Early Berriasian Research Articles

Cretaceous and Jurassic intrusions in Crimean Mountains: The first data of U–Pb (SIMS SHRIMP) dating

U–Pb geochronological studies of igneous rocks of the Crimean Mountains were carried out for the first time. The ages of magma crystallization determined for gabbro–dolerites of the Dzhidair and Pervomaiskii intrusions point to the injection of these rocks during the Middle Jurassic Aalenian–Bajocian stage of magmatism. The Berriasian–Valanginian and Aptian age of sill-like bodies within the mass of volcanogenic–sedimentary rocks presumes the necessity to reconsider the common notion of an exclusively Albian magmatic event during the Cretaceous. High-precision U–Pb dating of magma intrusions allowed us to verify the age of Middle Jurassic magmatism and to distinguish the new Early Cretaceous Berriasian–Valanginian magmatism stage of basic composition.

Finding of two new radiolarian associations calibrated with ammonoids in the Vaca Muerta Formation (Late Jurassic–Early Cretaceous), Neuquén Basin, Argentina

An association of ammonoids and radiolarians retrieved from a sedimentary section of the Vaca Muerta Formation at Vega de Escalone, Neuquén Basin, Argentina, was analized under a strict stratigraphic control. Nine ammonoid assemblage biozones were identified, indicating an age span from Early Tithonian to Late Berriasian/earlymost Valanginian for the Vaca Muerta Formation at the studied section. In connection to the ammonoid record, two radiolarian faunas were identified and named J3A1 and J3B1. Fauna J3A1, corresponding to the Virgatosphinctes andesensis Biozone, is dominated by nasellarian genera and represents the first Lower Tithonian radiolarian fauna described from the Neuquén Basin. Fauna J3B1, linked to the interval assigned to the Substeueroceras koeneni Biozone (Late Tithonian–Early Berriasian), yields abundant representatives of the Pantanellid Family. The presence of Complexapora kozuri (Kiessling and Zeiss) and Loopus primitivus (Matsuoka and Yao), two important radiolarian primary markers of the Late Jurassic in North America, supports a Late Tithonian age for at least part of the S. koeneni Biozone in the studied area. Nor certain Berriasian radiolarian faunas nor elements of the Vallupinae Family were identified so far at the Vega de Escalone section.

Paleogeographic conditions in the West Siberian Basin during the Tithonian–Early Berriasian

Based on facies, structural, and general paleogeographic analyses, new models of the bottom topography and accumulation of the Tithonian–Early Berriasian Bazhenov Formation (West Siberian Basin) are proposed. According to these patterns, quite a low proportion of the terrigenous material in the high-carbon facies of the Bazhenov Formation can be explained by its accumulation in relatively deep troughs that frame the uplifted shallow-water central part of the West Siberian basin. In addition, the structure and dynamics of ocean currents are considered. During the Tithonian–Early Berriasian, these currents were related to the aeration stages of bottom waters enriched in hydrogen sulfide and carbon dioxide. As a result of the convection of the water mass suffocation periods occurred.

Biostratigraphical study around the Jurassic/Cretaceous boundary in Central Tunisia zonal schemes and correlation

The fossil data from Central Tunisia has led to the recognition of ten calpionellid and ammonite zones and subzones in the Upper Tithonian-Middle Berriasian interval. The results of this revision are congruent with local interval zones and they were tested with the Mediterranean zonal schemes.Six subzones of calpionellids constitute the basis of our investigations in this study. We recognized the A2+A3, B1, B2, B3, C1 and C2 Subzones. These subzones are calibrated with the ammonite biozones: Berriasella jacobi and Subthurmannia occitanica Zones. Integration of the biostratigraphy of ammonites and calpionellids has allowed us to define the J/K boundary interval and the Middle/Upper Berriasian boundary. Biostratigraphic data provided by the two sections in Central Tunisia allowed the revision of the biostratigraphic attribution of Sidi Kralif Formation. These faunas suggest a late Tithonian to mid Berriasian age for the Jebel Rheouis section, and early Berriasian to mid Berriasian age for Jebel Meloussi section; correlating with their equivalents in other regions of the Tethyan Realm.

