Granitoids from the Moonbi district, New England Batholith, Eastern Australia
作者:
B. W. Chappell,
期刊:
Journal of the Geological Society of Australia
(Taylor Available online 1978)
卷期:
Volume 25,
issue 5-6
页码: 267-283
ISSN:0016-7614
年代: 1978
DOI:10.1080/00167617808729035
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
The late Palaeozoic granitoids of the Moonbi district are derived both from igneous (I‐type) and sedimentary (S‐type) sources. Field and petrographic observations and chemical data on theI‐type granitoids show that they are derived from four separate and distinct source‐rock compositions and that, consequently, these granitoids may be grouped into four suites. Mafic xenoliths and microxenoliths are relatively more abundant in more maficI‐type granitoids. Such xenoliths are interpreted as restite, or material residual from partial melting of the source rocks. Variation within the granitoids is ascribed to varying degrees of separation of restite from the melt produced during each fusion event. The source material of theI‐type granitoids is considered to have been material underplated beneath the crust during an earlier subduction event. Two suites ofS‐type granitoids can be recognized. These are derivatives of pelitic materials that have undergone only a small amount of chemical weathering.
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