Upper Albian, Cenomanian and Lower Turonian Stratigraphy, Ammonite and Inoceramid Bivalve Faunas from the Cauvery Basin, Tamil Nadu, South India
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Acta Geologica Polonica, Vol. 69 (2019), No. 2, pp. 161–338 DOI: 10.24425/agp.2019.126438 Upper Albian, Cenomanian and Lower Turonian stratigraphy, ammonite and inoceramid bivalve faunas from the Cauvery Basin, Tamil Nadu, South India ANDREW S. GALE1, WILLIAM J. KENNEDY2 and IRENEUSZ WALASZCZYK3 1 School of Earth and Environmental Sciences, University of Portsmouth, Portsmouth PO1 3QL, United Kingdom. E-mail: [email protected] 2 Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW and Department of Earth Sciences, South Parks Road, Oxford OX1 3AN, United Kingdom. E-mail: [email protected] 3 Faculty of Geology, University of Warsaw, Al Żwirki i Wigury 93, Pl-02-089 Warszawa, Poland. E-mail: [email protected] ABSTRACT: Gale, A.S., Kennedy, W.J. and Walaszczyk, I. 2019. Upper Albian, Cenomanian and Lower Turonian strati- graphy, ammonite and inoceramid bivalve faunas from the Cauvery Basin, Tamil Nadu, South India. Acta Geologica Polonica, 69 (2), 161–338. Warszawa. The lithostratigraphy, biostratigraphy, sequence stratigraphy, ammonite and inoceramid faunas of the Upper Albian, Cenomanian, and Lower Turonian Karai Formation, the highest unit of the Uttatur Group in the Pondicherry Sub-Basin of the Cauvery Basin in Tamil Nadu, south India, are documented. Detailed logs and descriptions of sections between Karai and Kulakkalnattam, Odiyam and Kunnam, and north-west of Garudamangalam are presented. They provide the evidence for an ammonite zonal scheme that can be cor- related in detail with sequences developed in Europe, with successive Upper Albian zones of Pervinquieria (Subschloenbachia) rostrata and P. (S.) perinflata (the latter on slight evidence), Cenomanian zones of Mantelli- ceras mantelli, Cunningtoniceras cunningtoni, Calycoceras (Newboldiceras) asiaticum, Pseudocalycoceras harpax, Euomphaloceras septemseriatum and Pseudspidoceras footeanum. The Lower Turonian is repre- sented by a Neoptychites cephalotus–Mytiloides borkari fauna. Over 120 ammonite species are described, of which Puzosia (Bhimaites) falx, Protacanthoceras parva, Watinoceras elegans, Euomphaloceras varicostatum, Kamerunoceras multinodosum, and Carthaginites multituberculatus are new. The new genus Kunnamiceras, with Ammonites tropicus Kossmat, 1865 as type species, is interpreted as a paedomorphic dwarf derivative of Pseudocalycoceras harpax (Stoliczka, 1864). Ammonite faunas from shales are dominated by feebly-orna- mented taxa: leiostraca; those from sandstones by strongly ornamented taxa: trachyostraca, differences inter- preted as reflecting the preferred habits of adults in life. 15 species of inoceramid bivalves, including a newly described species Inoceramus chiplonkari, are recognised, with a mixed East African–Euramerican–North Pacific affinity. On the basis of the stratigraphic framework developed, a sequence stratigraphic interpretation of the Karai Formation is proposed, and correlated with those recognised in Europe, Morocco, and the United States Gulf Coast and Western Interior. Key words: Cretaceous; Ammonites; Inoceramid bivalves; Sequence stratigraphy; South India. 162 ANDREW S. GALE ET AL. PREFACE: ON FERDINAND STOLICZKA (1838–1874) All work on the fossil invertebrate faunas of south India is founded on the extraordinary contribution of Ferdinand Stoliczka, a summary of whose life and work is set out below. Stoliczka was born near Kroměříž in the Slin region of Moravia, in what is now the Czech Republic, on June 7th 1838. His father was a forester in the employ of the Archbishop of Olomouc. He studied geology in Prague and Vienna under Eduard Suess and Rudolf Hoernes, and gradu- ated with a doctorate from the University of Tübingen in November 1861. He joined the Imperial Geological Institute of Austria and published on recent and fossil bryozoans, as well as the fauna of the Gosau Group. Ferdinand Stoliczka (1838–1874) Stoliczka joined the Geological Survey of India in 1862, and was tasked with describing the Cretaceous faunas of south India, publishing monographs on the Cephalopoda, Gastropoda, Brachiopoda, Bivalvia, de Beaumont and D’Omalius D’Halloy are also noted. Echino dermata and other invertebrate and vertebrate There is a more accessible account of Stoliczka’s life groups in Palaeontologica Indica between 1870 and to be found on Wikipedia under his name.) 1873. As his obituary notes, this extends to around 1500 pages, illustrated by 178 plates, an extraordinary contribution from a man in his twenties and early thir- INTRODUCTION ties. Palaeontology apart, there were also publications on Indian mammals, birds, reptiles, molluscs, bryozo- Largely owing to their rich, diverse, fossil