Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Bishnupriya Basak ¹, G. L. Badam ¹, Anupama Kshirsagar ¹, S. N. Rajaguru ¹

Affiliations
1 Deccan College Postgraduate and Research Institute, Pune 411 006, IN

Abstract

The authors present an integrated data on the Quaternary studies carried out during the 1993-95 field seasons in a lesser known area, the Tarafeni Valley in Midnapur District, West Bengal. Microliths primarily made on chert, quartzite have been found in association with colluvial deposits formed more or less contemporaneously with underlying nodular calcrete of pedogenic Oligin. Occurrence of several vertebrate fossils on the surface of the calcrete at Dhuliapur indicates Late Pleistocene age of the artefact bearing colluvial deposits. The formation of pedogenic calcrete in a sub-humid environment, with an average annual rainfall of 1600 - 2000 mm, suggests the presence of semi-aridity in Late Terminal Pleistocene period.

Keywords

Palaeoenvironment, Tarafeni Valley, Late Quaternary, Vertebrate Fossils, West Bengal.

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R. V. Joshi ¹, S. N. Rajaguru ¹, G. L. Badam ¹, P. C. Khanna ²

Affiliations
1 Deccan College, Post-graduate and Research Institute, Poona, IN
2 Geological Survey of India, Chandigarh, IN

Abstract

Recent geo-archaeological investigations in parts of Kashmir valley and Himachal Pradesh show that there is no positive evidence for the existence of early mall prior to Middle Pleistocene. The Stone age tools found in the area are dominated by choppers of Indian Lower Palaeolithic tradition.

The climate was warmer in the early Pleistocene than in the late Pleistocene. There is no convincing evidence of lowering of snow line below 2500m during the whole of the Pleistocene.

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S. N. Rajaguru ¹, V. S. Kale ¹

Affiliations
1 Department of Archaeology, Deccan College, Pune 411006, IN

Abstract

Recent geomorphological, archaeological, palaeontological and carbon -14 dating of alluvial deposits and the observations on buried as well as exposed channel deposits of Upper Krishna, Bhima and the Upper Godavari rivers of Western Maharashtra have brought out five major phases of fluvial activity, since late middle Pleistocene. These rivers were dominantly aggrading during theTermial late Pleistocene (c 40.000-11,000 yrs. B.P.) and incision predominated during the major port of the Holocene. These changes in the fluvial activity can be explained in terms of climatic changes of the late Quaternary period.

The present study disproves the earlier view that the late Quaternary geomorphic history of the study area has been stable and uneventful.

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Vishwas S. Kale ¹, S. N. Rajaguru ²

Affiliations
1 Department of Geography, University of Poona, Pune- 7, IN
2 Department of Archaeology, Deccan College, Pune-6, IN

Abstract

A detailed micro-level statistical analysis has brought out the spatial variation in the terrain of Pravara and Mula sub-basins. Principal component analysis has aided in establishing three groups of inter-related variables; and the Factor Analysis has been able to synthesize patterns of six geomorphic variables into a single comprehensive pattern labelled as 'Morphogenetic Regions'. The multivariate analysis has been able to derive equations of high predictive and descriptive value. Such an approach to terrain analysis has been found to be very fruitful than the conventional morphometric analysis.

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M. Baskaran ¹, S. V. Deshpande ², S. N. Rajaguru ³, B. L. K. Somayajulu ¹

Affiliations
1 Physical Research Laboratory, Ahmedabad 380009, IN
2 KDMIPE, Oil and Natural Gas Commission, Dehra Dun 248195, IN
3 Post-Graduate and Research Institute, Deccan College, Pune 411 006, IN

Abstract

Preliminary geochemical, mineralogical and geochronological studies using ²³⁰Th/²³⁴U method, of nine rniliolite rocks from Kutch are reported. The Kutch miliolites are characterised by lower CaCO₃and higher quartz contents compared to their Saurashtra counterparts. The range of ages for the Kutch and Saurashtra miliolites are same and both can be accommodatedin the 50-70, 75-115 and > 140 K. Yr age groups proposed by Baskaran (1985).

The origin of the Kutch miliolites, like those of Saurashtra, appears to be marine. Theories to explain their occurrence in Kutch have to await more detailed studies of this type alongwith ichnological and petrographic observations.

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S. N. Rajaguru ¹

Affiliations
1 Post-Graduate and Research Institute Deccan College, Pune 411 006, IN

Abstract

No Abstract.

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R. P. Dhir ¹, S. N. Rajaguru ², A. K. Singhvi ³

Affiliations
1 Central Arid Zone Research Institute, Jodhpur-342 003, IN
2 Deccan College, Pune-411 006, IN
3 Physical Research Laboratory, Ahmedabad-380 009, IN

Abstract

Morphogenetic manifestations and stratigraphy of the Quaternary alluvial and aeolian formations of the desertic tract of Rajasthan have been described. The stratigraphy is based on a study of deep sections (-15 m) from different locations. Additionally, well-logs have been used to prepare the isopach maps of these formations. It is inferred that during the major part of the Pleistocene, the region witnessed widespread alluvial sedimentation. Though the region was well-watered then, the presence of large masses of lime coupled with negligible in-situ weathering suggests, that over-all the environment must have been predominantly semi-arid. Presence of nodular and lithic calcrete bands suggests an episodic character of this sedimentation. The form and distribution of surficial calcretes (including polycyclic lime nodules) suggest several cycles of calcrete formation.

