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Tectono-sedimentologic and lithostratigraphic control in Aures Region: Case study Djebel Metlili, Batna, Algeria

Touahri Abdeldjebar, Sahraoui Salah, Benmansour Sana, Hadjkouider Mohammed

Geomatics, Landmanagement and Landscape

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2024

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no. 2

111--124

EN

This research delves into the geological features of the western section of the Aures Basin, with a primary focus on Djebel Metlili. The geological characteristics span Mesozoic and Tertiary deposits, ranging from the Triassic to the Quaternary epochs. Notably, the higher Cretaceous period stands out for its substantial carbonate-rich sequence. The research relied on geological maps, field observations, core samples, and laboratory analyses, including lithostratigraphic examinations (cross-section) and thin section. Structural features show that is formed by large regular folds of ENE-WSW or E-W direction. Anticlines and synclines are often affected by transverse accidents at the axes of the folds. In its northern part is located immediately south of the Belezma-Batna mountains. Structural analysis highlights significant tectonic disturbances, oriented in a northwest-southeast direction. A detailed lithostratigraphic examination reveals marly formations interspersed with limestone-rich layers containing Inoceramus. The southern part of Dj. Metlili, particularly the Santonian-Campanian series, unveils three distinct meso-transgressive sequences, linked to sea-level fluctuations associated with sedimentary basin subsidence. The studied area exhibits three distinct facies: one characterized by gray phosphate limestone with crisscrossed stratifications and agitated bioclastic sand, another featuring a mollusk-rich bioclastic limestone indicating a turbulent intertidal environment, and a third presenting a clay limestone bank with fine to medium grains and lumachels rich in oysters and gastropods. The associated grainstone texture in the microfacies suggests an internal platform environment marked by dissolution, bioturbation, and ferruginization. This comprehensive exploration provides valuable insights into the geological history of the region, significantly contributing to our understanding of its evolution over time.

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Palynostratigraphy of dinosaur bone-bearing deposits from the Upper Cretaceous of Western Bulgaria

Pavlishina Polina, Dochev Docho, Nikolov Vladimir, Yaneva Marlena, Konyovska Ralitsa

Acta Geologica Polonica

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2019

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Vol. 69, no. 4

617--626

EN

Palynological investigation of the Vrabchov dol locality (Western Bulgaria) which recently yielded fragmentary dinosaur bones attributed to the clade Titanosauria, reveals well-preserved sporomorph assemblages dominated by angiosperm pollen from the Normapolles group, spores and rare gymnosperms. The age assessment of the studied sequence is based on the diagnostic Normapolles species, such as Oculopollis orbicularis Góczán, 1964, Oculopollis zaklinskaiae Góczán, 1964, Krutzschipollis spatiosus Góczán in Góczán et al., 1967 and Krutzschipollis crassus (Góczán, 1964) Góczán in Góczán et al., 1967. The concurrent presence of these pollen species suggests a late Santonian–early Campanian age for the succession. The sporomorph association is encountered in a palynofacies dominated by continental elements, including translucent phytoclasts (tissues, wood remains and plant cuticles). The sedimentary succession shows no evidence of marine elements and a very low proportion of AOM that attests to deposition within a lagoonal to foreshore marine environment, with high continental input and short transportation. The vegetation in the studied area was primarily composed of a range of Normapolles-producing angiosperms and secondarily of pteridophyte spore-producing plants. Gymnosperms were rare. Such a vegetation pattern reflects a warm, seasonally dry climate during the late Santonian–earliest Campanian in the studied area. The dinosaurs inhabited a wet lowland area, probably rich in herbaceous plants.

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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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Marsupites (Crinoidea, Uintacrinida) jako narzędzie datowania skał górnosantońskich w krach glacjalnych wschodniej Polski

Łukowiak M., Gorzelak P.

Przegląd Geologiczny

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2006

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Vol. 54, nr 9

784-786

EN

In the Santonian chalk glacial deposits exposed at Kornica (eastern Poland) an assemblage of echinoderms comprising asteroids, echinoids, ophiuroids, and crinoids (comatulids, roveacrinids, and Bourgueticrinus, Isocrinus, Isselicrinus, Marsupites) is documented. The Santonian age of sediments at Kornica has been determined with foraminifers. Numerous occurrences of the crinoid Marsupites testudinarius, indicate their late Santonian age.