Decompression reactions and P–T conditions in high-pressure granulites from Casares-Los Reales units of the Betic-Rif belt (S Spain and N Morocco)
✍ Scribed by Faouziya Haissen; Antonio Garcia-Casco; Rafael Torres-Roldan; Abdelmouhsine Aghzer
- Publisher
- Elsevier Science
- Year
- 2004
- Tongue
- English
- Weight
- 404 KB
- Volume
- 39
- Category
- Article
- ISSN
- 1464-343X
No coin nor oath required. For personal study only.
✦ Synopsis
High-pressure granulites are exposed in the Casares-Los Reales group (internal zones of Betic-Rif belt, S Spain-N Morocco) as part of the crustal envelope of Beni Bousera-Ronda Peridotites. They are mostly metapelitic but include intercalations of mafic composition. The metamorphic history is marked by the preservation of early high-pressure assemblages together with secondary lowpressure assemblages suggesting a state of textural and compositional disequilibrium. The P-T path constrained by geothermobarometry and reaction textures from mafic and pelitic lithotypes passes from P800 °C/15 kbar to 600 °C/5 kbar, to indicating a strong decompression related to cooling, followed by a near-isobaric cooling 430 °C and 4 kbar. Such P-T evolution of granulites is thought to reflect some sort of rapid tectonic collapse of crust previously thickened through collision.