Paleogeothermal gradient in the boskovice furrow

1994 ◽  
Vol 38 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Jan Šafanda ◽  
Lubomír Malý
1998 ◽  
Vol 41 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Yiqun Liu ◽  
Tao Wu ◽  
Hanyun Cui ◽  
Qiao Feng

2020 ◽  
Author(s):  
Nicolas Saspiturry ◽  
Abdeltif Lahfid ◽  
Thierry Baudin ◽  
Laurent Guillou-Frottier ◽  
Philippe Razin ◽  
...  

<p>Examples of fossil and present-day passive margins resulting from mantle exhumation at the ocean–continent transition appear to have developed under conditions of high mantle heat flow. The pattern of geothermal gradients along these hyperextended margins at the time of rifting is of interest for exploration of geothermal and petroleum resources, but is difficult to access. The fossil rift in the North Pyrenean Zone, which underwent high temperature–low pressure metamorphism and alkaline magmatism during Early Cretaceous hyperextension, was studied to explore the geothermal regime at the time of rifting. Data from a set of 155 samples from densely spaced outcrops and boreholes, analyzed using Raman spectroscopy of carbonaceous material, shed light on the distribution of geothermal gradients across the inverted hyperextended Mauléon rift basin during Albian and Cenomanian time, its period of active extension. The estimated paleogeothermal gradient is strongly related to the structural position along the Albian-Cenomanian rift, increasing along a proximal-distal margin transect from ~34°C/km in the European proximal margin to ~37–47°C/km in the two necking zones and 57–60°C/km in the hyperextended domain. This pattern of the paleogeothermal gradient induced a complex competition between brittle and ductile deformation during crustal extension. A numerical modeling approach reproducing the thermal evolution of the North Pyrenees since 120 Ma suggests that mantle heat flow values may have peaked up to 100 mW.m-2 during the rifting event. We demonstrate that the style of reactivation during subsequent convergence influences the thermal structure of the inverted rift system.</p>


2013 ◽  
Vol 47 (4) ◽  
pp. 2131
Author(s):  
N. Rigakis ◽  
V. Karakitsios ◽  
F. Marnelis ◽  
Sp. Sotiropoulos

A detailed petroleum geochemical study has been performed in the previous years in the Western Greece. Several source rock horizons have been identified, the oil window has been calculated for the most significant sub-basins and the oil correlation study has distinguished the different oil groups of the area, generated from different hydrocarbon sources. These results are very significant and useful for the oil exploration. But, further to these, some more geochemical observations can also be very important on solving some geological problems of the area.- A major problem is the deposition and preservation of the organic matter in the Western Greece.- The dolomitization in relation with the oil generation is also an issue.- Another issue is the calculation of the eroded overburden formations thickness.- The Paleogeothermal gradient determination is also very important.The last two parameters are absolutely necessary for organic matter maturity calculations.The study of all the above parameters completes the geochemical study of the Western Greece, and in relation with other geological studies can provide solutions in the petroleum exploration of the area.


1985 ◽  
Vol 22 (12) ◽  
pp. 1793-1802 ◽  
Author(s):  
Erik J. Schwarz ◽  
Kenneth L. Buchan ◽  
Alain Cazavant

Remanent magnetization in five Indin, three Dogrib, two Archean, and one Mackenzie dyke contact zone(s) from the Yellowknife area of the Canadian Precambrian Shield has been studied in order to establish the ambient temperature of the host rock and the depth of burial of the present erosion surface at the time of intrusion. A positive baked-contact test for an Aphebian Indin dyke demonstrates the primary nature of the dyke magnetization. From this contact, eight individual specimen determinations of the ambient host-rock temperature at the time of intrusion yield an average of 211 °C, with a standard deviation of 18 °C and probable error of ± 36 °C. Assuming a paleogeothermal gradient of 44 °C/km (± 30%) the estimated depth of burial of the present erosion surface is [Formula: see text]. None of the remaining contacts yield estimates of the depth of burial. However, the results from the three Dogrib contacts illustrate complications such as chemical overprinting that must be considered when analysis is made of magnetization in igneous contact zones. Thus, only one spot reading of the depth of burial of the area has been obtained. Correlation of the Indin result with a result from the Matheson area of Ontario and with stratigraphic indicators is uncertain because of large intervening distances and the occurrence of younger structural zones.


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