Characteristics of tectonic deformation of the melange zone in the Lachlan Orogen along eastern coast of Australia

The Narooma-Batemans Bay(NBB)area along the southeast coast of Australia is a part of the eastern zone of the Early Paleozoic Lachlan Orogen.In the NBB,a set of rock association consisting of turbidites,siliceous rock,basic lava,and argillaceous melange zone is mainly developed.According to systematic field geological survey,the deformation of 3 stages(D1,D2,and D3)was identified in the NBB.At stage D1,with the original bedding S0 in a nearly east-west trending as the deformation plane,tight folds,isoclinal folds,and other structures formed in the NBB accompanied by structural transposition.As a result,crenulation cleavage developed along the axial plane of the folds and schistosity S1 formed.At stage D2,with north-south-trending schistosity S1 as the deformation plane,a large number of asymmetrical folds and rotated porphyroclasts formed owing to thrusting and shear.At stage D3,leftlateral strike-slip occurred along the main north-south-trending schistosity.Based on the analysis of the characteristics of tectonic deformation in the NBB and summary of previous research results,it is determined that the early-stage(D1)deformation is related to Ordovician Macquarie arc-continent collision and the deformation at stages D2 and D3 is the result of the westward subduction of Paleo-Pacific Plate.That is,it is not the continuous westward subduction of the Paleo-Pacific Plate that constitutes the evolution model of the NBB as previously considered.

澳大利亚拉克兰造山带成矿地质条件与主要矿化类型

澳大利亚拉克兰造山带(又称拉克兰褶皱带,简称LFB)由强烈变形的寒武纪—泥盆纪深海沉积岩、燧石和基性火山岩,以及更年轻的盖层所构成,其造山过程表现为澳大利亚板块向东南方向不断增生的过程。该造山带的长期演化,形成了以维多利亚金矿省为典型代表的造山型金矿床及其它类型的多金属矿床,本质上这些矿床的形成与特殊的成矿地质条件密切相关。对该区相关文献进行分析和总结,提炼出拉克兰造山带金及多金属矿床的主要地质特征,划分出5种主要矿化类型:造山型金矿、花岗岩中细脉浸染型钨—锡矿、斑岩型铜—金矿、火山喷流铜—锌—金硫化物矿床、产于断陷盆地沉积岩中的铜—铅—锌—金矿。5种矿化类型各具特色,空间上有规律性地分布。

中草药地牯牛幼虫乙醇提取物GC/MS分析

通过对中草药地牯牛幼虫乙醇提取物进行GC/MS分析 ,发现该虫提取物中主要化学成分是脂肪羧酸和脂肪羧酸酯 ,其中Z ,Z 9,1 2 十八碳二烯酸和Z 9 十八碳烯酸乙酯分别占出峰面积的 2 2 2 4%和 2 3 83 % ,十二烷酸乙酯、十六烷酸乙酯、十四烷酸乙酯和十四烷酸分别占出峰面积的 1 0 0 0 %、 1 6 1 2 %、 1 1 1 1 %和 8 1 3 % ,共占峰面积的 91 47%。

澳大利亚卡迪亚里奇韦斑岩型铜金矿床成矿特征

与碱性岩有关的斑岩型铜金矿床具有较高的经济价值,是矿床学研究的热点。本文以位于澳大利亚拉克兰造山带东带内的与碱性岩有关的卡迪亚里奇韦斑岩型铜金矿床为例,通过研究该矿床的地质特征,总结出该矿床的成矿岩体为富碱富钾的钾玄质中性侵入岩,矿床矿化类型以石英脉型为主,钾化蚀变发育且与主矿化期的关系密切。对比认为该矿床在构造背景、矿化蚀变、成矿元素、矿化类型等方面与典型的斑岩型铜金矿床有显著差别。通过区域对比,总结该类矿床的主要控矿因素,认为该类铜、金矿床在我国东部地区也具有较好的找矿前景。