Origin of Micropores In Late Jurassic (Oxfordian) Micrites of the Eastern Paris Basin, France

Abstract: Porous micritic facies, either primary chalks or resulting from secondary destructive micritization, can constitute important hydrocarbon or water reservoirs. Characterization of reservoir properties and the understanding of factors which controlled the distribution of porosity are of primary interest to evaluate the prospective reserves. Middle and late Oxfordian limestones of the eastern Paris Basin show several horizons with porosities higher than 20%. The porosity is mainly microporous and located either within secondary micritized grains or in the micritic matrix. Using SEM, cathodoluminescence, as well as confocal microscopy, stable oxygen and carbon isotope ratios, and petrophysical measurements, a scenario for the evolution of the micropores is proposed. Lime mudstones to packstones constitute the majority of the high-porosity facies (HPFs). Inner lagoonal deposits are more micritized and thus more porous than grainstones, and facies rich in leiolitic oncoids and echinoid clasts are less impacted by micritization. Micritization was responsible for an increase of the intragranular porosity in most grain types. During both eogenesis and shallow burial, mineralogical stabilization dissolved aragonitic particles and allowed precipitation of calcite rhombs. This process was probably enhanced below surfaces of subaerial exposure. During burial, Ostwald ripening allowed the growth of larger micrite crystals at the expense of smaller ones during early Berriasian and late Aptian recharges of deep aquifers when the northern margin of the basin was exposed. Overgrowths on micrite crystals were more important in intervals strongly affected by chemical compaction, which favored oversaturation of waters with respect to calcite. In low-porosity horizons (LPFs), the dense micritic texture of oncoids and the monocrystalline architecture of echinoid clasts prevented an intense micritization, while the strong chemical compaction enhanced poronecrosis. Telogenetic fracturing created new fluid pathways that favored inputs of meteoric fluid in porous micrite and allowed the continuation of Ostwald ripening during Cenozoic times. As a whole, mesogenetic inputs of waters undersaturated with respect to calcite in deep aquifers during exposure of basin margins are a more efficient process than early subaerial exposure for enhancing aggrading neomorphism and appearance of microporous micrites. Initial mineralogical heterogeneities also impact the intensity of chemical compaction and thus the stratigraphical distribution of microporous limestones.

The bivalve Anopaea (Inoceramidae) from the Upper Jurassic–lowermost Cretaceous of Mexico

In Mexico, the Upper Jurassic to lowermost Cretaceous La Casita and coeval La Caja and La Pimienta formations are well-known for their abundant and well-preserved marine vertebrates and invertebrates. The latter include conspicuous inoceramid bivalves of the genus Anopaea not formally described previously from Mexico. Anopaea bassei (Lecolle de Cantú, 1967), Anopaea cf. stoliczkai (Holdhaus, 1913), Anopaea cf. callistoensis Crame and Kelly, 1995 and Anopaea sp. are rare constituents in distinctive Tithonian–lower Berriasian levels of the La Caja Formation and one Tithonian horizon of the La Pimienta Formation. Anopaea bassei was previously documented from the Tithonian of central Mexico and Cuba, while most other members of Anopaea described here are only known from southern high latitudes. The Mexican assemblage also includes taxa which closely resemble Anopaea stoliczkai from the Tithonian of India, Indonesia and the Antarctic Peninsula, and Anopaea callistoensis from the late Tithonian to ?early Berriasian of the Antarctic Peninsula. Our new data expand the palaeogeographical distribution of the high latitude Anopaea to the Gulf of Mexico region and substantiate faunal exchange, in the Late Jurassic–earliest Cretaceous, between Mexico and the Antarctic Realm.

Purranisaurus potens Rusconi, an enigmatic metriorhynchid from the Late Jurassic–Early Cretaceous of the Neuquén Basin

