers often argue that debt forgiveness should come with a conditionality clause, for instance, a requirement that countries have a track record of implementing economic reforms designed to prevent a repeat of the errors that first created the need for debt forgiveness. This is the approach taken by the World Bank’s HIPC (highly indebted poor country) initiative, launched in 1996 and expanded in 1999. However, by 2003, only eight of the 38 poor countries eligible under the programme had made enough progress in reform to have some debt forgiven.

Econometrics : Mathematics and sophisticated computing applied to economics. Econometricians crunch data in search of economic relationships that have statistical significance. Sometimes this is done to test a theory; at other times the computers churn the numbers until they come up with an interesting result. Some economists are fierce critics of theory-free econometrics.

Economic Appraisal : See Economic evaluation.

Economic Burden of Disease : See Cost of Illness.

Economic Competition : The effort of two or more parties to secure the business of a third party by offering, usually under fair or equitable rules of business practice, the most favorable terms.

Economic evaluation (Economic appraisal) : The comparison of alternative courses of action in terms of their costs and consequences, with a view to making a choice.

Economic Evaluation : The systematic appraisal of costs and benefits of projects, normally undertaken to determine the relative economic efficiency of programs. See also Cost-benefit analysis, Cost-effectiveness analysis, Cost-minimization analysis, Cost-utility analysis.

Economic indicator : A statistic used for judging the health of an economy, such as GDP per head, the rate of unemployment or the rate of inflation. Such statistics are often subject to huge revisions in the months and years after they are first published, thus causing difficulties and embarrassment for the economic policymakers who rely on them.

Factor cost : A measure of output reflecting the costs of the factors of production used, rather than market prices, which may differ because of indirect tax and subsidy.

Factors of production : The ingredients of economic activity : land, capital, labour and enterprise.

Factory prices : The prices charged by producers to wholesalers and retailers. Because these prices are eventually passed on to the end customer, changes in factory prices, also known as producer prices, can be a leading indicator of consumer price inflation.

Fair trade : Many politicians and NGOs argue that free trade is not enough; it should also be fair. On the face of it, fairness is self-evidently a good thing. However, fairness, in trade as in beauty, lies in the eye of the beholder. Frederic Bastiat, a 19th-century French satirist, once observed that the sun offered unfair competition to candle makers. If windows could be boarded up during the day, he argued, more jobs could be created making candles. American trade unions complain that Mexicans’ lower wages, say, give them an unfair advantage. Mexicans say they cannot compete fairly against more productive American counterparts. Both sides are wrong. Mexicans are paid less than Americans largely because they are, in general, less productive. There is nothing unfair about that; indeed, it helps to make trade mutually beneficial. The mutual benefits of trade also disprove the fair traders’ other complaint, that free trade harms poor countries. (See comparative advantage).

FDI : See Foreign direct investment.

Fee : A charge for a service rendered.

Game theory : How to win at Twister? No, but maybe at monopoly. Game theory is a technique for analysing how people, firms and governments should behave in strategic situations (in which they must interact with each other), and in deciding what to do must take into account what others are likely to do and how others might respond to what they do. For instance, competition between two firms can be analysed as a game in which firms play to achieve a long-term competitives advantage (perhaps even a monopoly). The theory helps each firm to develop its optimal strategy for, say, pricing its products and deciding how much to produce; it can help the firm to anticipate in advance what its competitor will do and shows how best to respond if the competitor does something unexpected. It is particularly useful for understanding behaviour in monopolistic competition. In game theory, which can be used to describe anything from wage negotiations to arms races, a dominant strategy is one that will deliver the best results for the player, regardless of what anybody else does. One finding of game theory is that there may be a large first-mover advantage for companies that beat their rivals into a new market or come up with an innovation. One special case identified by the theory is the zero-sum game, where players see that the total winnings are fixed; for some to do well, others must lose. Far better is the positive-sum game, in which competitive interaction has the potential to make all the players richer. Another problem analysed by game theorists is the prisoners’ dilemma. (See also nashequilibrium).

GATT : See general agreement on tariffs and trade and world trade organisation.

