Late Barremian Research Articles

Multidisciplinary evidence for synchroneity between Ontong Java Nui volcanism and early Aptian oceanic anoxic event 1a.

The volcanic episodes forming Ontong Java Nui (OJN) likely caused late Barremian to mid-Aptian paleoenvironmental perturbations, the most substantial of which was early Aptian oceanic anoxic event (OAE) 1a (120 million years ago). However, recent estimates on younger OJN eruption ages cast doubt on the link between OJN volcanism and OAE1a. Here, we further demonstrate the synchroneity between OJN volcanism and OAE1a by refining the chronology of Pacific volcanogenic sedimentary records on Magellan Rise, nearby OJN, with detailed osmium and carbon isotopic stratigraphy. Our geochemical data reveal that a thick tuffaceous interval at this site was deposited during OAE1a. Furthermore, multisite compilation of osmium isotopes, Pacific volcanic ash beds, and paleontological data just above OJN basalts illustrate that explosive OJN eruptions spanned ~5 million years, peaking around OAE1a. Their synchroneity strongly indicates that OJN volcanism most likely caused OAE1a and relevant late Barremian to mid-Aptian environmental perturbations.

Latest Barremian - early Aptian chronostratigraphy and sedimentary evolution of the northwestern Maestrat Basin

Latest Barremian - early Aptian chronostratigraphy and sedimentary evolution of the northwestern Maestrat Basin

First results of stratigraphic drilling in the North-Eastern Laptev Sea

The Stratigraphic Drilling Project of the Russian Arctic Shelf conducted by the PJSC Rosneft is aimed at discover the stratigraphic age and rock composition of sedimentary succession of its subsurface. In 2021, six shallow wells for the first time have been drilled with core sampling in the east of the Laptev Sea. Drilling revealed folded sedimentary succession dated back to the Late Barremian – Early Aptian. The synrift complex overlying unconformably dates to the Paleocene. The upper strata dates from Eocene to Pleistocene and contains significant hiatuses. The data discovered together with the results of seismic interpretation clarified the regional geological model and dated the stages of its tectonic evolution.

STRATIGRAPHY AND DIAGENESIS OF THE THAMAMA‐B RESERVOIR ZONE AND ITS SURROUNDING DENSE ZONES IN ABU DHABI OILFIELDS AND EQUIVALENT OMAN OUTCROPS

We review published studies characterizing the Thamama‐B reservoir zone in the upper Kharaib Formation (late Barremian) in Abu Dhabi oilfields and at outcrops in Oman. Available data for oxygen and carbon isotope compositions, fluid inclusion measurements, cement abundance and formation water composition are interpreted in terms of a paragenetic model for the Thamama‐B in field F in Abu Dhabi where the interval is deeply buried. The present synthesis provides a useful basis for understanding and predicting reservoir quality in static models and undrilled prospects, as well as for planning promising directions for further research. The goals of this study were to summarize the geologic setting and petrology of the Thamama‐B reservoir and its surrounding dense zones, and to examine how sedimentology, stratigraphy and diagenesis have interacted to control porosity and permeability. Results that may have useful applications for similar microporous limestone reservoirs in general include: the depositional environments and stratigraphy of the subject strata; a model for how porosity variations result mainly from calcite cementation sourced from stylolites, with little dependence on lithofacies other than the localization of chemical compaction by depositional clay linked to sequence stratigraphy; the use of solidity (rock thickness with porosity removed) as a check on porosity creation by burial dissolution; observations linking high‐permeability streaks with storm lag beds and fractures; the concept of strata being gradually buried through a relatively static salinity‐stratified water column; integration of conventional and clumped stable‐isotope data with petrologic observations to constrain the timing of porosity evolution.

