scholarly journals Large dasycladalean algae from Upper Jurassic limestone deposits of the Apuseni Mountains (Romania) — habitat and depositional environment

Geodiversitas ◽  
2012 ◽  
Vol 34 (1) ◽  
pp. 219-239 ◽  
Author(s):  
Ioan I. Bucur ◽  
Emanoil Săsăran
Keyword(s):  
Depositional Environment ◽  
Upper Jurassic ◽  
Apuseni Mountains ◽  
Jurassic Limestone

scholarly journals The taphonomy of dinosaurs from the Upper Jurassic of Tendaguru (Tanzania) based on field sketches of the German tendaguru expedition (1909–1913)

Fossil Record ◽  
1999 ◽  
Vol 2 (1) ◽  
pp. 25-61 ◽  
Author(s):  
W.-D. Heinrich
Keyword(s):  
Old Age ◽  
Late Jurassic ◽  
Depositional Environment ◽  
Upper Jurassic ◽  
Skeletal Remains ◽  
Time Span ◽  
Post Mortem ◽  
Seasonal Drought ◽  
Long Time

Tendaguru is one of the most important dinosaur localities in Africa. The Tendaguru Beds have produced a diverse Late Jurassic (Kimmeridgian to Tithonian) dinosaur assemblage, including sauropods (<i>Brachiosaurus, Barosaurus, Dicraeosaurus, Janenschia</i>), theropods (e.g., <i>Elaphrosaurus, Ceratosaurus, Allosaurus</i>), and ornithischians (<i>Kentrosaurus, Dryosaurus</i>). Contrary to the well studied skeletal anatomy of the Tendaguru dinosaurs, the available taphonomic information is rather limited, and a generally accepted taphonomic model has not yet been established. Assessment of unpublished excavation sketches by the German Tendaguru expedition (1909–1913) document bone assemblages of sauropod and ornithischian dinosaurs from the Middle Saurian Bed, Upper Saurian Bed, and the Transitional Sands above the <i>Trigonia smeei</i> Bed, and shed some light on the taphonomy of the Tendaguru dinosaurs. Stages of disarticulation range from incomplete skeletons to solitary bones, and strongly argue for carcass decay and post-mortem transport prior to burial. The sauropod bone accumulations are dominated by adult individuals, and juveniles are rare or missing. The occurrence of bones in different superimposed dinosaur-bearing horizons indicates that skeletal remains were accumulated over a long time span during the Late Jurassic, and the majority of the bone accumulations are probably attritional. These accumulations are likely to have resulted from long-term bone imput due to normal mortality events caused by starvation, seasonal drought, disease, old age and weakness. The depositional environment of the Middle and Upper Saurian Bed was mainly limnic to brackish in origin, while the palaeoenvironment of the Transitional Sands was marginal marine. <br><br> Tendaguru zählt zu den bedeutendsten Dinosaurier-Lagerstätten Afrikas. Aus den Tendaguru-Schichten sind zahlreiche Skelettreste von Sauropoden (<i>Brachiosaurus, Barosaurus, Dicraeosaurus, Janenschia</i>), Theropoden (z.B. <i>Elaphrosaurus, Ceratosaurus, Allosaurus</i>) und Ornithischiern (<i>Kentrosaurus, Dryosaurus</i>) geborgen worden. Sie stammen aus der späten Jura-Zeit (Kimmeridge — Tithon). Während der Skelettbau der Tendagurusaurier gut untersucht ist, wirft die Taphonomie des Sauriervorkommens von Tendaguru noch immer Fragen auf. Unklar ist bislang, wie die enormen Anreicherungen von Dinosaurierknochen in den Tendaguru-Schichten zustandekamen. Unveröffentlichte Grabungsskizzen der Deutschen Tendaguru Expedition (1909–1913) erweitern unsere Kenntnisse über die Taphonomie der Tendagurusaurier. In den ausgewerteten Grabungsskizzen sind Knochenansammlungen von Sauropoden und Ornithischiern aus dem Mittleren und Oberen Sauriermergel sowie aus den Übergangsschichten über der <i>Trigonia smeei</i>-Schicht dokumentiert. Die Lage und der Erhaltungszustand der Funde lassen auf erheblichen Zerfall der Kadaver und post-mortalen Transport von Skelettelementen vor der Einbettung schließen. Das Vorkommen von Saurierknochen in mehreren übereinanderliegenden Profilabschnitten der Tendaguru-Schichten zeigt, daß Skelettreste während der späten Jura-Zeit über einen längeren Zeitraum hinweg akkumuliert wurden. Die Ansammlungen von Skelettresten gehen wahrscheinlich auf „normale” Sterbe-Ereignisse zurück, wie z. B. Verhungern, Verdursten, Kankheit, Altersschwäche und jahreszeitliche Dürre. Als Ablagerungsraum der Mittleren und Oberen Saurierschicht kommt ein küstennaher limnischer, zeitweise wohl auch brackischer Küstenstreifen in Betracht. Die knochenführenden Übergangsschichten unter- und oberhalb der Saurierschichten sind randlich marine Ablagerungen. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.1999.4860020102" target="_blank">10.1002/mmng.1999.4860020102</a>

