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Upper Albian, Cenomanian and Lower Turonian stratigraphy, ammonite and inoceramid bivalve faunas from the Cauvery Basin, Tamil Nadu, South India

Gale Andrews S., Kennedy William J., Walaszczyk Ireneusz

Acta Geologica Polonica

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2019

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Vol. 69, no. 2

161--338

EN

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 correlated 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 Mantelliceras mantelli, Cunningtoniceras cunningtoni, Calycoceras (Newboldiceras) asiaticum, Pseudo calycoceras harpax, Euomphaloceras septemseriatum and Pseudspidoceras footeanum. The Lower Turonian is represented 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-ornamented taxa: leiostraca; those from sandstones by strongly ornamented taxa: trachyostraca, differences interpreted 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.

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Inoceramid stratigraphy and depositional architecture of the Campanian and Maastrichtian of the Miechów Synclinorium (southern Poland)

Jurkowska A.

Acta Geologica Polonica

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2016

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Vol. 66, no. 1

59--84

EN

Dynamic evolution of the Campanian and Maastrichtian (Upper Cretaceous) of the Miechów Synclinorium is presented. Through chronostratigraphic analysis, the geometry of the Campanian and Maastrichtian of the area is interpreted, while microfacies analysis allowed determination of some of the paleoenvironmental parameters (rate of sedimentation, bottom condition and terrigenous input). The chronostratigraphy is based on inoceramid biostratigraphy. Nine inoceramid zones are recognized: Sphenoceramus patootensiformis, Sphaeroceramus sarumensis-Cataceramus dariensis and ‘Inoceramus’ azerbaydjanensis-‘Inoceramus’ vorhelmensis, ‘Inoceramus’ tenuilineatus, Sphaeroceramus pertenuiformis, ‘Inoceramus’ inkermanensis and ‘Inoceramus’ costaecus-‘Inoceramus’ redbirdensis (Campanian); Endocostea typica and Trochoceramus radiosus (Maastrichtian). Five unconformities (isochronous in the study area) represented by horizons of slower sedimentation rate, were recognized. They correlate with eustatic sea-level changes, well recorded in European successions (Jarvis et al. 2002, 2006; Niebuhr et al. 2011). Unconformity horizons allow six alloformations to be distinguished. The thickness of particular chronostratigraphic units within the Campanian and Lower Maastrichtian increases progressively toward the axis of the Danish-Polish Trough, which indicates that the inversion of the trough could not have started before the Late Maastrichtian.

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Turonian (Upper Cretaceous) inoceramid bivalves of the genus Mytiloides from the Sredna Gora Mountains, north-western Bulgaria

Dochev D.

Acta Geologica Polonica

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2015

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Vol. 65, no. 1

101--119

EN

The inoceramid bivalves of the genus Mytiloides, from the Turonian (Upper Cretaceous) of the Sredna Gora Mts (north-western Bulgaria), are studied. The material comes from three sections: Izvor, Filipovtsi, and Vrabchov dol. Eight species are described taxonomically, with one left in open nomenclature: M. cf. mytiloides (Mantell, 1822), M. mytiloidiformis (Tröger, 1967), M. incertus (Jimbo, 1894), M. scupini (Heinz, 1930), M. herbichi (Atabekian, 1969), M. striatoconcentricus (Gümbel, 1868), M. labiatoidiformis (Tröger, 1967) and M. carpathicus (Simionescu, 1899). Mytiloides incertus and Mytiloides scupini are index species for the eponymous Upper Turonian inoceramid biozones

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An integrated study (inoceramid bivalves, ammonites, calcareous nannofossils, planktonic foraminifera, stable carbon isotopes) of the Ten Mile Creek section, Lancaster, Dallas County, north Texas, a candidate Global boundary Stratotype Section and Point

Gale A.

