c h a i >t e :r 2

STUDY AREA

2.1 The Study Area

Geographically, the basin forms the south central part of the Indian Peninsula. The study area is o o confined between the latitudes 15 39' N and 16 30'N and o o the longitudes 74 E and 76 61' E, and has a geographical area of about 7231.25 sq km.

The basin covers the parts of Kolhapur district of state and and districts of state (Survey sheet nos. 48 1,47 L ,and 47 P; scale 1 : 250,000). More than three fourth area of the basin lies in the Belgaum and Bijapur districts of Karnataka state (Fig.2.1).

The area is drained mainly by the Ghataprabha river (a major southerly tributary of the ) and its major tributaries like Hiranyakeshi, Tamraparni and

Markendeya.

A brief account of the present environmental setting viz. physiography, river system, geology, climate, soils, and vegetation is outlined in this chapter to know the resource potentiality, the availability and distribution of the raw materials, plants and the nature of climatic conditions during the Quaternary period.

17 This data is partly based on the published sources such as district gazetteers (Bijapur district (Sri Sathyan (ed.),1966), Kolhapur district (Setu Madhav Rao (ed.) 1960), and Karnataka state Gazetteers ( Karaath (ed.) 1982) and also other publications which have been referred in the text at relevant places and partly based on writer's own

observations during field studies in the study area.

This data forms the basis for the reconstruction of past

environment and is helpful in understanding the palaeoenvironment.

2.2 Topography

Physiographically ,the Ghataprabha basin can be divided into the following three relief units :

1. The region. 2. Sub- Sahyadrian belt. 3. Isolated hills.

The land over 1000 ra elevation is mostly confined to the main Western Ghats region. This hilly region is known as

"Maland". The Western Ghats form the major hill complex which acts as the western boundary of the Ghataprabha basin. It runs as a long chain of lofty hills in a roughly north-west to south-east direction. The Western Ghats form the backbone of the entire landscape and in many respects influence the orientation of the landscape of the area. In the real sense of the term, the Western Ghats are not mountain ranges but they are mainly the uplifted western border of the Peninsula, formed of different geological formations of varied origin and structure. In general, the Western Ghats have a well-eroded landscape with 6 more 18 resistant rocks appearing as peaks and softer rocks yielding to intense stream erosion (Deshpande,1968). These ghats have steep precipitous scarp for often over 600 m on the coastal Konkan side. The slope towards east is, however, gentle and the landscape on this side has a mature and mellow appearance. The sub-Sahyadrian belt also known

as Maidan region is situated to the irnraediate east of tha Western Ghats. The land ranging in elevation between 850 ra to 1000 rn is restricted to this region. From the gently uneven and mature looking crest line of the Sahyadris, this plateau is marked by several hill ranges which emerge from the main ghat and merge into the plains towards the east. Among these, the north-Ghataprabha range is the prominent one. This spur divides the drainage area of the Ghataprabha from that of the Krishna to the north and that of the Malaprabha to the south. This range begins at the Sahyadris and runs as a low continuous chain with a scarp face towards the and a dip-slope to the south.

Besides these hill ranges, there are isolated detached residual hills not connected with the Sahyadrian spurs especially in the lower reaches of the Ghataprabha valley. This area is characterized by the outcrops of limestones, quartzites and shales of the Kaladgi series which introduce a fundamental change in the local topography. This region as a whole is characterized by denudational features. 19 2.3 Geology An outline of the solid geology of the Ghataprabha basin is given here which is essential for a better understanding of the raw materials available to Early man for making artefacts. Robert Bruce Foote (1876) made the systematic and detailed geological study of the study area. The Ghataprabha basin is covered by three well-marked geological groups (Fig. 2.2) each having distinctive characters as follows : 1. Pre-Cambrian a. Archaeans, b. Kaladgis 2. Cretaceous-Eocene a, Deccan Traps, b. Intertrappeans 3. Tertiary and Quaternary a. Laterites, b. Alluvia, c. Soils « 1. Pre-Cambrian

a . Archaeams Archaean system which forms the basement of all the subsequent formations has been classified into two main groups in Indian Peninsula, the Dharwar system and the

Granite gneisses, the former being the older of the two (Rama Rao,1961).

