Aspects of volcanism and metamorphism of the Onverwacht group lavas in the South-Western portion of the Barberton greenstone belt.

[摘要] A volcanological study of the Onverwacht Group in the southwestern part of theArchaean (-3.5 - 3.2 Ga) Barberton greenstone belt (BGB), South Africa, shows thatvolcanic extrusion rates of the Komati and Hooggenoeg Formations must have been highto have maintained the degree of submarine sheet flooding that is evident. It isconcluded that the volcanic attributes of the Komati and Hooggenoeg Formations arenot typical of MOR crust, as has been claimed, but rather closely resemble those ofmodern oceanic plateaus. The shear-zone-bound basal contact of the Komati Formationsuggests that the top of the ancient oceanic plateau was allochthonously emplaced anddelaminated from its basal (intrusive) part. (Abbreviation abstract)

[发布机构] University of the Witwatersrand