Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/j.epsl.2013.09.003 |
Unique chemistry of a diamond-bearing pebble from the Libyan Desert Glass strewnfield, SW Egypt: Evidence for a shocked comet fragment | |
Kramers, Jan D.1; Andreoli, Marco A. G.2,3; Atanasova, Maria4; Belyanin, Georgy A.1; Block, David L.5; Franklyn, Chris2; Harris, Chris6; Lekgoathi, Mpho2; Montross, Charles S.7; Ntsoane, Tshepo2; Pischedda, Vittoria8,9; Segonyane, Patience2; Viljoen, K. S. (Fanus)1; Westraadt, Johan E.7 | |
通讯作者 | Kramers, Jan D. |
来源期刊 | EARTH AND PLANETARY SCIENCE LETTERS
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ISSN | 0012-821X |
EISSN | 1385-013X |
出版年 | 2013 |
卷号 | 382页码:21-31 |
英文摘要 | We have studied a small, very unusual stone, here named "Hypatia", found in the area of southwest Egypt where an extreme surface heating event produced the Libyan Desert Glass 28.5 million years ago. It is angular, black, shiny, extremely hard and intensely fractured. We report on exploratory work including X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy with EDS analysis, deuteron nuclear reaction analysis, C-isotope and noble gas analyses. Carbon is the dominant element in Hypatia, with heterogeneous O/C and N/C ratios ranging from 0.3 to 0.5 and from 0.007 to 0.02, respectively. The major cations of silicates add up to less than 5%. The stone consists chiefly of apparently amorphous, but very hard carbonaceous matter, in which patches of sub-mu m diamonds occur. delta C-13 values (ca. 0 parts per thousand) exclude an origin from shocked terrestrial coal or any variety of terrestrial diamond. They are also higher than the values for carbonaceous chondrites but fall within the wide range for interplanetary dust particles and comet 81P/Wild2 dust. In step heating, Ar-40/Ar-36 ratios vary from 40 to the air value (298), interpreted as a variable mixture of extraterrestrial and atmospheric Ar. Isotope data of Ne, Kr and Xe reveal the exotic noble gas components G and P3 that are normally hosted in presolar SiC and nanodiamonds, while the most common trapped noble gas component of chondritic meteorites, Q, appears to be absent. An origin remote from the asteroid belt can account for these features. We propose that the Hypatia stone is a remnant of a cometary nucleus fragment that impacted after incorporating gases from the atmosphere. Its co-occurrence with Libyan Desert Glass suggests that this fragment could have been part of a bolide that broke up and exploded in the airburst that formed the Glass. Its extraordinary preservation would be due to its shock-transformation into a weathering-resistant assemblage. (C) 2013 Elsevier B.V. All rights reserved. |
英文关键词 | Libyan Desert Glass shock diamonds extraterrestrial carbonaceous matter carbon isotopes noble gas isotopes comet nucleus |
类型 | Article |
语种 | 英语 |
国家 | South Africa ; France |
收录类别 | SCI-E |
WOS记录号 | WOS:000327229100003 |
WOS关键词 | INTERPLANETARY DUST PARTICLES ; NOBLE-GASES ; ISOTOPIC COMPOSITIONS ; POLYCRYSTALLINE DIAMOND ; CARBONACEOUS CHONDRITES ; ORGANIC-MATTER ; SOLAR NEBULA ; CHEMICAL-COMPOSITION ; ORIGIN ; STARDUST |
WOS类目 | Geochemistry & Geophysics |
WOS研究方向 | Geochemistry & Geophysics |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/176624 |
作者单位 | 1.Univ Johannesburg, Dept Geol, ZA-2006 Auckland Pk, South Africa; 2.NECSA, ZA-0001 Pretoria, South Africa; 3.Univ Witwatersrand, Sch Geosci, ZA-2050 Johannesburg, South Africa; 4.Council Geosci, ZA-0001 Pretoria, South Africa; 5.Univ Witwatersrand, Sch Computat & Appl Math, AECI & AVENG Cosm Dust Lab, ZA-2050 Johannesburg, South Africa; 6.Univ Cape Town, Dept Geol Sci, ZA-7701 Rondebosch, South Africa; 7.Element Six Pty Ltd, ZA-1559 Springs, South Africa; 8.Univ Lyon 1, LPMCN, F-69622 Villeurbanne, France; 9.Univ Lyon 1, CNRS, UMR 5586, F-69622 Villeurbanne, France |
推荐引用方式 GB/T 7714 | Kramers, Jan D.,Andreoli, Marco A. G.,Atanasova, Maria,et al. Unique chemistry of a diamond-bearing pebble from the Libyan Desert Glass strewnfield, SW Egypt: Evidence for a shocked comet fragment[J],2013,382:21-31. |
APA | Kramers, Jan D..,Andreoli, Marco A. G..,Atanasova, Maria.,Belyanin, Georgy A..,Block, David L..,...&Westraadt, Johan E..(2013).Unique chemistry of a diamond-bearing pebble from the Libyan Desert Glass strewnfield, SW Egypt: Evidence for a shocked comet fragment.EARTH AND PLANETARY SCIENCE LETTERS,382,21-31. |
MLA | Kramers, Jan D.,et al."Unique chemistry of a diamond-bearing pebble from the Libyan Desert Glass strewnfield, SW Egypt: Evidence for a shocked comet fragment".EARTH AND PLANETARY SCIENCE LETTERS 382(2013):21-31. |
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