Geochemistry of sedimentary rocks from Permian–Triassic boundary sections of Tethys Himalaya: implic

来源 :Acta Geochimica | 被引量 : 0次 | 上传用户:hxjswordin123456
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The geochemical characteristics of two sections—the Permian–Triassic boundary(PTB) Guryul Ravine section, Kashmir Valley, Jammu and Kashmir,India; and the Attargoo section, Spiti Valley, Himachal Pradesh, India—have been studied in the context of provenance, paleo-weathering, and plate tectonic setting.These sections represent the siliciclastic sedimentary sequence from the Tethys Himalaya. The PTB siliciclastic sedimentary sequence in these regions primarily consists of sandstones and shales with variable thickness. Present studied sandstones and shales of both sections had chemical index of alteration values between 65 and 74; such values reveal low-to-moderate degree of chemical weathering. The chemical index of weathering in studied samples ranged from 71 to 94, suggesting a minor K-metasomatism effect on these samples. Plagioclase index of alteration in studied sections ranged from 68 to 92, indicating a moderate degree of weathering of plagioclase feldspars. The provenance discriminant function diagram suggests that the detritus involved in the formation of present studied siliciclastic sedimentary rocks fall in quartzose sedimentary and felsic igneous provenances. These sediments were deposited in a passive continental margin plate tectonic setting according to their location on a Si_2 O versus K_2O/Na_2 O tectonic setting diagram. The geochemical characteristics of two sections - the Permian-Triassic boundary (PTB) Guryul Ravine section, Kashmir Valley, Jammu and Kashmir, India; and the Attargo section, Spiti Valley, Himachal Pradesh, India- have been studied in the context of provenance, paleo-weathering, and plate tectonic setting. These sections represent the siliciclastic sedimentary sequence from the Tethys Himalaya. The PTB siliciclastic sedimentary sequence in these regions is primarily composed of sandstones and shales with variable thickness. Present studied sandstones and shales of both sections had chemical index of alteration values ​​between 65 and 74; such values ​​reveal low-to-moderate degree of chemical weathering. The chemical index of weathering in studied samples ranged from 71 to 94, suggesting a minor K-metasomatism effect on these samples. Plagioclase index of alteration in studied sections ranged from 68 to 92, indicating a moderate degree of weathering of plagioclase feldspars. The provenance discriminant function diagram suggests that the detritus involved in the formation of pre-treated siliciclastic sedimentary rocks fall in quartzose sedimentary and felsic igneous provenances. These sediments were deposited in a passive continental margin plate tectonic setting according to their location on a Si_2 O versus K_2O / Na_2 O tectonic setting diagram.
其他文献
为探讨棉纺织作业职工死亡原因 ,我们对某棉纺织厂 1 981~ 1 997年间职工死亡情况作一般死因分析。结果表明 ,该棉纺织厂平均死亡年龄为 46 8岁。恶性肿瘤、脑血管 ,意外死
请下载后查看,本文暂不支持在线获取查看简介。 Please download to view, this article does not support online access to view profile.
【本刊讯】2008年12月23日,天才少年钢琴家牛牛将在中国国家大剧院音乐厅为大家带来一场精彩的钢琴独奏音乐会,当天恰逢国家大剧院周岁生日。牛牛,学名张胜量。生于钢琴之乡
暑期的生活总是多姿多彩,而08年的上海国际弦乐夏令营又使我们的假期更加丰富、更加充实。这个由上海音乐学院丁芷诺教授发起的弦乐夏令营,每年都有特定的节目,今年也不例外
山东省棉花铃期遭受多种病菌的侵害而造成的棉铃腐烂、纤维腐朽无收,统称为烂铃。据多年调查,一般年份因烂铃要减产15%~25%,严重年份减产30%以上,而且严重影响了棉花的品质,
“卫网”医院信息系统软件 (视窗版 ) ,是山东兴业信息技术工程中心根据卫生部信息化工作领导小组 1998年4月颁布的关于《医院信息系统软件评审管理办法 (试行 )》、《医院信
随着生活质量的日益提高,人们对瓜、果、蔬菜、烟草、茶叶上的农药残留问题的重视程度越来越高。1999年河北省宣化农药厂成功地开发出了新型环保无公害杀虫、杀螨剂——力杀
请下载后查看,本文暂不支持在线获取查看简介。 Please download to view, this article does not support online access to view profile.