Thermoluminescence dating of aeolian sands sampled from 28 to 65 metre depths suggest that the antiquity of the aeolian dynamism extends to atleast 100 ka B.P. The period from c.25 to 50 ka B.P. consistently shows the presence of wetter interludes with weaker aeolian dynamism, a fluvial redistribution of sediments and formation of nodular calcretes and gypcretes. The last major aeolian activity peaked at LGM in the Sahara, the Australian and the Kalahari deserts. However, the evidence on Thar suggests a peak in aeolian activity post-dating the LGM.

Keywords

Thar, Quaternary Stratigraphy, Geomorphology, Paleoenvironment, Rajasthan.

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Hema Achyuthan ¹, S. N. Ghate ², S. N. Rajaguru ²

Affiliations
1 Department of Geology, Anna University, Chennai 600 025, IN
2 Department of Archaeology, Deccan College, Pune 411 006, IN

Abstract

Micromorphology, XRD analyses and SEM studies of rhizoliths from Late Middle Pleistocene yellowish brown silty fluvial sediments of Yedurwadi reveal that calcium carbonate has a localized source. Silica and calcium carbonate are formed by the plant ischolar_mains through their metabolic activity creating a favourable microenvironment for the processes of SiO₂ and CaCO₃ precipitation and replacement.

Keywords

Sedimentology, Karnataka.

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N. R. Karmalkar ¹, S. N. Ghate ², Shiella Mishra ², S. N. Rajaguru ²

Affiliations
1 Department of Geology, University of Pune, Pune-411 007, IN
2 Deccan College, Pune-411 006, IN

Abstract

An ash bed varying in thickness from 20 cm to 2 m occurs within the lower part of 10 m thick yellowish-brown clay and calcareous silt unit that contains occasional lenses of calcrete, gravels and channel lag gravels both at the base and top of the sequence. The volcanic ash has yielded a K/Ar age of 1.4 Ma. The volcanic ash is highly siliceous in composition with SiO₂ content varying between 72 to 78%. It is dominantly constituted of silt sized angular glass shards, and pumice fragments with sharp edges. Petrography, SEM and chemical composition of the glass shards helps in relating the ash morphology to magma composition and the type of eruption. On the basis of petrographic and morphological characters displayed by the volcanic ash, the formation of the glass shards is attributed to magmatic processes.

Keywords

Petrology, Pleistocene, Tephra, Maharashtra.

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R. V. Karanth ¹, S. Kathiroli ², S. Badrinarayanan ², D. Venkata Rao ², S. N. Rajaguru ², K. M. Sivakholundu ², B. Sasisekaran ²

Affiliations
1 Department of Geology, M.S. University of Baroda, Vadodara - 390 002, IN
2 National Institute of Ocean Technology, Chennai-600 031, IN

Abstract

No Abstract.

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S. N. Rajaguru ¹

Affiliations
1 Deccan College, Pune - 411 006, IN

Abstract

No Abstract.

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S. Kathiroli ¹, S. Badrinarayanan ¹, D. Venkata Rao ¹, S. N. Rajaguru ², K. M. Sivakholundu ¹, B. Sasisekaran ¹

Affiliations
1 National Institute of Ocean Technology, Chennai - 600 036, IN
2 Deccan College, Pune - 411 006, IN

Abstract

Detailed underwater surveys carried out in the Gulf of Cambay, about 20 km west of Hazira, deploying side scan sonar and sub bottom profiler brought to light, the presence of a submerged palaeochannel traceable to a length of 9 km. Associated with this on either side are basement like features found in a grid pattern at water depths of 20-40 m. Sub-surface sampling carried out with dredge and grab sampler revealed stone artefacts, potsherds, hearth pieces, animal bones and human teeth embedded in fluvial sands and silts. In the upper part of the deposit, a carbonised wooden log was found and dated to around 9500 years BP by ¹⁴C method. Marine magnetic survey carried-out does not indicate the presence of any major metallic debrislobjects. This appears to be one of the early records of prehistoric human activity of early Holocene age in the marine environment of India.

Keywords

Marine Archaeology, Holocene, Palaeo Channel, Side Scan Sonar, Sub Bottom Profiler, Carbon Dating, Artefacts, Gulf of Cambay.

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R. K. Ganjoo ¹, S. N. Rajaguru ², Avijit Gupta ³

Affiliations
1 PG Department of Geology, University of Jammu, Jammu - 180 004, IN
2 Department of Archaeology, Deccan College, Pune - 411 006, IN
3 Department of Geography, National University of Singapore, Singapore 0511, SG

Abstract

Reasonably convincing evidences of neotectonic activities in the Central Narmada Valley have come to light. The geomorphic investigation of litho-sections at Bedhaghat, near Jabalpur and Siddhaghat highlights the occurrence of such event in geologically younger times. The integration of observations has further helped in understanding the genesis and dating the waterfall at Bedhaghat.

Keywords

Geomorphology, Bedhaghat Water Falls, Neotectonics, Late Pleistocene Madhya Pradesh.

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