83 research outputs found
In situ study of magmatic processes: a new experimental approach
We present an internally heated autoclave, modified in order to allow in situ studies at pressure up to 0.5 GPa and temperature up to 1000°C. It is equipped with transparent sapphire windows, allowing the observation of the whole experiment along the horizontal axis. In the experimental cell the sample is held between two thick transparent plates of sapphire or diamond, placed in the furnace cylinder. The experimental volume is about 0.01 cm3. Video records are made during the whole experiment. This tool is developed mainly to study magmatic processes, as the working pressures and temperatures are appropriate for subvolcanic magma reservoirs. However other applications are possible such as the study of subsolidus phase equilibria as we have used well known phase transitions, such as the system of AgI, to calibrate the apparatus with respect to pressure and temperature. The principle of the apparatus is detailed. Applications are presented such as studies of melt inclusions at pressure and temperature and an in situ study of magma degassing through the investigation of nucleation and growth processes of gas bubbles in a silicate melt during decompression
A plesiosaur containing an ichthyosaur embryo as stomach contents from the Sundance Formation of the Bighorn Basin, Wyoming
Herein we report the discovery of an ichthyosaur embryo from the Upper Member of the Sundance Formation (Oxfordian) of the Bighorn Basin, Wyoming. The specimen is the first known ichthyosaur embryo from the Upper Jurassic, and is the first Jurassic ichthyosaur embryo from North America. The embryo was discovered in close association with the abdomen of an articulated partial plesiosaur skeleton, and several lines of evidence support the interpretation of the embryo as plesiosaur stomach contents. The small size and extremely poor ossification of the embryo indicate that the animal was probably not a neonate. Although the taxonomic affinities of the fossil are unknown, the large ichthyosaurian (sensu stricto) Opthalmosaurus natans is the only known ichthyosaur from the Sundance Formation, and the embryo may belong to that taxon
magma and volatile supply to post collapse volcanism and block resurgence in siwi caldera tanna island vanuatu arc
V24C-04. Allen, S. R. (2005). Complex spatterand pumice-rich pyroclastic deposits from an andesitic caldera forming eruption: The Siwi pyroclastic sequence, Tanna, Vanuatu. Bulletin of Volcanology 67
Short-Snouted Toothless Ichthyosaur from China Suggests Late Triassic Diversification of Suction Feeding Ichthyosaurs
Ichthyosaurs were an important group of Mesozoic marine reptiles and existed
from the Early Triassic to the early Late Cretaceous. Despite a great
diversity in body shapes and feeding adaptations, all share greatly enlarged
eyes, an elongated rostrum with numerous conical teeth, and a streamlined
body.. may be linked to the Late
Triassic minimum in atmospheric oxygen
New insights on the systematics, palaeoecology and palaeobiology of a plesiosaurian with soft tissue preservation from the Toarcian of Holzmaden, Germany
© Springer-Verlag Berlin Heidelberg 2017. The attached document is the author’s submitted version of the journal article. You are advised to consult the publisher’s version if you wish to cite from it. The final publication is available at Springer via http://dx.doi.org/10.1007/s00114-017-1472-
Experimental crystal growth in glass inclusions: the possibilities and limits of the method
Phonolitic origin of Roque-Nublo ignimbrites of Gran-Canaria (Canary-Islands, Spain) from clinopyroxene melt inclusion studies
The Roque Nublo non-welded ignimbrites - which are Pliocene in age (5-3.5 Ma.) - are characteristic deposits of the second magmatic cycle on Gran Canaria. They are very heterogeneous, with 30-50 % volume lithic fragments, 15-20 % mildly vesiculated pumice, 5-10 % phenocrysts and 30-40 % ash matrix. The juvenile materials (pumice fragments and ash matrix) are largely altered to zeolites. A melt inclusion study using microthermometric and electron-microprobe analyses was carried out on clinopyroxenes from Roque Nublo ignimbrites. The chemical composition of melt inclusions indicates that the original melt prior to the eruptions that formed the ignimbritic Roque Nublo deposits was phonolitic in composition.106978SCI
A new Barremian (Early Cretaceous) ichthyosaur from western Russia
A new ophthalmosaurid ichthyosaur, Sveltonectes insolitus gen. et sp. nov., is
described from a sub-complete and three-dimensionally preserved specimen from the late
Barremian of western Russia. This new taxon is supported by 11 cranial, dental, and
postcranial autapomorphies, and is also characterized by features previously considered as
autapomorphic for some other Ophthalmosauridae, such as a processus narialis on the
prefrontal and relatively long hindfins with pre- and postaxial accessory digits. We conducted
a new phylogenetic analysis of Thunnosauria, which supports a ‘Stenopterygius-origin’ for
Ophthalmosauridae. Sveltonectes is regarded as the sister taxon of Aegirosaurus, which shares
a similar skull roof construction. Contrary to most other Cretaceous ichthyosaurs,
Sveltonectes is characterized by delicate and sharply pointed teeth, confirming that the
Ophthalmosauridae were ecologically highly diversified during the Early Cretaceou
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