Systematic of a Massively Constructed Specimen of Iguanodon galvensis (Ornithopoda, Iguanodontidae) from the Early Barremian (Early Cretaceous) of Eastern Spain

Styracosternan ornithopods are plenty abundant in the Lower Cretaceous fossil record of Europe. In particular, Iguanodon, the second genus of dinosaurs described worldwide, has been found in UK, Belgium, France, Germany, and Spain, evidencing a wide geographical distribution. Currently, the genus Iguanodon comprises two species, the type species I. bernissartensis from the late Barremian–Aptian of Europe and I. galvensis from the early Barremian of Teruel, Spain. The latter species is well known mainly from perinate and juvenile specimens. Here, axial and appendicular fossils of an adult, large and massively constructed ornithopod from the lower Barremian (Lower Cretaceous) Camarillas Formation of Galve (province of Teruel, Spain) are described. Fossil dimensions and some osteological evidence reveal that the specimen was a large (roughly 10 m long) ornithopod. An autapomorphic feature in the ischium and other characters allow us to ascribe this specimen to I. galvensis. In addition, postcranial co-ossification and fusion of the neurocentral suture indicate that the specimen was skeletally mature. Part of the material studied here was unknown in adults of I. galvensis, providing a better knowledge of the axial and appendicular region of this species.

First report of the Mid Barremian Event from the Transdanubian Range (Hungary) and associated Leptoceratoididae (Ammonoidea) fauna

Here the distribution of criocone members of the family Leptoceratoididae that proliferated during the early and late Barremian is investigated. We attempted to identify environmental factors that may have influenced the abundance, diversity and palaeoecology of the group. Specimens of this ammonite family were found at two Hungarian localities: the Bersek Hill (Gerecse Mountains) and the Sümeg Süt-17 drill core (Southern Bakony). Our most important stratigraphic result is the integration of stratigraphic frameworks of different autors from the Bersek Hill section which enabled us to precisely evaluate the stratigraphic distribution of this ammonite family. This integrated stratigraphy can be used with high accuracy for the Toxancyloceras vandenheckii Zone and is reliable for the Moutoniceras moutonianum Zone, but its accuracy for the lower part of the Kotetishvilia compressissima Zone is less stable. Our taxonomic analysis confirmed that Karsteniceras and Leptoceratoides should be kept as separate genera. In the Bersek Hill sections, family Leptoceratoididae is represented by Karsteniceras ibericum is the most common species found in basal K. compressissima to basal T. vandenheckii Zones. Leptoceratoides balernaensis occurs in the M. moutonianum and Leptoceratoides pumilus occurs mainly in the T. vandenheckii Zone. Their stratigraphic occurrence displays that only a few beds overlap at the top M. moutonianum Zone. In the Süt-17 borehole, the family is monospecific with L. pumilus occurrences. Unfortunately, the stratigraphic position of the Moutoniceras moutonianum Zone in Süt-17 borehole could only be inferred indirectly. Local response of Leptoceratoididae to the Mid Barremian Event shows spatial distribution patterns and resulted in different assemblage composition between the two localities. Discussion on lifestyle and paleoecology of criocone Leptoceratoididae ammonites is presented. Comparing our paleontologic findings to previously measured stable isotope data on belemnite rostra from Bersek Hill, we suggest that within the Moutoniceras moutonianum Zone, a sudden +1‰ shift in the stable carbon isotope excursion indicates the Mid Barremian Event (MBE). The -1.5‰ shift in the stable oxygen isotope excursion also indicates warming associated with rapid environmental change. During this time interval, increased organic matter entered into the Gerecse basin that could have induced increased primary productivity, hence dysoxic environment on the ocean floor. The increasing organic matter content was probably well tolerated by members of the family Leptoceratoididae and by other ammonite taxons that might have lived in the epipelagic zone, while certain groups of amonites are missing from these strata.

New Evidence for an Episode of Accelerated Environmental Change in the Late Barremian: Geochemical and Paleontological Records from the Subbetic Basin (Western Tethys)

We investigate a new event of accelerated environmental change that was recorded during the late Barremian in the pelagic Subbetic Basin (Western Tethys). Two pelagic sections have been studied using a multi-proxy approach based on C-isotope stratigraphy and a high-resolution quantitative study of nannofossil assemblages, along with major and trace elements and biomarkers. Our results provide a detailed biostratigraphy and C-isotope stratigraphy, and outline the paleoenvironmental conditions recorded during the early stages of the Taxy Episode. A disturbance has been identified in the C-isotope record, called the IFeNE (Intra-Feradianus negative C-excursion), which is coeval with environmental and biotic changes that predate the well-known ISNE (Intra-Sarasini negative C-excursion). The combined analysis of nannofossil associations, C-isotopes, major and trace elements, and biomarker distributions indicates a separate episode of warming heralding the ISNE, resulting in the acceleration of the hydrological cycle and a consequent increase in continental inputs and the fertilization of surface waters. The origin of the Taxy Episode (the IFeNE and ISNE) has been related to orbital factors (high-eccentricity cycles), and to a global increase in volcanism, probably related to the early phases of the Ontong Java Plateau.

Morphology and ultrastructure of cicatricose spores found in an isolated sporangium-bearing structure of a schizaealean fern from the Lower Cretaceous rocks at Casal do Borracho, Torres Vedras, western Portugal

Morphology and ultrastructure of cicatricose spores found in an isolated sporangium-bearing structure of a schizaealean fern from the Lower Cretaceous rocks at Casal do Borracho, Torres Vedras, western Portugal

Ammonite families Phylloceratidae, Gaudryceratidae, Oppeliidae and Desmoceratidae from Kopet Dagh Basin NE of Iran; Palaeobiogeographical and palaeoecological application

Ammonite families Phylloceratidae, Gaudryceratidae, Oppeliidae and Desmoceratidae from Kopet Dagh Basin NE of Iran; Palaeobiogeographical and palaeoecological application

Integrated multi-proxy source-to-sink analysis of Late Barremian (Lower Cretaceous) clastic systems in the Essaouira-Agadir Basin

This study investigates the provenance of the continental and marine Late Barremian clastics of the Bouzergoun Formation, exposed in the Essaouira-Agadir Basin (EAB). Thin section petrography, Scanning Electron Micrography, heavy minerals analysis, and detrital zircon dating were conducted and integrated with a large dataset of published Low-Temperature Thermochronology (LTT) studies to reconstruct the associated source-to-sink system(s). The results constrain the source and size of the system, and composition of deposited clastics, and investigate the mechanism for delivery of coarse clastics into the offshore domain, a key target for hydrocarbon exploration.The homogeneity of rock composition fingerprints throughout the basin indicates a common provenance for both the northern and southern studied transects. Hinterland analysis based on LTT data identifies the Western Meseta and Massif Ancien de Marrakech (MAM) regions as the only possible source candidates exhuming during the Late Barremian, confirmed by detrital zircon geochronology. Heavy mineral populations reveal partly recycled sediment including a probable igneous source. Rock fragment populations comprise limestones, sandstones, and volcanic composition, which correlate with lithologies of the MAM.The integration of all data suggests a best-fit model for the Late Barremian of a source-to-sink system of moderate size (200–300 km long), dominantly sourced from the MAM (western High Atlas). This provided a sand-rich mix of sediment resulting from the erosion of exhuming Triassic continental basins, with associated clays from the weathering of basalts and Triassic/Jurassic mudstones.Late Barremian eustatic sea level fall, together with regional uplift in the hinterland, is interpreted to have resulted in a forced regression that allowed the system to prograde towards the slope margin, offering enhanced potential for sand delivery into the deep offshore domain. Seismic imaging offshore provides tentative interpretation of synchronous high reflectivity deepwater channels located in structural lows controlled by diapiric salt movement.The Mesetian domain was likely undergoing denudation at the same time and shedding clastic-rich sediments to the northern part of the EAB, beyond the studied region. Sediment supply from the MAM may be mixed with the Mesetian sands to the northern part of the EAB and tentatively in the offshore Essaouira.

New theropod remains from the late Barremian (Early Cretaceous) of Eastern Iberian Peninsula

ABSTRACT In the last decade, the Iberian Peninsula has become a hot spot in the understanding of the early evolutionary history of large-bodied theropods from the Early Cretaceous, especially for the Spinosauridae and Carcharodontosauridae families. To date, at least five species of spinosaurids and one species of carcharodontosaurid inhabited the Iberian region during the Barremian. However, the discovery of new fossil remains suggests that such a diversity of medium- to large-sized theropods could be even higher. Here, we describe an unpublished large theropod tooth and two caudal vertebrae collected in the late 70s in the upper Barremian strata of the Arcillas de Morella Formation (Morella, eastern Spain). The tooth element displays a series of features that allow its identification as cf. Protathlitis, while the vertebral elements are tentatively attributed to an indeterminate carcharodontosaurid. Interestingly, these last remains are different from those of Concavenator, allowing speculation about the occurrence of another species of carcharodontosaurid allosauroids in the Iberian Peninsula during the Early Cretaceous apart from the famed humpbacked dinosaurs and with some reminiscence to Acrocanthosaurus. Therefore, the new findings clearly illustrate the significance of any new theropod remains in depicting the theropod diversity before the final break-up of Pangea in the Iberian Peninsula.

Rise and demise of the Urgonian platform in Switzerland

Abstract Defined in the Provence region of France, the rudist-bearing Urgonian Limestone is typical of northern Tethyan shallow-marine carbonate series, and is dated based on benthic fauna and flora, calcareous nannofossils and ammonites. This contribution reports on recent findings that refine the stratigraphy of the Urgonian Limestone in the western Swiss Jura and the Helvetic Alps of Switzerland. In the former location, the high-resolution facies and isotope analysis of samples permits the identification of major periods of subaerial exposure, while a diverse assemblage of calcareous nannofossils indicates a Barremian age for the Urgonian deposits. In the latter location, biostratigraphical data indicate a Late Barremian–Early Aptian age for Urgonian deposits, while the repartition of facies along a proximal-to-distal transect highlights the Late Barremian progradation of the platform. The detailed understanding of the stratigraphy of Urgonian deposits in these regions inscribes them into a broader context that acknowledges palaeoclimatic and palaeoenvironmental conditions. A warmer and more humid climate prone to continental weathering and transport of nutrients to an epicontinental sea characterized the Early Barremian; this was detrimental to the health of carbonate-producing benthic ecosystems. In the Late Barremian, a reduced nutrient supply allowed Urgonian communities to thrive.

TAXONOMIC AND BIOSTRATIGRAPHIC REMARKS ON TORINOSUELLA MAYNC, 1959 AND BALKHANIA MAMONTOVA, 1966, LARGER BENTHIC FORAMINIFERA FROM THE LOWER CRETACEOUS OF IRAN (SANGESTAN, TIRGAN FORMATIONS)

The monospecific genera Torinosuella Maync [type-species T. peneropliformis (Yabe & Hanzawa)] and Balkhania Mamontova (type-species B. balkhanica Mamontova) have been reported from the Lower Cretaceous of Iran, respectively the ‘Carbonate Member’ of the Sangestan Formation (Central Iran) and the Tirgan Formation (NE Iran). The literature review reveals a range of late? Tithonian–early Barremian for Torinosuella and late Barremian–early Aptian for Balkhania. In a recent publication dealing with the ‘Taft’ Formation (Central Iran) and the Tirgan Formation (northeastern Iran), both taxa have been lumped together and described as two morphotypes of B. balkhanica based essentially on size differences. This mixing was associated with incorrect phylogenetic, taxonomic, biostratigraphic (e.g., First Appearance Datum) and palaeoecological conclusions that are herein addressed and corrected. Without clarification about the spatial and temporal distribution of individual taxa, the usefulness of larger benthic foraminifera for biostratigraphy, palaeoecology and palaeobiogeography would be distinctly reduced.

Clay mineral assemblages as a tool in source-to-sink studies: an example from the Lower Cretaceous of the North Sea Basin

The alternating marlstone and chalk of the Lower Cretaceous succession in the Danish Central Graben (DCG) are important for the understanding of the evolution of the larger North Sea Basin. This study focusses on the clay mineral assemblages of the upper Hauterivian – lower Aptian in the DCG and Danish Basin (DB) and their implications. Clay mineral assemblages are predominantly used to assess palaeoclimate. In this study, however, they were additionally used in a source-to-sink context. Kaolinite was found to form a dominant component of the clay mineral assemblage in the sampled wells of the DCG and in the DB, suggesting that a feldspar- or kaolinite-rich source was present and actively eroded in the region during the Early Cretaceous. Moreover, a decreasing gradient west to east of average kaolinite content is observed in the three studied wells for the early Hauterivian to late Barremian (BC9-BC17), with the highest content observed in the North Jens-1 well (av. 74%), followed by the Boje-2C well (av. 49%) and lastly in the Vinding-1 well (av. 39%). Due to the relatively rapid settling of kaolinite in marine environments compared to other clay minerals, this gradient suggests that the main clay mineral source was located in the south-western part of the DCG. Isochore maps, a new palaeogeographic map of the DCG and the western part of the German sector of the North Sea illustrates where Lower Cretaceous rocks are absent in this region, due to either erosion or non-deposition. Potential subaerially exposed highs included the distant Baltic Shield to the north, the Ringkøbing–Fyn High to the east and the Heno Plateau within the DCG, with the latter being located closest to the North Jens-1 well and containing feldspar-rich sandstones of the Heno Formation (upper Kimmeridgian – lowermost Volgian/Tithonian). During the Early Cretaceous, part of the Heno Formation was potentially subaerially exposed or subject to wave reworking/erosion in parts of the Danish and German sectors. The sandstones could weather into kaolinite and this structural high is therefore suggested to have been the main source area for this part of the DCG, with minor sediment influxes from the Ringkøbing–Fyn High and Baltic Shield. In addition, the overall decrease in kaolinite in the DCG from the late Hauterivian to the late Barremian indicates a climatic change towards drier conditions, with some minor, slightly more humid periods.

Pachytraga gracilis sp. nov. (Hippuritida, Caprinidae) from the Barremian of the Sub-Alpine region (SE France). Evolutionary and biogeographic implications for the genus Pachytraga Paquier

Pachytraga gracilis sp. nov. (Hippuritida, Caprinidae) from the Barremian of the Sub-Alpine region (SE France). Evolutionary and biogeographic implications for the genus Pachytraga Paquier

Burial history and hydrocarbon generation model of the Lower–Middle Jurassic sediments in the Tarnovo depression

This study deals with the geodynamic evolution in the Tarnovo depression, contributes to a better understanding of the burial and thermal history, and gives a model of the generation of hydrocarbons from the Lower–Middle Jurassic rocks. The implications of the complex heat flow scenario for the timing of hydrocarbon generation from the Stefanets Member of the Etropole Formation in selected sections were also analyzed. The Tarnovo depression is defined as a small tectonic unit in the central part of the South Moesian Platform margin developed mainly during the Early–Middle Jurassic. Therefore, the sediment subsidence during the Early–Middle Jurassic is largely a consequence of the tectonic processes in an extensional basin with tilted, fault-bounded, and eventually rotated blocks. There is a trend of increasing tectonic and basin subsidence in southern direction, observed in modeled well sections. The Lower–Middle Jurassic rocks enter the “oil window” in the late Barremian, Hauterivian, or even the late Valanginian towards the south, starting active generation in the middle Aptian. The model shows that gas generation is possible only in the southern and marginal zones of the Tarnovo depression. Among the sequence, the Stefanets Member of the Etropole Formation (Aalenian–early Bajocian in age), composed of shales and siltstones, possesses source rock qualities and good hydrocarbon generation potential. The research model argues for peak of the oil generation from the Stefanets Member at the end of the Barremian up to the Albian to the north and gas generation starting in the Barremian and continuing during the Cenozoic only in the southern part.

New Insights into the Platform-to-basin Anatomy of the Urgonian Bas-Vivarais Domain (Lower Cretaceous; SE France)

This paper offers a new contribution to our ongoing harmonization efforts concerning the chronostratigraphic model of the southern France Urgonian-type carbonate platforms, which surrounded the Vocontian Basin during the Early Cretaceous. A multi-stratigraphic approach on the classical sections of the Ardèche River gorges and the Saint-Remèze Plateau have been used for reconstructing the evolution of the Bas-Vivarais Urgonian domain along an inner-to-outer platform profile; the latter being nearly perpendicular to the eastern Vocontian platform margin. In our transect, the installation and first developments of the Urgonian platform domain occured during the early Barremian Taveraidiscus hugii and Kotetishvilia nicklesi ammonite zones. This first platform stage was interrupted at a brief emersion episode that lasted through the Nicklesia pulchella ammonite zone, and resulted in the deposition of a sedimentary wedge with limited gradual downward, basinward shift in inner platform facies. This was followed by the regional deposition of shallow-water communities dominated by corals, echinoids, and orbitolinids, which passes basinward into open-marine, ammonite-bearing marly deposits in the Saint-Remèze Plateau outcrops. This change in facies was previously referred to as the Serre de Tourre Beds (STB), and dated to the Kotetishvilia compressissima and Moutoniceras moutonianum ammonite zones. The STB are further identified to as the local sedimentary expression of the Mid-Barremian Event recording a brief warming climate pulse testified by the presence of Offneria simplex, a caprinid rudist of Caribbean origin. Above, there is a regional recovery of inner platform Urgonian facies during the early late Barremian showing a striking progradational basinward trend. The latter, and its subsequent developments are in need of investigations. Taken together, the general evolution of the Urgonian Bas-Vivarais domain shows strong similarities with the sedimentary context of the nearby Subalpine Urgonian platform during the early Barremian. The finding of common sedimentary signals is more difficult with the Provence platform domain at that time.

A new pterosaur specimen from the Lower Cretaceous Yixian Formation of Liaoning Province, China: The oldest fossil record of Nurhachius

ABSTRACT The Istiodactylidae is one of three ornithocheiroid pterosaur lineages, characterised by a large nasoantorbital fenestrae and labiolingually compressed teeth. Their remains have been reported from Early Cretaceous rocks of northeastern China and Western Europe. A new istiodactylid pterosaur from the upper part of the Yixian Formation (Jingangshan Member) of the Jehol Group, distributed in western Liaoning Province and neighbouring areas, is described on the basis of an incomplete specimen including the partial skull, forelimb and hindlimb bones, and pelvis. This individual, here designated as a referred specimen of Nurhachius (Nurhachius sp.) is a skeletally almost mature pterosaur with an estimated wingspan of 1.6 m. This specimen is not only the geologically oldest known occurrence of Nurhachius, but also a new component of the pterosaur assemblage of the Jingangshan Member, and provides new information on the pelvis and hindlimb of istiodactylids and the palaeobiology of this clade. Considering previous reports of the istiodactylid remains and the geological ages of the strata that yielded them, it is suggested that different istiodactylids existed in Europe and China during the late Barremian.

The helochelydrid turtle Helochelydra nopcsai from the Early Cretaceous (late Barremian – early Aptian) fissure fills of Balve, North Rhine-Westphalia, Germany, including a large sample of granicones

Early Cretaceous (late Barremian – early Aptian) fissure fill deposits near Balve, North Rhine Westphalia, Germany, have yielded a rich continental vertebrate fauna over the course of the last two decades. More than 250 fragmentary specimens, including more than 150 osteoderms (i.e., granicones), represent the late Early Cretaceous helochelydrid Helochelydra nopcsai, which had previously been reported from the UK, France, and Spain. The new material mostly differs from that from the type section by exhibiting a reduced to absent entoplastral scute and by displaying distinct cranial scute sulci, both of which are interpreted as intraspecific variation. Although morphological insights are limited, the new material reveals that the visceral cavity extends anteriorly and posteriorly to the bridge, a relatively novel feature previously reported for an eclectic mix of compsemydids, pleurosternids, and other helochelydrids. The available sample of granicones reveals great shape diversity, but a morphometric analysis concludes that no distinct morphotypes exist.

Nomenclatural status of Orbitolina pileus Fossa-Mancini 1928 (Foraminifera) (junior synonym Palorbitolinoides orbiculatus Zhang 1986) from the Lower Cretaceous of the Himalaya (Ladakh, Tibet)

ABSTRACT The published literature concerning Lower to mid-Cretaceous (late Barremian–Albian, early Cenomanian) Tibetan Orbitolinidae suggests an apparent extreme high diversity with almost exclusive reference to taxa displaying a complex embryo (subfamily Orbitolininae). The majority of them, among Orbitolina pileus Fossa Mancini described in the late twenties from the border areas of Ladakh (India) and Tibet (China), however need taxonomic reconsideration. The original images of O. pileus are herein interpreted as a mixture of a high-conical mesorbitolinid (of unclear species identity) and a section of Palorbitolinoides orbiculatus Zhang described in the early 80ies from Tibet. The concluding new nomenclatural act considers P. orbiculatus a junior synonym of O. pileus validated herein as Palorbitolinoides pileus (Fossa-Mancini) comb. nov. with the designation of a lectotype. The present study refers to data from the literature and own material from the Albian Langshan Fm. of the northern Lhasa Block of Tibet.