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The study of microfacies, with special emphasis on the significance of larger benthic foraminifera, is used to interpret the occurrence of different marine subenvironments into a mixed carbonate-siliciclastic platform from the upper Campanian in the Prebetic domain, representing the southeastern margin of the Cretaceous Iberian paleoisland. Four foraminiferal assemblages have been recognized, each one specifically assigned to a depositional systems: (1) the outer to middle shelf with Neorotalia? pinetensis, Goupillaudina spp., gavelinellids, Orbitoides tissoti-media, Praesiderolites douvillei, and Navarella joaquini; (2) the upper part of the middle shelf with the presence of seagrass meadows Orbitoides tissoti-media, "Orbitoides" concavatus, Lepidorbitoides campaniensis, Planorbulina cretae, Sirtina ornata, Praesiderolites douvillei, Pseudosiderolites vidali, and Rotalia baetica; (3) the upper photic zone of the inner shelf, with constant wave agitation, inhabited by Orbitoides cf. megaloformis, Lepidorbitoides campaniensis, and Wannierina vilavellensis; and (4) the paralic shallow protected shelf with alternating marine/freshwater influences characterized by charophytes and Suturina minima. Results on larger foraminifera distribution show the similarities and differences with the benthic communities shallow water platform assemblages of the nearby Pyrenean paleobioprovince. This allows to rise the Upper Cretaceous shelfs of the Betic area as a fundamental biogeographic piece for larger benthic foraminifera migration patterns between the Tethyan domain and the other marine domains during the Late Cretaceous. [ABSTRACT FROM AUTHOR]

We analysed the stable isotope compositions of dinosaur eggshells and their associated depositional settings of the egg-bearing rocks in the Upper Cretaceous of the Qiyunshan area, Anhui Province, China. Data show that δ13C values for Similifaveoloolithus qiyunshanensis and Umbellaoolithus xiuningensis range between −5.94‰ and −3.55‰; this suggests that C3-type vegetation was consumed by dinosaurs with relatively high atmospheric CO2. δ18O values vary between −8.45‰ and −4.95‰, indicative of high temperature and low humidity within nesting areas. The lithological characteristics of the egg-bearing section evaluated in this study are dominated by red-brown fine sandy siltstone, correlating with pebbly medium-fine grained and medium-fine grained lithic sandstones. Grain size parameters, histograms, and sample probability cumulative curves are also all characterised by fine-grained sediments and suspension populations, likely indicative of floodplain and point bar environments. Therefore, the paleoclimate of the dinosaur nesting habitat was semiarid-to-arid based on food types as well as the colour and high Fe content of sediments. We suggest that this fluvial environment provided the best nesting and egg laying area for drought-adapted dinosaurs in the Upper Cretaceous of the Qiyunshan area and that the excavated nesting could be concluded in view of the periodic flooding events. [ABSTRACT FROM AUTHOR]

Cretaceous deposits containing pelagic red beds (CORBs - Cretaceous Oceanic Red Beds) are developed in the Ukrainian Carpathians. CORBs have a global distribution, they are sharply depleted in organic matter and their formation is associated with periods of cooling and intensive circulation of cold, oxygen-enriched deep-sea currents that oxidize organic carbon. CORBs in the Ukrainian Carpathians are common in the Upper Cretaceous, while the Lower Cretaceous sediments, especially in the Outer (Flysch) Carpathians, are often enriched in organic matter (in particular the black shales of the Shypot and Spas formations). Such change in sediments enriched and depleted in organic matter may be associated with regular climate changes. In the Inner Carpathians, in the both the Peniny Klippen Belt and the Marmarosh Klippen Zone, CORBs are represented by thick (100-200 m) mostly red-colored marls and shales that make up the Turonian - Maastrichtian Puchov Formation. A fragment of the Puchov Formation of the Turonian age is presented in the Marmarosh Massif. Stratigraphically, the lowest CORBs represented by layers of pink marls are noted in the upper part (Middle-Upper Cenomanian) of the Tysalo Formation in the Peniny Klippen Belt. Deposits containing CORBs in the Peniny Klippen Belt are intensively deformed, in some places they are transformed into thin shale rocks or friction mud and are part of the tectonic mélange, while in the Marmarosh Klippen Zone they lie monoclinally and are weakly deformed. In the Outer Carpathians, CORBs are represented by: Turonian-Paleocene variegated shales and marls of the Holyatyn Beds (Subsilesian Nappe); Turonian-Coniacian red-colored and variegated shales belonging to the lower member of the Yalovets Formation (Dukla, Chornohora, Svydovets, and Krasnoshora nappes); and pack of Turonian variegated marls included in the Sukhiv Formation (Burkut nappe). CORBs represented by red-brown interlayers, occur both in the uppermust Albian-lower Cenomanian (Eiffellithus turriseiffeli Zone) of the Sukhiv Formation, and in the Santonian upper member of the Yalovets Formation. CORBs in the Outer Carpathians are deformed to a greater or lesser extent, plastic marls of the Sukhiv Formation are especially strongly deformed, which makes it much more difficult to establish their stratigraphic sequence. The age of the deposits of the Ukrainian Carpathians, which contain CORBs, has been clarified. The studied sediments are correlated with the Geologic Time Scale (2020) on the basis of nannoplankton and planktonic foraminifera. The biozonal scale based on nannoplankton of A.M. Romaniv is compared in the range BC27/UC0 (upper Albian - lower Cenomanian) - UC20 (upper Maastrichtian) according to the first appearance of zonal species according to the scale of J. Barnett (1998). Accordantly, the Eiffellithus turriseiffeli Zone (uppermost Albian-Lower Senomanian); Gartnerago obliquum Zone (Middle Senomanian-lowermost Turonian); Eiffellithus eximius-Marthasterites furcatus Zone (Lower Turonian-lowermost Upper Coniacian); Micula staurophora-Tetralithus obscurus-Broinsonia parca Zone (Upper Coniacian-lowermost Middle Campanian); Tetralithus aculeus Zone (Middle Campanian); Tetralithus? trifidus (Middle Campanian-lowermost Upper Campanian); Nephrolithus frequens (Upper Campanian-Upper Maastrichtian) are distinguished. The biozonal division of the Upper Cretaceous of the Carpathians according to planktonic foraminifera after N.I. Maslakova was modified and compared with the biochronozones of a typical section of the Tethys region (Coccioni, Premoli Silva, 2015). In the studied sediments, the following zones are distinguished: Thalmanninella reicheli (middle part of the Lower Cenomanian), Rotalipora cushmani (middle part of the Lower Cenomanian-Upper Cenomanian), Helvetoglobotruncana helvetica (lower part of Turonian), Dicarinella concavata (top of Turonian-lowermost Santonian), Contusotruncana fornicata (most of Santonian), Globotruncanita elevata (lower part of the Campanian), Contusotruncana morozovae (middle part of the Campanian), Globotruncanita stuarti (top of the Campanian-lower part of the Maastrichtian), Abathomphalus mayaroensis (upper part of the Maastrichtian); beds with Thalmanninella globotruncanoides (lower part of the Lower Cenomanian), assemblage with Marginotruncana schneegansi, Marginotruncana sigali, Marginotruncana renzi (upper part of Turonian). Benthic foraminifera Uvigerinammina jankoi Zone (Turonian); Spiroplectinella costata Zone (Coniacian-Lower Santonian); Caudammina gigantea Zone (Upper Santonian-Lower Campanian); Rzehakina inclusa Zone (Upper Campanian-Maastrichtian); Rzehakina fissistomata Zone (Paleocene) were identified accordantly to zonal schemes of L.D. Ponomaryova and B. Olszewska. The lower boundary of the CORBs in the Ukrainian Carpathians is correlated with the Senomanian-Turonian boundary on the basis of appearance of planktonic foraminifers of Helvetoglobotruncana helvetica Zone and benthic foraminifers of Uvigerinammina jankoi Zone in the base of both Puchov Formation (Pieniny Klippen Belt) and Holyatun Beds (Subsilesian Nappe), as well as in the lowermost part of the Yalovets Formation (Dukla, Chornohora, Svydovets and Krasnoshora nappes). [ABSTRACT FROM AUTHOR]

