Search results for "Structural basin"
showing 10 items of 292 documents
OSL dating of Middle Weichselian age shallow basin sediments in Western Latvia, Eastern Baltic
2012
Abstract This paper presents the results of the first attempt to date the Quaternary sediments of western Latvia in the southeast Baltic region, using luminescence. The analyses have been carried out on sandy sediments of the Jurkalne Formation that are located between upper and lower Scandinavian sourced tills. Previous publications on the origin of the Quaternary sediments in the region are reviewed and it is found that there are a wide range of explanations for their processes of formation and their age of formation. It is concluded that although the sandy sediments were deposited in freshwater environment although they contain both marine and freshwater fauna and flora, a property that …
A Holocene relative sea-level database for the Baltic Sea
2021
Highlights: • A first standardized and publicly available Holocene relative sea-level database for the Baltic Sea is presented. • The database holds 1099 revised data points with an estimation of vertical and chronological uncertainties. • Negative RSL tendencies prevail over the positive and complex tendencies in the Baltic Sea Basin. • Mid-Holocene RSL highstand occurred around 7.5–6.5 ka BP being consistent with the end of the final melting of the LIS. • The contribution of ice loading in the eastern Baltic Sea Basin is likely overestimated in the ICE-5G and ICE-6G_C models. Abstract: We present a compilation and analysis of 1099 Holocene relative shore-level (RSL) indicators located aro…
The Purpose and Age of Underwater Walls in the Bay of Elaia of Western Turkey: A Multidisciplinary Approach
2014
Pergamum (modern: Bergama) was operating an important harbour used by military forces and merchants at the city of Elaia during Hellenistic and Roman Imperial times. Harbour-related facilities such as warehouses, breakwaters and wharfs document the importance of this harbour site not only for the Pergamenians. This paper focuses on the purpose and age of six submerged wall structures situated approximately 1 km south of the ancient closed harbour basin of Elaia. Geoelectric cross-sections and semi-aquatic coring near these walls failed to detect any solid basement under the walls which excludes their possible use as breakwaters or wharfs. Instead, the walls were most likely delineating and …
Inverted responses of the carbon cycle to orbital forcing in Mesozoic peri‐platform marginal basins: implications for astrochronology
2020
International audience; Astrochronology depends on the faithful record of insolation forcing in climatic proxies, including the carbon isotope composition measured on bulk carbonates (δ13Ccarb). In marginal basins close to carbonate platforms, the source of carbonate is varied, which can impact the record of the astronomical cycles in the δ13Ccarb signal. We compare here the δ13Ccarb values together with detrital and weathering proxies before and during a crisis in the platform carbonate production (Weissert event, Valanginian, ~135 Ma) to document how a change in the carbonate source can affect the record of the orbital forcing by the carbon isotope system. The level of burial diagenesis w…
Evidence of positive tectonic inversion in the north-central sector of the Sicily Channel (Central Mediterranean)
2016
In order to unravel the tectonic evolution of the north-central sector of the Sicily Channel (Central Mediterranean), a seismo-stratigraphic analysis of single- and multi-channel seismic reflection profiles has been carried out. This allowed to identify, between 20 and 50 km offshore the central-southern coast of Sicily, a ~80-km-long deformation belt, characterized by a set of WNW–ESE to NW–SE fault segments showing a poly-phasic activity. Within this belt, we observed: i) Miocene normal faults reactivated during Zanclean–Piacenzian time by dextral strike-slip motion, as a consequence of the Africa–Europe convergence; ii) releasing and restraining bend geometries forming well-developed pul…
The Messinian stromatolites of the Sierra del Colmenar (Western Mediterranean): facies characterization and sedimentological interpretation
2018
A representative outcrop of the Messinian stromatolites belonging to the Terminal Carbonate Complex unit, from the northern sector of the Bajo Segura basin (Caja de Ahorros del Mediterraneo section, Sierra del Colmenar, SE Spain) has been studied. Here, we present a detailed analysis of the architecture, external morphology, and internal morphology in order to reconstruct the environmental and palaeoecological conditions for their growth. The stromatolites macrostructure consists of a continuously doming type morphology (build up and sheets areas).These developed close to the coast and acted as a palaeogeographic barrier, reducing physical stress, channeling the erosive effect of water and …
New stratigraphical data on the Middle-Late Jurassic biosiliceous sediments from the Sicanian basin, Western Sicily (Italy)
2008
The reported data present the stratigraphy of several sections across a Middle–Late Jurassic Radiolaritic Unit, well exposed in different thrust sheets pertaining to the Maghrebian chain of Southwestern Sicily. The aim was to define the chronostratigraphical distribution of the Jurassic biosiliceous sedi- mentation in the Sicanian palaeogeographical zone, a deep water basin belonging to the Southern Tethys continental margin. The radiolarian biostratigraphy indicates that the switching from carbonate to siliceous sedimentation in the Sicanian Basin is referable to the Bajocian, as shown by the section of Campofiorito, near Corleone. The biostratigraphical dataset allows the correlation betw…
Mineralogical variability of Callovo-Oxfordian clays from the Paris Basin and the Subalpine Basin.
2006
High-resolution clay mineralogical data at the Middle/Upper Jurassic boundary from the French Subalpine Basin, the Jura Mountains and the Paris Basin (ANDRA boreholes) from Callovo-Oxfordian clayey deposits allow spatial and temporal terrigenous flux evolution to be considered over a period of 6 to 7 Myr. Recorded diachronisms of major mineralogical changes and complex clays distribution at the Paris Basin scale result to combined palaeogeographic/eustatic variations and climate input. In the French Subalpine Basin, mineralogical homogeneity confirms the burial diagenesis influence, but other terrigenous supplies must be involved in contrast to the Paris Basin domains. Volcanogenic clays (b…
Impact of hydrologically driven hillslope erosion and landslide occurrence on soil organic carbon dynamics in tropical watersheds
2016
The dynamics of soil organic carbon (SOC) in tropical forests play an important role in the global carbon (C) cycle. Past attempts to quantify the net C exchange with the atmosphere in regional and global budgets do not systematically account for dynamic feedbacks among linked hydrological, geomorphological, and biogeochemical processes, which control the fate of SOC. Here we quantify effects of geomorphic perturbations on SOC oxidation and accumulation in two adjacent wet tropical forest watersheds underlain by contrasting lithology (volcaniclastic rock and quartz diorite) in the Luquillo Critical Zone Observatory. This study uses the spatially-explicit and physically-based model of SOC dy…
The fossil rodent faunas of the localities Alcoy 2C and 2D (Alcoy Basin, Spain). Implications for dating the classical locality of Alcoy-Mina
2014
In the Gormaig area (Alcoy basin, SE Spain) a number of fossil mammal localities are known, of which only the classic site of Alcoy-Mina, known since the mid-19th century, has yielded remains of macrofauna. In the vicinity of this site are the localities of Alcoy-2C (AL2C) and Alcoy-2D (AL2D), probably representing the levels of Alcoy-Mina. The faunal assemblage allows dating the AL2C and AL2D localities as Early Pliocene (end of the Early Ruscinian or early-late Ruscinian boundary, MN14-MN15). Several taxa (Pliopetaurista and Glis) are thought to have affinities for humid and close biotopes. En el área del Gormaig (cuenca de Alcoy, SE España), se conocen toda una serie de yacimientos de ma…