A propos de l'age de la serie ophiolitique dans les Dinarides yougoslaves; la coupe de Mihajlovici aux confins de la Serbie et du Montenegro (region de Plevlja, Yougoslavie)

1964 ◽  
Vol S7-VI (1) ◽  
pp. 107-112 ◽  
Author(s):  
Jean Aubouin ◽  
Jean Paul Cadet ◽  
Jean Paul Rampnoux ◽  
Gonzague Dubar ◽  
Pierre Marie
Keyword(s):  
Upper Jurassic ◽  
Lower Jurassic ◽  
Jurassic Limestone

Abstract The Mihajlovici area in southwestern Yugoslavia is a mosaic of fault blocks produced by two sets of large faults, trending NW and NE. The horsts are lower Jurassic limestone, and the grabens are occupied by diabase-radiolarite, known as the ophiolitic series, of lower Malm age (upper Jurassic). Abundant ammonites and microfauna identify several horizons, notably the Toarcian (upper Lias, i.e., lower Jurassic) and the uppermost bed of the lower Malm, thus fixing the Malm age of the ophiolitic series.

An Early Cretaceous (Berriasian) fossil-bearing locality from the Rocky Mountains of Alberta, yielding the oldest dinosaur skeletal remains from western Canada

2020 ◽  
Vol 57 (4) ◽  
pp. 542-552 ◽  
Author(s):  
Ramon S. Nagesan ◽  
James A. Campbell ◽  
Jason D. Pardo ◽  
Kendra I. Lennie ◽  
Matthew J. Vavrek ◽  
...  
Keyword(s):  
North America ◽  
Early Cretaceous ◽  
Depositional Environment ◽  
Upper Cretaceous ◽  
Upper Jurassic ◽  
High Energy ◽  
Western Canada ◽  
Western North America ◽  
Terrestrial Vertebrate ◽  
Overlying Strata

Western North America preserves iconic dinosaur faunas from the Upper Jurassic and Upper Cretaceous, but this record is interrupted by an approximately 20 Myr gap with essentially no terrestrial vertebrate fossil localities. This poorly sampled interval is nonetheless important because it is thought to include a possible mass extinction, the origin of orogenic controls on dinosaur spatial distribution, and the origin of important Upper Cretaceous dinosaur taxa. Therefore, dinosaur-bearing rocks from this interval are of particular interest to vertebrate palaeontologists. In this study, we report on one such locality from Highwood Pass, Alberta. This locality has yielded a multitaxic assemblage, with the most diagnostic material identified so far including ankylosaurian osteoderms and a turtle plastron element. The fossil horizon lies within the upper part of the Pocaterra Creek Member of the Cadomin Formation (Blairmore Group). The fossils are assigned as Berriasian (earliest Cretaceous) in age, based on previous palynomorph analyses of the Pocaterra Creek Member and underlying and overlying strata. The fossils lie within numerous cross-bedded sandstone beds separated by pebble lenses. These sediments are indicative of a relatively high-energy depositional environment, and the distribution of these fossils over multiple beds indicates that they accumulated over multiple events, possibly flash floods. The fossils exhibit a range of surface weathering, having intact to heavily weathered cortices. The presence of definitive dinosaur material from near the Jurassic–Cretaceous boundary of Alberta establishes the oldest record of dinosaur body fossils in western Canada and provides a unique opportunity to study the Early Cretaceous dinosaur faunas of western North America.

scholarly journals [MnO|SiO2,Al2O3,FeO,MgO] balanced log-ratio in chlorites: a tool for chemo-stratigraphic mapping and proxy for the depositional environment

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 351-375
Author(s):  
Annette Süssenberger ◽  
Solveig Pospiech ◽  
Susanne Theodora Schmidt
Keyword(s):  
Depositional Environment ◽  
Regional Metamorphism ◽  
Upper Jurassic ◽  
Contact Metamorphism ◽  
Low Grade ◽  
Rock Composition ◽  
Magallanes Basin ◽  
Global Sea Level ◽  
Rock Analysis ◽  
Log Ratio