A study on depositional environment, diagenetic history, and sequence stratigraphy of the upper Cretaceous successions of the boundary between the Central and Eastern Alborz zones is lacking. This study attempts to tackle this issue by analyzing a succession composed of 120 meters of medium-to thick-bedded limestones. Facies analysis led to the identification of facies associations of terrestrial, inner ramp (proximal, mid, and distal lagoon and shoal), mid ramp, outer ramp, and basin settings. According to the lateral and vertical changes in facies associations indicating gradual facies variations and the absence of large barrier reef organisms, a carbonate platform of ramp type with a bioclastic shoal is suggested for the studied succession. However, regarding the presence of turbidites in the transition of mid and outer ramp facies, a distally steepened ramp better suits the studied succession. Diagenetic study reveals products of eogenesis, mesogenesis, and telogenesis stages. Sequence stratigraphic analysis based on facies analysis and field observation denoted one 3rd-order depositional sequence, which its maximum flooding surface is equivalent to MFS K180 of the Arabian Plate (AP) with middle Maastrichtian age. A disconformity at the topmost of the studied succession correlates with the upper sequence boundary of megasequence AP9 around the Cretaceous-Paleogene boundary. [ABSTRACT FROM AUTHOR]

The taxonomic typification of dinocyst assemblages was carried out on the basis of a qualitative and quantitative assessment of their generic composition for the Northern Hemisphere in the Cenomanian–Turonian time to identify correlation taxa. Three types of dinocyst assemblages were identified in the Cenomanian. Cenomanian dinocyst assemblages are poorly differentiated; a large number of cosmopolitan genera were identified, which is in good agreement with paleobotanical data indicating a very warm, humid climate. Three types of dinocyst assemblages were established for the Turonian. The number of cosmopolitan dinocyst genera decreases and species endemism sharply increases in some Turonian basins. The differentiation of assemblages increases and their correlation potential decreases. However, the identified common genera and species of dinocysts in different types of assemblages provide the possibility of interregional correlation of Upper Cretaceous deposits at the stage, substage, and, at some sections, even more detailed levels in different climatic zones. [ABSTRACT FROM AUTHOR]

The Anambra Basin has a relatively high hydrocarbon production base compared with other Cretaceous basins in Nigeria. Structural deformation, overpressures, and faulting in the Cretaceous sequence of the Anambra Basin have resulted in significant uncertainties regarding reservoir parameters, necessitating accurate reservoir characterization. This study uses several subsurface data, including 2D seismic data, a report of core descriptions, and well log data from an exploration well drilled in the Anambra Basin to identify reservoirs and assess the petrophysical parameters of Cretaceous Formations for hydrocarbon accumulations. Three reservoirs were identified in the interpreted seismic section of the Cretaceous strata, and the structural framework was described as a system of synthetic faults dipping north-south that controlled the thickness and lateral extension of the deposited sediments. The shale volume, total and effective porosity, permeability, water, and hydrocarbon saturation were estimated using standard equations. The low shale volume, good-to-very good porosity values, fair-to-moderate permeability values, and low-tomoderate hydrocarbon saturation of the identified Cretaceous reservoirs suggest that the reservoir sands have the capacity to produce hydrocarbons. The density-neutron cross-plots of the identified reservoirs show a dual mineral system and also indicate the effect of gas in the Cretaceous reservoirs. This study found that the Anambra Basin has gas potential. However, the identified gas reservoirs should be further evaluated using reservoir pressure data, if available, to aid in accurate hydrocarbon fluid typing. The reservoirs should be developed and optimized in such a way as to keep production risk to its minimum. [ABSTRACT FROM AUTHOR]

The Blattulidae Vishniakova, 1982 is an extinct family of cockroaches which was widely distributed around the world from Late Triassic to Late Cretaceous. Huablattula vrsanskyi sp. n., based on a well-preserved specimen from mid-Cretaceous Kachin amber differs from other species of genus Huablattula Qiu et al., 2019 in having different patterns on the pronotum, forewing with vein A bifurcated and hind wing without pterostigma. The new discovery enriched the diversity of the family Blattulidae in Kachin amber and expanded our understanding of cockroach structure and phylogeny. [ABSTRACT FROM AUTHOR]

Umenocoleidae is an enigmatic, extinct Mesozoic beetle-like roach family with cosmopolitan distribution erroneously attributed to various insect orders by past authors. Here unusual and well-preserved Archaeospinapteryx tartarensis gen. et sp. n., Trapezionotum vrsanskyi gen. et sp. n., Poikiloprosopon celiae gen. et sp. n., Vzrkadlenie karneri sp. n., and V. saintgermaini sp. n. are described from Cenomanian Burmese amber of the Hukawng Valley. Furthermore, Nigropterix angustata gen. et sp. n. and Umenotypus maculatus gen. et sp. n. are reported from Turonian sediments of Kzyl-Zhar, Kazakhstan. ?Classopolis pollen grains directly attached on the frons of the head of one specimen indiciate pollen transfer, as reported in other representatives of Umenocoleoidea. The herein studied material increases our knowledge of the diversity of this bizarre lineage and extends its temporal and paleogeographic distribution. [ABSTRACT FROM AUTHOR]

A systematic-stratigraphic revision of selected large Late Turonian–Early Coniacian inoceramids of the lamarcki group from Germany showed that both historical specimens of Goldfuss (1836), introduced as Inoceramus annulatus and later becoming the types of Late Turonian I. lamarcki stuemckei Heinz, 1928a and Early Coniacian I. annulatus Goldfuss, 1836, respectively, are of Late Turonian age. I. stuemckei Heinz, 1928a, as emended herein, is well represented by its lectotype. Bulky isolated hinges from Upper Turonian strata, used by Heinz (1932a) to erect Heroceramus hercules, are just fragments of contemporaneous large I. stuemckei; H. hercules is thus invalid. The common Late Turonian I. stuemckei occurs facies-independent from near- to offshore settings and its first common appearance is an excellent marker for the substage base. I. annulatus Goldfuss, 1836 was later applied to very large forms first appearing in the mid-Early Coniacian. Thus, I. annulatus sensu Walaszczyk and Wood (1998) is poorly represented by its medium-sized latest Turonian lectotype, causing some nomenclatorial issues. I. stuemckei (heightmax 500 mm) and I. annulatus (heightmax one metre) are characterized by a stratigraphically abrupt shell enlargement and hinge buttressing across the Middle/Upper Turonian boundary and within the Early Coniacian, respectively. This shift to larger sizes, a common passive defense strategy against predation, is accompanied by widespread evidence for increased Late Turonian predation pressure by marine durophages. We thus speculate that the size increase in Late Turonian–Early Coniacian inoceramid bivalves is part of an escalating arms race between prey and predators, ultimately triggering Late Cretaceous inoceramid gigantism. [ABSTRACT FROM AUTHOR]

We investigated the palynological organic matter (POM) recovered from shale horizons, intercalating the Nubian-type sandstones in middle Egypt, for paleoenvironmental reconstruction. Our palynofacies are dominated by either amorphous organic matter (AOM) or phytoclasts whereas palynomorphs are relatively rare, but not uncommon. The palynofacies categories revealed two different palynofacies types, reflecting estuarine/tidal and fluvio-lacustrine environments for the Maghrabi and the basal Quseir formations, respectively. The kerogen composition of our investigated material and the colors of the thin-walled spores suggest possible sources of hydrocarbons, which are poorly explored in the middle and southern areas of Egypt. Our findings confirmed the previously described marine origin of the Maghrabi Formation. The complete missing of any marine palynomorphs suggests that the basal sediments of the Quseir Formation are almost exclusively of terrestrial origin. This may reveal that the worldwide Late Cretaceous transgression was not effective during deposition of these basal clastics. [ABSTRACT FROM AUTHOR]

The authors discuss the results of studying the composition of the volcanogenic-sedimentary rocks of the Dzykhra sequence, which come to the surface in the upper reaches of the river Bolshaya Khosta (Khostinsky district, Krasnodar territory). In the rocks of the Cretaceous age of the Akhun series, composed of limestones of the Dzykhra sequence and the Kazachy Brod suite, an outcrop of clastic rocks was found. The structure and mineral composition of the rock sample, as well as its chemical composition according to X-ray fluorescence analysis, were studied in detail. In the sequence, two layers are distinguished: the lower (3 m) cream-brown and the upper (0.05 m) green. Macroscopically, it is a lenticular-layered, fine-grained, lithocrystal-clastic, polymictic sandstone with carbonate cement. The sequence is underlain by interbedded dark gray limestones and black siltstones of the Lower Cretaceous Agur Formation, and overlain by cream limestones with interlayers of brown cherts of the Upper Cretaceous Kazachy Brod Formation. The data of microscopic studies, as well as X-ray fluorescence analysis, made it possible to establish the following minerals in the composition of sandstones: quartz, potassium-feldspar and plagioclase, less often amphibole, as well as a large amount of carbonate matter, and to conclude that in composition they correspond to tuffs of medium composition (andesite-dacite).

