摘要
澳大利亚寒武系集中分布在一南北向分布的从澳大利亚的北部、中部直到南澳大利亚克拉通地块上,少量寒武纪地层分布在新南威尔士、维多利亚和塔斯马尼亚。寒武系的底在中澳大利亚的Amadeus盆地出露得最好。下寒武统(大致相当于纽芬兰统和第二统)在澳大利亚北部大多数是不含化石的火山岩,而在澳大利亚中部和南澳大利亚的盆地中,其中最有名的是南澳大利亚的Arrowie和Stansbury盆地则是各种含化石的巨厚沉积序列。澳大利亚的下寒武统没有分阶方案,尽管在生物地层研究上最近取得很大进展,现在可以利用疑源类、遗迹化石、古杯类、三叶虫、腕足类、软体动物和其他小壳化石进行化石带的划分。很长一段时间内澳大利亚中部和北部的Ord-ian阶被认为是中寒武世最早期的,现在证明它可能相当于第二统的全部或者一部分;含化石的中寒武统和芙蓉统(或上寒武统)在Georgina盆地东部发育非常完整,在中澳大利亚、新南威尔士、维多利亚和塔斯马尼亚也可见到,都可以划分到阶。芙蓉统的底大致与Idamean阶的底相当。化石带的建立主要综合考虑球接子三叶虫、多节类三叶虫,自Iverian期晚期起再加上牙形类化石。寒武系的顶大致相当于Warendan阶的底,相关地层在Georgina盆地东部发育得很好。
Australian Cambrian rocks are concentrated in a meridional cratonic tract extending through northern and central Australia into South Australia. Smaller areas are present in New South Wales, Victoria and Tasmania. The base of the Cambrian System is best exposed in the Amadeus Basin of central Australia. The Early Cambrian （approximately equivalent to Terreneuvian and Series 2） in northern Australia is mostly represented by unfossiliferous volcanic rocks, whereas the central and South Australian ba- sins include thick, variously fossiliferous sedimentary successions, most notably in the Arrowie and Stansbury Basins of South Australia. No stages have been proposed for the Australian Early Cambrian, despite recent advances in biostratigraphic knowledge, preliminary biozonations are now available for acritarchs, ichnofossils, archaeocyaths, trilobites, brachiopods, molluscs and other small skeletal fossils. The Ordian Stage of central and northern Australia, long regarded as earliest Middle Cambrian, may prove to be partially or entirely Series 2. Fossiliferous Middle Cambrian and Late Cambrian/Furongian rocks are most complete in the eastern Georgina Basin, but are also known in central Australia, New South Wales, Victoria and Tasmania. This interval is completely subdivided into stages, with the base of the Furongian Series conveniently coincident with the base of the Idamean Stage. Constituent zones are based mainly on a combination of agnostine and polymeran trilobites, with the addition of conodonts from the late Iverian onward. The top of the Cambrian System approximates the base of the Warendan Stage, best developed in the eastern Georgina Basin.
出处
《地层学杂志》
CSCD
北大核心
2009年第1期35-47,共13页
Journal of Stratigraphy
