Rhyolitic ignimbrites of the Cape Granite Suite, southwestern Cape Province, South Africa

✍ Scribed by R. Scheepers; A.N. Nortjé

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 806 KB
• Volume: 31
• Category: Article
• ISSN: 1464-343X
• DOI: 10.1016/s0899-5362(00)80012-3

✦ Synopsis

Based on textural and geochemical evidence, the existence of Late Precambrian rhyolitic volcanism related to the Cape Granite Suite is illustrated. Recrystallised rhyoliiic ignimbriies represent the volcanic phase of a subvolcanic to volcanic sequence composed of rhyodacite to rhyolitic magma. Textural features including fiamme, pumice fragments and glass shards provide unequivocal evidence for the volcanic origin of these rocks. o 2001 Published by Elsevier Science Limited. RESUME-Sur la base d'arguments texturaux et geochimiques, on montre I'existence d'un volcanisme rhyoliiique d'bge Precambrian terminal et associe B la Cape Granite Suite. Des ignimbrites rhyolitiques recristallisees representent la composante effusive d'une sequence volcanique B subvolcanique issue de magmas rhyodacitiques B rhyolitiques. Des caracteristiques texturales comme la presence de fiammes, fragments de ponces et dchardes de verre, temoigne sans equivoque de la nature volcanique originelle de ces roches.