Search results for "PLEISTOCENE"

Late Quaternary slip rates for the southern Elsinore fault in the Coyote Mountains, southern California from analysis of alluvial fan landforms and c…

2019

Abstract Offset alluvial fans along the Elsinore fault in the south-central Coyote Mountains were studied to resolve an average late Quaternary slip rate for this major western strand of the San Andreas fault system in southern California. Alluvial fans and their offsets were mapped using high-resolution DEMs combined with field observations of fan-surface morphology and the character of the soils developed in each fan remnant. Clast assemblage data was used to determine the source of each alluvial fan upstream of the fault, and U-series dating of pedogenic carbonate was used to estimate minimum ages of the alluvial fan surfaces. Forty U-Th dates on pedogenic carbonate confirm the utility o…

Plio-Pleistocene geological evolution of the northern Sicily continental margin (southern Tyrrhenian Sea): new insights from high-resolution, multi-e…

2003

High-resolution seismic profiles were acquired in the north Sicily offshore region with an innovative, multi-tip sparker array which lacks ringing and has a base frequency around 600 Hz. The new data, combined with published data, suggest that intra-slope and extensional basins formed as a consequence of the late Miocene (?)–early Pliocene shortening and thrusting, and the middle (?)–late Pliocene continental rifting affecting the internal side of the Sicilian-Maghrebian chain. Early (?) Pleistocene to Holocene high-amplitude and high-frequency sea-level changes resulted in repeated sub-aerial exposure and flooding of the shelf, and the deposition of cyclically arranged hemipelagic and shel…

Badlands in the Tabernas Basin, Betic Chain

2014

The complex badland landscape at Tabernas results from a combination of relief amplitude generated by tectonic uplift since the Pliocene and reactivated several times during the Pleistocene, the properties of the Tortonian sedimentary rocks and a predominantly arid climate. The landscape is dominated by deep incision of the main river systems, which continues in part of the headwater tributaries, and characterized by contrasting slope morphologies and a variety of microecosystems. The Tabernas badlands exhibit a diversity of landforms resulting from the combination of multi-age soil surface components that allow a variety of processes to operate at different rates. These are dominated by ri…

Effects of glaciation on karst hydrology and sedimentology during the Last Glacial Cycle: The case of Granito cave, Central Pyrenees (Spain)

2021

In Alpine regions, speleothem development on karst systems largely occurs during warm interglacial or interstadial phases due to their limited growth during cold stages. Still, recent attention has been given to the role of clastic sediments in caves, less dependent on temperature conditions. Yet, only a small number of caves worldwide preserve both speleothems and detrital deposits. Here we present an outstanding record of fine-grain laminated sediments and carbonate speleothems from the Granito cave (South Central Pyrenees, Spain) associated with seasonal to annual hydroclimatic pulses through the Last Glacial Cycle (LGC). Analysis of cave clastic facies together with new absolute dates o…

Speleothems in a north Cuban cave register sea-level changes and Pleistocene uplift rates

2018

Growth processes, dimensional parameters and scaling relationships of two conjugate sets of compactive shear bands in porous carbonate grainstones, F…

2012

Abstract Three main sets of deformation bands are identified in the Lower Pleistocene carbonate grainstones of Favignana Island (Italy). A bedding-parallel set is interpreted to contain compaction bands, based on the lack of evidence for shear. The other two sets are oriented at a high-angle to bedding, forming a conjugate pair comprised of compactive strike-slip shear bands. In this study, we focus on the compactive shear bands documenting their development, as well as analyzing their dimensional parameters and scaling relationships. Single compactive shear bands are thin, tabular zones with porosity less than the surrounding host rocks, and have thicknesses and displacements on the order …

Relation between climatic fluctuation and morphological variability in Microtus (Terricola) grafi (Arvicolinae, Rodentia) from Bacho Kiro (Bulgaria, …

2004

Morphological variability within the species Microtus (Terricola) grafi is investigated in relation to the parameters of time and climate. Microtus (Terricola) grafi has been described from the Upper Pleistocene cave of Bacho Kiro (Bulgaria), which has yielded numerous teeth from several levels reflecting climatic fluctuations. The first lower molars are analyzed by 23 biometric variables so as to quantify tooth shape and its variation with time and climate. This morphological analysis reveals a number of shape indexes reflecting whether an individual lived in warm or cold conditions. The most significant result is that individuals living in warm conditions exhibit the more primitive featur…

Distinguishing between Bos and Bison petrous bones. A case study: Bovines from the des-cubierta cave (Pinilla del Valle, Madrid)

2019

This research has been supported by the financial assistance of the Spanish Society of Palaeontology ID AJISEP-2017-07142. M.A. Galindo-Pellicena was also being supported by a postdoctoral grant from the Fundacion Atapuerca. We thank the Excavation Team of the Des-Cubierta cave for their work in the fi eld, and our colleagues from the Centro Mixto UCM-ISCIII of Madrid and from the Regional Archaeological Museum of Alcalá de Henares, especially to Belén Márquez, Elena Santos, Beatrice Vacca and Abel Moclánfor their suggestions during the elaboration of the manuscript. Thanks must be extended to the Restoration Team, especially to M. Cruz Ortega, to the photographers Alfonso Dávila and Mario …

Tectonic beheading of fluvial valleys in the Maestrat grabens (eastern Spain): Insights into slip rates of Pleistocene extensional faults

2013

Abstract Interaction between faulting and landscape evolution in regions of active tectonics allows us to use subtle geomorphological markers for estimating fault slip rates. Geomorphic features of two valleys connected with the bottom of the Alcala de Xivert graben, at the Maestrat graben system (eastern Spain), suggest that they correspond to the lowest segments of ancient valleys whose original heads were located at the axis of the neighbouring Irta range. They were beheaded owing to displacement of the Torreblanca and Irta faults during a period of active extensional faulting in Middle Pleistocene times. These faults produced a negative inversion of the relief, sinking a narrow graben (…

Phylogeny and biogeography of fossil and extant Microtus (Terricola) (Mammalia, Rodentia) of Sicily and the southern Italian peninsula based on curre…

2011

Abstract The fossil record of the Savi vole, Microtus ( Terricola ) savii , is analyzed in terms of morphological and morphometrical variability of the first lower molar, in order to reconstruct phylogenetic relationships between insular and mainland populations and the dispersal events. The present work gives a contribution to better understand the phylogenetic history of this taxon in Sicily and Southern Italy during the interval Middle Pleistocene – Holocene, in an attempt to reconstruct the relationships between insular and continental voles and to clarify some paleobiogeographical aspects. The morphometrical data have been acquired by traditional measurements of the first lower molar a…