Discovery of iridium and other element anomalies near the 1908 Tunguska explosion site

	Discovery of iridium and other element anomalies near the 1908 Tunguska explosion site
	Hou, QL ; Ma, PX ; Kolesnikov, EM
刊名	PLANETARY AND SPACE SCIENCE
	1998-02-01
卷号	46 期号:2-3 页码:179-188
ISSN号	0032-0633
文献子类	Article
英文摘要	Fifteen peat samples collected from a core including the layer affected by the 1908 Tunguska explosion in Tunguska area of central Siberia, Russia, were analyzed by NAA to determine the contents of Ir, REE, Ni,Co, Fe and Sb. The analytical results indicate that Ir concentration in and under the event layer were 0.54-0.24 ppb, about 10-20 times higher than those reported in the work of Korina et al. (1987) and more than 2 times higher than in layers above, and other elements were enriched by factors of 2 to 5. fn addition, the variation of Ni concentration is closely related with Ir in the explosive layer, and the patterns of chondrite-normalized REE are almost hat, which are different om the traps of Siberian plateform. Hence, it can be inferred from the characteristics of elemental geo-chemistry that the explosion likely was associated with an extraterrestrial object. Because it exploded before reaching the ground, the density of the projectile must have been quite low, and its chemical composition was probably similar to carbonaceous chondrites (Cl). According to the Ir flux in the explosion area, it can be estimated that the celestial body weighed more than 3.5 x 10(4) tons, corresponding to >60 m in diameter, and might have released energy equivalent to more than 10(6) t of TNT. If the projective was a comet, the total mass was more than 7 x 10(6) tons, and the diameter of core was more than 160 m. (C) 1998 Elsevier Science Ltd. All rights reserved.
WOS关键词	COSMIC BODY ; EVENT ; EXTINCTION ; IMPACT ; SEARCH
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000073658800007
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/75154]
专题	中国科学院地质与地球物理研究所
通讯作者	Hou, QL
作者单位	1.Chinese Acad Sci, Inst Geol, Lab Lithosphere Tecton Evolut, Beijing 100029, Peoples R China 2.Beijing Univ, Inst Heavy Ion Phys, AMS Lab, Beijing 100871, Peoples R China 3.Moscow MV Lomonosov State Univ, Fac Geog, Moscow 119899, Russia
推荐引用方式 GB/T 7714	Hou, QL,Ma, PX,Kolesnikov, EM. Discovery of iridium and other element anomalies near the 1908 Tunguska explosion site[J]. PLANETARY AND SPACE SCIENCE,1998,46(2-3):179-188.
APA	Hou, QL,Ma, PX,&Kolesnikov, EM.(1998).Discovery of iridium and other element anomalies near the 1908 Tunguska explosion site.PLANETARY AND SPACE SCIENCE,46(2-3),179-188.
MLA	Hou, QL,et al."Discovery of iridium and other element anomalies near the 1908 Tunguska explosion site".PLANETARY AND SPACE SCIENCE 46.2-3(1998):179-188.