【摘 要】
：
New integrated geochemical studies are reported for Jurassic granites of the Xingcheng area in the northeastern North China Craton. U–Pb zircon data indicate that the Huashan and Taili monzogranites were emplaced during the Early (189 ± 2 Ma) and Late (15
【机 构】
：
College of Earth Sciences,Jilin University,Changchun 130061,China;College of Earth Sciences,Jilin Un
论文部分内容阅读
New integrated geochemical studies are reported for Jurassic granites of the Xingcheng area in the northeastern North China Craton. U–Pb zircon data indicate that the Huashan and Taili monzogranites were emplaced during the Early (189 ± 2 Ma) and Late (155 ± 1 Ma) Jurassic, respectively. They are typical of high-K calc-alkaline series rocks and I-type granites, according to our whole-rock geochemical researches. Both Early and Late Jurassic monzogranites show adakitic rock characteristics because of their high Sr contents (221–347 ppm) and Sr/Y ratios (28.7–37.5), and low Y contents (7.83–14.7 ppm). The Early Jurassic monzogranite samples have an (87Sr/86Sr)i ratio of 0.7046, εNd(t) values of ?11.62 to ?11.51, and εHf(t) values of ?13.6 to ?6.4, whereas the Late Jurassic monzogranites have higher (87Sr/86Sr)i ratios of 0.7069–0.7071 and lower εNd(t) (?20.65 to ?20.46) and εHf(t) (?27.6 to ?20.0) values. We suggest that the Early Jurassic adakitic rocks were derived from partial melting of thickened lower crust contaminated with mantle-derived materials, related to subduction of the Paleo-Pacific Plate. The Late Jurassic adakitic rocks were derived from partial melting of thickened lower crust in an extensional tectonic setting associated with an active continental margin.
其他文献
基于高等数学课程中的条件极值的知识内容,通过启发诱导、问题探究结合的研究式教学方式,重新构建相应的教学设计与方案,着力培养、提高学生的创新思维和科研意识,力争为高等数学课程的教学探索和改革打开一个窗口.
We describe a new species of the genus Hebius and provide evidence for the validity of H.septemlineatus comb.nov..Morphological and molecular analyses of Hebius specimens collected in Yunnan Province,China,revealed three distinct lineages,namely the newly
Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is the etiologic agent responsible for the global coronavirus disease 2019 (COVID-19) pandemic.Numerous studies have demonstrated that cardiovascular disease may affect COVID-19 progression.In t
基于代数系统理论,证明了函数极限相等是一个等价关系、同余关系.并证明了极限存在的一元函数集合A的代数系统(A,±)是一个群,商代数(A/R,±)是一个商群.
Amolops chunganensis is a species complex and reported widely from eastern,southern,and southwestern China.Based on molecular data of 19 populations of A.chunganensis sensu lato from China,including the population from Mt.Wuyi (type locality),we recognize
In a precautionary response to the current coronavirus(COVID-19) pandemic,China\'s Ministries permanently banned eating and trading in terrestrial wild (non-livestock) animals on 24 February 2020,and extensively updated the list of Fauna under Special S
Phosphatidylserine (PS) is distributed asymmetrically in the plasma membrane of eukaryotic cells.Phosphatidylserine flippase (P4-ATPase) transports PS from the outer leaflet of the lipid bilayer to the inner leaflet of the membrane to maintain PS asymmetr
Inositol requiring mutant 80 (INO80) is a chromatin remodeler that regulates pluripotency maintenance of embryonic stem cells and reprogramming of somatic cells into pluripotent stem cells.However,the roles and mechanisms of INO80 in porcine pre-implantat
【摘要】能源是发展国民经济的基础, 近年来，随着人们对于自然能源无限度的开采与利用，现在已经造成了自然能源的严重匮乏，在建筑施工中实施节能技术是十分必要的，其具有的意义也是较为深远的。而建筑节能也越来越被国家重视,最近几年,国家相继颁发了一系列建筑节能标准来规范建筑节能市场。影响建筑能耗的因素很多,除了建筑设计要符合国家的节能标准外,施工中严格按照要求控制节能工程质量也是非常重要的。 【关键词
Viruses can be transmitted from animals to humans (and vice versa) and across animal species.As such,host-virus interactions and transmission have attracted considerable attention.Non-human primates (NHPs),our closest evolutionary relatives,are susceptibl