AbstractThe Sarvak Formation, with a total thickness of 1566 m and major limestone lithology in the Ahvaz and Mansouri oil fields, is studied to determine its palaeoenvironment, diagenetic overprint and geochemistry. In the studied wells, the formation conformably overlies the Kazhdumi Formation and is overlain by the Ilam Formation. The petrographical studies led to identifying twelve facies precipitated in four major sub-environments, including inner-, middle-, and outer ramp and an intra-shelf basin on a homoclinal ramp-type setting. Dissolution, compaction, and cementation are the main diagenetic alterations that changed the primary chemical composition and the reservoir property of the Sarvak Formation. These diagenetic processes occurred in phreatic marine, meteoric, and burial realms. Sedimentary geochemistry of major and trace elements, including Ca, Mg, Fe, Mn, and Sr, along with O and C stable isotopes, reveal aragonite as the original carbonate mineralogy of the Sarvak Formation. The depositional environment in the lower Sarvak with the predominant shallow open marine and stratigraphic succession with no evidence of exposure, change to stratigraphic succession with more shallow sub-environments (lagoon and bioclastic-shoal), and the evidence of exposure such as cementation and extensive dissolution, which led to depletion in Sr, δ18O, and δ13C and enrichment in Fe and Mn during sea level fall in the inner ramp microfacies. The Fe and Mn cross-plot with a positive trend shows the effects of diagenetic phases in minor phreatic marine and mainly meteoric realm, all confirmed by petrography. The Sr/Ca ratio has the most correlation to the modern tropical warm-water shallow marine that could confirm the primary aragonite mineralogy; which is supported by the predominance of carbonate mud in the identified facies, primary isopachous fibrous marine cements, and extensive dissolution evidence. The cross-plot of Fe versus Sr and Mn versus Sr/Mn ratio suggests deposition in mainly an oxygenation state that experienced low to high water/rock interaction during different depositional sequences. The δ18O and δ13C co-variation and their comparison with the other fields of the Sarvak conducted in different regions show precipitation in an isotopic equilibrium in the carbonates with the Upper Cretaceous seawater, since calculating salinity (Z=130) and temperature (T= 26°C) of the Sarvak Formation confirm the above statement.Keywords: Diagenesis, Sedimentary geochemistry, Water/rock interaction, Upper Cretaceous, Sarvak Formation. Introduction:The Albian–Turonian Sarvak Formation (Motiei 1993), which forms a part of the Bangestan Group the second most important reservoir succession in the Zagros Basin and Persian Gulf (Esrafili-Dizaji et al. 2015; Assadi et al. 2016). This succession is equivalent to Mishrif, Ahmadi and Rumaila in Saudi Arabia, Natih in Oman, Derder in Turkey, and Mishrif in Iraq, which was deposited on a shallow carbonate platform along with interashelf basins on the passive margin of the Arabian Plate (Ziegler 2001; Piryaei et al. 2011; Alsharhan 2014). Various studies conducted on the geochemistry of carbonates reveal its adequacy in determining palaeoclimate and original mineralogy, defining the rate and type of diagenetic alteration, distinguishing diagenetic realms and trends as well as the stratigraphic position of depositional sequence stratal surfaces and boundaries (Adabi and Asadi Mehmandosti 2008; Crowe et al. 2013; Fallah-Bagtash et al. 2020; Omidpour et al. 2021). In this study, regarding the oil industry needs for exploration and production and based on petrographical and geochemical analysis, the facies, paloeoenvironment, diagenetic characteristics and geochemistry of the Sarvak Formation are studied in the northern Dezful Embayment, southern Iran. Material & MethodsThe facies analysis and diagenetic characteristics of the Sarvak Formation in two wells in the Ahvaz and Mansouri oil fields are studied using 900 thin sections obtained mainly from core samples. The nomenclature for carbonate rocks used in this study is the terminology introduced by Dunham (1962) and its modified classification by Embry and Klovan (1971). The facies analysis and interpretation of the depositional environments were conducted using the standard microfacies of Burchette and Wright (1992) and Flügel (2010). All thin sections were stained with potassium ferricyanide and Alizarin Red-S to distinguish carbonate minerals (Dickson 1965). The geochemical studies are done using analyzing trace and major elements including Ca, Mg, Fe, Mn, and Sr along with O and C stable isotopes of carbonate rocks both in the Exter University of England on 57 samples from the Ahvaz Oil Field and 43 samples from the Mansouri Oil Field. The trace and major elements are analyzed using Agilent 5110 VDV Inductively Coupled Optical Emission Spectrometer (ICP-OES) with 0.02 mmol/mol precision for Mg/Ca ratio, 0.4 µmol/mol for Sr/Ca ratio, 0.02 mmol/mol for Fe/Ca ratio and 0.006 mmol/mol for Mn/Ca ratio. For stable isotopes, the analysis is done using SerCon 20-22 Gas Source Isotope Ratio Mass Spectrometer (GS-IRMS) based on the Copenhagen University Standard (LEO, Carrara Marble) and with the precision of ±0.08‰ for δ13C and 0.28‰ for δ18O. Discussion of Results & ConclusionThe Sarvak Formation, with dominant limestone lithology and 831 and 735 m thickness, respectively in Ahvaz and Mansuri Oil Fields, conformably overlies the Kazhdumi Formation and is unconformably overlain by the Ilam Formation. The petrographical studies led to determinate five facies association deposited on a low angle ramp type setting along with an intrashelf basin. Diagenetic studies reveal the impact of marine, unconformity-related meteoric, and shallow and deep burial diagenesis that mainly caused intense compaction, dissolution and cementation. These main diagenetic features changed the nature of the associated facies regarding the reservoir property of the Sarvak Formation. The impact of main diagenetic features along the Sarvak succession improved the understanding of the elemental, and O and C stable isotope analyses. The geochemical analysis as well as petrographical evidences such as diversity of fauna and flora and primary marine diagenetic features confirm the original aragonite mineralogy for the Sarvak carbonate, which was formed in a warm and humid condition on a shallow marine platform. The analyzed δ18O and δ13C, along with the variable concentration of Sr, Fe and Mn suggest maintenance of the primary composition along with alteration in burial realm and mainly meteoric diagenesis. The cross-plot of trace element and O and C stable isotopes indicate that the Sarvak carbonate rocks altered in the open to close diagentic system during different depositional stratigraphic sequences depending on the exposure of the carbonate platform and its scale and duration