ABSTRACTThe Tithonian record from northwestern Patagonia (Neuquén Basin) documents a complete succession of lower, middle, and late Tithonian marine reptiles. From the late Tithonian–early Berriasian of Patagonia, three marine crocodyliforms have been recorded: Dakosaurus andiniensis, Cricosaurus araucanensis, and Purranisaurus potens. Although P. potens includes the first metriorhynchid skull described from Patagonia, no detailed description and/or illustrations have been published. Since the mid-20th century, several authors have discussed the validity of P. potens. Recent preparation of the type material allowed a detailed description as well as exploration of its phylogenetic relationships. We consider P. potens as a valid taxon characterized by a unique combination of characters, such as medial and posterolateral processes of the frontal forming an angle of 60°; supratemporal fossae reaching the minimum interorbital distance, with the dorsal margin of the supratemporal arch being slightly concave in lateral view; thin bony lamina projecting from the lateral and medial alveolar margins of the maxilla; occipital surface ventral to occipital condyle parallel to transverse plane of skull; well-developed crest that extends along the entire height of the supraoccipital; and orbital process of the quadrate very conspicuous and acute, horizontal, and without bony attachment. Phylogenetic analysis recovers P. potens as deeply nested within Geosaurini and, contrary to previous proposals, not closely related to ‘Metriorhynchus’ casamiquelai and ‘M.’ westermanni. Internal relationships within Geosaurini are unresolved. Purranisaurus, as a monotypic genus, is restricted to the late Tithonian–early Berriasian.http://zoobank.org/urn:lsid:zoobank.org:pub:CDB288F2-087C-4E19-A897-8AB94BD60EC2SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP

Late Jurassic-earliest Cretaceous belemnites (Cephalopoda: Coleoidea) from northeastern Mexico and their palaeobiogeographic implications

In northeastern Mexico, the Upper Jurassic to lowermost Cretaceous La Caja and La Casita formations are well-known for their abundant and well-preserved marine vertebrates and invertebrates. The latter include conspicuous belemnites not formally described previously. They were identified as Cylindroteuthis spicularis modica SachS & NalNjaeva, 1964, Cylindroteuthis lenaensis SachS & NalNjaeva, 1964, Cylindroteuthis sp. ind. and a new species of the genus Rhaphibelus, R. aciculiformis. They are present in distinctive stratigraphic levels of the La Caja and La Casita formations (Early Kimmeridgian to earliest Berriasian). Cylindroteuthis spicularis modica was previously known from the Upper Jurassic of northern Siberia, European Russia and Spitsbergen, while C. lenaensis is common in the Upper Jurassic of Siberia. Both taxa thus indicate a Boreal distribution. The sporadic presence in northeastern Mexico of belemnite taxa of Boreal origin in distinct and welldefined intervals of the Kimmeridgian and the Tithonian appears to be linked to recurring ingression of cold-water into the Gulf of Mexico. Rhaphibelus, on the other hand, is only known from the Late Kimmeridgian and earliest Tithonian of southern Germany and Rhaphibelus aciculiformis n. sp. in the earliest Berriasian of northeastern Mexico and is therefore considered to be of Tethyan origin. Our new data expand both the palaeogeographical distribution as well as the stratigraphic range of these belemnites. Furthermore it substantiates faunal exchange between the Boreal Pacific and the Gulf of Mexico in the Late Jurassic. However, the presence of the genus Rhaphibelus in the earliest Berriasian could be an additional proof that a new connection opened in the earliest Cretaceous between the northeastern Gulf of Mexico and the European Tethys (Hispanic Corridor).

The northernmost occurrence of the Lower Berriasian ammonite Pseudosubplanites grandis (Štramberk Limestone, Outer Western Carpathians, Czech Republic)

Abstract The first finding of the index ammonite Pseudosubplanites grandis (Mazenot, 1939) in the Lower Berriasian Štramberk Limestone (Outer Western Carpathians, northeastern Czech Republic) is important from the point of view of both the paleogeographical distribution of this species and of more precisely defining the upper boundary of the Štramberk Limestone (Early Berriasian Berriasella jacobi Zone) formerly regarded as Late Tithonian in age. From the taxonomical point of view, new data on a non-deformed cross-section of the adult whorl and above all on the shape of the adult suture line of this species have been obtained.

