Corals from the Tithonian carbonate complex in the Dąbrowa Tarnowska-Szczucin area (Polish Carpathian Foreland)

The studied corals have been collected from cores of boreholes located in the central part of the Polish Carpathian Foreland in the Dąbrowa Tarnowska–Szczucin area. The Jurassic complex in this area presents a continuous stratigraphic section from the Upper Callovian to Tithonian, locally passing to the Lower Cretaceous (Berriasian). Its thickness exceeds 1,100 m in this area. This complex is composed of marine, mainly shallow-water deposits. The corals occur within the upper part of the Upper Jurassic (Tithonian) deposits, almost entirely within the Swarzów Limestone Formation (= coral-algal limestone formation). This occurrence marks the northernmost extent of Tithonian shallow-water corals in Poland and one of the northernmost in Europe. 42 coral species (among them 14 in open nomenclature) were identified in deposits of this formation. They include two new species: Complexastrea magna and Complexastrea dabroviensis. All taxa, except one, belong to the order Scleractinia. The described assemblage displays a Late Jurassic character. The broader stratigraphic span is assigned to some species, which are quoted from the Middle Jurassic and some species lasted until the Early Cretaceous, Berriasian and/or Valanginian

Environmental and climatic proxies for the Cañadón Asfalto and Neuquén basins (Patagonia, Argentina): review of middle to upper jurassic continental and near coastal sequences

In this review, we include several proxies (sedimentology, palynology, invertebrates) from the Cañadón Asfalto and Neuquén basins, to infer the environments and regional climatic context during the Middle to Late Jurassic of Patagonia. In central Patagonia, early in the Middle Jurassic, and associated with a magmatic arc, began the sedimentary fi lling of Jurassic continental sub-basins in the Cañadón Asfalto Basin. Lacustrine and fl uvio-deltaic sediments, bearing a continental Middle Jurassic palynobiota, correspond to the Las Chacritas Member, while the sediments and palynobiota from the Late Jurassic Puesto Almada Member (both in the Cañadón Asfalto Formation) indicate a palustrine wetland subenvironment immersed within an arid macroenvironment. Paleoinvertebrates (conchostracans and sponges) of this formation suggest wet-dry cycles in the water bodies they inhabited. The sedimentological information together with the continental and coastal palynomorph assemblages of the back arc Neuquén Basin, allowed distinguishing a complete regressive-transgressive sequence for the Middle Jurassic Lajas Formation. For the Upper Jurassic in this basin, the thick gypsum and anhydrite deposits of the evaporitic coastal Auquilco Formation correlate with extended deposits of eolian sandstones corresponding to the Botucatú paleodesert, and a saltmarsh environment is inferred from the palynofl ora. The palynologic associations from both basins indicate a regional warm climate with seasonal aridity. Climatic conditions would have been drier in the continental interior (Cañadón Asfalto Basin), with strongly seasonally distributed temperatures, and moister in the western coast of the continent (Neuquén Basin), during the marine transgressions.Na presente revisão foram incluídos vários proxies (sedimentologia, palinologia, invertebrados), das bacias de Cañadón Asfalto e Neuquén, para inferir o contexto climático regional e ambiental durante o Jurássico Médio e Superior da Patagônia. Na região central da Patagônia, no início do Jurássico Médio, e associado a um arco magmático, começou o preenchimento sedimentar de sub-bacias continentais jurássicas na bacia Cañadón Asfalto. Os sedimentos flúvio-deitaico e lacustres, tendo uma palinobiota continental do Jurássico Médio correspondente ao Membro Las Chacritas, enquanto os sedimentos e a palinobiota do Jurássico Superior do Membro Puesto Almada (ambos na Formação Cañadón Asfalto) indicam um subambiente palustre úmido imerso em um macroambiente árido. Os paleoinvertebrados (conchostráceos e esponjas) desta formação sugerem ciclos úmidos-secos nos corpos de água por eles habitados. A informação sedimentológica juntamente com as assembleias de palinomorfos continentais e costeiros do “back arc” da bacia Neuquén permitiu distinguir uma sequência completa regressiva-transgressiva para o Jurássico Médio da Formação Lajas. Para o Jurássico Superior, os depósitos de anidrita e gesso espessos da Formação Auquilco costeira evaporítica correlacionam-se com depósitos extensos de arenitos eólicos correspondentes ao paleodeserto Botucatu. Um ambiente “saltmarsh” é inferido a partir da palinoflora. As associações palinológicas de ambas as bacias indicam um clima regional quente com aridez sazonal. As condições climáticas teriam sido mais secas no interior continental (bacia Cañadón Asfalto), com temperaturas fortemente distribuídas de forma sazonal, e úmidas na costa ocidental do continente (bacia de Neuquén), durante as transgressões marinhas.Fil: Volkheimer, Wolfang. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Quattrocchio, Mirta Elena. Universidad Nacional del Sur. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabaleri, Nora Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Narvaez, Paula Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Rosenfeld, U.. Westfälische Wilhelms-universität Münster; AlemaniaFil: Scafati, Laura Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Melendi, Daniel Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentin

El volcanismo jurásico superior de la Formación Río Damas-Tordillo (33°-35,5°S): antecedentes su sobre petrogénesis, cronología, proveniencia e implicancias tectónicas

Los depósitos continentales y volcánicos de la Formación Rio Damas-Tordillo, Jurásico Superior, representan un período restringido de sedimentación continental dentro del registro mayormente marino de la Cuenca Neuquina. Datos anteriores y los presentados en este trabajo, sugieren que el cambio a un estado de mayor acoplamiento entre placas durante el Jurásico tardío (160-140 Ma), sumado a la continua efusión de material volcánico, resultaron en una progresiva emersión del dominio de arco y ante arco, para finalmente desconectar a la cuenca de tras-arco del Océano Pacífico. Este importante cambio en la configuración del margen tuvo como resultado el desarrollo de una regresión marina y posterior sedimentación continental con aportes desde el oeste, en una cuenca de tras-arco de tipo hemigraben. Una edad máxima de depositación de 146,4±4.4 Ma obtenida en la parte superior de la secuencia sedimentaria, sugiere que los potentes depósitos de volcanismo asociado a subducción, observados en la parte superior de la unidad, fueron eruptados en un período de tiempo muy restringido, lo cual probablemente fue facilitado por la presencia de estructuras extensionales relacionadas con el desarrollo de la cuenca de tras-arco. Datos geoquímicos elementales e isotópicos, junto con modelamientos de ACF, sugieren un manto astenosférico deprimido como fuente del material ígneo, y el fraccionamiento de olivino y plagioclasa, combinado con pequeños volúmenes de asimilación de corteza inferior, como los principales procesos involucrados en la evolución de los magmas. No es posible diferenciar, en términos geoquímicos, la fuente y procesos petrogenéticos del volcanismo Jurásico reconocido en la Cordillera de la Costa y el de la Formación Río Damas-Tordillo.The uppermost Jurassic continental and volcanic deposits of the Río Damas-Tordillo Formation represent an interval of intense continental deposition within the Jurassic to Early Cretaceous dominantly marine environment of the Mendoza-Neuquén back-arc basin. Stratigraphic and geochronological data indicate that progressive emersion of the arc and forearc domain, disconnecting the back-arc region from the Pacific Ocean, occurred during occurred during the Late Jurassic and probably the Early Cretaceous (~160-140 Ma). This change in the margin configuration induced a marine regression and the subsequent deposition of continental material in the back-arc basin. The most likely source of the sediments would have been the Jurassic arc, located west of the back-arc basin. The maximum depositional age of 146.4±4.4 Ma obtained from a red sandstone immediately below volcanic rocks confirms recent Tithonian maximum depositional ages assigned to the Río Damas-Tordillo Formation, and suggests that the volcanic rocks, overlain by marine fossiliferous Tithoninan-Hauterivian sequences, should have erupted within a short time span during the Late Jurassic. Volcanism was probably facilitated by the presence of extensional structures related to the formation of the back-arc basin. Elemental and isotopic data, along with forward AFC models, suggest a depleted sub-arc asthenospheric mantle source for the volcanic rocks and the fractionation of olivine and plagioclase, along with small volumes of lower crust assimilation, as the main processes involved in the magmatic evolution. It is not possible to establish a different source and petrogenetic conditions for the Río Damas-Tordillo Formation and the magmatism in the arc domain located further west, at the present-day Coastal Cordillera.Fil: Rossel, Pablo. Universidad de Concepción; ChileFil: Oliveros, Verónica. Universidad de Concepción; ChileFil: Mescua, Jose Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Tapia, Felipe. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas. Departamento de Geología; ChileFil: Ducea, Mihai Nicolae. University of Arizona; Estados UnidosFil: Calderón, Sergio. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas. Departamento de Geología; ChileFil: Charrier González, Reynaldo. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas. Departamento de Geología; ChileFil: Hoffman, Derek. University of Arizona; Estados Unido

Detrital events within pelagic deposits of the Umbria-Marche basin (Northern Apennines, Italy). Further evidence of Early Cretaceous tectonics