Both these groups have restricted distribution in the present study area and occupy small area where noteworthy inliers are exposed by denudation of younger and overlying formations. These are located in the following regions :

i. around Ajra in the upper reaches of the Hiranyakeshi valley;

ii. around Nesari in the upper reaches of the Ghataprabha valley;

iii. around in the middle reaches of the Ghataprabha valley; and iv. around Bilgi and Bagalkot in the lower reaches of the Ghataprabha valley. GHATAPRABHA BASIN GEOLOGY

f i g : 2 - 2 20 b. Kaiadgls The rocks of the Kaladgi series come next in succession and cover a major portion of the Ghataprabha basin. These are essentially made up of sedimentary and slightly metamorphosed rocks. The Kaladgi sediments were first identified around a small town Kaladgi in the Bijapur district and name Kaladgi series was proposed by Foote (1876) to an irregularly shaped basin running in east-west direction. In the

Ghataprabha basin they occupy the parts of Bijapur and Belgaum districts of Karnataka state and Kolhapur district of Maharashtra state. This basin lies in between the Deccan traps in the north and the Dharwars and granite gneisses in the south. This series forms a part of the group of unfossiliferous strata lying unconformably over the folded and eroded Archaean gneisses. The Kaladgi formations

consist mainly of basal conglomerates, ortho-quartzitic limestones, chert breccias and limestones.

Rocks of the Kaladgi series occupy both as inliers mainly exposed due to the removal of overlying younger formations

and as outliers resting unconformably over the Archaeans.

The best development of Kaladgi rocks is observed in the middle and lower reaches of the Ghataprabha valley between the Gokak and Bagalkot towns.

Foote (1876) classified these sedimentary formations into two divisions, the Lower and the Opper Kaladgis based mainly on lithological characters and structures (Table 2.1). He estimated the total thickness of 4700 m to 5000 m and suggested that no unconformity exits between the two divisions, 21 Lower Kaladgis

These are made up of basal conglomerates, sandstones,

quartzites, limestones and shales and occupy almost whole of central and southern parts of the study area. It has a a thickness of 3300 ra.

Among the rock types, quartzites and sandstones are of widespread occurrence and ‘form the major prevalent variety. These rock types are found in various shades of colors

namely gray, reddish, pink, brown or white. They often show

ripple marks, current bedding and joint planes. The limestones, clays and shales are restricted in the lower reaches of the Ghataprabha valley between Lokapur and

Table 2.1

Kaladgi Series

6. Shales,limestones and haematite 2000 ft UPPER schists.

KALADGIS 5.Quartzites,local conglomerates 1200- 1800 ft and breccias.

LOWER 4. Limestones, clays and shales 5000-6000 ft 3. Sandstones and shales KALADGIS 2. Siliceous limestones and horn- 3000-5000 ft stones or chert breccias 1. Quartzites, conglomerates and sandstones (Viswanathiah,1983).

Bagalkot towns. At Kaladgi town the development of limestone is remarkable. The common colour of the limestone is gray of various shades, banded with wavy gray chert. 22 Upper Kaladgis These consist of quartzites, conglomerates, shales, limestones and haematite schists and are resting conformably over the lower series. Some of the inliers are found near and Kaladgi in the study area. After Foote's pioneer work, a few attempts were made to classify the Kaladgi sediments, however, these are modified

restatements of the original classifications. Such studies were carried out by Roy {1958), Sahasrabudhe (1964) Nautiyal (1966), Viswanathiah (1983) and others.

Viswanathiah (1983) made an attempt for the first time to place on record a systematic lithostratigraphic and

biostratigraphic classification of the Kaladgi series. Awati and Kalaswad (1978) classified the sedimentary sequence around Yadwad as Lower Kaladgis on tectonic considerations. They used satellite imageries to interpret the major structural features of the sedimentary terrain.

2. Cretaceous-Eocene

a . Deccan Traps

The Deccan traps which cover the upper and middle portions of the Ghataprabha basin consist largely of extensive lava flows of the Cretaceous-Eocene period. The Deccan traps which are exposed in the study area form the southern fringe of this well-known geological formation of .

The traps in the study area are formed of a number of lava flows essentially of a-a type and have a rough and fragmentary top (Umarjikar,1983). 23

The Deccan traps are uniform in their petrographic character. In colour they are dark grey and purple. The chief varieties of the traps are hard compact basalt, amygdaloidal trap, vesicular trap and porphyritic trap. In

the study area, soft vesicular and amygdaloidal and hard

compact varieties are found.

b) Intertrappeans

Intercallated with different lava flows, there are in some

places fluviatile and lacustrine deposits of small

horizontal extent, generally with 1 to 3 cm thickness. They comprise cherts, impure limestones, brown and dark gray clays and pyroclastic materials. These formations occur near the local base of the traps and are found along or near to the south-east edge of the trap area.

