Association of Late Paleozoic Adakitic Rocks and Shoshonitic Volcanic Rocks in the Western Tianshan,

来源 :Acta Geologica Sinica(English Edition) | 被引量 : 0次 | 上传用户:cbir
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 late Paleozoic adakitic rocks are closely associated with the shoshonitic volcanic rocks in the western Tianshan Mountains, China, both spatially and temporally. The magmatic rocks were formed during the period from the middle to the late Permian with isotopic ages of 248-268 Ma. The 87Sr/86Sr initial ratios of the rocks are low in a narrow variation range (-0.7050). The 143Nd/144Nd initial ratios are high (-0.51240) with positive εND(t) values (+1.28-+4.92). In the εNd(t)-(87Sr/86Sr)i diagram they fall in the first quadrant. The association of the shoshonitic and adakitic rocks can be interpreted by a two-stage model: the shoshonitic volcanic rocks were formed through long-term fractional crystallization of underplated basaltic magma, while the following partial melting of the residual phases formed the adakitic rocks. The late Paleozoic adakitic rocks are closely associated with the shoshonitic volcanic rocks in the western Tianshan Mountains, China, both spatially and temporally. The magmatic rocks were formed during the period from the middle to the late Permian with isotopic ages of 248-268 Ma. The 87Sr / 86Sr initial ratios of the rocks are low in a narrow variation range (-0.7050). The 143Nd / 144Nd initial ratios are high (-0.51240) with positive εND (t) values ​​(+ 1.28- + 4.92). In the ε association of the shoshonitic and adakitic rocks can be interpreted by a two-stage model: the shoshonitic volcanic rocks were formed through the long-term fractional crystallization of ε-Nd (t) - (87Sr / 86Sr) i diagram underplated basaltic magma, while the following partial melting of the residual phases formed the adakitic rocks.
其他文献
摘 要:中高职课程衔接是在职高教育发展中必须经历的一个过程,是中高职教学的中间枢纽。在对中高职会计专业课程体系进行衔接时会发现,中职和高职没有太大的区别,然而却培养出不同层次的会计,不仅浪费教育资源还降低了学生学习的积极性。本文就中高职会计专业课程体系衔接一体化进行了探讨。  关键词:中高职;会计专业;课程体系;衔接;一体化设计  由于高职院校的生源越来越少,教育部对高职考试招生制度进行了改革,中
实践教学是思政政治课程当中的薄弱环节,也是思政政治教学中最易受到忽视的教学环节。思政课程作为一门理论知识强的课程,其实践教学能够有效加深学生对思政理论课程知识的印
职业教育行动导向的教学过程一般有六个步骤:信息、计划、决策、实施、检查、评估,每个步骤都有教学目标要求、能力培养要求、工作方法要求和完成时间要求。行动导向教学强调
在中职中医药专业的教学中,中药学是一门重要的课程,这对于中医药专业的学生来说,是其基础,也是桥梁。中药学作为一门对中药进行研究和阐述的基本学科,重视的是对基础理论知
This paper presents the studies on groundwater resources potential of the Yellow River (YR) terrace in Zhengzhou area, China. The main aim of the research was t
Cathodoluminescence (CL) and mineral inclu- sions investigations show that zircons from Yinggelisayi UHP metamorphosed granitoid gneiss in Altyn Tagh exhibit
全国城市勘测 5 0周年是一个值得庆祝的大事情 ,在这个会议上 ,我们表彰了 5 0个先进集体 ,表彰了10 0名先进勘测工作者 ,总结了 5 0年的经验。这个会议之后 ,中国城市规划协
The analyses of different sulfur forms, the trace elements in pyrites using electron microprobe and the trace elements in coal using INAA (instrumental neutron
本文提出了一种基于双微机的采用电液比例阀作为先导控制阀的水轮机轮叶控制系统。该系统具有结构简单、抗油污能力强、数字协联精度高、容错能力强等优点。 In this paper,
由中国地质科学院勘探技术研究所主办的“商务部TCDC(Technical co-operation among developingcountries)水文水井钻探技术培训班”于2004年8月1日正式开班,8月2日下午在中