Field observations, together with the results of gas chromatography–mass spectrometry (GC-MS) and stable carbon isotope analysis of bitumen, coupled with fluid inclusion microthermometry and stable isotope analyses of closely associated vug- and fracture-filling columnar calcite in the Upper Cretaceous Bekhme Formation, Kurdistan Region of Iraq, suggest that the degradation of crude oil was caused by the regional incursion of meteoric waters. This incursion, which is interpreted to have occurred during tectonic uplift during the Zagros Orogeny, is evidenced by: (i) the depletion of n-alkanes and acyclic isoprenoid alkanes (pristane and phytane) in the bitumen; (ii) low δ13CVPDB values (−8.5‰ to −3.9‰) and δ18OVPDB values (−22.9‰ to −15.0‰), with more radiogenic Sr isotopic ratios (0.70771–0.70772) compared to Cretaceous seawater; and (iii) low salinity and low temperatures (20 to 40 °C) in fluid inclusions of the columnar calcite. This study demonstrates that regional meteoric water incursion into sedimentary basins can be linked to crude oil degradation accompanied by calcite cementation events in carbonate reservoirs. [ABSTRACT FROM AUTHOR]

Two isolated metatarsals (III and IV) of theropod dinosaurs from the Bostobe Formation (Upper Cretaceous, Santonian–Campanian) of the Shakh-Shakh locality in Kazakhstan are assigned to the representatives of the families Caenagnathidae and Dromaeosauridae, respectively. The metatarsal III of Caena-gnathidae indet. confirms the presence of oviraptorosaurs in the dinosaur assemblage from the Bostobe Formation. This bone is very similar morphologically with the metatarsal III of Elmisaurus rarus Osmólska, 1981 from the Maastrichtian of Mongolia. The metatarsal IV of Dromaeosauridae indet. is characterized by a lateral crest, which among dromaeosaurids is known only for Velociraptor mongoliensis Osborn, 1924 from the Campanian of Mongolia. [ABSTRACT FROM AUTHOR]

Nanhsiungchelyidae are a group of large turtles that lived in Asia and North America during the Cretaceous. Here we report a new species of nanhsiungchelyid, Nanhsiungchelys yangi sp. nov., from the Upper Cretaceous of Nanxiong Basin, China. The specimen consists of a well-preserved skull and lower jaw, as well as the anterior parts of the carapace and plastron. The diagnostic features of Nanhsiungchelys include a large entire carapace length (~55.5 cm), a network of sculptures consisting of pits and ridges on the surface of the skull and shell, shallow cheek emargination and temporal emargination, deep nuchal emargination, and a pair of anterolateral processes on the carapace. However, Nanhsiungchelys yangi differs from the other species of Nanhsiungchelys mainly in having a triangular-shaped snout (in dorsal view) and wide anterolateral processes on the carapace. Additionally, some other characteristics (e.g., the premaxilla is higher than wide, the maxilla is unseen in dorsal views, a small portion of the maxilla extends posterior and ventral of the orbit, and the parietal is bigger than the frontal) are strong evidence to distinguish Nanhsiungchelys yangi from Nanhsiungchelys wuchingensis. A phylogenetic analysis of nanhsiungchelyids places Nanhsiungchelys yangi and Nanhsiungchelys wuchingensis as sister taxa. Nanhsiungchelys yangi and some other nanhsiungchelyids bear distinct anterolateral processes on the carapace, which have not been reported in any extant turtles and may have played a role in protecting the head. The Nanxiong Basin was extremely hot during the Late Cretaceous, and so we suggest that nanhsiungchelyids might have immersed themselves in mud or water to avoid the heat, similar to some extant tortoises. If they were capable of swimming, our computer simulations of fluid flow suggest the anterolateral processes could have reduced drag during locomotion. [ABSTRACT FROM AUTHOR]

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The "Marrón Emperador" ornamental stone is known for its characteristic deep brown colour filled with white spots and veins. It consists of a brecciated dolostone with different generations of calcite/dolomite veins and veinlets that represent repeated episodes of fracture opening and partial or complete cementation, which likely corresponds to individual stages of fluid expulsion. Mineralogical, petrographic and geochemical studies point to the formation of these rocks through brecciation, dolomitization and rapid cementation processes in an active tectonic regimen. The composition and textural features of the stratiform dolomite geobody point to a structurally controlled dolomitization model. The overall breccia geometry, breccia texture and vein characteristics are all consistent with a brecciation origin driven by hydraulic fracturing, with subsequent calcite precipitation in open space and partial solution replacement of clasts. A paragenetic sequence includes: (1) marine sedimentation of original tidal carbonate sediments; (2) early lithification and marine cementation; (3) burial diagenesis with early fracturation of limestones; (4) entrance of dolomitizing fluids through fractures causing pervasive dolomitization (brown dolostones) and dolomite cements (fracture-lining and saddle dolomites); (5) fracturation by hydraulic overpressure under an active tectonic regime; (6) calcite cementation (white veins and veinlets); and (7) uplift and meteoric diagenesis producing dedolomitization, karstification and local brecciation. [ABSTRACT FROM AUTHOR]

Alkaline dikes from the Santos-Rio de Janeiro coast, SE Brazil, mainly from São Sebastião and Búzios islands, yielded a Late Cretaceous paleomagnetic pole (SR) located at 319.7°E 81.2°S (N = 44, A95 = 3.0°, k = 44). This pole includes some sites of alkaline stocks from São Sebastião Island of the same age and supersedes the previous pole for this island. To match the available radiometric ages and the prevailing normal polarity remanence of the rocks with the geomagnetic polarity time scale, the SR pole is placed at 84 Myr. Another group of alkaline rocks, dikes located mainly in Rio de Janeiro, was assigned an age of less than 70 Myr. The ages of the Poços de Caldas, Itatiaia, and Passa Quatro paleomagnetic poles are also discussed based on available radiometric data. Assuming a rigid plate, the SR pole indicates the southward movement of about 7° with virtually no rotation between 100 and 84 Myr. From approximately 84 to 70 Myr, a clockwise rotation of 8° is postulated, with slight variation in latitude. [ABSTRACT FROM AUTHOR]

In the Lower Campanian, Pachydiscus (Pachydiscus) launayi (De Grossouvre) was found for the first time above a soap (bentonite) clay layer, which has been described well in the literature, in an abandoned quarry on the outskirts of Kudrino village in Southwestern Crimea. This finding expands our understanding of the distribution of this species and precises the biostratigraphic position of the soap clay layer. [ABSTRACT FROM AUTHOR]

Delta-plain strata of the Cenomanian Dunvegan Formation, in north-east British Columbia, represent anastomosed rivers that were flanked by vegetated crevasse splays, wetlands and shallow lakes. These rocks preserve a rich record of ankylosaur and ornithopod walking and wading tracks, as well as crocodylian swim traces and tracks. Analysis of depositional, erosional, and trace-making events reveals alternating phases of flooding and emergence that controlled both animal activity (walking, wading, swimming) and mud substrate consistency (firm vs. soupy), and hence fidelity of track preservation. Some tracks resemble those produced by both ankylosaurs and crocodylians, and confident attribution is difficult. The absence of tail drag marks suggests an ankylosaur trackmaker, whereas prominent claw marks might favour a crocodylian origin. Unusually large crocodylian swim traces suggest animals about 9 m, and possibly up to 12 m in length. These large traces may represent a precursor to the giant crocodylian Deinosuchus. Ankylosaur tracks are well-preserved in lake and channel-margin deposits, whereas crocodylian traces are most commonly preserved in firm muddy lake sediments that had experienced previous subaerial exposure and dewatering. Close integration of trace fossils with sedimentary and stratigraphic features makes it possible to reveal a detailed chronology of biotic and sedimentary events on palaeo-surfaces. [ABSTRACT FROM AUTHOR]

Studies of the paleopathology of the vertebrae provide an interesting, oblique approach to their paleobiology and even paleoethology. They tell us about possible ethological causes such as accidental blows with objects, social interactions within a group, and defense against predators, etc. There are numerous works on the anatomical and phylogenetic aspects of sauropod dinosaurs, and in recent years paleopathological studies have also increased. Here, we describe the injuries recorded in the caudal vertebrae of two indeterminate titanosaurids, and undertake a compilation and analysis of the pathological fossil record worldwide, focusing on the tails of sauropods. Two pathologies have been identified as present in the indeterminate titanosaurids under study: a possible case of spondyloarthropathy in MAU-Pv-LI-601, and a case of suppurative spinal osteomyelitis in MAU-Pv-LJ-472/1. Both titanosaurids are from Gondwana. In the world registry of pathologies associated with the tails of sauropod dinosaurs, it is observed that titanosaurs are the sauropods with the highest percentage of diagnosed pathologies (69% including the two new records from the province of Neuquén) and that all of these have been described in Gondwanan specimens. [ABSTRACT FROM AUTHOR]

