Facies Analysis and Paleoenvironmental Assessment of the Upper Campanian Hartha Formation in Y and J Fields Northwestern Zagros Basin, Iraq

The Upper Campanian Hartha Formation represents potential Cretaceous hydrocarbon-bearing reservoir rocks across the Y and J oilfields northwestern Zagros Basin, northern Iraq. The study objective is depositional environment which affects reservoir properties by tool, lithofacies, core, thin section, and logs, using petrel (V.2016) and strat software, facies distribution, grains, and diagenetic processes control and enhance reservoir properties which can plan platform production and minimize risks in choosing production wells location at two fields scale The current study is concerned with lithofacies and microfacies of the Hartha Formation within two fields in northern Iraq. Several subsurface well-log data, core, and cutting samples have been used in order to prepare thin sections that were subjected to sedimentological (lithofacies, and grain-size) examination. The petrography investigation revealed five rock-units including Hr. 1, 2, 3, 4, and 5, the thickness of 89 m in the Y-A field and increasing to up to 140 m in the J-B field might be due to erosion or tectonic uplift of the topography in Y subbasin. Which is locally sub-basin within study fields western banks of Tigris river as gentle slope ramp depositional condition with Spectrum microfacies from lime-mudstone to packstone texture with rudest and benthic debris enhances by diagenesis, dolomitization, dissolution moldic porosity, fracture; dolostone is more effective in the upper section of the formation in A than B Wells. Many factors, such as cementation, compaction, and pore-filling autogenic minerals, decrease reservoir quality, and their effects are similar in wells A and B.

Notes on some Late Cretaceous goniasterid starfish (Echinodermata, Asteroidea) from Belgium and Germany

Both partially articulated specimens and dissociated marginal ossicles form the basis for erection of two new species of Late Cretaceous goniasterids from the Mons and Liège-Limburg basins (Belgium) and the Hannover area (Germany). Chomataster breizh sp. nov., which recalls the type species, Chomataster acules Spencer, 1913, but differs in several respects, is based on a partial external mould of the marginal frame of disc and arms in flint (upper Campanian Spiennes Chalk Formation; Mons Basin), as well as on a more or less complete individual, preserving small, spherical spines and granules and encased in a flint nodule from the upper Maastrichtian Nekum Member (Maastricht Formation; Liège-Limburg Basin). In Ch. breizh sp. nov., supero- and inferomarginals bear close-set granule pits, of varying sizes, as well as bivalved alveolar scars of pedicellariae; median superomarginals and all inferomarginals lack large, crater-shaped spine pits – such are found only in the disc/arm transition and along the arms. Dissociated supero- and inferomarginal ossicles from the lower and upper Campanian of the Hannover area and the upper Campanian of northeast Belgium, previously recorded either as indeterminate astropectinids or as Nymphaster obtusus (Forbes, 1848) var. nov. and as Nymphaster sp., respectively, here are assigned to Nymphaster mudzborgh sp. nov. This species is characterised by a row of 3–5 large spine pits on the aboral and lateral surfaces of superomarginals; inferomarginals have an angular profile and a close cover of granule pits. Nymphaster tethysiensis Villier, 2001, from the upper Campanian of Landes (southwest France; Villier and Odin, 2001) appears best accommodated in Chomataster as well, because in the arm superomarginals alternate rather than meet over the mid-radial line.

Agglutinated Foraminiferal Acmes and Their Role in the Biostratigraphy of the Campanian–Eocene Outer Carpathians

The biostratigraphy of the Outer Carpathians is based mainly on the ranges of agglutinated foraminifera. Species acmes provide the opportunity to enhance and support the existing biozonations. Assemblages of agglutinated foraminifera from the Campanian to Eocene of various tectonic-structural units were analyzed in terms of their qualitative and quantitative occurrence. In this stratigraphic interval, 19 species display significantly increased abundance within a relatively short interval: Caudammina gigantea (Geroch) (upper Santonian–lowermost Maastrichtian), Caudammina ovulum (Grzybowski) (Campanian–Danian), Placentammina placenta (Grzybowski)-Saccammina grzybowskii (Schubert) (upper Campanian–Danian), Caudammina excelsa (Dylążanka) (lowermost Maastrichtian–Danian), Caudammina ovuloides (Grzybowski) (Danian–Selandian), Hormosina velascoensis (Cushman) (upper Danian–Selandian), Praesphaerammina gerochi (Hanzlíková) (Thanetian), Glomospira charoides (Jones et Parker)-Glomospira gordialis (Jones et Parker) (uppermost Thanetian–lowermost Ypresian), Trochammina spp. (upper Thanetian–lower Ypresian), Reticulophragmium amplectens (Grzybowski) (Lutetian–Bartonian), Reophax duplex (Grzybowski)-Reophax “pilulifer” Brady group of taxa (Lutetian–Priabonian), Haplophragmoides walteri (Grzybowski)-Haplophragmoides nauticus Kender, Kaminski et Jones (Lutetian–Bartonian), Spiroplectammina spectabilis (Grzybowski) (Lutetian–Priabonian), “Ammodiscus” latus Grzybowski (Bartonian–Priabonian), Praesphaerammina subgaleata (Vašíček) (Lutetian–Bartonian). The biostratigraphic position and quantitative data of species with increased abundance are presented.