Acta Geologica Polonica

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2007

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Vol. 57, no. 2

113-160

EN

The WalMart section on Ten Mile Creek, Lancaster, Dallas County, Texas, exposes a 23 metre section of Austin Chalk that can be integrated into a more than 60 m composite sequence for the Dallas area on the basis of bed-by-bed correlation. The section was proposed as a possible candidat e Global Boundary Stratotype at the 1995 Brussels meeting on Cretaceous Stage boundaries, with the first occurrence of the inoceramid bivalve Cladoceramus undulatoplicatus (ROEMER, 1852) as the potential boundary marker. An integrated study of the inoceramid bivalves, ammonites, planktonic foraminifera, and calcareous nannofossils places the first occurrence of Cl. undulatoplicatus in a matrix of ten ancillary biostratigraphic markers. The candidate Global boundary Stratotype Section and Point (GSSP) is located within a composite stable carbon isotope curve for the Austin Chalk as a whole. This shows it to lie 3.5 m below the Michel Dean stable carbon isotope event, originally recognised in the English Chalk. The first occurrence of Cl. undulatoplicatus lies in the same position in relation to stable carbon isotope events in both Texas and England that can in principle be recognised globally in marine sediments. The WalMart section satisfies many of the criteria required of a GSSP for the base of the Santonian Stage, although ownership and access require clarification.

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Biostratigraphy of the Santonian in the SW margin of the Holy Cross Mountains near Lipnik, a potential reference section for extra-Carpathian Poland

Remin Z.

Acta Geologica Polonica

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2004

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Vol. 54, no. 4

587-596

EN

The set of outcrops near the village of Kije, on the SW margin of the Holy Cross Mountains provides a nearly complete Santonian succession that has a great potential to become a Santonian reference section in Poland. The Coniacian/Santonian boundary is defined here by the first occurrence (FO) of the inoceramid bivalve species Cladoceramus undulatoplicatus (ROEMER 1852). The uppermost Santonian is characterized by common Sphenoceramus patootensiformis (SEITZ 1965). The top of the stage (and the base of the Campanian Stage) is documented by the last occurrence (LO) of the crinoid species Marsupites testudinarius (SCHLOTHEIM 1820). The substage division of the Santonian is based on inoceramids, with the lower boundary of the Middle Santonian indicated by the LO of Cladoceramus undulatoplicatus and the base of the Upper Santonian by the FO of representatives of Cordiceramus muelleri (PETRASCHECK 1906) group.

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Early Cenomanian (Cretaceous) inoceramid bivalves from the Kronsberg Syncline (Hannover area, Lower Saxony, Germany) : stratigraphic and taxonomic implications

Wilmsen M., Niebuhr B., Wood C.

Acta Geologica Polonica

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2001

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Vol. 51, nr 2

121-136

EN

An Early Cenomanian inoceramid bivalve assemblage collected from material excavated from a temporary exposure in the Kronsberg Syncline east of Hannover (northern Germany) is described. It consists of "Inoceramus" crippsi MANTELL, 1822, "I" hoppenstedtensis TROGER, 1967, Inoceramus virgatus scalprum BOHM, 1914 and I. virgatus virgatus SCHLUTER, 1877, as well as transitional forms between I. virgatus virgatus and I. virgatus scalprum and an apparently undescribed sulcate form. The inoceramid fauna is well preserved and very rich in individuals. Many of the inoceramids occur either as double-valved individuals or with the valves in close association and appear to be cocentrated in distinct layers. Co-occurring ammonites are Mantelliceras dixoni SPATH, Mantelliceras sp., Schloenbachia varians (J. SOWERBY), Hypoturrilities gravesianus (D'ORBIGNY) and Scaphites obliquus J. SOWERBY. Using event stratigraphy, the stratigraphic interval of the collected fauna can be assigned to the lower part of the Lower Cenomanian Mantelliceras dixoni ammonite Zone. It predominantly comprises material from the Inoceramus virgatus acme-event (the Schloenbachia/virgatus event of German event stratigraphy) at the top of the lower subzone (Mantelliceras dixoni & M. saxbii Subzone) of the dixoni Zone, which is known from the Lower Saxony, Cleveland (eastern England) and Anglo-Paris basins, where it invariably occurs in carbonate-rich rocks with low diversity faunas. The lithofacies and geochemistry of the strata are documented and the "Inoceramus" crippsi and Inoceramus virgatus groups are discussed, including the problematic provenance of the type series of Inoceramus virgatus scalprum.