Abstract Notosuchian crocodyliforms were major components of the South American Cretaceous biota and, for over 125 years, paleontological fieldwork in this continent recovered several well-preserved fossils of these animals. They are largely recognized for terrestrial life and specialized feeding habits, frequently presenting bizarre taxa such as Comahuesuchus. A new species, Comahuesuchus bonapartei n. sp. (MUCPv 597; cast MN), is described from geological strata of Sierra Barrosa Formation (Upper Turonian) and Portezuelo Formation (Lower Coniacian) of Lake Barreales, Patagonia, Argentina. The new fossil comprises a right dentary bone that shares important and unique anatomical features with specimens of Comahuesuchus brachybuccalis, such as the presence of a well-marked shelf on the lateral surface of the bone; a flat, low, and wide mandibular symphysis; an enlarged, labiolingually compressed caniniform tooth at caudal position in the dentary; the presence of serrated mesial and distal carinae in the caniniform with a faceted labial surface, and the absence or extremely reduction in number of the postcaniniform dentition. C. bonapartei differs from C. brachybuccalis in having individual dentary alveoli, rather a dentition set in groove. Phylogenetic analyses support a sister-relationship between both species, which are well nested within notosuchians.

Abstract Alkaline dikes from the Santos-Rio de Janeiro coast, SE Brazil, mainly from São Sebastião and Búzios islands, yielded a Late Cretaceous paleomagnetic pole (SR) located at 319.7°E 81.2°S (N = 44, A95 = 3.0°, k = 44). This pole includes some sites of alkaline stocks from São Sebastião Island of the same age and supersedes the previous pole for this island. To match the available radiometric ages and the prevailing normal polarity remanence of the rocks with the geomagnetic polarity time scale, the SR pole is placed at 84 Myr. Another group of alkaline rocks, dikes located mainly in Rio de Janeiro, was assigned an age of less than 70 Myr. The ages of the Poços de Caldas, Itatiaia, and Passa Quatro paleomagnetic poles are also discussed based on available radiometric data. Assuming a rigid plate, the SR pole indicates the southward movement of about 7° with virtually no rotation between 100 and 84 Myr. From approximately 84 to 70 Myr, a clockwise rotation of 8° is postulated, with slight variation in latitude.

The Upper Cretaceous (Turonian) Bissekty Formation of Uzbekistan has yielded many isolated bones and teeth representing a variety of non-avian theropod dinosaurs. A pedal phalanx II-2 indicates the presence of a dromaeosaurid theropod that attained a larger body size than any previously known member of that clade. The same formation also yielded a large maxillary fragment that has recently been described as a neovenatorid carcharodontosaurian (Ulughbegsaurus uzbekistanensis). However, this specimen lacks unambiguously diagnostic features of that clade, and its purported carcharodontosaurian characters are either taphonomic artefacts or also shared by dromaeosaurids. Thus, the phylogenetic relationships of Uleghbegsaurus uzbekistanensis remain uncertain. A giant dromaeosaurid occurred together with the medium-sized tyrannosauroid Timurlengia euotica in the Bissekty assemblage. [ABSTRACT FROM AUTHOR]

Planktonic foraminifers are abundant in the Upper Cretaceous deposits of the Mountainous Crimea, and their marker species are of great importance for biostratigraphy and correlation. Globotruncanita stuarti (De Lapparent, 1918) and Pseudotextularia elegans (Rzehak, 1891) are used as index species for local and regional biostratigraphic scales, and species of the genus Rugoglobigerina Brönnimann, 1952 are used as index species for beds with fauna. The biostratigraphically important species from five sections of the Mountainous Crimea, including Pseudotextularia elegans (Rzehak, 1891), Rugoglobigerina rugosa (Plummer, 1927), R. hexacamerata Brönnimann, 1952, R. milamensis Smith and Pessagno, 1973, R. macrocephala Brönnimann, 1952, and Globotruncanita stuarti (De Lapparent, 1918), are described systematically. [ABSTRACT FROM AUTHOR]

Forearc basin deposits on continental margins contain important information that can be used to reconstruct the tectonic setting, volcanism, and climate at the time of their deposition. Coal‐bearing terrestrial to shallow marine strata in Northeast Japan were deposited in a forearc basin along the Eurasian continental margin during the Cretaceous–Paleogene. The rocks exposed in the Kado district, Iwate Prefecture, in the northern Kitakami Mountains include the Upper Cretaceous Yokomichi Formation and the Paleogene Kogawa Group; the latter is known for high‐quality refractory clay (kaolin clay). However, their stratigraphy and sedimentological characteristics are not yet fully understood. To reconstruct the formation and filling of the basin, we investigated field observations, U–Pb dating of tuff samples, XRD analysis of tuff and mudstone samples, and vitrinite reflectance of coal samples in this sequence. The U–Pb ages of the Yokomichi Formation and the Kogawa Group are ∼86 Ma and 58–52 Ma, respectively. The U–Pb age of the kaolin‐dominated tuffaceous rock ("red rocks") is 56.1 ± 0.2 Ma. The mean random vitrinite reflectance (VRr) ranges from 0.37% to 0.53% through the sequence. We propose the following sequence for the formation and filling of the basin. (1) The basin initially formed during the Coniacian–Santonian (Late Cretaceous) and was filled by fluvial–lacustrine sediment. (2) These sediments kept the shallow burial depths during a ∼28 Myr and made a hiatus (86–58 Ma). (3) The basin was reactivated and covered by tuffs during the Thanetian, and the tuffs were altered to kaolin clay during the Paleocene–Eocene Thermal Maximum. (4) The basin was filled rapidly by alluvial fan deposits and subsided <2300 m (assuming a geothermal gradient of >30 K/km). (5) The basin was uplifted and exhumed at a rate of >50 m/Myr faster than the mean exhumation rate of the Kitakami Mountains since the Paleogene. [ABSTRACT FROM AUTHOR]

This study examines the geochemical and petrological characteristics of 16 carbonate-rich (i.e., chalky marl, chalky limestone, and limestone) samples of the Upper Cretaceous Shu'ayb Formation in the Ajloun region, northern Jordan, to decipher the organic matter characteristics and predict the geological temperatures for oil generation. The carbonate-rich sediments under investigation exhibit high TOC (up to 12.39 wt%) and high hydrogen index (314–920 mg HC/g TOC), indicating Types I-II kerogens. The dominance of such hydrogen-rich kerogen is confirmed by the fluorescent alginite, amorphous organic matter (AOM), and bituminite organic matter. The studied organic facies are sulfur-rich and comprise of Type II organic matter, exhibiting the possibility of producing paraffinic oil with a low wax component, according to pyrolysis–gas chromatography. The broad distributions of activation energy (37–66 kcal/mol) in the bulk kinetic model of the analyzed samples show a mixture of organic matter (i.e., mainly marine-derived organic matter and minor land plant input). The kinetic models suggest that bulk petroleum formation began at relatively low geological temperatures between 104 and 116 °C, which corresponds to a vitrinite reflectance range of 0.58–0.66%. These activation energy distributions and low anticipated vitrinite reflectance values are largely compatible with the Type II-S kerogen organic facies, suggesting that the investigated Upper Cretaceous organic-rich carbonate may have produced sulfur-rich oils during the initial phases of kerogen conversion. [ABSTRACT FROM AUTHOR]