GDP : Gross domestic product, a measure of economic activity in a country. It is calculated by adding the total value of a country’s annual output of goods and services. GDP = private consumption + investment + public spending + the change in inventories + (exports-imports). It is usually valued at market prices; by subtracting indirect tax and adding any government subsidy, however, GDP can be calculated at factor cost. This measure more accurately reveals the income paid to factors of production. Adding income earned by domestic residents from their investments abroad, and subtracting income paid from the country to investors abroad, gives the country’s gross national product (GNP).

Hard currency : Money you can trust. A hard currency is expected to retain its value, or even benefit from appreciation, against softer currencies. This makes it a popular choice for people involved in international transactions. The dollar, d-mark, sterling and the Swiss franc each became a hard currency, if only some of the time, during the 20th century.

Hawala : An ancient system of moving money based on trust. It predates western bank practices. Although it is now more associated with the Middle East, a version of hawala existed in China in the second half of the Tang dynasty (618-907), known as fei qian, or flying money. In hawala, no money moves physically between locations; nowadays it is transferred by means of a telephone call or fax between dealers in different countries. No legal contracts are involved, and recipients are given only a code number or simple token, such as a low-value banknote torn in half, to prove that money is due. Over time, transactions in opposite directions cancel each other out, so physical movement is minimised. Trust is the only capital that the dealers have. With it, the users of hawala have a worldwide money-transmission service that is cheap, fast and free of bureaucracy. From a government’s point of view, however, informal money networks are threatening, since they lie outside official channels that are regulated and taxed. They fear they are used by criminals, including terrorists. Although this is probably true, by far the main users of hawala networks are overseas workers, who do not trust official money transfer methods or cannot afford them, remitting earnings to their families.

IMF : Short for International Monetary Fund, referee and, when the need arises, rescuer of the world’s financial system. The IMF was set up in 1944 at bretton woods, along with the world bank, to supervise the newly established fixed exchange rate system. After this fell apart in 1971–73, the IMF became more involved with its member countries’ economic policies, doling out advice on fiscal policy and monetary policy as well as microeconomic changes such as privatisation, of which it became a forceful advocate. In the 1980s, it played a leading part in sorting out the problems of developing countries’ mounting debt. More recently, it has several times co-ordinated and helped to finance assistance to countries with a currency crisis.

Immunity, active : Resistance developed in response to stimulus by an antigen (infecting agent or vaccine) and usually characterized by the presence of antibody produced by the host.

Immunity, herd : The resistance of a group to invasion and spread of an infectious agent, based on the resistance to infection of a high proportion of individual members of the group. The resistance is a product of the number susceptible and the probability that those who are susceptible will come into contact with an infected person.

Immunity, passive : Immunity conferred by an antibody produced in another host and acquired naturally by an infant from its mother or artificially by administration of an antibody-containing preparation (antiserum or immune globulin).

Joint supply : Some products or production processes have more than one use. For instance, cows can both provide milk and be eaten.

Keynesian : A branch of economics, based, often loosely, on the ideas of keynes, characterized by a belief in active government and suspicion of market outcomes. 

Labour economics : The aspects of economics concerned with the supply and demand for labor. This includes factors affecting the participation rate, wage bargaining and organized labor, training, hours and conditions of work, practices concerning hiring, redundancy, labor turnover, migration and the age of retirement.

Labour intensive : A production process that involves comparatively large amounts of labour; the opposite of capital intensive.

Labour market flexibility : A flexible labour market is one in which it is easy and inexpensive for firms to vary the amount of labour they use, including by changing the hours worked by each employee and by changing the number of employees. This often means minimal regulation of the terms of employment (no minimum wage, say) and weak (or no) trade unions. Such flexibility is characterised by its opponents as giving firms all the power, allowing them to fire employees at a moment’s notice and leaving workers feeling insecure.

Labour theory of value : The notion that the value of any good or service depends on how much labour it uses up. First suggested by adam smith, it took a central place in the philosophy of karl marx. Some neo-classical economists disagreed with this theory, arguing that the price of something was independent of how much labour went into producing it and was instead determined solely by supply and demand.

