Helium and Argon Isotopes of the Tertiary Volcanic Rocks, Shandong Peninsula Significance for Crust-

来源 :中国地质大学学报 | 被引量 : 0次 | 上传用户:zhuyanmei
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
He and Ar isotopes of the Tertiary volcanic rocks from Jiyang basin and nearby Shanwang and Qixia areas in Shandong peninsula have been analyzed. The results show that all samples are characterized by an enrichment of radiogenic 4He leading to extremely low 3He/4He ratios (0.017 8-3.225)×10-6. They also have atmospheric-like 38Ar/36Ar ratios and slightly higher 40Ar/36Ar ratios (395.4-1 312.7) than air value. The enrichment of radioactive 4He is attributed to the long-term radiogenic accumulation of U and Th in the mantle. The low concentration of 3He is considered to be due to 3He loss during magma eruption. The loss is more obvious in the Neogene than in the Paleogene. Low 40Ar/36Ar ratios of all volcanic rocks may imply that subducted materials with atmospheric components have been preserved in the mantle, thus indicating that crust-mantle circulation occurred.
其他文献
对V型12缸柴油机缸盖振动燃烧段信号与缸内压力进行了时域对比,分析了失火时的缸盖振动响应,研究了供油规律随转速变化情况。分析表明缸盖振动中包含喷油器针阀落座的振动响
The chemical nitrogen cycle is becoming better characterized in terms of fluxes and reservoirs on a variety of scales. Galloway has demonstrated that reactive n
由于高速公路建设要求高、工期短、点多面广范围大,在施工中需要不断创新,运用新技术、新工艺成为必然。近年来,强夯路基技术在高速公路中广泛使用,并且取得了一定的效果。文
An analytical solution for scattering of plane P waves by a semi-cylindrical hill was derived by using the wave function expansion method, and convergence of th
Clear evidence provided by the singular value decomposition (SVD) analysis to the normalized difference vegetation index (NDVI) and precipitation data identifie
简述路基、地基及土质等各种结构物对桥头跳车产生的沉降,从而认识桥头跳车的原因,桥头出现的跳车现象,已成为高速公路的多发常见病害,严重影响行车的平稳性和安全性,是目前
Under harmonic wave excitation, the dynamic response of a bilinear SDOF system can be expressed by the Hilbert spectrum. The Hilbert spectrum can be formulated
利用大功率的激电测深法可以寻找焦家式深部金矿.首先,由物理和数学推导建立多层极化体的数理模型,其数理模型产生的极化场可由多层若干个极化单元场相叠加而成.由多次去除极