Temporal relationships between Mg-K mafic magmatism and catastrophic melting of the Variscan crust in the southern part of Velay Complex (Massif Central, France)

S Couzinié, JF Moyen, A Villaros… - Journal of …, 2014 - insu.hal.science
Journal of Geosciences, 2014insu.hal.science
Mg-K mafic intrusive rocks are commonly observed during the late stages of the evolution of
orogenic belts. The Variscan French Massif Central has many outcrops of these rocks,
locally called vaugnerites. Such magmas have a mantle-derived origin and therefore allow
discussion of the role of mantle melting and crust-mantle interactions during late-orogenic
processes. In the Southern Velay area of the French Massif Central, LA-ICPMS U-Pb dating
on zircons and monazites from three vaugnerites and four coeval granites reveals that the …
Mg-K mafic intrusive rocks are commonly observed during the late stages of the evolution of orogenic belts. The Variscan French Massif Central has many outcrops of these rocks, locally called vaugnerites. Such magmas have a mantle-derived origin and therefore allow discussion of the role of mantle melting and crust-mantle interactions during late-orogenic processes. In the Southern Velay area of the French Massif Central, LA-ICPMS U-Pb dating on zircons and monazites from three vaugnerites and four coeval granites reveals that the two igneous suites formed simultaneously, at c. 305 Ma. This major igneous event followed after an early, protracted melting stage that lasted for 20-30 My and generated mig- matites, but the melt was not extracted efficiently and therefore no granite plutons were formed. This demonstrates that widespread crustal anatexis, melt extraction and granite production were synchronous with the intrusion of vaugneritic mantle-derived melts in the crust. The rapid heating and subsequent melting of the crust led to upward flow of partially molten rocks, doming and collapse of the belt.
insu.hal.science
以上显示的是最相近的搜索结果。 查看全部搜索结果