ABSTRACTThe [MnO|SiO2,Al2O3,FeO,MgO] balanced ratio (i.e. the isometric log-ratio of the MnO concentration relative to the concentration of SiO2, Al2O3, FeO and MgO) of chlorite and of whole-rock composition is an effective discriminant between Mesozoic stratigraphic formations in the Magallanes Basin (Chile). The MnO content in chlorite is only controlled by the host rock chemistry and is dependent on the geological environment. The MnO content in chlorite remains unchanged at low-grade metamorphic conditions. Single-grain chlorite analysis (n = 1042, electron microprobe) and whole-rock analysis (n = 40, X-ray fluorescence) were used to discriminate stratigraphic formations and to decipher differences in the depositional environment in the Magallanes Basin. The samples are from one Upper Jurassic and three Cretaceous sedimentary units that were affected either by low-grade regional metamorphism or by Miocene contact metamorphism. The highest [MnO|SiO2,Al2O3,FeO,MgO] values are recorded in the upper Zapata Formation. The Punta Barrosa, Cerro Toro and Tobífera Formations show slightly lower [MnO|SiO2,Al2O3,FeO,MgO] values. Elevated [MnO|SiO2,Al2O3,FeO,MgO] values at the transition between Zapata and Punta Barrosa Formations record an oxygenated shallow marine environment that can be linked to the closure of the Rocas Verdes Basin and the onset of fold-and-thrust belt formation. Decreasing [MnO|SiO2,Al2O3,FeO,MgO] values from the Punta Barrosa towards the Cerro Toro Formation indicate gradually increasing water depths during the Upper Cretaceous that correlate well with the global sea level.

scholarly journals An Upper Jurassic ichthyosaur (Ichthyosauria: Ophthalmosauridae) from the Bowser Basin, British Columbia

2016 ◽  
Vol 53 (1) ◽  
pp. 34-40
Author(s):  
Robin L. Sissons ◽  
Michael W. Caldwell ◽  
Carol A. Evenchick ◽  
Donald B. Brinkman ◽  
Matthew J. Vavrek
Keyword(s):  
British Columbia ◽  
Body Size ◽  
Late Jurassic ◽  
Body Shape ◽  
Depositional Environment ◽  
Upper Jurassic ◽  
Generic Level ◽  
Shallow Marine ◽  
Northwestern North America ◽  
High Diversity

Although the Jurassic was a period of high diversity in ichthyosaurs, only a small number of specimens have been recorded from Canada to date. We describe here a new occurrence of an ophthalmosaurid ichthyosaur from a shallow marine depositional environment within the Bowser Basin of northern British Columbia. Based on vertebral diameters and the size of the humerus, the ichthyosaur was relatively large compared to other contemporaneous forms, yet possessed teeth that were small for its body size. As well, the height to length ratio of the preserved vertebrae suggests it may have had a more elongate, less regionalized body shape. Although indeterminate at a generic level, the presence of Late Jurassic ichthyosaurs in nearshore waters of northwestern North America further demonstrates their cosmopolitan distribution.

Solnhofener Plattenkalk: a heritage stone of international significance from Germany

2019 ◽  
Vol 486 (1) ◽  
pp. 103-113 ◽  
Author(s):  
M. Kölbl-Ebert ◽  
B. J. Cooper
Keyword(s):  
Eighteenth Century ◽  
Upper Jurassic ◽  
High Price ◽  
Natural History Museums ◽  
Early Bird ◽  
History Museums ◽  
Floor Tiles ◽  
The World ◽  
Jurassic Limestone ◽  
Solnhofen Limestone

AbstractIn Bavaria (Germany), between Solnhofen and Kelheim, numerous quarries allow utilization of a thinly plated Upper Jurassic limestone known in German as the Solnhofener Plattenkalk and in English as Solnhofen Limestone. Here limestone slabs have been quarried for centuries and it is not necessary to cut the limestone with a saw as it can be split conveniently into thin and even slabs or sheets which are used for floor tiles and wall cladding. Thick slabs of especially fine quality have been used for lithography. This later utilization began in the late eighteenth century with lithographic Solnhofen Limestone soon being marketed worldwide. The industry continues on a smaller scale today. Slabs are quarried by hand so as not to break them, accounting for their high price. Because of this ‘gentle’ quarrying method, fossils have also been found. Although rare, over time many Solnhofen fossil specimens have found their way into natural history museums throughout the world. Most noteworthy is the early bird Archaeopteryx. Given its utilitarian usage worldwide as a lithographic stone, and its sale for centuries as floor tiles, coupled with its being a source of unique fossils, Solnhofener Plattenkalk is recommended here as a Global Heritage Stone Resource.

Recherche d'eau dans les vallees seches; probleme typique de Sacy (Yonne) [with discussion]

1957 ◽  
Vol S6-VII (7) ◽  
pp. 929-935
Author(s):  
Claude Megnien
Keyword(s):  
Electrical Resistivity ◽  
Ground Water ◽  
Upper Jurassic ◽  
The Other ◽  
Paris Basin ◽  
Dry Valley ◽  
Jurassic Limestone

Abstract Combined geologic and geophysical (electrical resistivity) surveys in the dry valley of Sacy, Yonne, France, led to the discovery of two subsurface aquifers, one in the eluvial cover, the other in deeply weathered Rauracian (Jurassic) limestone. This type of exploration is considered suitable for ground-water investigations in the upper Jurassic plateaus of the Paris basin.

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