Laser Ar-40/Ar-39 isochron dating on Leizhou Quaternary volcanic rocks

	Laser Ar-40/Ar-39 isochron dating on Leizhou Quaternary volcanic rocks
	Li WeiRan 1; Ji JianQing 1; Sang HaiQing 2; Zhou Jing 1; Tu JiYao 1; Sa Xiao 3; Ye Heng 1
刊名	ACTA PETROLOGICA SINICA
	2013-08-01
卷号	29 期号:8 页码:2775-2788
关键词	Laser Ar-40/Ar-33 isochron dating Leizhou area Volcanic rocks
ISSN号	1000-0569
文献子类	Article
英文摘要	Leizhou area is one of the most important distribution areas of Cenozoic volcanic rocks. Volcanic activities in this area concentrate in mid to late Pleistocene. Researchers dated Leizhou volcanic rocks mainly by K-Ar method and the results indicate the isotopic ages vary from 0.38Ma to 3.04Ma. However, according to the stratigraphic sequence, Leizhou Quaternary volcanic rocks overlie the layers of 1.87Ma and 0.76Ma. Therefore, the ages of volcanic rocks must be younger than the underlying layers, which indicates the error of ages dated by K-Ar method. This paper dates samples taken from Leizhou area by laser Ar-40/Ar-39 dating method. The results show that ages mainly center on 0.18Ma, indicating the eruptions occurred approximately 180000a ago. We can also infer that, to young samples, the isotopic ages dated by K-Ar method and apparent ages dated by(40)Ar/(39)Armethod are all older than the real ages. By comparison, isochron ages by Ar-40/Ar-39 method are more reliable. Furthermore, reliable ages calculated with phenocryst and matrix from the same sample (phenocryst-matrix isochron) must base on the fact that the phenocryst and matrix are congenetic. To determine whether they are congenetic or not, this paper proposes as the first time to compare the uniformity of initial Ar-36/Ar-38 value of samples before irradiated by neutron, thus testing the reliability of phenocryst-matrix isochron. Based on that, isochron dating method could be extended to all the other datings on congenetic and isochronic samples from the same district.
WOS关键词	ALDER-CREEK ; K-AR ; INTERCALIBRATION ; AGES
WOS研究方向	Geology
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000323689100013
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/86826]
专题	中国科学院地质与地球物理研究所
通讯作者	Li WeiRan
作者单位	1.Peking Univ, Sch Earth & Space Sci, Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 3.China Univ Geosci, Beijing 100083, Peoples R China
推荐引用方式 GB/T 7714	Li WeiRan,Ji JianQing,Sang HaiQing,et al. Laser Ar-40/Ar-39 isochron dating on Leizhou Quaternary volcanic rocks[J]. ACTA PETROLOGICA SINICA,2013,29(8):2775-2788.
APA	Li WeiRan.,Ji JianQing.,Sang HaiQing.,Zhou Jing.,Tu JiYao.,...&Ye Heng.(2013).Laser Ar-40/Ar-39 isochron dating on Leizhou Quaternary volcanic rocks.ACTA PETROLOGICA SINICA,29(8),2775-2788.
MLA	Li WeiRan,et al."Laser Ar-40/Ar-39 isochron dating on Leizhou Quaternary volcanic rocks".ACTA PETROLOGICA SINICA 29.8(2013):2775-2788.