The Cretaceous Farrokhi Formation is located in theKhur area of central Iran and yielded a reasonablywell-preserved rich planktonic foraminiferal assemblage. This formation consists of 154mof fossiliferous marl and limestone. The lower and upper bounding surfaces of the Farrokhi Formation are unconformable with the underlying Haftoman Formation and the overlying Chupanan Formation. In this research, 46 planktonic foraminiferal species belonging to 19 genera were identified and resulted in recognition of the following three biozones (from base to top); the Globotruncana aegyptiaca Interval Zone (IZ), the Gansserina gansseri IZ, and the Contusotruncana contusa IZ. This biozonal framework places deposition of the Farrokhi Formation during the late Campanian to early Maastrichtian. Biostratigraphic comparison between the samples for this research and data from three other studied sections within the Farrokhi Formation indicates that the basal and upper boundaries of the formation are time-transgressive and migrate chronologically from north to southeast. Since the first occurrences of Pseudoguembelina palpebra and Rugoglobigerina pennyi mark the latest Campanian worldwide, we approximate the Campanian/Maastrichtian boundary based on the FOs of Trinitella scotti and Rugoglobigerina hexacamerata, and identify the basal Maastrichtian by the last occurrence of Laeviella bollii. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous succession (Coniacian to lowermost Maastrichtian, with focus on the Campanian) at Petrich, Central Srednogorie Zone in Bulgaria, is described and calibrated stratigraphically based on nannofossils, dinoflagellate cysts and inoceramids. The following standard nannofossil zones and subzones are identified: UC10–UC11ab (middle to upper Coniacian), UC11c–UC12–UC13 (uppermost Coniacian to Santonian), UC14a (lowermost Campanian), UC14bTP–UC15cTP (lower Campanian to ‘middle’ Campanian), UC15dTP– UC15eTP (upper Campanian), UC16aTP (of Thibault et al. 2016; upper part of the upper Campanian), and UC16b (Campanian–Maastrichtian boundary). The base of the Campanian is defined by the FO of Broinsonia parca parca (Stradner) Bukry, 1969 and Calculites obscurus (Deflandre) Prins and Sissingh in Sissingh, 1977 (a morphotype with a wide central longitudinal suture). The Areoligera coronata dinoflagellate cyst Zone (upper lower Campanian to upper upper Campanian) is identified, corresponding to the UC14bTP–UC16aTP nannofossil subzones. The inoceramid assemblage indicates the ‘Inoceramus’ azerbaydjanensis–‘Inoceramus’ vorhelmensis Zone, correlated within the interval of nannofossil subzones UC15dTP–UC15eTP. The composition of the dinoflagellate cyst assemblages and palynofacies pattern suggest normal marine, oxic conditions and low nutrient availability within a distal shelf to open marine depositional environment during the Campanian. [ABSTRACT FROM AUTHOR]

Chaabet El Bellout iron mine is located in the Medjerda Mountains, constituting a connection zone between the Maghrebides chain and the Saharan Atlas. This deposit is mainly embedded in Upper Cretaceous (Campanian and Maastrichtian) and Miocene limestones with clusters and veins replacing both carbonates and sandy-carbonate levels. In this study, field observations and mineralogical analyses combined with geochemical and oxygen isotopic data were used to determine the origin of the mineralizing fluid and the source of mineralization. The results indicate that the iron ore of Chaabet El Bellout is of medium quality resulting following two main phases: first, the replacement of Cretaceous carbonates by ankerite and siderite, followed by the alteration of iron oxides (hematite and magnetite), then, a deposit of high temperature sulfides, sulfosalts, and sulfates (pyrrhotite, pyrite, chalcopyrite, gray copper, and barite) in a fractured zone. However, the contribution of magmatic fluids cannot be excluded, as some samples reveal high V-Mo-Ni and Zn contents and a negative isotopic signature (-0.6‰ VSMOW) different from the rest of samples that all indicate positive values (0.6 to 1.6‰ VSMOW), suggesting the participation of metasomatic saline fluids interacting with marine carbonate levels deposited in the Cretaceous and Triassic formations. [ABSTRACT FROM AUTHOR]

This paper presents the results of a comprehensive study of the Maastrichtian sequence of Mount Kyz-Kermen located in the Southwestern Crimea. The section consists of a rhythmically bedded carbonate sequence gradually replaced by carbonate sandstones. The study of rocks in thin sections made it possible to identify eight lithotypes, and the chemical analyses yielded variations in individual elements in the rock composition. The interpreted data on planktonic and benthic foraminifera made it possible to determine the age of deposits within the accuracy of zones and beds with fauna and to find one more supposed break in the middle of this section, coinciding with a noticeable change in the rock composition. The assay analysis of foraminifera assemblages together with lithological and geochemical results made it possible to determine that the studied section was formed in open carbonate-platform conditions at the depth of the middle–outer shelf. [ABSTRACT FROM AUTHOR]

Abstract Background Dinosaur eggs containing embryos are rare, limiting our understanding of dinosaur development. Recently, a clutch of subspherical dinosaur eggs was discovered while blasting for a construction project in the Upper Cretaceous red beds (Hekou Formation) of the Ganzhou Basin, Jiangxi Province, China. At least two of the eggs contain identifiable hadrosauroid embryos, described here for the first time. Results The eggs, attributable to Spheroolithidae indet., are thin-walled and small (~ 660 mL) compared to those of Lambeosaurinae. The shape of the embryonic squamosal is reminiscent of that seen in the Late Cretaceous hadrosauroids Levnesovia transoxiana, Tanius sinensis, and Nanningosaurus dashiensis, suggestive of possible affinities. Conclusion The small size of the eggs and embryos, similar to those of Hadrosaurinae, indicates that the larger eggs and hatchlings typical of Lambeosaurinae are evolutionarily derived.

The deeplying Mesozoic and Paleogene deposits of the Middle Kura depression have significant resource potential. They are the main complexes in terms of prospectivity for oil and gas exploration. The lithological-facies characteristics of the host rocks, accumulation of which is tectonically conditioned, are among major indicators responsible for their oil and gas content. Based on actual core material from parametric, prospecting and exploratory wells, along with downhole logging data the marker horizons have been established for individual exploration areas within the depression. An overview of the lithostratigraphic features and thickness distribution of the Upper Cretaceous and Eocene deposits is given. Distribution of the fluid conducting strata, regional variation of their reservoir properties in buried structures of the Middle Kura depression is addressed as well. Within the study area a typical Upper Cretaceous section is comprised of three genetic rock types: sedimentary, igneous-sedimentary and igneous. The Eocene sediments are represented by shaly (Lower Eocene), terrigenous-carbonate (Middle Eocene) and terrigenous (Uppere Eocene) lithofacies. The regularities that have been revealed in lithofacies and thickness variation enabled highlighting the areas of highest subsidence and sedimentation, tracing basinal limits in Late Cretaceous and Eocene ages and depicting them on the maps presented. The compiled schematic maps clearly demonstrate the paleorelief in the study area at the close of Late Cretaceous and Paleogene times. Sections of the indicated sedimentary complexes contain effusive, carbonate, sandstone and siltstone reservoirs, exhibiting substantial occurrence and thickness, the latter having a marked trend to increasing toward the centerline of the Lower Kura depression. Thus, it is likely that the alteration in facies within the Upper Cretaceous and Eocene sections is closely interrelated with the breaks in sedimentation and erosions, favouring for formation of traps controlled by diverse screening features. At basin scale the major regionally persistent seal horizons are the Maykop shales of Oligocene-Lower Miocene age, which in a number of cases unconformably cover petroleum containing horizons.