Macroeconomic policy : Top-down policy by government and central banks, usually intended to maximise growth while keeping down inflation and unempoyment. The main instruments of macroeconomic policy are changes in the rate of interest and money supply, known as monetary policy, and changes in taxation and public spending, known as fiscal policy. The fact that unemployment and inflation often rise sharply, and that growth often slows or gdp falls, may be evidence of poorly executed macroeconomic policy. However, business cycles may simply be an unavoidable fact of economic life that macroeconomic policy, however well conducted, can never be sure of conquering.

Macroeconomics : The big picture analysing economy-wide phenomena such as growth, inflation and unemployment. Contrast with microeconomics, the study of the behaviour of individual markets, workers, households and firms. Although economists generally separate themselves into distinct macro and micro camps, macroeconomic phenomena are the product of all the microeconomic activity in an economy. The precise relationship between macro and micro is not particularly well understood, which has often made it difficult for a government to deliver well-run macroeconomic policy.

Managed Care : Managed care is a livestock health care plan that integrates the financing and delivery of livestock health care services by using arrangements with selected health care providers to provide services for covered individuals. Plans are generally financed using capitation fees. There are significant financial incentives for members of the plan to use the health care providers associated with the plan. The plan includes formal programs for quality assurance and utilization review.

NAIRU : The non-accelerating-inflation rate of unemployment (see natural rate rate of natureal rate of unemployment).

Nash equilibrium : An important concept in game theory, a Nash equilibrium occurs when each player is pursuing their best possible strategy in the full knowledge of the strategies of all other players. Once a Nash equilibrium is reached, nobody has any incentive to change their strategy. It is named after John Nash, a mathematician and Nobel prize-winning economist.

Nation building : Creating a country that works out of one that does not - because the old order has collapsed (as in the former Soviet Union), or been destroyed by war (Iraq), or never really functioned in the first place (Afghanistan). To transform a failed country can involve establishing order through the rule of law and creating legitimate government and other effective social institutions, as well as a credible currency and a functioning market economy. Nation building is rarely easy, and often fiendishly difficult, especially where there are deep ethnic, religious or political divisions in the population or the country has no history of ever functioning effectively. Outside expertise, such as from the world bank, and money (as in, most famouly, the marshall plan) can help, but they are no guarantee of success.

Observational study : Epidemiological study in situations where nature is allowed to take its course. Changes or differences in one characteristic are studied in relation to changes or differences in others, without the intervention of the investigator.

Odds ratio : A measure of association which quantifies the relationship between an exposure and health outcome from a comparative study; also known as the cross-product ratio.

OECD : The Organisation for Economic Co-operation and Development, a Paris-based club for industrialised countries and the best of the rest. It was formed in 1961, building on the Organisation for European Economic Co-operation (OEEC), which had been established under the marshall plan. By 2003, its membership had risen to 30countries, from an original 20. Together, oecd countries produce two-thirds of the world’s goods and services. The oecd provides a policy talking shop for governments. It produces forests-worth of documents discussing public policy ideas, as well as detailed empirical analysis. It also publishes reports on the economic performance of individual countries, which usually contain lots of valuable information even if they are rarely very critical of the policies implemented by a member government.

Pandemic : An epidemic occurring over a very wide area (several countries or continents) and usually affecting a large proportion of the population.

Partial Evaluation : Partial evaluations constitute a number of economic study types which consider costs and/or consequences, but which either do not involve a comparison between alternative interventions or do not relate costs to benefits.

Participation bias : People who participate in a study, especially volunteers, may be systematically different from those who do not, in a way that can affect the response to a treatment. For example, if volunteers are chosen to test the effects of a vaccine, one might find a lower incidence of disease in this population simply because they are more health conscious than those who would not volunteer for such a study.

Path dependence : History matters. Where you have been in the past determines where you are now and where you can go in future. Indeed, even small, apparently trivial, differences in the path you have taken can have huge consequences for where you are and can go. In economics, path dependence refers to the way in which apparently insignificant events and choices can have huge consequences for the development of a market or an economy.

Quality Adjusted Life Years (QALYs) : Calculated by adjusting the estimated number of life-years an individual is expected to gain from an intervention for the expected quality of life in those years. The quality of life score will range between 0 for death, to 1 for perfect health, with negative scores being allowed for states considered worse than death

Safe harbour : Protection from the rough seas of regulation. Laws and regulations often include a safe harbour clause that sets out the circumstances in which otherwise regulated firms or individuals can do something without regulatory oversight or interference.

