Ar-40/Ar-39 geochronology of the Faku tectonites: Implications for the tectonothermal evolution of the Faku block, northern Liaoning

doi:10.1360/03yd0208

	Ar-40/Ar-39 geochronology of the Faku tectonites: Implications for the tectonothermal evolution of the Faku block, northern Liaoning
	Zhang, XH; Wang, H; Li, TS
刊名	SCIENCE IN CHINA SERIES D-EARTH SCIENCES
	2005-05-01
卷号	48 期号:5 页码:601-612
关键词	Northern Liaoning Tectonite Ar-40/ar-39 Age Zircon U-pb Age Faku Faulted Convex
ISSN号	1006-9313
DOI	10.1360/03yd0208
文献子类	Article
英文摘要	For lack of reliable isotopic chronological data, the metamorphic rock series in the Faku region of northern Liaoning has long been regarded as the platform basement. Recent studies reveal that these deformed and metamorphosed rocks, with a variety of protoliths of plutonic intrusions and supracrustal volcanic and sedimentary rocks, were genetically related to later ductile shearing events, and they, together with the syntectonic intrusions, constituted the large-scale Faku tectonites. In this paper, we report new Ar-40/Ar-39 data on hornblende, biotite, and K-feldspar from typical granitic mylonites in this suite of tectonites. The plateau age 256 Ma of FK53 homblende and the high-temperature plateau age 262 Ma of Fk51-1 biotite should represent the cooling ages when the granites, formed as a result of Paleozoic oceanic crustal subduction beneath the continental crust or collision of multiple micro-continental blocks, were exhumed into shallow crustal levels. The plateau age 231 Ma of FK51-1 boitite and the apparent age 227 Ma of Fk51-2 K-feldspar are interpreted to record the time of ductile deformation occurring under greenschist facies conditions, i.e. the formation age of the Faku tectonites, while the age gradient from 197 Ma to 220 Ma of Fk51-2 K-feldspar probably record the subsequent stable uplift-cooling process. The tectonic exhumation event indicated by the plateau age 180 Ma of Fk51-2 K-feldspar may be associated with the onset of paleo-Pacific subduction beneath the North China plate. In addition, the U-Pb dating of FK54 zircon from later-intruded granite yields the age of crystallization of this super-unit intrusion at 159 Ma, thus establishing an upper limit for the formation age of the Faku tectonites, while the plateau age 125 Ma of Fk54 K-feldspar most likely corresponds to the rapid cooling and tectonic denudation event associated with the final collision between the Siberian plate and the North China plate. These isotopic ages provide important geochronological constraints for re-evaluating the tectonic essence of the Faku Faulted Convex and ascertaining the suturing boundary between the North China Platform and the Xingmeng Fold System.
WOS关键词	A-TYPE GRANITES ; NE CHINA ; SONGLIAO BASIN ; AGE ; PETROGENESIS ; CONSTRAINTS ; MOUNTAINS ; COLLISION ; BENEATH ; ZIRCON
WOS研究方向	Geology
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000230472800002
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/65668]
专题	中国科学院地质与地球物理研究所
通讯作者	Zhang, XH
作者单位	Chinese Acad Sci, Inst Geol & Geophys, Key Lab Lithosphere Tecton Evolut, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Zhang, XH,Wang, H,Li, TS. Ar-40/Ar-39 geochronology of the Faku tectonites: Implications for the tectonothermal evolution of the Faku block, northern Liaoning[J]. SCIENCE IN CHINA SERIES D-EARTH SCIENCES,2005,48(5):601-612.
APA	Zhang, XH,Wang, H,&Li, TS.(2005).Ar-40/Ar-39 geochronology of the Faku tectonites: Implications for the tectonothermal evolution of the Faku block, northern Liaoning.SCIENCE IN CHINA SERIES D-EARTH SCIENCES,48(5),601-612.
MLA	Zhang, XH,et al."Ar-40/Ar-39 geochronology of the Faku tectonites: Implications for the tectonothermal evolution of the Faku block, northern Liaoning".SCIENCE IN CHINA SERIES D-EARTH SCIENCES 48.5(2005):601-612.