content, ans, arachnids, coleoptera, and corals, and there are the Upper Cretaceous strata of the Cauvery Basin in bats, birds, butterflies, fish, lizards, mammals and south-east India have been the focus of considerable snakes that bear his name. Added to this, he lent his interest since the pioneering work of Blanford (1862), name to Stoliczka Island, the northernmost island of Stoliczka (1863–1866, 1870–71, 1872, 1872–1873) and the Franz Joseph Archipeligo (81º11’ N, 58º16’ E) in Kossmat (1895–1898). Albian to Turonian macrofau- the Arkhangelsky Oblast of the Russian Federation. nas have long been known from the regions to the Stoliczka took part in a series of expeditions visit- west of Ariyalur, and ammonite zonal schemes have ing Burma (Myanmar), Malaya, the Andaman and been proposed for this interval (e.g. Sastry et al. 1968; Nicobar Islands, Kutch, and the Ladakh Valley, on Ayyasami 1990). Planktonic foraminiferal stratigraphy which he contributed numerous publications. His fi- has been based upon samples from a series of cored nal expedition was to Turkestan, as part of the Second boreholes around Karai and Kunnam (Govindan et Yarkan Mission. He suffered severe headaches as the al. 1996). A nannofossil biostratigraphy has also been expedition crossed the Karakorum Pass (altitude 5580 established for the region (Kale and Phansalkar 1992a, m); on the 18th of June he set off to examine a se- b). Gale et al. (2002) outlined a sequence stratigraphy quence of dolomitic limestones and shales, in spite for part of the Cenomanian, and recorded the presence of deteriorating health. He died (of chronic mountain of international zonal Cenomanian ammonite species, sickness) at Moorghi in Ladakh on June 19th 1874, but did not provide further details. A useful review of ten days after his 36th birthday. There is a monument the literature was provided by Govidan et al. (1996). to his memory in the Moravian Mission Cemetery in Leh, in Jammu and Kashmir. (An obituary, by W.T. Blanford, appeared in GEOLOGICAL SETTING Nature on July 9 1874. This is reproduced in part in the Anniversary Address of the President of the The Cauvery Basin (Text-fig. 1) is one of a number Geological Society, John Evans, on pp. xlvii–xlix of of passive-margin sedimentary basins along the coast the Proceedings of the Geological Society of London of south-east India that formed during the break-up for 1874–1875, where the passing of John Phillips, Élie of eastern Gondwana in Early Cretaceous times (e.g. CRETACEOUS OF SOUTH INDIA 163 Text-fig. 1. A – simplified geological map of the Cauvery Basin. B – simplified geological map of a part of the Pondicherry Sub-Basin, showing the position of the three study areas Powell et al. 1988). Structurally, the basin is domi- nated by north-east–south-west trending en-echelon GROUP FORMATION MEMBER extensional faults which define a series of sub-basins and intervening horst blocks of Precambrian base- KUNNAM ment (Sastri et al. 1981; Prabhakar and Zutshi 1993). KARAI ODIYAM Albian, Cenomanian and Turonian strata are exposed only in the Ariyalur district of the Pondicherry Sub- DALMIAPURUM Basin (Text-fig. 1B), where they constitute part of a UTTATUR 2.3-km-thick Cretaceous succession (Sundaram et al. AROGYAPURUM 2001). The Cenomanian strata form part of the mud- stone-dominated Karai Formation (Late Albian–mid Turonian; Sundaram and Rao 1986; Sundaram et al. TERANI 2001) of the Uttatur Group (Text-fig. 2). The Uttatur Group is thought to have been deposited in a partly Text-fig. 2. Lithostratigraphic divisions of the Uttatur Group (modi- enclosed north-north east-south-south west elongated fied after Henderson et al. 2001) 164 ANDREW S. GALE ET AL. embayment some 20–30 km across, connected to Group (for discussion see Sunduram et al. 2001). the open ocean in the north but separated from it to The Karai Formation passes laterally into a sandy, the south-east by an emergent (Sundaram and Rao nearshore to marginal marine facies in the region of 1986) or shallowly submerged (Sastri and Raiverman Odiyam and Kunnam (Text-fig. 1B), distinguished as 1968) basement high. The locally developed, sandy the Odiyam and Kunnam Members (Sundaram et al. Odiyam–Kunnam succession was deposited relatively 2001; Text-fig. 2). No detailed lithostratigraphic logs of close to the fault-controlled basin margin; Archaean these sequences have been published to date. high-grade metamorphic rocks are exposed c. 2 km north-east of the study area. The Karai Formation Present observations generally dips gently (5–10º) to the south-east, except in the vicinity of minor low-amplitude closures. Sections were logged in three areas: between Karai and Kulakkalnattam, north-west of Garudamangalam, and between Odiyam and Kunnam (Text-fig. 1B). LITHOSTRATIGRAPHY Detailed accounts are given below. Previous work Karai Formation, Karai–Kulakkalnattam