Evolution of the ridges of Midelt-Errachidia section in the High Atlas revealed by paleomagnetic data



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Torres Lorenzo, Sara and Casas Sáinz, Antonio María and Villalaín Santamaría, Juan José and Moussaid, B. and Ruiz Martínez, Vicente Carlos and El-Ouardi, Hmidou (2018) Evolution of the ridges of Midelt-Errachidia section in the High Atlas revealed by paleomagnetic data. Tectonics, 37 (9). pp. 3018-3040. ISSN 0278-7407

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Official URL: http://dx.doi.org/10.1029/2017TC004936


New paleomagnetic data (43 sites) from Mesozoic sediments are contributed in this work, verifying the presence of a pervasive syntectonic Early Cretaceous remagnetization in the easternmost area of the Moroccan High Atlas. Using the small circle intersection method, we have calculated the characteristic remagnetization direction (Dec: 337.3, Inc: 38.4) that fits with a 100-Ma age, according to the Apparent Polar Wander Path of Africa. The paleomagnetic vectors of remagnetization are used to obtain the geometry during the remagnetization stage (100Ma) of one of the most renowned geological cross sections of the High Atlas, the Midelt-Errachidia profile. The partial restoration of the cross section at 100Ma allows us to determine the dips of the beds at the remagnetization stage in five structures (ridges or anticlines). Our results indicate that the five ridges that configure the Midelt-Errachidia profile were initiated to different degrees prior to wholesale compressive deformation during the Cenozoic. This configuration can be explained according to two different scenarios that we discuss in this paper: transpression and diapirism. The geological model obtained, both at present and at 100Ma, indicates the existence of a Mesozoic cover substantially decolled from the Paleozoic basement, what strongly contrasts with previously published transects of the same area.

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©2018 Amer Geophysical Union
This study was financed by the research projects CGL2012-38481 and CGL2016-77560 of the MINECO (Spanish Ministry of Economy and Competitiveness) with also FEDER founding (European Union). Sara Torres-Lopez acknowledges the financial support given by the grant of FPI by the Ministerio de Economia y Competitividad of the Spanish government. The data used are listed in the table.

Uncontrolled Keywords:Low-temperature thermochronology; Late paleozoic remagnetization; Mountains northwest Africa; Plate-boundary zone; Central appalachians; Sedimentary basins; Vertical movements; Orogenic fluids; Morocco; Inversion; Paleomagnetism; Atlas; Cross-section; Diapirism; Transpression; Mesozoic
Subjects:Sciences > Physics > Geophysics
Sciences > Physics > Meteorology
ID Code:50254
Deposited On:28 Nov 2018 12:39
Last Modified:17 Mar 2019 00:01

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