In the study area these formations are reported at Doddihal near Bilgi in Bijapur district, at Upparhatti and Mamdapur near Gokak in Belgaum district (Foote,1876).

3- Tertiary zind Quaternary

a . Laterites

In the study area the basalts are capped by laterites in the upper reaches of the valley. These are primary laterites and occur ar an elevation of 700 m above mean sea level.

According to Foote (1876) the laterites which occupy in a

large area between Kaladgi and Bagalkot towns in the Ghataprabha basin are of lacustrine origin. The greatest development of the laterites occur near Anagwadi and 24

Kaladgi where laterites are found in patches at different places. A small hillock, situated at a distance of about 2 km north-west of Anagwadi village, is completely made up of compact laterite having a total thickness of 20 to 25 m The laterites occurring at Kaladgi rest upon a very uneven limestone surface and are of varied thickness.

b. Alluvia

The Quaternary formations in the form of alluvial deposits are well preserved throughout the basin. These formations consist of bouldery, cobbly, pebbly or sandy pebbly gravels and associated sands, silts and clays.

The detailed account of both these formations has been given in subsequent chapter.

2.4 Other Aspects of the Landscape

2-4.1 Climate

Climate is the prime factor of the physical environment, along with geology and physiography, which affects soils, vegetation and the geomorphic processes. Because of the frequency and nature of the climatic changes, it is necessary to consider the influence not only of present climate, but also of past climate. The prevailing climate of any region is dependent on several factors such as temperature, rainfall intensity and distribution, barometric pressure, wind, humidity and altitude. The climate of the Ghataprabha basin is typically mcnsoonal 25 in character with four months of rainy season followed by eight months of dry period of winter and summer. The annual climatic cycle consists of four well marked seasons, namely the cold season, the hot season, the south-west monsoon and the post monsoon season.

The cold season starts by beginning of November and continues till the end of February and during this season fine weather prevails with strong, dry easterly winds. In this season the mean daily maximum temperature in the

o eastern part of the basin in the plains varies from 30 C

o to 33 C, while the mean daily minimum temperature varies o o from 10 C to 14 C. December is the coldest month (Table

2 . 2 ) .

The hot summer season sets by the beginning of March and extends to the end of May and the prevailing wind is westerly one. Places like Bagalkot in the eastern part of o o the basin record a daily maximum of 37 C to 41 C especially in the month of May. The rise in the temperature is more marked in the plains than in the hilly region .

The south-west monsoon accounts for 85 to 90 % of the annual rainfall in the region which normally begins in the first week of June and lasts till the end of September. The heaviest rainfall occurs in the main Western Ghats region of the basin. But a most remarkable feature is its rapid decrease to the east of the crest of the Ghats. The 4 decrease of rainfall from west to east is steady and remarkable (Table 2.3 ). The south-west monsoon is incomparably the more important and more constant in its 26 phenomena than the post monsoon or the north-east raonsoon. The decrease of rainfall is accompanied by a decided change in the aspect of local flora.

The post monsoon sets in after the withdrawal of south-west monsoon by the beginning of October and continues till middle of November. October marks the transition from rainy season to winter. There is sudden change in temperature {Table 2.2) that produce a familiar phenomena of 'October heat' and there is a certain amount of rainfall accompanied by thunderstorms.

The air is highly humid in the four south-west raonsoon months, while in other months it is dry. The dryness is more marked in the plains than in the upland regions {Table. 2.4). The winds are strong , particularly on the hills, in south-west monsoon season. In the rest of the year they are light to moderate.

Though the rainfall is extremely irregular, varying both in amount and in distribution, one can distinguishes major hytal zones. On the basis of regional differences in the total annual rainfall the Ghataprabha basin can be divided into three hytal zones, viz. the wet, intermediate and the semi-arid zone. 27 2.4.2 Vegetation

The type and growth of vegetation in any region is mainly dependent on the annual rainfall and soil, though other factors such as altitude, relief, temperature and the human interference also influence to some extent the general pattern of vegetation. At present about 60-70 per cent of the total land has been taken for cultivation and only 30- 40 per cent remains as a natural cover consisting of forests, scrubs and waste. There are only a few areas in the Ghataprabha basin which share some glimpses of the virgin vegetation. The serious depletion of natural vegetal cover has taken place as a result of clearing land for agriculture, felling trees and overgrazing.