Forty-six species of radiolarians recovered from the Upper Cretaceous Smoking Hills and Mason River formations in the Northwest Territories represent the first assemblage of this age from mainland Arctic Canada. Four interval zones and two subzones, calibrated to radiometric ages, are proposed based on the lowest and highest occurrence of index radiolarian species. These are 1) the Santonian/early Campanian Kuppelella aff. cayeuxi Zone, 2) the middle Campanian Diacanthocapsa aff. rotunda Zone (subdivided into the Kreuzstella vierkantiga and Lithostrobus borealis subzones), 3) the late Campanian Canadasphaera inuita Zone, and 4) the early Maastrichtian Stichomitra cf. communis-Xitus sp. B Zone. Integration of these radiolarian biozones with previously reported diatom, silicoflagellate, palynological and foraminiferal biozones and new radiometric ages indicate a middle Coniacian-middle Campanian age for the Smoking Hills Formation and a middle Campanian-late Maastrichtian (probably Paleocene) age for the Mason River Formation. The radiolarian assemblages reported here resemble those of the North Slope of Alaska and western Siberia, allowing for biostratigraphic correlations within the Arctic Realm. • Highly diverse Cretaceous radiolarian assemblage recovered from the Canadian Arctic. • Four radiolarian biozones identified, spanning Santonian to lower Maastrichtian. • Age refined using correlation with siliceous microfossils and radiometric dating. • Potential for an Upper Cretaceous radiolarian biozonation in the Arctic Realm. [ABSTRACT FROM AUTHOR]

The Gobi Desert of southern Mongolia is home to an incredibly rich record of dinosaurs and other vertebrate fossils from the latest Cretaceous Period. Together, more than a dozen sites in several basins have produced one of the richest palaeofaunas known from this interval anywhere in the world. Most of this diversity has been recovered from the fluvial deposits of the Nemegt Formation. Despite historic and ongoing research in southern Mongolia, accurate maps and geological data for the main fossil sites are still lacking, limiting our ability to investigate how local palaeoecological dynamics influenced Nemegt taxa, their geographic distribution, and their evolutionary patterns. One of these sites, Guriliin Tsav, has produced more than a hundred significant fossil specimens to date, but still remains one of the lesser known Nemegt localities. In part this is because many expeditions have instead focused on the nearby Bügiin Tsav, one of the largest and richest localities for the Nemegt Formation. To address this gap, a project was initiated in 2018 to produce a high-resolution topographic map of Guriliin Tsav using Unmanned Aerial Vehicles (UAV), and consequently, to plot the geographic and stratigraphic distributions of palaeontological resources on this map. In so doing, we also collected stratigraphic and taphonomic data from the area, allowing for the first detailed palaeoecological interpretation of Guriliin Tsav and a comparison with other localities of southern Mongolia. Here we present the results of this project, and also discuss new topographic and stratigraphic data from Bügiin Tsav. This sheds new light into the temporal and geographic distribution of vertebrate taxa in the latest Cretaceous of Mongolia. • We provide the first high-resolution maps of Guriliin Tsav, a rich Gobi Desert fossil locality. • We comprehensively describe the stratigraphy and taphonomy of the site and its impact on fossil resources. • We tabulate more than 100 fossil occurrences into the first detailed documentation of the fauna at Guriliin Tsav, showing distinct differences from sites further southeast. • We document Baruungoyot-like aeolian beds within the middle Nemegt Formation, challenging assertions that these represent sequential time intervals. • We demonstrate how channel architecture at Bugiin Tsav and Guriliin Tsav corresponds to spatial distribution of fossils. [ABSTRACT FROM AUTHOR]

This paper presents the first Upper Cretaceous remains of fish in Serbia, discovered near the village of Struganik. This is also the first described find of Mesozoic fish in Serbia. A stone slab with visible contours of an almost complete fish, with a total body length of about 20 cm, was excavated from the Struganik quarry. Most bones are preserved as imprints. The number of vertebrae, the shape and position of the cranial bones, the type of teeth, and the position of the first dorsal fin all indicate that the studied specimen belongs to the genus Enchodus known from several Upper Cretaceous localities in the Tethys domain.

Las dataciones propuestas por diversos autores para la base de los depósitos del Flysch Calcáreo del Cretácico Superior, que afloran en el margen NW del macizo paleozoico de Bortziriak (margen NE de la Cuenca Vasco-Cantábrica) presentan diferencias, por lo que se ha procedido a realizar un estudio bioestratigráfico en detalle de estos sedimentos. Los resultados del análisis bioestratigráfico basado en el estudio de foraminíferos planctónicos, arrojan una edad diacrónica para su base. Por una parte, se constata la existencia de un hiato general que abarca desde el Cenomaniense inferior hasta el Turoniense superior y que alcanza el Campaniense superior en el anticlinal de Txoritokieta, reflejo de un paleoalto submarino que no fue cubierto completamente por lo menos hasta esa edad. Por otro lado, materiales de resedimentación, brechas, de edad Turoniense superior-Coniaciense indican procesos erosivos de unidades estratigráficas subyacentes, que localmente pueden ampliar el hiato general del área. La existencia de calizas someras de edad Cenomaniense medio-superior en la zona de Fagollaga, citada por varios autores, sugeriría la sedimentación y posterior erosión de materiales de plataformas someras cenomanienses durante la sedimentación del Flysch Calcáreo. Finalmente, este estudio constata una transgresión marina durante el Cretácico Superior, que inundó y cubrió de materiales marinos relativamente profundos el macizo paleozoico de Bortziriak. ABSTRACT: The base of the Upper Cretaceous Calcareous Flysch along the NW margin of the Bortziriak Palaeozoic massif (NE margin of the Basque-Cantabrian Basin) has been dated differently by a number of authors. Thus, the aim of this work has been to carry out a detailed biostratigraphic study based on planktonic foraminifera of these basal deposits. The results of the biostratigraphic analysis yield a diachronic age for their base. On the one hand, a general hiatus from lower Cenomanian to upper Turonian is observed in the study area. However, in the Txoritokieta anticline, the hiatus expands to late Campanian ages, reflecting a submarine paleohigh that was not covered at least until that period. On the other hand, resedimented upper Turonian-Coniacian breccia clasts indicate the erosion of previous stratigraphic units, which may locally extend the hiatus. In addition, several authors have previously suggested the existence of limestones of middle to upper Cenomanian age in the Fagollaga area. This would demonstrate the sedimentation and subsequent erosion of shallow platform limestones during the sedimentation of the Calcareous Flysch. Finally, this study confirms the occurrence of a marine transgression during the Upper Cretaceous, which gradually flooded the Palaeozoic massif of Bortziriak.

The present work focuses on the upper Cretaceous (Cenomanian-early Campanian) carbonate successions in selected wells from northwestern Iraq. These successions are represented by Gir Bir (Cenomanian-early Turonian), Wajna (late Santonian) and Mushorah (early Campanian) Formations. The succession has affected by early burial near-surface, unconformity-related and deep burial diagenesis represented by cementation, neomorphism, dolomitization, dedolomitization, silicification, authigenesis of glauconite and pyrite, compaction, micritization, solution and porosity formation. The common porosity types are intergranular, fenestral, intercrystalline, moldic, vuggy, channel and fracture. Three porosity zones (I, II, and III) are identified depending on variation in gamma ray which reflects their shale content. The upper part of zone (II) is highly porous and regarded on the main reservoir unit in the middle and upper parts of the Gir Bir Formation. Fracture and moldic and vuggy dissolution features in addition to karstic and fissure features are responsible for the porosity increase in the fractured reservoir unit.

The Cerro Overo-La Invernada area in north Patagonia has provided a rich record of Cretaceous continental tetrapods in the last two decades, mainly from the Bajo de la Carpa Formation (Upper Cretaceous, Santonian). The dinosaur fauna from this area is diverse, including several new taxa, with abelisaurid theropods particularly abundant. Recently, a new isolated caudal vertebra (MAU-Pv-CO-598) was here recovered. Although fragmentary, it shows features that differentiate it from other abelisaurid remains previously found in this area. It is considered a mid-caudal vertebra and is mainly characterized by a longitudinal groove on the ventral surface of the centrum; a scarcely elevated transverse process with an anteroposteriorly expanded and laterally concave distal end; a longitudinal dorsal crest anteriorly extended from the anterior border of the neural spine; and small tubercles extended from the ends of the zygapophyses, which are considered as accessory interlocking structures between vertebrae. Some characters, such as the dorsal longitudinal crest and the accessory tubercles of the zygapophyses, are present also in the non-brachyrostran abelisaurid Majungasaurus. However, the transverse process is similar to that of caudal vertebrae of non-furileusaur brachyrostrans, such as Ilokelesia, Ekrixinatosaurus, and Skorpiovenator. A phylogenetic analysis here conducted clusters MAU-Pv-Co-598 with the latter three taxa. MAU-Pv-CO-598 comes from lower levels of the Bajo de la Carpa Formation than the furileusaurs Viavenator and Llukalkan. The presence of a specimen with non-furileusaurian affinities in this formation indicates that a possible replacement from non-furileusaur to furileusaur brachyrostrans occurred during the Santonian, after the proposed Turonian faunal turnover.

