The hidden monzogranite of Soultz-sous-Forêts (Rhine Graben, France)
Jean-Marc Stussi and Alain Cheilletz and Jean-Jacques Royer and Philippe Chevremont and Gilbert Féraud. ( 2002 )
in: G{\'e}ologie de la France:1 (45-64)
Abstract
Drilling at Soultz-sous-Forêts, France, conducted as part of the European Hot Dry Rock (HDR) Project, penetrated granitic basement down to 5,080 m and revealed a porphyritic monzogranite that has no equivalent in the granitic outcrops of adjacent basement aeras. The EPS-1 borehole core (from 980 to 2,230 m) shows a monzogranite that has a high-K calcalkaline composition and is enriched in K, Th, U , and REE. Petrological and mineralogical characteristics indicate that the monzogranite formed through two crystallization stages: a first, deep-seated, stage was characterized by the crystallization of liquidus phases in the 755-790^{\circ}C range, at 3.5 kb (11-12 km depth). This was followed, during ascent and at emplacement level, by consolidation at 665-715^{\circ}C, 1.5-2.0 kb (4.5-5.5 km depth) associated with the development of K-feldspar layering. Published Rb/Sr ages (325 Ma), new 40Ar/39Ar cooling ages (319 Ma), a U/Pb on zircon emplacement age of 331 Ma, and petrological arguments such as the presence of monzogabbrodiorite to quartz-syenite enclaves, indicate that the Soultz monzogranite had a mainly crustal origin with a possible contribution of mantle-derived components represented by the enclaves. Emplacement was related to collision tectonics during the transition between Early and Late Carboniferous.
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BibTeX Reference
@article{stussi:hal-04055905,
abstract = {Drilling at Soultz-sous-Forêts, France, conducted as part of the European Hot Dry Rock (HDR) Project, penetrated granitic basement down to 5,080 m and revealed a porphyritic monzogranite that has no equivalent in the granitic outcrops of adjacent basement aeras. The EPS-1 borehole core (from 980 to 2,230 m) shows a monzogranite that has a high-K calcalkaline composition and is enriched in K, Th, U , and REE. Petrological and mineralogical characteristics indicate that the monzogranite formed through two crystallization stages: a first, deep-seated, stage was characterized by the crystallization of liquidus phases in the 755-790^{\circ}C range, at 3.5 kb (11-12 km depth). This was followed, during ascent and at emplacement level, by consolidation at 665-715^{\circ}C, 1.5-2.0 kb (4.5-5.5 km depth) associated with the development of K-feldspar layering. Published Rb/Sr ages (325 Ma), new 40Ar/39Ar cooling ages (319 Ma), a U/Pb on zircon emplacement age of 331 Ma, and petrological arguments such as the presence of monzogabbrodiorite to quartz-syenite enclaves, indicate that the Soultz monzogranite had a mainly crustal origin with a possible contribution of mantle-derived components represented by the enclaves. Emplacement was related to collision tectonics during the transition between Early and Late Carboniferous.},
author = {Stussi, Jean-Marc and Cheilletz, Alain and Royer, Jean-Jacques and Chevremont, Philippe and F{\'e}raud, Gilbert},
hal_id = {hal-04055905},
hal_version = {v1},
journal = {{G{\'e}ologie de la France}},
keywords = {Monzogranites ; Major-element analyses ; Trace-element analyses ; Rare earths ; K-Ar ; Ar40-Ar39 ; Crustal origin ; Variscan orogeny ; Bas-Rhin France ; Rhine Graben ; Monzogranite ; Analyse {\'e}l{\'e}ments majeurs ; Analyse {\'e}l{\'e}ment trace ; Terre rare ; K-Ar ; Ar40-Ar39 ; Origine crustale ; Orog{\'e}nie varisque ; Bas-Rhin ; Foss{\'e} Rh{\'e}nan},
number = {1},
pages = {45-64},
publisher = {{BRGM}},
title = {{The hidden monzogranite of Soultz-sous-For{\^e}ts (Rhine Graben, France)}},
url = {https://hal.univ-lorraine.fr/hal-04055905},
year = {2002}
}