In the study area ,four main distinct vegetation belts are found namely, semi evergreen, moist deciduous, dry deciduous and thorn and scrub.

Serai evergreen vegetation is confined to Western hilly wet part of the basin with annual rainfall above 2000 mm and

height above 700 m AMSL. These forests mark a transition from the evergreen to the moist deciduous. Moist deciduous forest is well developed in areas having an average rainfall about 1250 mm, with a fairly long and distinct dry period. Dry deciduous forest has a widespread distribution in the region and occurs where annual rainfall ranges from 750 to

1250 mm. Thorn and scrubs are confined to eastern part of the basin where annual rainfall is less than 700 mm. The natural vegetation is open and abounds in thorny trees, scrubs and coarse grasses. 28 The common species of each group are given in Table 2,5.

2-4.3 Soils

The region under study is represented by the following three types of soils - lateritic red soils, mixed red and black soils and black soils.

Lateritic soils are present in the hilly track of heavy rainfall in the source region of the Ghataprabha and other rivers in the western parts of Kolhapur and Belgaum districts. These are formed in situ under conditions of

high rainfall with alternating wet and dry periods. These soils are red to reddish yellow in color. Immense leaching

during rainy season has rendered these soils rich in sesqi- oxides and poor in lime organic matter and to a great extent of available phosphorous and potash. This process has thus removed from soil all the bases giving it distinctly acidic character with pll ranging between 4.5 to 6.0 and are classified as belonging to pedalfer type. These soils are usually loamy in texture,porous, fairly deep, but with lower tenacity of moisture. The clays are mostly of kaolinite type ( Vaidya and Sahasrabudhe, 1973).

Mixed red and black soils are formed from the mixture of decomposed materials from the Deccan traps and laterites and these show best development in the transitional areas where rocks of the above two types occur side by side. In a predominantly red soil area, patches of black soils may occur in the lower elements of sloping terrain or in the low lying flat lands the red colored soils occur at higher the elevations. Alternatively in areas predominantly of black soils, occurrence of red soil in patches is not usual. In such cases the black soils may overly the red 23 soils and may have originated from the weathering of intrusive basic rocks or basalts, the midst of granites, gneissic or sandstone areas of red soils (Govind Rajan and Gopal Rao,1978 ). Such raixed red and black soils occur in various parts of the basin under study.

Black soils cover the a major portion of the basin and have characteristically dark color, varying from dark brown to deep black. These are mainly formed by the in. situ weathering of trap rocks. They are referred to as "regur" soils and are classified as belonging to pedocal or vertisol type. These soils have been further divided into three groups based on the depth of their formations. Soils with a depth over 100 cm are described as deep black soils, those having depths varying from 30 to 100 cm as medium black soils and those with depth of 30 cm or less as shallow {Govind Rajan and Gopal Rao, 1978 ).

Deep black soils are heavy textured with a clay content ranging from 40 to 60 per cent. These are highly fertile, and thus, supporting excellent vegetational growth. They are alkaline with pH varying from 7.5 to 8.5 and are plastic and sticky when wet and very hard when dry. The main clay mineral is montmorillonite. These soils show strong swelling and severe shrinkage under changing moisture conditions leading to heavy fissuring and deep cracking on drying. Medium black soils occur extensively in the study area and exhibit more or less the same characters as shown by deep black soils but to a lesser degree. They are mildly alkaline and poor in nitrogen and organic matter f but contain adequate amount of potash and lime. Shallow black soils are relatively low in organic matter and 30 usually quite low in fertility. Though the most characteristics black soils cap the Deccan traps, the area of the black soils by no means coincides with boundary of the Deccan trap formations (Ray Chaudhari ai ai. ,1963). In the eastern and southern parts of the basin black soils are found capping the Kaladgis and Archaeans.

