1,721,041 research outputs found
The Early Toarcian anoxic event and shale gas potential: the case history of the Marne del Monte Serrone Formation (Central Italy)
No full textThe anoxic facies of the Lower Toarcian of Central Italy have been studied in order to define they depositional environment and they potentiality as source rock
Introduzione. Turismo, percorsi, territori, eventi
No full textSin dai primi mesi di lockdown si è parlato di “opportunità” relativamente a quei cambiamenti strutturali che, resi necessari e non più dilazionabili, dall’emergenza avrebbero potuto configurarsi come risorse innovative per un Paese come l’Italia che in molti ambiti ha accumulato ritardo rispetto ad altri. Questa stessa riflessione si può avviare anche in merito al turismo, settore imprescindibilmente centrale per le economie finanziarie e professionali del tempo contemporaneo, ma rispetto al quale l’Italia deve per necessità avviare una fase di scelte ponderate finalizzate alla ridefinizione del senso dei luoghi e all’innovazione delle proposte
Palynostratigraphy and palynofacies of the Upper Triassic Streppenosa Formation (SE Sicily, Italy) and inference on the main controlling factors in the organic rich shale deposition
No full textThis paper focuses on the Upper Triassic Streppenosa Formation, penetrated by the Pachino 4 on-shore well, (Southern Sicily, Italy) in order to find stratigraphic age constrains and to reconstruct the paleoenvironmental evolution of this basin within the Upper Triassic palaeogeographic scenario of the western Tethys. Pachino 4 is one of the wells drilled by Eni Exploration and Production in the south-eastern Hyblean plateau with the purpose to better define the time and space distribution of reservoirs and source rocks in an area characterised by considerable subsidence and strong tectonic activity, balanced by high sedimentation rate. The Streppenosa Formation depocenter consists of a thick sequence (>2500 m) of organic rich shales, turbiditic limestones and marly limestones, grouped into three members (Lower, Middle and Upper). The well diversified microflora assemblages allow the dating of the upper part of the Lower Member and the Middle Member as Norian and the Upper Member as Rhaetian. The palynofacies variations across the Streppenosa Formation show significative changes in the relative abundances of the organic debris that, associated with the lithological and sedimentological features, allowed a reconstruction of the depositional facies successions and a hypothesis for the forcing mechanisms driving the black shale deposition. We considered that the deposition of the Streppenosa Formation occurred in an epeiric basin, under oxygen-depleted bottom waters, with different depth that varied through time in response to the sedimentation rates, eustatic sea level changes, and basin subsidence. The integration of palynofacies and lithofacies data suggest a crucial role for river runoff, responsible for water stratification and for primary productivity increase in the water column. The process was triggered by warmer and wetter climate conditions as documented in many Upper Triassic successions of the western Tethys realm
Stratigraphy and sedimentation setting of the Triassic Gokdere-type pelagic succession in western Taurides (southern Turkey)
No full textThe article is focused on the Upper Triassic volcano-sedimentary succession (western Taurids, ) . Integrated sedimentary and organic facies point to an epicontinental basinal environment for the late Triassic Gokdere-type pelagic sediments, which evolution was controlled by relative sea level fluctuations. The in situ palynomorphs confirm a late Carnian-Norian age for the Gokdere-type pelagic succession. The relative good preservation degree and TAI data of recycled sporomorphs and the presence of quartz of sedimentary provenance indicate unmetamorphosed Palaeozoic sandstones and shales as source area. According to the present knowledge on regional geology the Palaeozoic reworked debris could be originated from Sultandagi Region, at the northern part of the Anamas-Akseki Autochthonous
Analisi delle facies organiche nell'Argillite di Riva di Solto (Bacino Lombardo, Sudalpino occidentale): considerazioni biostratigrafiche e paleoclimatologiche
No full textPalynological characterisation of the Lower Carnian of the Kea5 borehole (Koudiat El Halfa Dome; Central Atlas, Tunisia)
No full textIn Central Tunisia, the Triassic outcrops of the Koudiat El Halfa and Rheouis Domes are mainly composed of an evaporite-dominated succession.
The scarce biostratigraphic data available to date assign a Ladinian-Carnian age for the outcropping strata. The present palynological study data demonstrate an Early Carnian (Julian) age for the Triassic sediments penetrated by the KEA5 borehole in the Koudiat El Halfa Dome, which were previously considered to represent Middle Triassic. The palynological record mainly consists of Enzonalasporites vigens, Patinasporites densus,
Vallasporites ignacii, Brodispora striata, Samaropollenites speciosus, Ovalipollis pseudoalatus in association with Circumpolles species such as Praecirculina granifer, Camerosporites secatus and Duplicisporites granulatus. In addition, Lagenella martini and Aulisporites astigmosus occur in the upper part of the drilled succession and their first appearance could indicate a Julian-Early Tuvalian age. These new data allow a palynostratigraphic correlation with the Rheouis Formation cropping out along the structural ‘‘North–South Axis’’ of Central Tunisia, particularly in the Jebel Rheouis Dome. The drilled succession can be correlated with the Black Dolostones (Tr3) and the Middle Gypsum (Tr4) members of the Rheouis Formation
Mid- to late Permian microfloristic evidence in the metamorphic successions of the Northern Apennines: insights for age-constraining and palaeogeographical correlations
No full textRecent studies on the stratigraphy of Paleozoic successions belonging to key sectors of the inner Northern Apennines
provide data that can be used to propose new hypotheses about the palaeogeography of the western Mediterranean domain
during post-Hercynian times.We report here the first evidence of mid- to late Permian (Guadalupian–Lopingian) palynomorphs
in the chronostratigraphically highly debated metamorphic units of the Northern Apennines (the Rio Marina Formation, the Mt
Calamita Formation and the Le Cetine Formation) and consider the stratigraphic implications for the Tuscan ‘basement’ to
which the study rocks belong and their palaeogeographical attribution considering their Gondwana affinity. These results agree
with the interpretation that the Alpine Tethyan sedimentary cycle was already active during the mid- to late Permian
- …