Iberoccitanemys atlanticum (Lapparent de Broin & Murelaga, 1996) n. comb.: new data on the diversity and paleobiogeographic distributions of the Campanian-Maastrichtian bothremydid turtles of Europe

Bothremydidae is the most abundant clade of turtles in the Campanian and Maastrichtian (Upper Cretaceous) fossil record of southwestern Europe. Several members of Foxemydina Gaffney, Tong & Meylan, 2006 are known in an area that includes Southern France and the North-Eastern half of Spain. The problematic ‘Polysternon’ atlanticum is the worst characterized, lacking a diagnosis that allows its specific validity to be confirmed, and whose generic attribution has been recognized as doubtful. Its presence was exclusively proposed in its type locality, the upper Campanian quarry of Laño, in Treviño County (Burgos Province, North of Spain). Despite the fact that knowledge about Bothremydidae has markedly increased after the description of ‘Polysternon’ atlanticum Lapparent de Broin & Murelaga, 1996, no new information about this species has been published since the 1990s. The analysis of abundant unpublished material of the bothremydid from Laño allows us to confirm the validity of this species. As a consequence of this study, it is not only identified in its type locality, but also in other Spanish regions and in the south of France. The diversity of Bothremydidae Baur, 1891 in the Upper Cretaceous of Europe is lower than previously considered. Thus, the species ‘Iberoccitanemys convenarum’ (Laurent, Tong & Claude, 2002), originally defined for the French record, and subsequently also identified in Spain, is identified here as a synonym of the species described in Laño. An emended diagnosis for the upper Campanian to upper Maastrichtian, Iberoccitanemys atlanticum (Lapparent de Broin & Murelaga, 1996) n. comb., is proposed.

The oldest occurrence of brachylophosaurin hadrosaurids in Canada

Hadrosaurids are a diverse and widely distributed group of ornithischian dinosaurs that are particularly well represented in the upper Campanian Dinosaur Park Formation of the Belly River Group of Alberta. However, the origin of this hadrosaurid diversity in Alberta is poorly understood, as the lower Campanian terrestrial deposits of the underlying Oldman and Foremost formations of the group have produced comparatively few body fossils. Here we provide the first description of a partially articulated hadrosaurid and hadrosaurid material from a bonebed from the Foremost Formation and refer it to the brachylophosaurin Probrachylophosaurus sp. indet. The material represents the oldest occurrence of Brachylophosaurini in Alberta and the oldest known hadrosaurid diagnostic to the genus level from Canada. In Alberta, Hadrosaurinae display a distinct pattern of replacement with the tribes Brachylophosaurini and Kritosaurini being confined to the lower to middle Campanian strata (below the marine Bearpaw Formation) and replaced above the Bearpaw Formation by members of Saurolophini (Prosaurolophus, Saurolophus) and Edmontosaurini (Edmontosaurus), with the latter clade persisting to the end of the Maastrichtian. Although the worldwide stratigraphic distribution of the Hadrosaurinae is complex, this pattern generally holds true for northern Laramidian hadrosaurine tribes, suggesting that their pattern of evolution and replacement may be driven by some common underlying factor such as an environmental response to fluctuations in the margins of the Western Interior Seaway due to sea level change.

Stratigraphic And Microfacies Study Of Upper Campanian - Lower Maastrichtian Succession (Shiranish Formation) In Bade Village, Bekhere Anticline, Kurdistan Region, Northern Iraq

The Upper Cretaceous Shiranish Formation outcropped close to Bade village and Bekhere anticline, Kurdistan region at northern Iraq and consists of alternating mixed tough grey limestone, marly limestone, marl beds interpreted as a middle - outer shelf – upper bathyal environments (basinal) depositional environment. Fifteen thin sections were studied under a polarized microscope to find out the petrographic component, fauna content, and for microfacies analysis. The major petrographic constituents are fossils, bioclastic grains, micrite matrix, and extraclast (quartz grains). Planktic foraminifera and nannofossils are the major particles within wackestone and packstone microfacies types. The planktonic foraminifera biozones from previous study (such as Globotruncana aegyptiaca, Gansserina gansseri, Racemiguembelina fructicosa, Plummerita hantkeninoides) and the recorded calcareous nannofossils biozones of Broinsonia parca, Reinhardtites levis, Arkhangelskiella cymbiformis, suggest a late Campanian to late Maastrichtian age.