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EN
A new borehole in Rożce (SW Mazovian Lowland) drilled in 2012, combined with a wide variety of research methods (palaeomagnetism, palynological analysis, studies of plant macroremains and textural features of deposits) shed new light on the age and stratigraphic position of the Early Pleistocene deposits, formerly assigned as the Lower Pleistocene. The study focuses on the deposits from 50.7-104.0 m depth, between glacial till of the Nidanian Glaciation (ca. 0.9 Ma) and the Poznań Clays (ca. 5.322 Ma). The deposits situated directly underneath the till (50.7-60.2 m) are related to the Nidanian Glaciation and show a reversed polarity and correlate with the end of the Matuyama Epoch. The deposits from 60.2-104.0 m depth were accumulated during the Early Pliocene, i.e. approximately 5.332-4.6 million years ago. They appear to correlate with the middle part of the Gilbert Palaeomagnetic Epoch and thus they are considerably older than previously thought. The cored section indicates a stratigraphic gap of about 3.5 Ma from the Lower Pliocene to the first advance of the Scandinavian ice sheets into Poland, which are thought to have occurred in the early Middle Pleistocene. The analysed deposits accumulated under variable climatic conditions showing two periods with significant aridity alternated with two periods of increased humidity. Deposits of the arid periods contain no pollen, butaeolian sand quartz grains are found. During periods of more humid climate the area was covered by various types of mixed forest.
EN
A sinkhole, developed in Middle Triassic limestones and filled with clastic and organic deposits, including lignite, was studied, in terms of its origin and age. The sinkhole represents a solution sinkhole, which originated through the subsidence of surficial deposits into an underlying cave system. The study permitted the recognition of three main stages of sinkhole evolution. During the initial stage, subterranean and surface karstification proceeded concurrently. As a result, a terra rossa cover developed at the surface and a cavern system was formed in the underlying bedrocks. During the second phase, both systems became connected and the soil cover subsided. This, in turn, involved the formation of a depression at the land surface and ponding of the drainage water. The pond was filled with plant debris, later giving rise to lignite formation. During the third and final stage, the sinkhole was filled with quartz sands with kaolinite, derived from eroded, Upper Cretaceous sandstones and marls. Results of pollen analysis from the sinkhole indicate the presence of mesophytic forests and show a significant role of riparian forests and herbaceous vegetation. The occurrence of abundant, freshwater algae and the pollen of aquatic plants evidences sedimentation of the infill in a water body (pond). The apparent dominance of arctotertiary and cosmopolitan, palaeofloristical elements, as well as the occurrence of only sparse, palaeotropical elements (mainly subtropical), indicate a warm-temperate climate (cooler than during the Early and Middle Miocene period). A comparison of the sporomorph association from the sinkhole with those from other Neogene sites provides evidence of its Late Miocene age (Late Pannonian–Early Pontian).
4
Content available remote The fossil echinoids of Santa Maria Island, Azores (Northern Atlantic Ocean)
EN
In the relatively young archipelago of the Azores, fossiliferous deposits are restricted to the oldest island (Santa Maria), mainly from late Miocene.early Pliocene deposits, and a few from the Pleistocene. echinoid material collected from these deposits comprises mainly disarticulated skeletal material (primary spines and coronal fragments) and a few complete tests. The taxa present in the Upper Miocene to lower Pliocene beds comprise Eucidaris tribuloides, Echinoneus cf. cyclostomus, Clypeaster altus, Echinocyamus pusillus, Echinocardium sp. 1, Echinocardium sp. 2, Schizobrissus sp. and undetermined spatangoids. The spatangoids and E. cf. cyclostomus, are new records for the Miocene.Pliocene strata of the island. The material collected from Upper Pleistocene outcrops (MISS 5e) included three regular echinoid species, Sphaerechinus granularis, Arbacia lixula and Paracentrotus lividus. The two latter species are recorded for the first time from the Pleistocene deposits of the island. Compared to the older deposits, the Pleistocene record represents a very narrow range of environments and is basically restricted to deposits associated with an ancient rocky shore. Moreover, the conspicuous presence of taxa typical of tropical seas in the Mio-Pliocene sediments contrasts with the Pleistocene and modern echinoid fauna, which is warm temperate in composition.
EN
The Tanais Palaeobay was located in the northern periphery of the eastern Paratethys Sea during the Late Miocene. New data from the Safianovo section (Rostov Dome, South-West of Russia) confirm that skeletal limestones (coquinites) of the Merzhanovskaja Formation belong to the Congeria (Andrusoviconcha) amygdaloides navicula Zone of the upper Upper Maeotian (the Maeotian is a regional chronostratigraphic unit of the Upper Miocene). Correlation of reference sections of these Upper Maeotian deposits within the Rostov Dome results in pattern of the palaeobay transgression, which was punctuated. The relative importance of local and global controls on this trangsression is not yet clear.
EN
The Northern Sicilian-Maghrebian Chain courses W-E from the Trapani Mts to the Peloritani Mts and is composed by a set of tectonic units deriving from the Miocene-Pleistocene deformation of the Northern African Continental Margin. Inside it three main geotectonic elements ("external", Sicilide and "Austroalpine") are present and outcrop juxtaposed with a W-E trend. The external element composes the more western Trapani, Palermo and Western Madonie Mts, the Sicilide composes the Eastern Madonie and Nebrodi Mts, while the "Austroalpine" composes the more eastern Peloritani Mts. The orogen shows a culmination in the Trapani Mts and a depression in the Peloritani Mts. The main plicative stages are relatable to late Oligocene-early Miocene from the more internal sectors, while the deformation of the more external sectors starts from early-middle Miocene. The Sicilian chain body is re-involved in tectonism since late Tortonian, which persists until the recent time. During this interval, the deformation of the Sicilian Chain continued by activation of fault systems with different displacements. In the present paper, an important extensional tectonic stage is recognised, starting from the Tortonian; it is supported by structural data and shows through several geological sections across the northern sectors of the Sicilian orogen. This deformation is of exceeded wedge critical taper values, controls the early stages of the Tyrrhenian Basin opening, and is represented by low-angle fault system, producing tectonic omissions in the stratigraphic sequence. The detachment fault system is subsequently displaced by a complicated grid of Plio-Pleistocene net- and strike-slip fault system that controls the genesis of tectonic depressions in the northern off-shore areas of the Sicilian Chain. This neotectonic system may be reconnect to a W-E trending simple shear system, which controls the more recent Tyrrhenian Basin development.
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