Charophytes from the Upper Berriasian of the Western Interior Basin of the United States

A charophyte flora from the Upper Berriasian is described from the Lakota (Black Hills, South Dakota) and Cedar Mountain formations (San Rafael Swell, Utah) of the Western Interior Basin, United States of America. Whereas the latter is dominated by monotonous assemblages of the clavatoracean Nodosoclavator bradleyi (Harris, 1939), found in temporary lakes within palustrine facies, the flora of the Lakota Formation consists of more varied assemblages of the clavatoraceans N. bradleyi (Harris, 1939), Clavator grovesii grovesiiHarris 1939, C. bilateralisPeck 1957 and early characeans (Mesochara sp. or Tolypella sp.). This flora was found in deposits related to permanent lakes in fluvial floodplains, i.e. lacustrine marls and limestones that do not show any evidence of subaerial exposure. To date, little is known about C. bilateralis, we provide a new definition on the basis of its particular structure, which shows lateral bract-cell units with a pinnate arrangement. This species appears to be endemic to North America and stratigraphically limited to the earliest Cretaceous. C. grovesii grovesii is part of a long-lasting charophyte lineage, which until now was considered to have originated in the Central Tethyan Archipelago (Europe) during the Early Berriasian, about 145 Ma, and limited to Eurasia until most of the Early Cretaceous. The new data presented here suggest that during the Berriasian this species was very broadly distributed, comprising North America, Europe and China.

A review of the enigmatic microalga Tetranguladinium Yu et al. 1983 ex Chen et al. 1988; palaeoecology, stratigraphy and palaeogeographical distribution

The probable zygnematacean zygospore Tetranguladinium is recorded in Mesozoic strata from southern Scandinavia for the first time. Tetranguladinium, which exhibits morphological similarities to the extant filamentous green alga Mougeotia, occurs in Jurassic–Cretaceous (J/K) boundary (latest Tithonian–Early Berriasian) assemblages from the Vomb Trough, southern Sweden and on the Danish island of Bornholm. The J/K boundary strata of southern Scandinavia were deposited in marginal marine settings, varying from freshwater marshes, lakes and flood plains, to lagoons, shoreface, and shallow marine to fully marine environments. The assemblages containing Tetranguladinium are diverse, consisting of spores and pollen, the colonial green alga Botryococcus, various other zygnematacean zygospores e.g. Ovoidites, Schizosporis and Tetraporina, and rare marine dinoflagellate cysts. A review of published fossil occurrences of Tetranguladinium reveals that its stratigraphical range extends at least from the Late Guadalupian (Mid Permian) to the Holocene. It has been recorded from Africa (Tanzania), Asia (China, Korea), Australia, northwest Europe (Denmark, Great Britain, Sweden), North America (Canada, USA), and South America (Argentina). Depositional and palaeoclimatological data for the known localities of Tetranguladinium confirm a preference for freshwater settings in a humid warm temperate to subtropical–tropical climate, often with a pronounced dry season. The palaeogeographical positions of all the known Tetranguladinium localities indicate that it is has stayed restricted within narrow belts between 30–40 south and 30–60 north of the palaeoequator since the Late Jurassic.

Nannostratigraphy and palaeoecology of uppermost Mozduran Formation in the Kopeh-Dagh range (NE Iran)

The Mozduran Formation includes light-coloured, thick-bedded to massive limestone and porous dolomitic limestone and dolomite. In this study, 13 samples from the uppermost Mozduran Formation were taken from two localities and examined for calcareous nannofossils. A total of 19 species and 12 genera were identified in the Mozduran section and19 species and 13 genera for the Taherabad section. Based on these assemblages, the uppermost Mozduran Formation is assignable to Sissingh's (1977) biozone CC1 (Early Berriasian) at the Mozduran section and to biozone CC3 (Late Valanginian) at the Taherabad section. Thus, the formation is younger from east to west across the basin.

Triploporella remesi (Steinmann, 1903), dasycladalean green alga from the Tithonian–Lower Berriasian of Štramberk (Czech Republic) revisited

The dasycladalean green alga Triploporella remesi (Steinmann) is redescribed based on material collected from the Kotouc quarry near Stramberk (Moravia, Czech Republic), probably corresponding to the type locality. The alga is Tithonian–early Berriasian in age according to the age assigned to the Stramberk Limestone. The new material, in addition to the detailed description of Steinmann, indicates that the short club-shaped calcareous skeleton probably represents the fertile upper part of a far longer club-shaped thallus. The well-developed phloiophorous primary laterals are similar to those of other species of Triploporella in having a proximal cylindrical sterile part followed by a stronger distal cylindrical fertile part. Secondary phloiophorous laterals probably combined to create a cortex at their distal ends. The simple undivided spores inferred by previous authors are shown to be recrystallized cyst containers.