Sample : A selected subset of a population. A sample may be random or non-random and it may be representative or non-representative.

Satisficing : Settling for what is good enough, rather than the best that is possible. This may occur in any situation in which decision makers are trying to pursue more than one goal at a time. Classical economics and neo-classical economics assume that individuals, firms and governments try to achieve the optimum, best possible outcome from their decisions. Satisficing assumes they decide for each goal a level of achievement that would be good enough and try to find a way to achieve all of these sub-optimal goals at once. This approach to decision making is commonplace in behavioural economics. It can be regarded as a realist’s theory of how decisions are taken.

Savings : Any income that is not spent. Ultimately, savings are the source of investment in an economy, although domestic savings may be supplemented by capital from foreign savers or themselves be invested abroad. In an economic sense, savings include purchases of shares or other financial securities. However, many official measures of a country’s savings ratio—total savings expressed as a percentage of total income—leave out such financial transactions. At times when the demand for financial securities is unusually high, this can give a misleading impression of how much saving is taking place. How much individuals save varies significantly among different age groups (see life-cycle hypothesis) and nationalities. Everywhere, people of all ages save more as their income rises. The supply of savings rises when interest rates rise; a rise in interest rates causes demand for funds to invest to fall; a rise in demand for investment funds may cause interest rates, and thus the cost of capital, to rise. The level of savings is also influenced by changes in wealth (see wealth effect) and by taxation policies.

Table shell : A table that is complete except for the data.

Table : A set of data arranged in rows and columns.

Tangible assets : Assets you can touch : buildings, machinery, gold, works of art, and so on. Contrast with intangible assets.

Tariff : Often used to describe a tax on goods produced abroad imposed by the government of the country to which they are exported. Many countries have reduced such tariffs as part of the process of freeing up world trade.

Tax arbitrage : Creating financial instruments or transactions that allow the parties involved to exploit loopholes in or differences between their tax exposures, so that all involved pay less tax.

Tax avoidance : Doing everything possible within the law to reduce your tax bill. Learned Hand, an American judge, once said : “There is nothing sinister in so arranging one’s affairs as to keep taxes as low as possible … nobody owes any public duty to pay more than the law demands.” Contrast with taxevasion.

Tax base : The thing or amount to which a tax rate applies. To collect income tax, for example, you need a meaningful definition of income. Definitions of the tax base can vary enormously, over time and among countries, especially when tax breaks are taken into account. As a result, a country with a comparatively high tax rate may not have a high tax burden if it has a more narrowly defined tax base than other countries. In recent years, the political unpopularity of high tax rates has lead many governments to lower rates and at the same time broaden the tax base, often leaving the tax burden unchanged.

Uncertainty : See information.

Underground economy : See black economy.

Underinsured : Refers to livestock which have some type of livestock health insurance, such as catastrophic care, but not enough insurance to cover all their health care costs.

Unemployment trap : When unemployed people who receive benefits, either from the goverment or from private charity, are deterred from taking a new job because the reduction or removal of benefit if they do will make them worse off. Also known as the poverty trap, it can be addressed, to an extent, by continuing to pay benefit for a while to unemployed people returning to work. (See welfare to work).

Validity : The degree to which a measurement actually measures or detects what it is supposed to measure.

Value added : This usually refers to firms, where it is defined as the value of the firm’s output minus the value of all its inputs purchased from other firms. It is therefore a measure of the profit earned by a particular firm plus the wages it has paid. As a rule, the more value a firm can add to a product, the more successful it will be. In many countries, the main form of indirect indirect taxation is value-added tax, which is levied on the value created at each stage of production. However, it is paid, ultimately, by whoever consumes the finished product. Another definition of value added refers to the change in the overall economic value of a company. This takes into account changes in the combined value of its shares, assets, debt and other liabilities. Part of the pay of company bosses is often linked to how much economic value is added to the company under their management.

Value at risk : Value at risk models, widely used for risk management by banks and other financial institutions, use complex computer algorithms to calculate the maximum that the institution could lose in a single day’s trading. These models seem to work well in normal conditions but not, alas, during financial crises, which is arguably when it is most necessary to know how much value is at risk.