2.5 Ovorviow

The study area lies to the immediate east of the Western Ghats. Geologically, it consist of the three main formations namely the Archaeans, the Kaladgis and the Deccan traps. Physiographically, the basin exhibits three major relief units namely western hilly tract, central valley with isolated hills and almost plain area in the lower reaches. The climate of basin is typically monsoonal in character with four months of rainy season followed by eight months of dry period of winter and summer. Three type of soils are found in the basin namely lateritic red soils, mixed red and black soils and black soils. Four distinct vegetation belts namely semi evergreen, moist diciduous, dry deciduous and thorn and scrub are found in the basin. Table. 2.2

Monthly Temperature 0

Section Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sept. Oct. Nov. Dec. Annual

Max. 30.7 33.1 35.9 37.1 35.7 30.0 26.3 26.1 28.5 30.3 30.3 30.3 31.2 Kolhapur Min. 15.0 16.2 18,8 21.5 22,5 22.0 21,2 20.8 20.4 20.1 16.7 14.9 19.2

Max. 30.1 32.2 35.0 35.7 34.0 27.5 25.2 25.6 27.0 30.1 29.3 29.3 30.1 Belgaum Min. 14.0 15.1 18.0 19.5 20.6 20.6 19.8 19.4 19.0 18.6 17.1 13.9 18.0

Max. 30.2 32.9 36.0 38.0 38.5 33.3 30.1 30.1 30.6 31.0 29.7 ' 29.0 32.5 Bi japur Min. 1'6.2 18.1 21.3 23.8 23.9 22.4 21.7 21.3 21.1 20.6 17.4 15.2 20.3

Go Table 2.3

Monthly Hainfall (in b i b )

Station Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sept. Oct. Nov. Dec. Annual

C^andgad 4.1 0.5 13.5 34.0 51.3 499.6 1141.0 599.4 174.4 123.9 44.7 9.7 2696.4 Belgaum 3.6 1.3 9.9 43.2 66.5 190.0 459.0 247.1 118.9 111.0 40.6 11.4 1303.2 2.5 1.5 11.9 40.4 62.5 139.7 288.0 157 .5 101.3 113.8 38.1 8.1 965.3 1.8 2.5 8.4 32.8 66.5 82.5 129.8 82.8 103.9 109.2 43.7 11.7 675.6 Gokak 3.6 1.3 5.6 30.0 57..A 68.8 75.9 63.0 953.0 109.5 44.2 9.7 564.0

Mudhol 2.8 2.0 7.1 22.6 41.9 71.4 65.0 62.0 134.1 78.1 35.3 8.1 530.3

Bagalkot 1.3 4.6 5.6 19.8 41.7 67.8 71.1 62.5 153.8 84.1 33.8 8.4 544.5 Table. 2.4 Relative HuMidity (%)

Station Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sept. Oct. Nov. Dec. Annual

M 60 55 55 63 73 82 90 91 87 81 66 60 72 Kolhapur E 28 22 26 38 50 71 83 83 73 61 41 32 51

M 66 61 62 72 78 85 90 92 89 81 70 67 76 Belgauro E 30 30 32 46 58 76 92 87 81 64 47 35 57

M 56 47 45 50 58 75 80 80 80 70 60 58 63 BiJapur

* E 31 26 34 25 28 52 62 60 59 49 40 34 41

M = Morning E = Kvening

Co Table 2.5

Vegetation : Cottmon Species

(jroup Species Kanxiada name Marathi na»e

Semi Evergreen Eugenia .lambolana Lam. Jambu Jambhul Forests ActinQdaplme hookeri Meis. Haggodiroara Pisa Anthocephalua gftdamba Miq. Kadaga Kadamb E)albergia latifollia Roxb. Biti Sissura Terminalla cfaebula Retz, Harde Hirda Memecylon edule Roxb. Limb Toli An jan Termlnalla tomentoaa W & A. Kareroatti Ain Holoptelea Intearifolia Planch Tavisi Wavli

Moist Deciduous Tectona grandla Linn. Tegu Sagwan Forests Terminalia tomentoaa W & A. Kare roatti Ain Emblica officinalis Qaertn Nellikai Avala Xylla Dolabrlformla Benth Jamba Yerul Bambuaa arundlaacea Willd. Bidiru Bamboo <3rQHla tilaefolia Vahl, Tadasu Dhaman

Dry Deciduous Tactona grandla Linn. Tega Sagwan Forests Anogeissufi latifolia Wall. BoJJale Dhavda cacia catechu Willd. Kachu Khair aimoa grandis Engl. Gojal Moi tladliuga longifolla Mecbr Doddippa Mohwa

Thorn and Scrub Zizvphua .^u.iuba Lamk. Bogari Bor CO Forests Acacia leucuphlea Willd. Bilijali Hiwar Aaadiarachta ladiaa Juss. Beru Kadu limb Tamarindsa iadica Linn. Hunase Chinch Acacia arabica Willd. Jaligida Babhul CaBParla horrlda Linn. Shippri-gidde Tarati