The first findings of frogs (Anura) from the Upper Cretaceous of Russia—the distal part of the humerus and a tibiofibula fragment—were described. They come from the Maastrichtian dinosaur locality in the city of Blagoveshchensk (Amur oblast). The described remains are characterized by the outer and inner structure typical of Anura, and their exact taxonomic affiliation is not defined. These are the easternmost and the youngest frog remains from the Upper Cretaceous of Asia. [ABSTRACT FROM AUTHOR]

The Tarbur Formation is a carbonate stratigraphic unit in the Zagros Basin. This formation is exposed between the Main Zagros Reverse and High Zagros faults and Sabzpoushan Fault. In this study, we describe the depositional characteristics of the Upper Cretaceous sediments (Tarbur Formation) in the Tang‐e Vanak section. In this section, the lower conglomeratic boundary below the Tarbur Formation is named the Amiran Formation and the upper boundary of the Tarbur Formation is disconformably overlain by white dolomitic deposits of the Shahbazan Formation. The Tarbur Formation was interpreted to be deposited in a carbonate homoclinic ramp due to the lack of a deep lagoon environment in the back of the reef structures and the turbidity sediments in its frontal margin. Based on this study, 8 microfacies were recognized including (1) Algal‐foraminiferal wackestone/packstone (2) Bioclastic‐ algal wackestone/packstone, (3) Intraclast bioclastic packstone, (4) Coral boundstone, (5) Rudist boundstone, (6) Bioclastic grainstone, (7) Bioclastic‐foraminiferal wackestone, and (8) Planktonic foraminiferal intraclastic wackestone/packstone. These microfacies were located in the inner, middle, and outer ramp. [ABSTRACT FROM AUTHOR]

Here we describe new marine vertebrate remains, mainly isolated teeth, from the Upper Cretaceous (Coniacian-Santonian) of near Mardin, SE Turkey. This is the first report in this area of ptychodontid sharks (elasmobranchs), enchodontid teleosts (actinopterygians) and mosasaurid squamates (reptiles). The respective taxa Ptychodus cf. mortoni, Enchodus sp., Platecarpus sp. and Mosasaurinae indet. are described. These new data improve our knowledge on early Late Cretaceous marine vertebrate faunas from the Arabic Platform, classically known previously mostly from the Maastrichtian outcrops of Middle-East and Northwestern Africa, and extend the palaeobiogeographical distribution of these taxa into the western part of the Mediterranean Tethys, confirming their cosmopolitan status. [ABSTRACT FROM AUTHOR]

• The age of belemnites from the "Sponge horison" of Volga has been updated. • It is a first evidence on the Senomanian-Coniacian Sr-isotope minimum from Volga. • This minimum appears to have a connection with Caribbian basaltic volcanism. We present the first strontium, carbon and oxygen isotope data on belemnites from the Upper Cretaceous (Turonian-Santonian) strata of the Lower Volga region, located between Saratov and Volgograd. The Sr-isotope evidence confirms the regional biostratigraphic data, indicating a deep erosion at the Coniacian-Santonian boundary, which suggests that some belemnitellid rostra from the lower Santonian so-called "Sponge horizon" of the Ozerki, Pudovkino and Mizino-Lipshinovka sections were redeposited from middle and upper Coniacian deposits and that the first representatives of the genus Belemnitella are thought to be late Coniacian in age. This study provides the first evidence of the Cenomanian-Coniacian Sr-isotope minimum from the East European (Russian) Platform, likely related to underwater Caribbean basaltic volcanism. New data suggest that the initial phase of Caribbean volcanism coincided with the temperature maximum and development of oceanic anoxic conditions (OAE 2), but the peak of the assumed volcanic activity in the late Turonian (90.8 Ma) was probably accompanied by a decrease in temperature and phytoplankton productivity. The problem of the regional Coniacian-Santonian oceanic anoxic event 3 (OAE 3) and global end-Cretaceous cooling is also touched upon. [ABSTRACT FROM AUTHOR]

New paleocurrent directions of the gravity flow sediments were measured in the Slovak part of the Biele Karpaty Mts. Paleocurrent directions were sorted and grouped according to lithostratigraphic units and lithotypes. The sedimentation area of the Biele Karpaty Unit was located in the westernmost part of the Magura Basin. Paleocurrent analysis proves the direct connection between the former sedimentary area of the Biele Karpaty Unit with the Magura Basin and the Rhenodanubian Basin during the Late Cretaceous to middle Eocene. The transport of the distal turbidites was parallel to the southern edge of the basin in the Ondrášovec Mb (Campanian). One lateral proximal source of debris flows of the Drietomica Mb (Maastrichtian), several lateral sources of debris flows of the Chabová Mb (Danian), several lateral sources from SE and one massive source of turbidites of the Javorina Mb (Campanian—Maastrichtian) and one massive source of the Svodnice Fm (Danian—Ypresian) turbidites supplied quartz–carbonate material in to the basin from NE. The occurrence of glauconite Sst and Magura type Sst proves the connection with the rest of the Magura Basin at the end of the sedimentation of the Svodnice Fm (Danian—Ypresian), when the paleocurrent directions tend from NE from Bystrica Mb in the eastern part of the region and were fed from the Fore-Magura Ridge and Southern Magura Ridge. The paleocurrents directed also from NW from Greifenstein Fm of the Rhenodanubian Flysch in the western part of the region. The sea floor relief in the studied area was mostly flat until the Campanian. Since the Maastrichtian, the relatively flat sea floor has been segmented into shallow paleo-valleys and elevations, which was manifested in significant thickness fluctuations of accumulated deposits. [ABSTRACT FROM AUTHOR]

The results of a comprehensive study of the boundaries of the Turonian–Coniacian in the Upper Cretaceous deposits of the Abinskii region of the Northwestern Caucasus, composed of rhythmically constructed carbonate strata of the hemipelagic type, are presented. Biostratigraphic analysis of foraminifera complexes made it possible to identify zones in the section that are comparable to those proposed for the Point of the Global Stratotype of the boundary of the Coniacian in Germany. On the basis of chemostratigraphic (isotope) studies, the levels of abiotic events traced in the section and other territories have been established. The Shapsug section, after further study, can be proposed as a possible Hypostratotype (Limitotype) of the Turonian–Coniacian boundary for the territory of the Russian Federation. [ABSTRACT FROM AUTHOR]

The Cenomanian/Turonian strata of the Kasserine area: Tunisia exhibit a unique sedimentological and palaeontological pattern. Five lithological units have been identified: 1) lower unfossilferous black shale; 2) well-bedded marly unit with thin limestone interbeds; 3) marl unit, 4) same as 2, and 5) unfossilferous dolomitic thick-bedded limestone. The middle three units contain low diversity macrofaunal communities dominated mainly by oyster bivalves with few gastropods and echinoids. Fortunately, three marker ammonite species were identified and are used to subdivide the studied interval into three biozones, including 1) Calycoceras cenomanense, 2) Pseudaspidoceras pseudonodosoides and 3) Neoptychites Cephalotus. Based on constrained clustering and ordination techniques, three distinct macrofaunal associations were identified: 1) Ceratostreon flabellatum, 2) Ilymatogyra africana and 3) Tylostoma (Tylostoma) globosum. In general, the macrofaunal diversity decreases at the Cenomanian-Turonian boundary, which is interpreted to be a consequence of a global sea-level rise and the destruction of shallower habitats. Based on the life habits of the macrofaunal communities, a change from a high-energy (Ceratostreon and Ilymatogyra) to a low-energy (Tylostoma) shallow marine environment was indicated. The dominance of oysters in these nutrient-rich sediments was attributed to their ability to tolerate high turbidity water and to colonise soft-substrate sea bottoms. [ABSTRACT FROM AUTHOR]