Wage drift : The difference between basic pay and total earnings. Wage drift consists of things such as overtime payments, bonuses, profit share and performance-related pay. It usually increases during periods of strong growth and declines during an economic downturn.

Wages : The price of labour. In theory, wages ought to change so that the sopply and demand in the labour market are always in equilibrium. In practice, wages are often sticky, especially in a downward direction when demand for labour falls, wages do not fall. In this situation, the fall in demand results in higher involuntary unemployment. Trade unions may use collective bargaining to keep wages above the market-clearing rate. Furthermore, many governments impose a minimum wage that employers must pay.

Wealth effect : As people get wealthier, they consume more. This wealth effect has important consequences for monetary policy. When there is an interest rate increase, future income from assets such as equities must be discounted at a higher rate than before. As a result their owners feel poorer and spend less. A cut in interest rates has the opposite effect. Economists disagree on the wealth elasticity of consumption how much consumer spending would rise if wealth increased by, say, 1%. Different consumers may have different wealth elasticity. If most of the increase in wealth goes to poorer people this may have a different wealth effect than if most of it went to people who are already wealthy. The source of the wealth increase may also matter. If share prices rise or interest rates fall, consumers may be slow to spend out of their increased wealth if they think the increase may be temporary. However, if they think a sharp rise in share prices is permanent and the stockmarket then tumbles, the result may be that consumption falls by enough to cause a recession. The wealth effect of rising house prices is particularly uncertain.

X-efficiency : Producing output at the minimum possible cost. This is not enough to ensure the best sort of economic efficiency, which maximises society’s total consumer plus producer surplus, because the quantity of output produced may not be ideal. For instance, a monopoly can be an X-efficient producer, but in order to maximise its profit it may produce a different quantity of output than there would be in a surplus-maximising market with perfect competition.

Years of potential life lost : A measure of the impact of premature mortality on a population, calculated as the sum of the differences between some predetermined minimum or desired life span and the age of death for individuals who died earlier than that predetermined age.

Zero-sum game : When the gains made by winners in an economic transaction equal the losses suffered by the losers.

Over the past 12,000 years Homo sapiens have moved from the hunter–gatherer life-style to settled agriculture to advanced civilization in urban society with improved quality of life. Livestock has played an important role as an instrument of bringing out this change. Farmers all over the world, attach great importance to livestock ownership as a source of nutrition, as a mechanism for capital accumulation, and concomitantly, as a symbol of wealth and status in the community. Just as in today’s society, money is used to exchange goods and services, livestock including goats used to play the same role in times gone by. Most farmers consider livestock as a important resource for income generation. Livestock sector plays a significant role in supplementing family income and generating gainful employment in the rural sector, particularly among the landless, marginal and small farmers and women, besides providing cheap nutritional food to millions of people. History indicates that livestock has been not only a resource, but also an instrument of dominance and a source of conflict in the society. Livestock especially small ruminants have often served as a means for exchange of goods and services and thus becoming increasingly important in the growth of agriculture in developing economies.

Livestock species which man domesticated for improving the quality of human life include goat, sheep, cattle, buffalo, pig, poultry, horses and camels. Among these goats were the first among livestock species domesticated by man. Goats are among the smallest domesticated ruminants and have served mankind longer than cattle or sheep. Goat is an important source of meat, milk, skin, fiber and manure since then. Traditionally goats have been an important source of income generation among small households. Goats have been used to buy salt, cloth and groceries in many communities. Goats provide a large part of the cash income for smallholder farmers. Goats are friendly animals; with proper attention they maintain good health and can be managed easily even by children.

Sailors and other explorers out on the high seas kept goats as a ready stock of meat & milk on long voyages. Captain Cook’s goat had already sailed around the world before it entered on its first voyage with Cook, and helped save everyone on board the ship from scurvy. Goats are some times kept as pet or companion animal. Their use as pet is common in European countries especially U.K. Some owners keep goats for purpose of goat shows.

