Inhaltszusammenfassung

Metapelitic rocks in the aureole beneath the Bushveld Complex preserve evidence for both high- and low-a(H2O) anatexis. The aureole is characterized by an inverted thermal structure in which suprasolidus rocks potentially interacted with an H2O-rich volatile phase derived from underlying, dehydrating rocks. At lower grade (T 725degreesC), volatile-phase-absent, biotite-consuming melting and melt extraction produced coarse-grained garnet-cordierite granofels. At the contact, leucodiatexites d...Metapelitic rocks in the aureole beneath the Bushveld Complex preserve evidence for both high- and low-a(H2O) anatexis. The aureole is characterized by an inverted thermal structure in which suprasolidus rocks potentially interacted with an H2O-rich volatile phase derived from underlying, dehydrating rocks. At lower grade (T 725degreesC), volatile-phase-absent, biotite-consuming melting and melt extraction produced coarse-grained garnet-cordierite granofels. At the contact, leucodiatexites devoid of peritectic phases suggest effective segregation of melt from an underlying source. Migmatitic metapelites and their lower-grade stratigraphic equivalents have similar bulk-rock oxygen isotope values, consistent with very limited volatile phase infiltration and precluding the Bushveld Complex magmas as the source of the volatiles. » weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
3.42 - Geologie und Paläontologie

DDC Sachgruppe:
Geowissenschaften