Search results for "Facie"
showing 10 items of 297 documents
LA-ICP-MS U–Pb dating of detrital rutile and zircon from the Reynolds Range: A window into the Palaeoproterozoic tectonosedimentary evolution of the …
2014
Abstract The Palaeoproterozoic Reynolds Range of the Arunta Region, central Australia, comprises a series of shallow marine clastic sediments (Reynolds Range Group) which overlies deeper water sequences of turbidites (Lander Rock Formation) and minor sandstones (“unnamed sandstone”). U–Pb age data collected from detrital rutile and zircon in these rocks indicates these sequences contain very similar age spectra, although with a notable and important shift to younger ages within the stratigraphically younger Reynolds Range Group. Detrital zircons from the “unnamed sandstone” directly underlying the unconformity with the Reynolds Range Group contain a major age component at ca. 1860 Ma, toget…
The Residual Shear Strength of the Shaly and Sandy Facies of the Opalinus Clay
2018
The paper presents a comprehensive laboratory campaign carried out with the aim to asses the residual strength of the Opalinus Clay. Ring shear tests with vertical effective stress up to 1 MPa were performed on remoulded samples of two different facies of the Opalinus Clay. Test results show that the «Shaly» facies is characterized by a low range of variation of residual strength while the strength of the «Sandy» facies is very sensitive to the variation of grain size distribution. Microstructural analyses (SEM) suggest that the difference in the observed mechanical behavior of the two facies can be related to different particles arrangements along the shear surfaces.
Multifactorial control of sedimentation patterns in an ocean marginal basin: the Lusitanian Basin (Portugal) during the Kimmeridgian and Tithonian
1987
The Mesozoic Lusitanian Basin developed as a part of the North Atlantic rift system. Tectonic rifting activity was rejuvenated during the Upper Jurassic, leading to intensive differentiation of facies development. Kimmeridgian and Lower Tithonian calcareous and siliciclastic sediments represent basinal and slope, shallow marine, and terrestrial environments. The lithostratigraphic arrangement of facies units is demonstrated. Sediment character, distribution and thicknesses are mainly controlled by synsedimentary faulting, with a partial overprint by uprise of salt diapirs. Eustatic sea level fluctuations, exogenic and biogenic factors resulted in additional control on facies development.
Biogeography of the Pleistocene pleniglacial malacofaunas in Europe. Stratigraphic and climatic implications
1990
Abstract As determined by Lozek, malacological associations are significant of a particular vegetal environment. In Quaternary sequences, different types of associations are recognized which can be assimilated to the present types of malacofaunas. There are associations of grass group, of forest group and of the ecotone of these two biogeographical entities. On the European scale, in Pleistocene sequences, the interglacial faunas indicate similarly the same differences as today, being of stratigraphic interest. On the contrary, pleniglacial faunas, which are mainly preserved in the loess belt, seemed not interesting for stratigraphy since they indicate more generalized and more homogeneous …
On the interpretation of retrograde reaction textures in granulite facies rocks
2010
Retrograde reaction textures, such as partial pseudomorphs, coronae and symplectic coronae are a relatively common feature of granulite facies rocks and represent evidence of change of mineral modes or assemblages. Thus, such reaction textures represent one of the more potentially useful indicators of retrograde P-T evolutions. However, the interpretation of such textures requires the simultaneous consideration of the formation of the texture itself in terms of the spatial relationships in a rock, and of the changes in P-T conditions that drove the development of the reaction texture. Calculated phase diagrams provide a robust framework in which to consider reaction textures, especially via…
Inner vs. outer wedge-top depozone “sequences” in the Late Miocene (late Tortonian–early Messinian) Sicilian Foreland Basin System; new data from the…
2012
Abstract The wedge-top depozone belongs to the innermost portion of a Foreland Basin System (FBS) ( DeCelles and Giles, 1996 ) and includes all sediments, typically coarse-grained proximal facies, that bury the active frontal part of a fold and thrust belt. The Terravecchia Formation ( Flores, 1959 , Schmidt Di Friedberg, 1962 , Schmidt Di Friedberg, 1964 , Catalano, 1979 ) is a composite lithostratigraphic unit widespread in Sicily (southern Italy) which has been recently considered ( Gugliotta, 2010 ) as a part of the stratigraphic record of the Late Miocene (late Tortonian to early Messinian) Sicilian wedge-top depozone and represent the main object of this paper. Two end-member wedge-to…
Estimation of the density of the protocatechuate-degrading bacterial community in soil by real-time PCR
2008
Summary The β-ketoadipate pathway is the major route for degradation of aromatic compounds by various soil microorganisms. Protocatechuate 3,4-dioxygenase, a key enzyme of this pathway and which is encoded by pcaGH genes, catalyses the ring cleavage of protocatechuate. Microorganisms harbouring pcaGH genes are widely distributed in the environment but little is known about their relative abundance within the total microflora. Hence, this paper reports the development of a real-time PCR assay to quantify the bacterial pcaH sequence that encodes the β sub-unit of the protocatechuate 3,4-dioxygenase. This real-time PCR assay was linear over seven orders of magnitude with a calculated efficienc…
Multistratigraphic records of the Lower Cretaceous (Valanginian–Cenomanian) Puez key area in N. Italy
2016
Abstract We present a stratigraphic investigation of a Hauterivian to Cenomanian hemipelagic succession from Col Puez, in the Dolomites (Southern Alps, northern Italy). A composite section of seven segments was studied with bio-, magneto-, and chemostratigraphy, which enabled detailed and robust age calibration of the Puez succession. It also revealed the paleoceanographic history and helped identify the important global climatic events of that period. The age of the Lower Cretaceous Puez Formation in the Dolomites is refined as late Hauterivian to early Cenomanian. Ammonoids provide a detailed biostratigraphic subdivision that forms the basis for analyses of the faunal distribution and the…
Age-dependent epileptic encephalopathy associated with an unusual co-occurrence of ZEB2 and SCN1A variants.
2020
Mowat-Wilson syndrome is a genetic disorder associated with a variable phenotype including peculiar facial features associated with intellectual disability, epilepsy, language impairment, and multiple congenital anomalies caused by heterozygous mutation of the ZEB2 gene. The ZEB2 protein is a complex transcription factor that encompasses multiple functional domains that interact with the regulatory regions of target genes including those involved in brain development. Recently, it has been documented that ZEB2 regulates the differentiation of interneuron progenitors migrating from the medial ganglionic eminence to cortical layers by repression of the Nkx2-1 homeobox transcription factor. It…
The trace fossil gyrochorte: ethology and paleoecology
2021
Specimens of the trace fossil Gyrochorte from the Ordovician, Jurassic and Cretaceous of Utah, and the Pliocene of Spain are described. These occurrences expand the stratigraphic range of the ichnogenus, and allow for a reexamination of this paleoenvironmentally sensitive and puzzling trace fossil. The recognition of the penetrative characteristic of the trace is essential for a correct identification, as some trace fossils have been erroneously ascribed to Gyrochorte in the past. The producer must have been a detritus-feeding worm-like animal, probably an annelid, that created a bilobed, vertically penetrating and sometimes plaited meandering trace. Gyrochorte typically occurs in sandy f…