Worldwide, almost 90% of the human food supply is provided by only 15 crop species and eight livestock species. The eight livestock species useful to man include cattle, buffalo, sheep, goat, pig, poultry, camel and horses. All or some of these species provide milk, meat, skin, fiber and manure for use of mankind. Whereas, milk and meat are important component of human food supply, skin, fiber and manure are also useful in different manner. Goats are important food-producing animals especially in tropical and subtropical regions. Goats are the most adaptable and geographically wide spread livestock species.

A breed of livestock is a group of animals that, through selection and breeding, have distinguishable characteristics and resemble one another and pass those traits uniformly to their offspring. Or A breed is defined as a group of animals that has been selected by humans to possess a set of inherited characteristics that distinguishes it from other animals within the same species. A cluster of domestic animals of a species where individuals are homogeneous in certain distinguishable characters which differ from one to the other group of animals constitute the breeds. Breeds are primarily distinguished by visual characteristics: color pattern, polled or horned condition, or extreme differences in form and shape. Breed is indicative of the perception of the breeders and the livestock industry which decides when a group of individuals constitutes a “breed”. Livestock breeds have evolved over time through genetic changes that are both natural and selected by man.

Primarily breeds have been developed to provide increased production of meat, milk and/or wool, pashmina within a certain environmental area. This breed development is a process of continuous selection over a number of generations so as to stabilize the characters in the animals for the selected traits. The distinguishable characters are quite often color markings, size, and shape, hair pattern which may have little economic significance in terms of meat, wool or pashmina production. Breed development may have begun soon after animals were first domesticated. Breed is a group of animals related by descent and similar in most characteristics like general appearance, features, size, configuration, etc. In most cases, selection has been practiced for many generations in order to fix certain characteristics in the breed. The goat breeds have since long been described primarily in terms of physical conformation (chiefly, ear, nose, face and horn), body coat/colour characteristics and body measurements with subtle reference to production traits. Today there are more than 300 breeds of goats, and they live in climates ranging from high altitude mountains to deserts. Some breeds are known by the same name in different places, but are phenotypically different from one place to another. Conversely, there are breeds that look alike but have different names in different places.

Mostly goats are reared in extensive small holder systems in developing countries. Goat breeding programmes in these environments have been limited, amongst other factors, by the non availability of pedigree and performance records for traits of economic importance. Cross-breeding and selection play an important role in increasing production in the goats.The development of breeding strategy for the improvement of goats should be based on genetic parameter estimates of economically important traits. Biological, cultural, statistical, socio-economical and management aspects should also be an important component of the selection process.

Goats were domesticated for the triple purpose of milk, meat and hair. Although the development of milk and hair producing animals did not go together, the development of meat and hair together worked very well and there are several breeds like Angora which in addition to providing fiber, are excellent meat animals too. The development of meat breeds was favored by natural selection. The characters which aided to this aspect were high fertility rates and the relatively more active life which goats were forced to lead in order to get enough of nutrition in poor agricultural lands, deserts etc. where these animals were domesticated. These animals were exposed to the vagaries of the environment resulting in decline in production traits such as milk, meat etc. But meat production was not. Most of the breeds of Asia and Africa are thus predominant meat breeds which have been improved little by conscious effort of breeders. Some of them still have slow growth rate and feed conversion efficiency. The preference for goat meat had eroded the dairy potential of Indian goats, as the fastest growing males are slaughtered for meat purposes and only poor animals are retained for breeding purposes. Careful selection and utilisation of breeding males can alleviate this problem to a large measure and animals for both milk and meat production can be developed.There are several goat breeds that have good potential for meat production. Generally, there have been limited planned selection and breeding programs carried out by animal scientists to improve rate of growth and carcass composition of goats. As a result, many goat breeds deposit less intramuscular and subcutaneous fat. In the past, domesticated meat animals were selected for heavier mature weight and greater rate of gain. Selection for such parameters usually resulted in undesirable characteristics because some of the animals had not only gained weight faster and were heavier at maturity, but also had more subcutaneous and intramascular fat. Since consumers currently prefer leaner red meat, the livestock industry is making significant changes to satisfy these demands. Goat meat has unique attributes which will be beneficial to the present day consumer. Goat meat has 10% more lean carcass than cattle. At the same time the fat content is lower by 47% than beef. These qualities of the goat meat need to be emphasized so that the general public can become aware of this useful product.