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

D. K. Srivastava ¹, A. K. Bhandari ², N. Srimal ¹, R. P. Radcliffe ¹

Affiliations
1 Geological Survey of India, Lucknow-226 006, IN
2 Geological Survey of India, Himachal Pradesh Circle, SCO 98-100, Sector-17, Chandigarh, IN

Abstract

The ichnogenus Chondrites Sternberg, 1833 is recorded and described from the rocks of Tegar Formation exposed near Skampu in the Shyok Valley of Ladakh district, Jammu and Kashmir, India.

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Manoj Shukla ¹, Rupendra Babu ¹, V. K. Mathur ², D. K. Srivastava ²

Affiliations
1 Birbal Sahni institute of Palaeobotany, Lucknow - 226 007, IN
2 Palaeontology Division, Geological Survey of India, Northern Region, Lucknow - 226 024, IN

Abstract

Black carbonaceous shale associated with black chert nodules of Infra Krol Formation, Baliana Group yielded diversified assemblage comprising 20 taxa of Organic-walled microfossils (OWM) represented by acritarchs and cyanobacterial remains. Out of these, 16 taxa are reported for the first time from this area which include five genera of acritarchs (sphaeromorphida subgroup) viz. Margominuscula simple, Granomarginata primiriva, Satka colonialica, Paracrassosphaera dedalea, Microconcentrica incrustata, and six genera (sphaerohystrichomorphida subgroup) viz. Baltisphaeridium perrarum, trachyhystrichosphaera vidalii, Gorgonisphaeridium maximum, Micrhystridium echintiatum, M. regulare, M. eatonensis, Archaeohystrichosphaeridium cellulare, A. semireliculatum,Germinosphaera unispinosa; four taxa of the cyanobacterial remains viz. Globophycus rugosum, Bavlinella faveolata, Eomicrocystis inalgica, Tetraphycus hebeiensis, Eophormidium orculiformis belong to Synaplomorphitae subgroup and single genus of VSM viz, Melanocyrillium hexodiadema.

The recovered microbiotic assemblage compares well with the assemblages known from the Terminal Proterozoic sediments. The large sized acanthomoph Trachyhystrichosphaera vidalii, recorded here for the first time, is known globally after. Varanger glaciation and before diversification of Ediacaran biota. An analysis of the recovered microbiotic assemblage in the Infra Krol Formation suggests its autochthonous nature. It was deposited in stable, shallow water, restricted pond or lake which had occasional contact with the open sea.

Keywords

Terminal Proterozoic, Organic-Walled Rnicrofossils, Infra Krol Formation, Nainital Syncline, Uttaranchal

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V. K. Mathur ¹, D. K. Srivastava ¹

Affiliations
1 Palaeontology Division, Geological Survey of India, Sector - E, Aliganj, Lucknow - 226024, IN

Abstract

The assemblage of ichnofossils and inarticulate brachiopods are recorded and described systematically from the Early Cambrian rocks of Tal Group exposed in Nigalidhar and Korgai synclines, Himachal Lesser Himalaya, India. The ichnofossil assemblage occurring in the rocks of Arenaceous Member of Deo ka Tibba (Lower Tal) Formation and Quartzite Member of Dhaulagiri (Upper Tal) Formation, Tal Group exposed in Rayon-Koti Dhaman section of Nigalidhar Syncljne contains Bergaueria sp., Cruziana sp., Didymaulichnus sp., Monomorphichnus sp., Neonereites biserialis, Palaeophycus sp., Plagiogmus sp., Planolites sp., Rusophycus sp., Skolithos sp. and Treptichnus sp. A few ichnofossils i-e. Palaeophycus sp., Planolites sp. and Skolithos sp. have also been recorded from the Arenaceous Member of Deo ka Tibba Formation exposed in Birpa - Bhitar ka Khala section in the Korgai Syncline. This ichnofossil assemblage is known worldwide in the Early Cambrian (Upper Meishucunian to Lower Qiongzhusian) rocks and is corllatable with Ichnozone - III (Crimes, 1987). The inarticulate brachiopods viz. Lingulellu sp., Magnicanalis sp., Mickwitzia sp., Obolella sp. and Obolus sp. of Tsanglangpuian Stage (Early Cambrian) occur alongwith ichnofossils namely, Palaeophycus sp. and Planolites sp, in the shale unit of Quartzite Member of Dhaulagiri Formation, Tal Group exposed in Birpa - Bhitar ka Khala section of Korgai Syncline.

Keywords

Ichnofossils, Inarticulate Brachiopods, Tal Group, Himachal Lesser Himalaya, India.

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V. K. Mathur ¹, D. K. Srivastava ¹

Affiliations
1 Palaeontology Division, Geological Survey of India, Sector-E, Aliganj, Lucknow - 226 024, IN

Abstract

The tissue grade colonial eucaryote Horodyskia Yochelson and Fedonkin and wrinkle structures including Kenneyia ripples and polygonal patterned structures representing microbial mats associated with Ediacaran fossils are recorded from siltstone-shale intercalation of the Kauriyala Formation, Krol Group, exposed about 300 m southeast of Chairkhola (lat. 29°42'35": 10ng.78°58'10") in the Garhwai Synche, Pauri Garhwal district, Uttaranchal (Fig.1). The Ediacaran fossils earlier have been recorded by RaviEdiacaran fossils earlier have been recorded by Ravi in the Garhwal Syncline.

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V. K. Mathur ¹, D. K. Srivastava ¹

Affiliations
1 Palaeontology Division, Northern Region, Geological Survey of India, Sector - E, Aliganj, Lucknow - 226 024, IN

Abstract

The note records Ediacaran fossil cf. Dickinsonia sp. from the rocks of Kauriyala Formation (= Krol C, D and E of Auden, 1934), Krol Group exposed at about 400 m west of Thalla (30°37'15": 77° 39'30"), Sirmaur district, Himachal Pradesh, India in the northern limb of Nigalidhar Syncline (Fig. la, b). The Kauriyala Formation (after Shanker et al. 1993) has also yielded other Ediacaran fossils viz. Conomedusites lobatus, Tirasiana sp. and Beltanelliformis cf. brunsae and microbial mat structures from the same horizon and locality in the northern limb of Nigalidhar Syncline, Sirmaur district, Himachal Pradesh, India (Shanker et al. 1997). The microbial structures have also been recorded in association with Ediacaran fossil of Kauriyala Formation, Krol Group in the Garhwal Syncline (Mathur and Srivastava, 2004). The genus Dickinsonia is restricted in Proto-Gondwana (McMenamin, 1982).

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