Search results for " ROC"

Sicilian Lithostratigraphic Units

2018

This chapter includes the description of the Sicilian lithostratigraphic units (Fig. 2.1). They are grouped in a generally chronological order and the complete list of the worksheets is shown in the Table of contents. In each chronologic group the worksheets of the described formations are organized in alphabetic order. The Permo-Triassic units are the oldest deposits outcropping in Sicily that originated during the early stages of the Southern Tethyan continental rifting. The Meso-Cenozoic carbonate units represent the sedimentary sequences of the various stratigraphic successions differentiated in the field along the Sicilian outcrops. The deposits of the Sicilide Complex (Tethyan units) …

Erratum to “Sedimentary dynamics and extensional structuring related to Early Cretaceous rifting of Neocomian and Barremian deposits of the interior …

2013

1991

The Triassic of the NW Iberian Ranges consists of two carbonatic formations equivalent to the Upper Carbonatic Formation of the Muschelkalk Facies and pass laterally into siliciciastic deposits to the NW. Fossillocalities have been found in both formations. Taphonomic and sedimentologic studies allow for the interpretation as autochthonous associations of the infaunal Bivalves of shallow water marine environments with siliciciastic input. Three faunal associations have been distinguished: 1. Costatoria-Lyriomyophoria association, found in the lower carbonatic formation and the equivalent siliciciastic formation; 2. «Teruel Fauna» association, found in the upper carbonatic formation; 3. Ling…

Mass mortality or exceptional fossilization ? The case of the early and middle Toarcian fossiliferous beds from the Digne-Les-Bains area (southeaster…

2003

Abstract The latest Domerian to late Toarcian sedimentary series (from −190 Ma up to −180 Ma) from the « Réserve Géologique de Haute-Provence » (southeastern France) yields two kinds of remarkable fossiliferous beds. The greatest interest of the early Toarcian type is the occurrence of ichtyosaur remains (at least in six sites) among many other fossils such as ammonites, belemnites, bivalves, wood. The middle Toarcian type is specifically rich in ammonites and nautiluses. Litho- and biostratigraphical, palaeontological, sedimentological and geochemical analyses allow us to determine whether these fossiliferous beds are the results of mass mortalities, linked or not to biological crisis, o…

Taphonomic and Sedimentary Factors in the Fossil Record of Mammals

1990

The composition of the fossil assemblages of mammals (MFA) is traditionally considered as being controlled by historical factors. Its variations are attributed to biochronological changes due to evolutionary process or to biogeographic changes due to geodynamic process. The different MFA are compared as sampling units of similar nature. The presence or absence of taxa and their relative abundance are used as biochronologic and biogeographic indicators, and the samples (MFA) are considered homologous, although they appear in a different sedimentological, taphonomical, or tectonic context.

Structural framework and crustal characteristics of the Sardinia Channel Alpine transect in the central Mediterranean

2000

Abstract The submerged area located between the Sardinia Channel and the western Sicily offshore has been investigated based on deep crustal and conventional seismic lines with the aim of illustrating the relationships between the crust and its overlying crystalline and sedimentary thrust wedge. Analyses of seismic attributes and reflector pattern, supported by dredge hauls, also provided data in areas where stratigraphic and lithologic control is absent. Crustal geometries, tectonic processes and timing of the deformation are discussed here. North of the Elimi chain (central Sardinia Channel) the reflecting body consists of superposed tectonic wedges of crystalline rocks and their Meso-Cen…

The role of geochronology in understanding continental evolution

2010

Geochronology has become one of the most essential tools in reconstructing processes of continental growth and evolution, and in situ dating of minerals has become common practice through the development of high-resolution ion microprobes and laser ablation inductively coupled plasma mass spectrometry techniques. Zircon has established itself as the most robust and reliable mineral to record magmatic and metamorphic processes. The combination of mineral ages with Sm–Nd, Lu–Hf and O isotopic systematics constrains magma sources and their evolution, and a picture is emerging that supports the beginning of modern-style plate tectonics in the early Archaean. Major fields for future research in …

Natural and human induced environmental changes preserved in a Holocene sediment sequence from the Etoliko Lagoon, Greece: New evidence from geochemi…

2013

Abstract A key feature of Greece is the large amount of historical and archaeological records. The sedimentary record of the Etoliko Lagoon, Aetolia, Western Greece, offers an ideal opportunity to study human–environment interaction and to disentangle natural and anthropogenic imprints in the sedimentary record. By applying an interdisciplinary approach of combining geoscientific methods (XRF, LOI, grain size analysis) with archaeological and historical records, the 8.8 m long sedimentary sequence ETO1C reveals the palaeoenvironmental history of the lagoon and its catchment since 11,670 cal BP. With a thorough chronology based on 14 C age-depth-modelling including varve counting, different …

Upper Pleistocene biostratigraphy and traces of glaciotectonics at the Satiki site, western Latvia

2007

Structural, lithological, palynological and plant macroremain investigations of test-boring cores and gravel pit walls at the Satiki site suggest that gyttja and sandy gyttja units of basin sediments were deposited during the Felicianova (Eemian) Interglacial. A pollen diagram reflects the characteristic forest succession of the Eemian Interglacial: Betula, Pinus, Ulmus, Corylus, Quercus, Fraxinus, Tilia, Carpinus, Picea and Pinus. Forests of broadleaved trees and thermophilous plants dominated in the surroundings of the lake during the interglacial climatic optimum. The basin sediments contain a large number of warmth-demanding water plants such as Salvinia natans and Trapa sp. Paleobotani…

Palynology and lithostratigraphy of Late Elsterian to Early Saalian aquatic sediments in the Ziemupe–Jūrkalne area, western Latvia

2000

Abstract This study is based upon lithological and palynological investigation of test-drilling cores along the Baltic Sea coast. Three intertill units of basin sediments are underlain by a thin layer of Lētiža (Elsterian) till and overlain by glaciotectonically deformed Kurzeme (Saalian Complex) till. The Kurzeme till differs from the Lētiža till by higher contents of limestone clasts and rounded hornblende grains. The lowermost intertill unit consists of glaciolacustrine to glaciomarine laminated clay of the Sudrabi member, a late glacial deposit of the Lētiža glaciation. Treeless vegetation covered the adjoining land. Next is the marine to brackish Akme n rags formation, deposited during…