scholarly journals Thermal Maturity of the Grajcarek Unit (Pieniny Klippen Belt): Insights for the Burial History of a Major Tectonic Boundary of the Western Carpathians

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1245
Author(s):  
Magdalena Zielińska

The Grajcarek Unit of the Pieniny Klippen Belt (PKB), at the boundary between the Central (Inner) and Outer Carpathians, resulted from the convergence of the ALCAPA (the Alps–Carpathians–Pannonia) block and European plate. The strongly deformed slices of the Grajcarek Unit consist of Jurassic–Cretaceous sedimentary rocks associated with Late Cretaceous–Middle Palaeocene synorogenic wild-flysch, and sedimentary breccias with olistoliths. Maximum burial temperatures and burial depths were estimated based on vitrinite reflectance data. The vitrinite reflectance values were wide scattered through the Grajcarek sedimentary succession, especially in the flysch formations. This is attributed mainly to the depositional effects that affected the vitrinite evolution. The determined maximum burial temperatures were interpreted due to the regional compression controlled by tectonic burial coeval with thrusting and strike-slip faulting. The regional vitrinite reflectance variations might estimate cumulative displacement around the NNW–SSE and oriented the strike-slip Dunajec fault, which is a continuation of the deep fracture Kraków–Myszków fault zone.

2021 ◽  
Author(s):  
Ryo Okuwaki ◽  
Wenyuan Fan

A devastating magnitude 7.2 earthquake struck Southern Haiti on 14 August 2021. The earthquake caused severe damages and over 2000 casualties. Resolving the earthquake rupture process can provide critical insights into hazard mitigation. Here we use integrated seismological analyses to obtain the rupture history of the 2021 earthquake. We find the earthquake first broke a blind thrust fault and then jumped to a disconnected strike-slip fault. Neither of the fault configurations aligns with the left-lateral tectonic boundary between the Caribbean and North American plates. The complex multi-fault rupture may result from the oblique plate convergence in the region that the initial thrust rupture is due to the boundary-normal compression and the following strike-slip faulting originates from the Gonâve microplate block movement, orienting towards the SW-NE direction. The complex rupture development of the earthquake suggests that the regional deformation is accommodated by a network of segmented faults with diverse faulting conditions.


2012 ◽  
Vol 63 (4) ◽  
pp. 335-342 ◽  
Author(s):  
Paweł Kosakowski ◽  
Magdalena Wróbel

Burial history, thermal history and hydrocarbon generation modelling of the Jurassic source rocks in the basement of the Polish Carpathian Foredeep and Outer Carpathians (SE Poland)Burial history, thermal maturity, and timing of hydrocarbon generation were modelled for the Jurassic source rocks in the basement of the Carpathian Foredeep and marginal part of the Outer Carpathians. The area of investigation was bounded to the west by Kraków, to the east by Rzeszów. The modelling was carried out in profiles of wells: Będzienica 2, Dębica 10K, Góra Ropczycka 1K, Goleszów 5, Nawsie 1, Pławowice E1 and Pilzno 40. The organic matter, containing gas-prone Type III kerogen with an admixture of Type II kerogen, is immature or at most, early mature to 0.7 % in the vitrinite reflectance scale. The highest thermal maturity is recorded in the south-eastern part of the study area, where the Jurassic strata are buried deeper. The thermal modelling showed that the obtained organic matter maturity in the initial phase of the "oil window" is connected with the stage of the Carpathian overthrusting. The numerical modelling indicated that the onset of hydrocarbon generation from the Middle Jurassic source rocks was also connected with the Carpathian thrust belt. The peak of hydrocarbon generation took place in the orogenic stage of the overthrusting. The amount of generated hydrocarbons is generally small, which is a consequence of the low maturity and low transformation degree of kerogen. The generated hydrocarbons were not expelled from their source rock. An analysis of maturity distribution and transformation degree of the Jurassic organic matter shows that the best conditions for hydrocarbon generation occurred most probably in areas deeply buried under the Outer Carpathians. It is most probable that the "generation kitchen" should be searched for there.


arktos ◽  
2019 ◽  
Vol 6 (1-3) ◽  
pp. 17-38
Author(s):  
Malte Michel Jochmann ◽  
Lars Eivind Augland ◽  
Olaf Lenz ◽  
Gerd Bieg ◽  
Turid Haugen ◽  
...  

AbstractA hitherto unrecognized Paleogene outcrop has been discovered at Sylfjellet, a mountain located at the northern side of Isfjorden, Svalbard. The strata, which cover an area of 0.8 km2, have until now been assigned to the Lower Cretaceous succession of the Adventdalen Group. In this study, the Sylfjellet site was studied in detail to provide an updated structural and sedimentological description of strata and lithostratigraphy. The age and burial history of the investigated succession were constrained by absolute (U/PB) and relative dating methods in addition to vitrinite reflectance analyses of coal seams. The results show a Paleogene age of the deposits, which is supported by the occurrence of an angiosperm pollen grain, plant macrofossils, and a tephra layer of early Selandian age (61.53 Ma). The 250 m-thick succession of Sylfjellet is assigned to the Firkanten, Basilika and Grumantbyen formations. This succession unconformably overlies the Lower Cretaceous Helvetiafjellet Formation. Sylfjellet is incorporated into the West Spitsbergen Fold-and-Thrust Belt and interpreted to be a fourth structural outlier of the Van Mijenfjorden Group. Vitrinite reflectance data indicate that at least 2000 m overburden has been eroded above the Sylfjellet coal seams, and that maximum burial of the strata predates folding and thrusting in the area.


1994 ◽  
Vol 131 (4) ◽  
pp. 545-558 ◽  
Author(s):  
E. Fitzgerald ◽  
M. Feely ◽  
J. D. Johnston ◽  
G. Clayton ◽  
L. J. Fitzgerald ◽  
...  

AbstractVitrinite reflectance data from Namurian rocks in west Clare suggest that high maturation levels, corresponding to palaeotemperatures of 340–370 °C, were attained prior to Variscan deformation. Fluid inclusions in syntectonic quartz veins homogenize between 330 °C and 50 °C with an accompanying decrease in salinity from 27 to 5 eq. wt % NaCl. Maximum fluid inclusion entrapment temperatures ranged from more than 300 °C to 250 °C during Variscan folding in County Clare. The observed maturation levels (c. 7.5% Rmax) far exceed values for simple burial maturation based on the estimated burial history and ‘normal’ geothermal gradients, and do not increase with depth in the Doonbeg No. 1 exploration well. Fluid advective heating is suggested as the most likely mechanism consistent with the Clare reflectance and thermometric data. Vein and shear zone dimensions preclude rapid vertical movements of hot fluids through the section, and extensive lateral fluid migration from sedimentary basins undergoing tectonically driven dewatering to the south or west is therefore proposed.


2019 ◽  
Vol 56 (4) ◽  
pp. 365-396
Author(s):  
Debra Higley ◽  
Catherine Enomoto

Nine 1D burial history models were built across the Appalachian basin to reconstruct the burial, erosional, and thermal maturation histories of contained petroleum source rocks. Models were calibrated to measured downhole temperatures, and to vitrinite reflectance (% Ro) data for Devonian through Pennsylvanian source rocks. The highest levels of thermal maturity in petroleum source rocks are within and proximal to the Rome trough in the deep basin, which are also within the confluence of increased structural complexity and associated faulting, overpressured Devonian shales, and thick intervals of salt in the underlying Silurian Salina Group. Models incorporate minor erosion from 260 to 140 million years ago (Ma) that allows for extended burial and heating of underlying strata. Two modeled times of increased erosion, from 140 to 90 Ma and 23 to 5.3 Ma, are followed by lesser erosion from 5.3 Ma to Present. Absent strata are mainly Permian shales and sandstone; thickness of these removed layers increased from about 6200 ft (1890 m) west of the Rome trough to as much as 9650 ft (2940 m) within the trough. The onset of oil generation based on 0.6% Ro ranges from 387 to 306 Ma for the Utica Shale, and 359 to 282 Ma for Middle Devonian to basal Mississippian shales. The ~1.2% Ro onset of wet gas generation ranges from 360 to 281 Ma in the Utica Shale, and 298 to 150 Ma for Devonian to lowermost Mississippian shales.


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