Search results for "Glacial period"
showing 10 items of 196 documents
Sedimentary, stable isotope and micropaleontological records of paleoceanographic change in the Messinian Tripoli Formation (Sicily, Italy)
2002
Abstract The Tripoli Formation (6.96–5.98 Ma) of the Central Sicilian Basin provides a good record of the paleoceanographical changes that affected the Mediterranean during the transition from slightly restricted conditions to the onset of the Messinian Salinity Crisis. The Falconara/Gibliscemi section has been selected for an integrated approach at a high resolution scale using sedimentology, stable isotopes of the carbonates and microfossils. The sedimentary succession includes 46 precession-controlled cycles resulting from the periodical increase in biosiliceous productivity (diatomites) that followed the deposition of marls and pinkish laminites, which appear as sapropel-type deposits i…
The Grotta Grande of Scario (Salerno, Italy): Archaeology and environment during the last interglacial (MIS 5) of the Mediterranean region
2011
Abstract Archeological and paleo-environmental researches carried on the Grotta Grande site illustrate the importance of a multidisciplinary approach among archeologists, palynologists and paleontologists. The archaeology, fauna, pollen and micro-charcoal recovered in two short sedimentary successions (trenches A, F) located close to the entrance of the cave are discussed. The cave opens directly on the Tyrrhenian Sea, 2 km from Scario (Salerno, Campania, Southern Italy). The morphology of the cave and sedimentary processes were controlled by eustatic fluctuations during the late Middle Pleistocene and the early Late Pleistocene. The sea repeatedly occupied the cave. The cave was frequented…
Astronomic forcing on the planktonic foraminifera assemblage in the Piacenzian Punta Piccola section (southern Italy)
2006
[1] A high-resolution quantitative analysis of the calcareous planktonic assemblages (planktonic foraminifers and calcareous nannofossils) at the Punta Piccola section (at the base of which, the global standard stratotype-section and point of the Piacenzian stage is defined) provided a more accurate biostratigraphy for the Mediterranean middle Pliocene (2.6–3.6 Ma). In particular, an astronomically calibrated age of 2.87 Ma was estimated for the Pliocene first occurrence of Neogloboquadrina atlantica instead of the younger previously proposed age of 2.72 Ma. Spectral analysis performed on the Globigerinoides species (spp.) planktonic foraminifera assemblage along with cross-spectral analysi…
Benthic foraminifera and environmental changes in the Quaternary of the western Mediterranean coast: the core of Xeraco, Valencia, Spain
2020
The evolution of the benthic foraminiferal assemblages from a 60 m core drilled in the Quaternary lagoon of Xeraco (Valencia, Spain) is studied. Two moments of warm climate, high sea-level and maximal marine influence in the lagoon have been identified. The first one at the base of the core, punctuated by highly frequent changes during the Upper Pleistocene, and the other one in the upper end of the series during the Holocene. The presence of a middle core section with low diversity and a nearly total absence of marine foraminifers is interpreted as a regressive interval of cold climate conditions linked to a glacial stage.
Surviving the Holocene: Human Ecological Responses to the Current Interglacial in Southern Valencia, Spain
2009
For hunter-gatherer groups, the dramatic changes in climate at the end of the last glacial cycle necessitated rearrangement of land use, including shifts in mobility strategies, settlement location, and resource use. We examine these behavioral changes using lithic attribute data as well as spatial distributions of artifacts and features. Using data from intensive survey and excavation, we trace human ecological response through the onset of the current interglacial in central Mediterranean Spain, comparatively far from the margins of the north-temperate ice sheets.
In glacial environments beyond glacial terrains: Human eco-dynamics in late Pleistocene Mediterranean Iberia
2013
The Iberian Peninsula south of the Ebro River enjoyed one of the mildest climates of Pleistocene Europe, but still experienced significant and rapid environmental shifts caused by global climate regimes. We examine the interplay between technological, social, and land-use dynamics as culturally mediated responses to climate change outside the periglacial zone. We combine information from excavated sites across eastern and southeastern Spain with systematic survey data from an intensive study area within this larger region to examine Upper Paleolithic behavioral adaptations to the environmental shifts of the late Pleistocene (late MIS-3 through MIS-2). We define indexes that serve as proxies…
A HYDRAULIC CONDUCTIVITY MODEL POINTS TO POST-NEOGENE SURVIVAL OF THE MEDITERRANEAN OLIVE
2004
Research on the subfossil record and paleoecology of Olea europaea suggests a new interpretation of its history and ecology with reference to the Mediterranean climate since the Neogene. New results are based on the wood anatomy of ancient and extant Olea and a model estimating hydraulic conductance established for wild forms belonging to Olea europaea subsp. europaea. These suggest that during glacial periods wild olive populations survived in protected microenvironments, particularly riparian habitats. Thereafter, the postglacial expansion of olive associated with climatic warming took place from these refuge areas. This new evidence suggests that the continued existence of Olea in Medite…
Mutual Climatic Range Methods for Quaternary Ostracods
2012
Abstract The development of Mutual Climatic Range (MCR) methods for ostracods has included the estimation of marine bottom-water palaeotemperatures, but it has focused mainly on the use of non-marine ostracods to infer past air temperatures. The Delorme analogue MCR method, using only those components of a fossil assemblage that co-exist today, has yielded mean annual air temperature and annual precipitation estimates for North American Quaternary sites. The Mutual Ostracod Temperature Range (MOTR) non-analogue MCR method utilises all species in a fossil assemblage; calibrations based on a European database have been applied to the estimation of mean July and January air temperatures for En…
Valanginian isotope variation in glendonites and belemnites from Arctic Svalbard: Transient glacial temperatures during the Cretaceous greenhouse
2010
Oxygen and carbon isotope data from Cretaceous (Valanginian) glendonites and belemnites from Arctic Svalbard are presented. Oxygen isotope data from well-preserved glendonites, in conjunction with the ikaite to glendonite pseudomorph transition temperature, are used to provide an estimate of the oxygen isotope composition of ambient seawater. Calculation of such a factor is essential for robust paleotemperature estimates. Using this methodology, our paleotemperatures calculated from the oxygen isotope compositions of coexisting belemnites yield cool temperatures (4–7 °C) consistent with transient glacial polar conditions during the Cretaceous greenhouse. Cool polar temperatures during the C…
Sedimentation in the Kandi extensional basin (Benin and Niger): fluvial and marine deposits related to the Late Ordovician deglaciation in West Africa
2003
Abstract The Lower Paleozoic detrital succession of the half-graben Kandi Basin in West Africa (Niger-Benin) is about 600 m thick and rests unconformably on the Pan-African basement. Along the western edge of the basin, the base of the succession locally features large glacial fault-bounded paleovalleys. These valleys are filled by the lowermost continental deposits of the Were Formation characterized by massive diamictites with dropstones, and coarse to conglomeratic sandstones associated with large-scale channel structures and internal erosional truncations. The uppermost braided-river deposits of the Were Formation deposited across the entire basin are overlain by the Late Ordovician–Ear…