Michel Faure | University of Orleans, France (original) (raw)
Papers by Michel Faure
AGU Fall Meeting Abstracts, Dec 1, 2015
HAL (Le Centre pour la Communication Scientifique Directe), 2006
ABSTRACT In order to better constrain the Neoproterozoic paleogeographic reconstruction of contin... more ABSTRACT In order to better constrain the Neoproterozoic paleogeographic reconstruction of continents and improve the understanding of the snowball Earth hypothesis, paleomagnetic collections on Neoproterozoic rocks were carried out in the Aksu area of the northwestern Tarim basin from 2001 to 2005. Six sites of limestone from the Chigebrak formation, 38 sites of sandstone and 4 sites of volcanic rocks from the Sugetbrak formation were sampled. The remaining 24 sites of sandstone and volcanic rocks reveal stable characteristic remanent component (ChRm) isolated from 500 to 680? The computed magnetic directions from these components are relatively consistent and significantly distinguished from those of younger ages. Both normal and reverse polarities have been observed though the normal one is dominant, moreover, the positive fold test is revealed after bedding corrections at 95% confidence level. A paleomagnetic pole is, therefore, calculated: l =19.1? f =149.7? k = 11.2, A95 = 9.3?with n = 24, yielding a paleolatitude of ~27 for the sampling area. The chemostratigraphic correlation of this section with reference ones reveals an average of ~595 Ma for the age for this collection. Comparing paleomagnetic data of the similar ages from Australia and South China as well as other major blocks, the Tarim block seemed being closely located in the north of Australia. A new paleogeographic reconstruction has been attempted which showing a general feature of lower paleolatitude for these blocks. Referring to the paleogeographic reconstruction at about 760Ma proposed by Chen et al. (2004), the continental landmass including the above mentioned blocks seemed having experienced a relatively slow southward kinematic drift and kept their rather low paleolatitude. These observations provide, therefore, evidences to the snowball Earth hypothesis in the late Neoproterozoic time.
Precambrian Research, Mar 1, 2014
Comptes Rendus. Géoscience
We found Middle and Late Triassic conodonts and radiolarians from the pelagic carbonates and succ... more We found Middle and Late Triassic conodonts and radiolarians from the pelagic carbonates and successive siliceous sediments of the Buruanga Peninsula in Panai Island, North Palawan Block. The carbonate units, long estimated to be Jurassic, revealed late Anisian and late Norian. The pelagic limestone carapace of basalt was constrained within the conodont Gladigondolella tethydis – Paragondolella excelsa Zone (late Illyrian/early Fassanian). The successive bedded-chert unit starts from Fassanian (lower Ladinian) radiolarian Triassocampe spp. – Yeharaia spp. Zone. The early to late Norian conodont mixed faunas (from Ancyrogondolella quadrata Zone to Mockina bidentata Zone and Misikella hernsteini Zone) were extracted from the turbiditic clastic-carbonate unit that intertongues with the pelagic limestone/chert unit of latest Norian age (conodont Misikella hernsteini Zone).
BSGF - Earth Sciences Bulletin, 2021
The Montagne Noire located in the southern part of the French Massif Central represents the north... more The Montagne Noire located in the southern part of the French Massif Central represents the northern part of the South-Variscan Foreland. It is subdivided into three parts. The granite-migmatite Axial Zone dome is surrounded by non- or weakly metamorphosed Paleozoic sedimentary series. Both northern and southern flanks of the Montagne Noire dome are deformed by km-scale, south to southeast facing recumbent folds and thrusts sheets. The Raman Spectroscopy of Carbonaceous Material (RSCM) method, carried out in the low-grade metamorphic rocks of the southern flank of the Montagne Noire, yielded temperatures comprised between 400 °C near the dome, and 230 °C in the southern domain. Three Raman geothermometers were used to cover this temperature range. RSCM temperatures comply qualitatively with previous estimates based on illite crystallinity, conodont color alteration, and fluid inclusions carried out in the same area, which document a metamorphic temperature increase towards the dome....
Ore Geology Reviews, 2020
Earth and Planetary Science Letters, 2015
Quaternary Geochronology, 2014
Sciences géologiques, 1984
La chaine mesozoique du Japon du SW est caracterisee par trois phases tectoniques. La premiere (J... more La chaine mesozoique du Japon du SW est caracterisee par trois phases tectoniques. La premiere (Jurassique moyen-superieur), associee au metamorphisme Sanbagawa de type HP/ВТ, correspond a un cisaillement ductile d'Ouest en Est, responsable des lineations E — W et du charriage des formations de schistes verts sur une unite greseuse, consideree comme la couverture d'un socle sialique : le bloc Oboke-Kurosegawa. Pendant la seconde phase, des nappes post-metamorphiques sont mises en place, au Jurassique terminal -Eocretace, avec une vergence principalement vers le Sud ou le SW, dans toutes les zones : Sanbagawa, Chichibu, Mino-Tanba ; la chaine paleozoique septentrionale (zones Sangun-Maizuru) est elle-meme remobilisee. La phase 3, d'âge Cretace inferieur-moyen, est responsable de plis droits disposes en echelon, associes au jeu decrochant de la ligne tectonique mediane, lequel est subcontemporain du metamorphisme Ryoke de type HT/BP. En admettant l'existence d'un socle Pre-Ryoke, un modele geodynamique de subduction continentale oblique du bloc Oboke-Kurosegawa, suivi par sa collision avec le bloc Pre-Ryoke, est propose pour expliquer la premiere phase.
Journal of Asian Earth Sciences, Sep 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Tectonophysics, Sep 1, 2019
Pre-Variscan tectonic setting of the south margin of Armorica: Insights from detrital zircon ages... more Pre-Variscan tectonic setting of the south margin of Armorica: Insights from detrital zircon ages distribution and Hf isotopic composition of the S t-Georgessur-Loire Unit (S. Armorican Massif, France
AGU Fall Meeting Abstracts, Dec 1, 2015
HAL (Le Centre pour la Communication Scientifique Directe), 2006
ABSTRACT In order to better constrain the Neoproterozoic paleogeographic reconstruction of contin... more ABSTRACT In order to better constrain the Neoproterozoic paleogeographic reconstruction of continents and improve the understanding of the snowball Earth hypothesis, paleomagnetic collections on Neoproterozoic rocks were carried out in the Aksu area of the northwestern Tarim basin from 2001 to 2005. Six sites of limestone from the Chigebrak formation, 38 sites of sandstone and 4 sites of volcanic rocks from the Sugetbrak formation were sampled. The remaining 24 sites of sandstone and volcanic rocks reveal stable characteristic remanent component (ChRm) isolated from 500 to 680? The computed magnetic directions from these components are relatively consistent and significantly distinguished from those of younger ages. Both normal and reverse polarities have been observed though the normal one is dominant, moreover, the positive fold test is revealed after bedding corrections at 95% confidence level. A paleomagnetic pole is, therefore, calculated: l =19.1? f =149.7? k = 11.2, A95 = 9.3?with n = 24, yielding a paleolatitude of ~27 for the sampling area. The chemostratigraphic correlation of this section with reference ones reveals an average of ~595 Ma for the age for this collection. Comparing paleomagnetic data of the similar ages from Australia and South China as well as other major blocks, the Tarim block seemed being closely located in the north of Australia. A new paleogeographic reconstruction has been attempted which showing a general feature of lower paleolatitude for these blocks. Referring to the paleogeographic reconstruction at about 760Ma proposed by Chen et al. (2004), the continental landmass including the above mentioned blocks seemed having experienced a relatively slow southward kinematic drift and kept their rather low paleolatitude. These observations provide, therefore, evidences to the snowball Earth hypothesis in the late Neoproterozoic time.
Precambrian Research, Mar 1, 2014
Comptes Rendus. Géoscience
We found Middle and Late Triassic conodonts and radiolarians from the pelagic carbonates and succ... more We found Middle and Late Triassic conodonts and radiolarians from the pelagic carbonates and successive siliceous sediments of the Buruanga Peninsula in Panai Island, North Palawan Block. The carbonate units, long estimated to be Jurassic, revealed late Anisian and late Norian. The pelagic limestone carapace of basalt was constrained within the conodont Gladigondolella tethydis – Paragondolella excelsa Zone (late Illyrian/early Fassanian). The successive bedded-chert unit starts from Fassanian (lower Ladinian) radiolarian Triassocampe spp. – Yeharaia spp. Zone. The early to late Norian conodont mixed faunas (from Ancyrogondolella quadrata Zone to Mockina bidentata Zone and Misikella hernsteini Zone) were extracted from the turbiditic clastic-carbonate unit that intertongues with the pelagic limestone/chert unit of latest Norian age (conodont Misikella hernsteini Zone).
BSGF - Earth Sciences Bulletin, 2021
The Montagne Noire located in the southern part of the French Massif Central represents the north... more The Montagne Noire located in the southern part of the French Massif Central represents the northern part of the South-Variscan Foreland. It is subdivided into three parts. The granite-migmatite Axial Zone dome is surrounded by non- or weakly metamorphosed Paleozoic sedimentary series. Both northern and southern flanks of the Montagne Noire dome are deformed by km-scale, south to southeast facing recumbent folds and thrusts sheets. The Raman Spectroscopy of Carbonaceous Material (RSCM) method, carried out in the low-grade metamorphic rocks of the southern flank of the Montagne Noire, yielded temperatures comprised between 400 °C near the dome, and 230 °C in the southern domain. Three Raman geothermometers were used to cover this temperature range. RSCM temperatures comply qualitatively with previous estimates based on illite crystallinity, conodont color alteration, and fluid inclusions carried out in the same area, which document a metamorphic temperature increase towards the dome....
Ore Geology Reviews, 2020
Earth and Planetary Science Letters, 2015
Quaternary Geochronology, 2014
Sciences géologiques, 1984
La chaine mesozoique du Japon du SW est caracterisee par trois phases tectoniques. La premiere (J... more La chaine mesozoique du Japon du SW est caracterisee par trois phases tectoniques. La premiere (Jurassique moyen-superieur), associee au metamorphisme Sanbagawa de type HP/ВТ, correspond a un cisaillement ductile d'Ouest en Est, responsable des lineations E — W et du charriage des formations de schistes verts sur une unite greseuse, consideree comme la couverture d'un socle sialique : le bloc Oboke-Kurosegawa. Pendant la seconde phase, des nappes post-metamorphiques sont mises en place, au Jurassique terminal -Eocretace, avec une vergence principalement vers le Sud ou le SW, dans toutes les zones : Sanbagawa, Chichibu, Mino-Tanba ; la chaine paleozoique septentrionale (zones Sangun-Maizuru) est elle-meme remobilisee. La phase 3, d'âge Cretace inferieur-moyen, est responsable de plis droits disposes en echelon, associes au jeu decrochant de la ligne tectonique mediane, lequel est subcontemporain du metamorphisme Ryoke de type HT/BP. En admettant l'existence d'un socle Pre-Ryoke, un modele geodynamique de subduction continentale oblique du bloc Oboke-Kurosegawa, suivi par sa collision avec le bloc Pre-Ryoke, est propose pour expliquer la premiere phase.
Journal of Asian Earth Sciences, Sep 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Tectonophysics, Sep 1, 2019
Pre-Variscan tectonic setting of the south margin of Armorica: Insights from detrital zircon ages... more Pre-Variscan tectonic setting of the south margin of Armorica: Insights from detrital zircon ages distribution and Hf isotopic composition of the S t-Georgessur-Loire Unit (S. Armorican Massif, France
Ar/Ar geochronology in the western Tianshan (northwestern China): from Carboniferous (ultra)high-pressure metamorphism and thrusting to Permian strike-slip deformation and fluid ingress, Apr 1, 2012
The Tianshan belt (northwestern China) is a major tectonic element of the southern Central Asian ... more The Tianshan belt (northwestern China) is a major tectonic element of the southern Central Asian Orogenic Belt that contains a number of ophiolitic mélanges and (ultra)high-pressure metamorphic belts formed after closure of oceanic and back-arc basins that resulted in terrane collisions. Deciphering its tectonic evolution is thus crucial for understanding the amalgamation of Central Asia. We produce robust 40Ar/39Ar laser-probe evidence that the Tianshan is a Late Palaeozoic (ultra)high-pressure metamorphic collision belt, not a Triassic one, as suggested by some SHRIMP zircon ages in recent literature. Instead of trying to date the peak pressure conditions we focused on 40Ar/39Ar analysis of white mica formed during retrograde recrystallisation when the (ultra)high-pressure meta-morphic rocks of the Changawuzi-Kekesu complex were exhumed. Exhumation was coeval with their northward thrusting over the southern margin of the Yili terrane, the easternmost element of the Kazakhstan composite super-terrane, which produced main phase tectonic structures. The Yili terrane comprises a Proterozoic basement covered by metasediments, intruded by Early Carboniferous granites when it formed part of a continental margin arc. During the Permian deformation was partitioned in vertical brittle-ductile strike-slip fault zones that reactivated these suture zones and in which bimodal magmatism was concentrated. We also investigate the effects of these events on the isotopic ages of mica. 40Ar/39Ar laser-probe dating of white mica reveals that the strongest retrogressed blueschists immediately above the basal thrust fault of the Changawuzi-Kekesu belt gave the youngest plateau age of 316 ± 2 Ma (1σ). White mica in greenschist-facies metamorphic quartzite from the ductilely deformed metasedimentary cover of the Yili terrane's crystalline basement, taken at about 1 km below the thrust contact with the overlying Changawuzi-Kekesu belt, yielded a plateau age of 323 ± 1 Ma (1σ). Elsewhere, such metasediments yielded plateau ages (1σ) of 253 ± 1 (muscovite) and 252 ± 1 (biotite) Ma, whereas biotite from an undeformed ca. 340 Ma-old granite intruding the Yili terrane's southern margin gave a 263 ± 1 Ma plateau age (1σ). The 263-252-Ma-old samples were taken between 2 and 5 km across strike from the Permian Qingbulak–Nalati strike-slip fault, and within the 15–20 km wide zone with steeply dipping tectonic fabrics used by intruding Permian granites, and associated mineralisations. We interpret these Permian ages by recrystallisation of the mica by (late magmatic?) fluid flow channeled into these steep zones. Laser-probe dating of mylonite whole-rock samples from the North Tianshan – Main Tianshan strike-slip fault zone yielded 40Ar/39Ar spectra with step ages in the 255–285 Ma range, which date the movement on this ductile shear zone. The picture is emerging that a convective fluid system partly driven by magmatic heat, existed in a strongly fractured and weakened crust with an elevated heat flow, leading to regional-scale isotope resetting. We suggest that surprisingly young isotopic ages for early orogenic (ultra)high-pressure metamorphism are similarly due to fluid-mediated recrystallisation, leading to the erroneous view that the Tianshan is a Triassic orogenic belt.