U-Pb zircon and Rb-Sr whole-rock dating of low-grade metasediments example: Montagne Noire (Southern France)

1976 ◽  
Vol 59 (1) ◽  
pp. 13-32 ◽  
Author(s):  
D. Gebauer ◽  
M. Gr�nenfelder
Keyword(s):  
Low Grade ◽  
Southern France ◽  
Montagne Noire

Isograds and mineral assemblages in the eastern axial zone, Montagne Noire (France): implications for temperature gradients and P–T history

1982 ◽  
Vol 19 (1) ◽  
pp. 129-143 ◽  
Author(s):  
Peter H. Thompson ◽  
Jean-Pierre Bard
Keyword(s):  
Metamorphic Grade ◽  
Temperature Gradients ◽  
Low Grade ◽  
Reaction Sequence ◽  
Axial Zone ◽  
Rock Composition ◽  
Mineral Assemblages ◽  
Montagne Noire ◽  
Sequence Study

Detailed petrography across a metapelitic sequence in the eastern axial zone of the Montagne Noire, France, is the basis for a sequence of isograds marking the first appearance of biotite–cordierite, staurolite, andalusite, and sillimanite. The juxtaposition of low-grade biotite-free rocks against medium-grade rocks at the gently dipping biotite–cordierite isograd is attributed to tectonic telescoping of the metamorphic sequence. Study of mineral assemblages with respect to an AFM reaction sequence indicates the staurolite isograd is related to changes in rock composition, and complex assemblages in the sillimanite zone may be the result of unstable persistence of minerals formed when metamorphic grade was lower. These assemblages are interpreted to contain a record of part of the P–T history during which pressure decreased as temperature increased. P–T profiles show that temperature gradients of 200–300 °C/km suggested by previous workers are not required to explain the isograd pattern; gradients of 37 °C/km or less are sufficient.

Depositional controls on Early Cambrian microbial carbonates from the Montagne Noire, southern France

1998 ◽  
Vol 89 (3) ◽  
pp. 135-143 ◽  
Author(s):  
J. Javier Álvaro ◽  
Emmanuelle Vennin ◽  
Daniel Vizcaïno
Keyword(s):  
Lower Cambrian ◽  
Southern France ◽  
Microbial Structures ◽  
Subaerial Exposure ◽  
Open Sea ◽  
Montagne Noire ◽  
Constructed Self ◽  
Depositional Controls ◽  
First Time ◽  
Open Shelf

AbstractLower Cambrian shallow-water carbonates enclosing microbial structures are documented for the first time from the upper Lastours Member of the Montagne Noire (southern France). Microbial organisms constructed self-supported boundstones resulting in the formation of exclusively microbial-accreted buildups, which exhibit three main types of non-skeletal microbialites: planar stratiform stromatolites, dome-shaped stromatolites and nonlaminated (thrombolitic) biostromes. In addition, thrombolitic boundstones display four distinct microbial microstructures: clotted andRenalcis-like forms, branching bushy forms, clusters of unbranching straight filaments and crustose forms.The upper member of the Lastours Formation records an upward transition from a shalydominant open shelf to a protected shelf environment bounded by a surface representing a major subaerial exposure. Initially, at the inception of the highstand systems tract, flat stratiform stromatolites formed on open sea subtidal shaly substrates, while stacked domal stromatolites developed in peritidal areas which record subaerial exposure. In contrast, prograding shoal barriers of the transgressive systems tract favoured the establishment of thrombolitic boundstones in protected (back-shoal) environments.

scholarly journals Early Late Cambrian Trilobites OF Australo-Sinian Aspect From The Montagne Noire, Southern France

Palaeontology ◽  
2000 ◽  
Vol 43 (4) ◽  
pp. 599-632 ◽  
Author(s):  
John H. Shergold ◽  
Raimund FEIST ◽  
Daniel Vizcaino
Keyword(s):  
Southern France ◽  
Late Cambrian ◽  
Montagne Noire ◽  
Early Late

Observations lithostratigraphiques nouvelles sur la serie de base (Ordovicien inferieur) des nappes de Cabrieres, region de Gabian-Glauzy (Montagne-Noire, Herault)

1964 ◽  
Vol S7-VI (3) ◽  
pp. 419-427 ◽  
Author(s):  
Henri Gonord ◽  
Jean Paul Ragot ◽  
Luc Saugy
Keyword(s):  
Southern France ◽  
Montagne Noire ◽  
Volcanic Series

Abstract A previously unsuspected series of volcanics has been discovered on the southeastern flank of the Montagne Noire in southern France. The lower Arenig-upper Tremadoc beds (Ordovician) are overlain successively by a lower pyroclastic series, andesitic porphyrite, and an upper detrital volcanic series. The volcanics are overlain by Devonian and Caradoc (Ordovician) strata of the Cabrieres nappe. The age of the volcanics is middle Arenig to Llandeilian (Ordovician).

Sur quelques especes nouvelles de Bryozoaires de l'Ordovicien superieur de la Montagne-Noire

1963 ◽  
Vol S7-V (1) ◽  
pp. 34-40 ◽  
Author(s):  
Marie Francois Boulange
Keyword(s):  
The South ◽  
Upper Ordovician ◽  
Southern France ◽  
Montagne Noire

Abstract Six species of bryozoa are described from the upper Ordovician of the south flank of Montagne Noire in southern France: Crepipora vesiculosa n. sp., Atactoporella irregularis n. sp., Cyphotrypa magna n. sp., Heterotrypa magnopora n. sp., Trematopora hirsuta n. sp., and Enallopora lineata n. sp.

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