Re-sedimented deposits characterize different stratigraphical intervals in the pelagic successions of the Umbria-Marche-Sabina Domain (Central and Northern Apennines, Italy). Three stratigraphic sections of the Maiolica and Marne a Fucoidi Formations, characterized by breccias and calcarenites embedded in pelagic sediments, were sampled across the Mt. Primo area (Umbria- Marche Ridge, Northern Apennines). Facies analysis indicates a gravity-driven origin for the clastic levels, interpreted as debris-flows, or turbidity flows. The massive lensoid-to-tabular levels are composed of loose shallow-water benthic material, sourced from an unknown carbonate platform, associated with: i) lithoclasts made of Lower Jurassic and Lower Cretaceous shallow-water carbonates; ii) Jurassic mudstones and wackestones referable to the pelagic succession; iii) calpionellid/radiolarian-rich soft pebbles (Maiolica-type facies). The compositional features of the studied detrital deposits imply submarine exposure and dismantling of portions of the stratigraphic succession older than the Barremian/Aptian, which had to be buried in the late Early Cretaceous. Such evidence led us to refer the investigated clastic event to an extensional tectonic phase. Our interpretation well fits with data coming from different geological settings of Italy, strongly suggesting the occurrence of a widespread extensional phase in the late Early Cretaceous

Geological structure and evolution of the Pieniny Klippen Belt to the east of the Dunajec River : a new approach (Western Outer Carpathians, Poland)

The area studied, known as the Małe (Little) Pieniny Mts., belongs to the Pieniny Klippen Belt (PKB), a suture zone that separates the Central Carpathians from the Outer Carpathian accretionary wedge. Along its northern boundary the PKB is separated from the Paleogene to Early Miocene flysch deposits of the Magura Nappe by a narrow, strongly deformed belt belonging to the Grajcarek tectonic Unit. This unit is composed of Jurassic, Cretaceous and Paleocene pelagic and flysch deposits. The Klippen units of the PKB are represented by Jurassic–Lower Cretaceous carbonate deposits overlain by Upper Cretaceous variegated marls and flysch deposits. We describe geological and biostratigraphic evidence concerning the palaeogeographic, stratigraphic and structural relationships between the Pieniny Klippen Belt and the Magura Nappe, that significantly modify previously held views on the evolution of the Małe Pieniny Mts. and the Polish sector of the PKB

JURASSIC PALEONTOLOGICAL HERITAGE OF MURCIA (BETIC CORDILLERA, SOUTH-EASTERN SPAIN)

Jurassic rocks of the External and Internal Zones of the Betic Cordillera are widespread in the province of Murcia. Four areas are considered of special interest for stratigraphical and paleontological analysis: a) Sierra Quípar and b) Sierras Lúgar-Corque (External Subbetic), c) Sierra Ricote (Median Subbetic) and d) Sierra Espuña (Malaguide Complex). The first two contain Jurassic sections including Sinemurian-Tithonian deposits, and major stratigraphic discontinuities, containing significant cephalopod concentrations of taphonomic and taxonomic interest, occuring in the Lower-Upper Pliensbachian, Lower/Middle Jurassic and Middle/Upper Jurassic boundaries. These areas are also relevant for biostratigraphical analysis of the Middle-Upper Jurassic interval. In the Sierra de Ricote, the Mahoma section is of especial interest for the study of Lías/Dogger transition. Casa Chimeneas section constitutes the best Subbetic site for the analysis of the Lower/Upper Bajocian boundary. In the La Bermeja-Casas de Vite area, the Bajocian-Tithonian interval is well-represented, including a parastratotype of the Radiolarite Jarropa Formation. Finally, the Malvariche section in Sierra Espuña represents the best Jurassic succession of Internal Zones of the Betic Cordillera and could be considered as a reference section for this Betic Domain. In this paper a heritage evaluation has been carried out for these classical jurassic sections with the object of protecting these sites according to the legal framework prevailing in the province of Murcia

Quantification of a distributive fluvial system; the Salt Wash DFS of the Morrison Formation, SW USA

Peer reviewedPostprin

Geology of the Mt. Cosce sector (Narni Ridge, Central Apennines, Italy)

This paper is companion to a 1:15,000 scale geological map of the southern sector of the Narni Range in Central Italy. This sector of the Apenninic Chain was affected by the western Tethyan rifting stage during the Early Jurassic, and the inherited architectural setting in turn influenced the Mesozoic stratigraphy and the Neogene-Quaternary tectonic evolution of the area. Based on stratigraphic and structural field evidence, a Jurassic structural high has been identified in the Mt. Cosce sector, flanked northward and westward by deeper basins. The basin that had to exist to the east, as well as the top of the horst-block, cannot be observed due to recent erosion and orogenic deformation. The western margin of the Mt. Cosce High was rejuvenated during an extensional tectonic phase which took place in the late Early Cretaceous. This synsedimentary faulting is reported in this area for the first time, and is documented by a sedimentary breccia (Mt. Cosce Breccia) resting unconformably on the Jurassic footwall-block