Purbeck beds (Late Jurassic) in the Phare de Chassiron section (Île d’Oléron, NW Aquitaine Basin, France): Refined age-assignment and long-term depositional sequences

In western european basins, lowering of relative sea-level during the Late Jurassic-Early Cretaceous led to the widespread deposition in numerous basins of so-called Purbeck facies. Age-assignment and long-distance correlations are difficult to establish in such shallow marine to continental deposits, where ammonites are generally lacking. This paper aims to present new biostratigraphical and sedimentological data from the Phare de Chassiron section, located at the western part of the Aquitaine Basin (SW France), where Purbeck beds crop out. Marine bands, interfingered within the Purbeck beds, allow refining the age-assignment of these beds using dinoflagellate cysts, calcareous nannofossils and magnetostratigraphy. Most of the Purbeck beds appear to have a Tithonian age. Uppermost beds of the section, although not precisely dated, are not younger than the Early Berriasian. Field sedimentology, palynofacies and trace-element data (strontium) on carbonates, allow depositional environments to be characterized and a sequence-stratigraphy scheme to be established. This section provides an unique, continuous record, within the Aquitaine Basin, of the final exposure, during the Tithonian, of the former Late Kimmeridgian open-marine platform. The Phare de Chassiron may be considered as one of the most important exposures of Purbeck facies of Tithonian age in Europe.

Tectonostratigraphic evolution of the northern Porcupine Basin, Irish Atlantic margin, during the Late Jurassic–Early Cretaceous, implication for a regional compressional event

The conventional interpretation of the Jurassic–Lower Cretaceous succession in the Porcupine Basin suggests an extensional setting with progressive deepening of the basin. However, well data show a prominent gap of several million years between the Upper Jurassic and Lower Cretaceous. A data base of 15 key wells and approximately 5,000 km of seismic reflection data were examined in the northern Porcupine Basin, in order to understand the nature, controls and mechanisms of this unconformity. Seven seismic markers, constrained by well data, are mapped. It is shown that during the Late Jurassic (possibly the Oxfordian–Kimmeridgian), the basin experienced extension and synrift deposition. During the latest Jurassic–earliest Cretaceous (possibly the Tithonian–early Berriasian), a series of north-trending structural highs and lows developed and extensive areas in the northern Porcupine Basin experienced folding, uplift and erosion. Evidence from the study suggests that compression, uplift and erosion played an important role in the shaping of the depositional and structural architecture of the basin and caused formation of the regional Base Cretaceous Unconformity in the northern basin. It is suggested that the deformation in the northern Porcupine Basin during the latest Jurassic–earliest Cretaceous may be related to the initial closure of the Alpine Tethys during the late Tithonian. This tectonic event may also have resulted in compressional deformation and formation of the Base Cretaceous Unconformity elsewhere in Western Europe.

A new family of giant Jurassic-Cretaceous littorinoid gastropods from the northern Tethys shelf

The giant, up to 40 cm high littorinoid gastropods from the Middle Tithonian to Berriasian carbonates of the Alpine-Carpathian northern Tethys margin are assigned to the genus Leviathania. The genus is distributed from Spain to the Caucasus. Some species formed dense populations in the wide-spread, highly productive lagoonal environments situated on the carbonate platforms of Ernstbrunn (Austria), Mikulov, stramberk (both Czech Republic), and Nyzhniv (Ukraine). The conspicuous morphology, comprising very large shells with strongly angulated whorls and especially the phaneromphalous umbilicus exclude the traditional attributions of this genus to the families Purpurinidae and Purpuroideidae. Therefore, we establish the new family Leviathaniidae for the type genus Leviathania. The family comprises the largest pre-Cenozoic gastropods, represented by a yet unnamed gigantic Leviathania species from the latest Tithonian or early Berriasian of Ukraine. The gastropods are tentatively assumed to have fed omnivorous...

Strontium isotopic ages of the Torinosu-type limestones (latest Jurassic to earliest Cretaceous, Japan): Implication for biocalcification event in northwestern Palaeo-Pacific

The ages of the Late Jurassic to the Early Cretaceous shallow marine limestones in Japan (the Torinosu-type limestones) were evaluated by Sr isotopic stratigraphy. The 87Sr/86Sr ratios of 17 brachiopods collected from three sections revealed ages that are consistent with the previous assumption based on biostratigraphy. The age of the upper horizon of the Koike Limestone Member (the Soma-Nakamura Group, NE Japan) ranges from 150.6Ma to 149.2Ma (the latest Kimmeridgian to the early Tithonian). The limestones from two sections (the Torinosu and Imaidani Group) on Shikoku Island of SW Japan yield the younger ages, which evaluate the depositional rate of the two limestones 6.3–14.5m/m.y. By applying these rates, the depositional period was estimated for the whole limestone of each section; from 151.1Ma (the latest Kimmeridgian) to 140.3Ma (the latest Berriasian) for the Torinosu Group, from 151.5Ma (the late Kimmeridgian) to 143.0Ma (the early Berriasian) for the Imaidani Group. These results confirm active carbonate deposition in the shallow fore-arc platform in SW Japan from the Tithonian to the Berriasian. The biocalcification event recognized in relevant age in the Tethyan region was likely expanded to the Palaeo-Pacific. The carbonate deposition in the platform was terminated by sea level fall during the early Valanginian.

Early Berriasian ammonites from Shal, Talesh region (NW Alborz Mountains, Iran)

An early Berriasian ( Berriasella jacobi Zone) ammonite fauna is described for the first time from the Alborz Mountains in northwest Iran. It has been collected from a section located near the village of Shal (Talesh region); in addition to rare phylloceratids, lytoceratids and Neolissoceras, the majority of ammonites belong to the neocomitid subfamily Berriasellinae. With the exception of a new genus and species, Taleshites fuersichi, these taxa are common in European and North African Tethyan successions. Associated calpionellids confirm the early Berriasian age of the ammonite-bearing levels.

New information about the stratigraphic position and age of the sauropodAragosaurus ischiaticusfrom the Early Cretaceous of the Iberian Peninsula

AbstractThe sauropodAragosaurus ischiaticusSanz, Buscalioni, Casanovas & Santafé, 1987 was the first dinosaur to be described in Spain. The holotype was recovered from the site of Las Zabacheras (Galve, Teruel province). This site has traditionally been situated in the El Castellar Formation (in the lower part of the Wealden facies). Recently, it has been proposed that the remains ofAragosaurusstem from the Villar del Arzobispo Formation (late Tithonian–upper part of the early Berriasian), which would mean that the sauropod was almost 15 million years older than previously thought. Detailed field work has been carried out, making it possible to pinpoint the position of the low-angle unconformity between the Villar del Arzobispo Formation and the El Castellar Formation. This unconformity originated as a result of block tilting that occurred during the early stages of the Early Cretaceous rifting episode. The upper levels of the Jurassic sequence (i.e. the Villar del Arzobispo Formation) were exposed to erosion and karstification, leading to the formation of a discontinuous conglomeratic level. This level has been locally preserved at the bottom of the Wealden syn-rift sequence (i.e. the El Castellar Formation). The results of our detailed mapping demonstrate that theAragosaurusholotype was found in the lower part of the El Castellar Formation. Moreover, our revision of the existing datings suggests that the El Castellar Formation as a whole is Valanginian?–early Barremian in age. Given thatAragosauruswas located in its lower part, it is probably Valanginian?–Hauterivian in age.

New evidence of a herd of titanosauriform sauropods from the lower Berriasian of the Iberian range (Spain)

A study of the undescribed part of the Las Cerradicas tracksite in Galve (Teruel, Spain) has revealed 6 trackways made by small sauropods showing gregarious behaviour (parallel trackways). Las Cerradicas is located towards the top of the Villar del Arzobispo Formation (early Berriasian). The wide-gauge condition, the manus–pes distance, the kidney-shaped morphology of the manus, and the subtriangular morphology of the pes (with a big digit I that swells medially and a narrow heel oriented posterolaterally) suggest that the sauropods in question are more similar to Sauropodichnus giganteus than to any other sauropod ichnotaxa. Some of the features point to the titanosauriforms as the best candidates to be the trackmakers. Recent work in bone histology, the differences with respect to other Iberian tracksites of similar age, and the differences with respect to other sauropod herds of the track record, do not allow us to establish whether the sauropods were juvenile or dwarfs. The sauropod skeletal record and other large sauropod footprints in the Villar del Arzobispo Formation could tip the scales in favour of the first hypothesis.