Polygenetic mélange in the Hodgkinson goldfield, Northern Tasman Orogenic Zone
作者:
S. G. Peters,
期刊:
Australian Journal of Earth Sciences
(Taylor Available online 1993)
卷期:
Volume 40,
issue 2
页码: 115-129
ISSN:0812-0099
年代: 1993
DOI:10.1080/08120099308728069
出版商: Taylor & Francis Group
关键词: clast‐in‐matrix rock;cleavage;folding;Hodgkinson Province;mélange
数据来源: Taylor
摘要:
Polygenetic mélange is intercalated with multiply deformed Siluro‐Devonian shale, greywacke, clast‐in‐matrix rock, spilite and chert in the Hodgkinson goldfield of northeast Australia. Differing sedimentary facies, fold styles, veining events and mélange units occur in six fault‐bounded domains. Locally coherent stratigraphic units can be traced into the mélange. The chief mechanism of fragmentation in the mélange was an intense domainal cleavage event which formed chlorite‐illite‐vitrinite seams. Multiple tight folding and local shale diapirism pre‐dated cleavage development and greatly contributed to desegregation and mixing. Late brittle shear zones further juxtaposed coherent phacoidal megablocks within zones of clast‐in‐matrix rock. Laminated protolith sequences aided the formation of clast‐in‐matrix rock, whereas more massive units became slabs, blocks and clasts. The rocks are of sub‐greenschist metamorphic facies, based on spilite and sandstone mineral assemblages, textures and illite crystallinity. Sequential genesis of the mélange correlates well with the known progression of Late Palaeozoic deformation, and contains characteristics of both collision and overthrust type margins.
点击下载:
PDF (1631KB)
返 回