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M’hamed El Janati Abderrahmane Soulaimani Hassan Admou Nasrrddine Youbi Ahmid Hafid Kevin Patrick Hefferan 《Arabian Journal of Geosciences》2014,7(6):2407-2422
Satellite remote sensing is shown to provide critical support for geological and structural mapping in semiarid and arid areas. In this work, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data were used to clarify the geological framework of the Precambrian basement of the Iguerda Proterozoic inlier in the Moroccan Central Anti-Atlas. In this study, the interpretation of the processed digital data has been ground truthed with geological field data collected during a reconnaissance-mapping program in the Central Anti-Atlas. The Iguerda inlier offers a deeply eroded Precambrian massif dominated by a Paleoproterozoic basement composed of supracrustal metasedimentary units intruded by various Eburnian granitoids. Impressive mafic dyke swarms mainly of Proterozoic age crosscut this basement. Eburnian basement rocks are unconformably overlain by Lower Ediacaran volcanosedimentary rocks of the Ouarzazate Group and Upper Ediacaran–Lower Cambrian carbonates. The applied ASTER analyses are particularly effective in the lithological differentiation and discrimination of geological units of the Iguerda inlier. The spectral information divergence (SID) classification algorithm coupled with spectral angle mapper and maximum likelihood classification effectively discriminates between metamorphic rocks, granitoid bodies, and carbonate cover. SID classification improves geologic map accuracy with respect to the spatial distribution of plutonic bodies and metamorphic units. In addition, Paleoproterozoic granitoids have been well discriminated into separate distinct suites of porphyritic granites, granodiorites, and peraluminous leucogranite suites. This discrimination was initially identified via remote sensing analysis and later ground truthed in the field. This methodology enhances geological mapping and illustrates the potential of ASTER data to serve as a vital tool in detailed geologic mapping and exploration of well-exposed basement of arid regions, such as the Proterozoic of the Anti-Atlas Mountains of Morocco. 相似文献
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Marta Neres Pedro F. Silva Moha Ikenne Sofia Martins Ahmid Hafid João Mata Francisco Almeida Nasrrddine Youbi Moulay A. Boumehdi 《Studia Geophysica et Geodaetica》2016,60(4):700-730
No paleomagnetic data exist for Paleo-Mesoproterozoic times of the West African Craton (WAC). Therefore, paleogeographic reconstructions for such old geological times are difficult to constrain. Gaps on the sedimentary record and intense remagnetizations are the major problems that paleomagnetic studies come across. Recent geochronological results for dyke swarms that intrude several Proterozoic inliers of WAC in the Anti-Atlas Belt (southern Morocco) revealed ages between Paleoproterozoic and early Neoproterozoic, opening for the first time a window of opportunity to conduct paleomagnetic studies and tentatively infer about the paleoposition of WAC during Proterozoic. On this scope we conducted a paleomagnetic study on seven Proterozoic dykes of the Iguerda inlier. The meaning of the obtained paleomagnetic directions was evaluated by rock magnetic and mineral analyses, complemented by petrographic observations. Our samples record the presence of a complex history of remagnetization, mostly assigned to several Phanerozoic thermal/chemical events, in particular to the late stages of Pan African orogeny (s.l.), to the Late Carboniferous Variscan orogeny, and even to more recent events. The recognized remagnetization processes are related to widespread metamorphic events under greenschist facies followed by low-temperature oxidation, both responsible for the formation of new magnetic phases, like magnetite and hematite. These events obliterated the primary (magmatic) thermo-remanent magnetization and promoted multiple remagnetizations of the dykes, thermally and chemically. For only one dyke the presence of primary magnetization is possible to infer, though not to confirm, and would place WAC at an equatorial position around 1750 Ma. 相似文献
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Miguel Doblas Nasrrddine Youbi Julia De Las Doblas Antonio Jesús Galindo 《Natural Hazards》2014,74(2):1223-1261
A total of 2,300 swarmquake-type seisms have been striking the Torreperogil–Sabiote Hill (TSH) in southern Spain (Jaen) from October 2012 to the present, involving a major seismic crisis with six subseries until May 2013 (TSH seismic series, TSHS), followed by seven final series (FS). Two mild premonitory events occurred nearby in 2010–2011. Several evidences suggest cause–effect relationships between water and seismicity at the TSH: (1) The characteristics of seisms with a vast majority of ill-defined shallow/small events, spatial/temporal variations of the better constrained diffuse swarmquakes, increasing seismic velocities preceding stronger events, marked periodicities, abundant hydro-tremors, etc. (2) A series of spatial/temporal relationships between water and seismicity: Time lags between rainfall/reservoir peaks and seismic peaks; spatial links between swarmquakes and several factors (underground hydrogeology, reservoirs, etc.); etc. (3) From May 2013 to January 2014 evolution of rainfall and FS seismicity declined drastically at the same time. We suggest a hydroseismic hypothesis for TSH swarmquakes resulting from a complex series of cumulative factors: (1) A million-years natural setting involving geological, hydrogeological, geomorphological and tectonic elements. (2) A decades-long series of natural and anthropogenic factors are as follows: the 2012/2013 meteorological change, the massive overexploitation of the confined aquifers and alternating impoundment/emptying of the Giribaile reservoir. 相似文献
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Gärtner Andreas Youbi Nasrrddine Villeneuve Michel Sagawe Anja Hofmann Mandy Mahmoudi Abdelkader Boumehdi Moulay Ahmed Linnemann Ulf 《International Journal of Earth Sciences》2017,106(8):2747-2769
International Journal of Earth Sciences - Detrital zircon provenance studies are an established tool to develop palaeogeographic models, mostly based on zircon of siliciclastic rocks and isotope... 相似文献
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Naoual Gamrani Khalid R’kha Chaham Mouncif Ibnoussina Fabio Fratini Luisa Rovero Ugo Tonietti Mohammed Mansori Lehcen Daoudi Claude Favotto Nasrrddine Youbi 《Environmental Earth Sciences》2012,66(1):129-140
This work focuses on the building material used in the Saadian sugar refinery of Chichaoua (about 70 km southwest of Marrakesh).
The study involved a classification of different types of rammed earth, followed by their mineralogical characterization based
on optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). These studies are complemented by chemical
investigations, X-ray fluorescence, and thermal analysis (DTA and TGA). The results demonstrate the use of two types of earth
for the realisation of rammed earth, the first one non-plastic, -grained with added lime, the other one of low plasticity,
and fine grained without addition of lime. Mechanical tests on site and in laboratory how at the first type of material exhibits
great strength, exceeding the values known for rammed earth. 相似文献
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