摘要:

The Allan Hills A77307 meteorite has variously been described as a CO, CV, and a unique CO‐CM related chondrite. We have found that its thermolum‐inescence properties are very different from the established members of the CO chondrite class; it has a TL peak at 170 and a suggestion of a peak at 250°C, while CO chondrites have peaks at 91 ± 7 and 203 ± 11°C. Either the meteorite has suffered some form of alteration or it is not a normal CO chondrite. The latter is consistent with petrologic and compositional data which we interpret to indicate that although Allan Hills A77307 is related to CO chondrites it is not a normal member of tha

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1983.tb00570.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

An attempt to find out more about tektite finds at Riam, Indonesian Borneo (Kalimantan), has uncovered a long‐standing and complicated confusion about tektite localities in the southern portion of Borneo. It appears that the only authentic localities in the whole of Indonesian Borneo are at Martapura, Pelaihari, and the Sungei (River) Riam Kanan, all within 40 km of each other in the southeastern corner of the island, and all documented, mainly in Dutch and German works, by the early 20th century. Other localities mentioned and shown on maps in more recent French and English publications are mere phantoms resulting from a succession of misinterpretations of previous literatur

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1983.tb00571.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Welded breccias and faults in Muong Nong‐type indochinite tektites from Thailand are illustrated. Electron probe analyses of these tektites show somewhat higher Al and alkalies in light‐colored layers, and somewhat higher Si and Ca in dark‐colored l

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1983.tb00572.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

The size distribution and morphology of metal grains have been examined in 11 sections of types I and II E‐chondrites. The changes in the grain‐size distribution and morphology of metal grains correspond with the petrologic types and define a series that reflects increase in thermal metamorphism in the following order: type I, Kota Kota‐Indarch‐South Oman‐St. Mark's; and type II, Jajh deh Kot Lalu‐Atlanta‐Daniel's Kuil‐Hvittis‐Pillistfer‐Khairpur‐Blithfield. Concentrations of metal grains adjacent to the perimeters of chondrules are observable throughout the sequence and delineate relic chondritic structure in six of the seven type II E‐chondrites; relic structures are

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1983.tb00573.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Two new large iron meteorites, weighing 840 kg and 800 kg respectively, have been recovered from the Nullarbor Plain in the vicinity of the original Mundrabilla meteorite site, and are now at the Western Australian Museum in Perth. Numerous small knucklebone‐shaped irons were also found at Tookana Rock Hole in the vicinity of Eucla. X‐ray fluorescence spectrometry of these meteorites confirms that the additional finds are members of the Mundrabilla meteorite sho

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1983.tb00574.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

A total of seven lithic clasts from the polymict eucrites ALHA76005 and ALHA77302 have been studied petrographically and analyzed with the electron microprobe. All clasts are composed predominantly of pyroxene and plagioclase, ± ilmenite, troilite, Fe‐Ni metal, mesostasis, and silica. Pyroxene compositions in unequilibrated clasts and clast bulk compositions, calculated by modal recombination, indicate that the clasts originally crystallized under similar conditions and that they may be genetically related to each other by fractionation of pigeonite and plagiocla

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1983.tb00575.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Within the chondritic matrix of Romero (H3–4) is a metal‐poor inclusion consisting largely of olivines showing quench textures, minor low‐Ca pyroxene and rare metal and sulphide. The olivines within this inclusion have the dominant composition Fa8with a range Fa7, 5–17. The matrix (Romero host) olivines are, in the main, equilibrated with an average composition of Fa18, but are lower in CaO and Cr2O3than the inclusion olivines. The high chromium content of the inclusion olivines suggests that they formed under conditions different from those represented by the other olivines in

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1983.tb00576.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Eleven recent chondrite finds from the Texas Panhandle have been examined and classified according to mineralogical and petrological criteria: five H's, five L's, and one LL chondrite. Five are distinct from nearby finds, while three remain ambiguous and three are related to previously reported chondrites. In addition, data are provided to classify the Muleshoe, Silverton, and Vigo Park chondrites, all of which were previously undescribed in the literature.

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1983.tb00577.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1983.tb00579.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY