摘要:

With the exception of a distinctive olivine‐bronzite chondrite recognized by H. H. Nininger: “Ness County (1938)”, most of the numerous stony meteorites found in Ness County, Kansas, have been lumped together under the designation “Ness County (1894)”. It is the purpose of this paper to show that at least three separate falls are covered by

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00123.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Yilmia, a new enstatite chondrite contains moderately well defined radiating and granular chondrules. The plagioclase to enstatite ratio is appreciably higher within than outside of the two granular chondrules in our microprobe sections. Osbornite was observed within the granular chondrules, but not in the rayed chondrules or surrounding matrixMajor phases include enstatite, plagioclase (Ab80An16Or4), silica, silicon‐rich kamacite and titanian troilite. Minor phases are many and varied: sinoite, silicon‐rich taenite, schreibersite, graphite, osbornite, oldhamite, “normal” and zincian daubreelite, ferroan alabandite and a new FeZnMn monosulfideThe new mineral (Fe.538Zn.246Mn.159Mg.004S) closely resembles albandite and could easily have been overlooked in other meteorites unless a microprobe was used. A new form of oldhamite was also found. Indarch oldhamite, analyzed for comparative purposes, consists of two similar but distinct species: Ca.96Mn.005Mg.04Fe.01S and Ca1.000Mn.004Mg.02Fe.005S. These have not been reported from other meteoritesBased on its mineralogy and texture this is a type II (E6) enstatite chondrite that is transitional toward the intermediate type (E5). It is unique in its mineralogical complexity, abundance of taenite, diversity of zincian minerals and monosulfides, and restriction of osbornite to certain ch

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00124.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The Washougal, Washington, U.S.A., howardite fell in 1939. We studied its mineralogy optically and determined the ranges of composition of plagioclase and pyroxenes from measurements of densities and indices of refraction. Notable among many unique xenoliths are a round object whose morphology is that of an armored chondrule; a stratified fragment; and a centimeter‐sized dunite xenolith (olivine Fa12.8). The abundances of 27 elements, including all major elements and 15 trace elements (Sc, V, Co, Ni, Cu, Ga, Sr, Y, Ba, La, Sm, Eu, Yb, Lu and Hf) are reported. To a first approximation, the composition of Washougal corresponds to a mixture of 51 weight percent of eucritic material and 49 percent of a diogenitic component, but excesses of some elements suggest a minor component of chondritic compositi

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00125.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The Seminole Meteorite was found near Seminole, Texas in 1961 and recognized as a meteorite in 1963. Two fragments weighing a total of 41.1 kg were recovered. Analyses showed these to be fragments of a single black olivine‐bronzite, or H4‐group chondrite, showing brecciation and a moderate number of individual chondr

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00126.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

A 1.5 kg iron found in 1960 at Gosnells, near Perth, Western Australia, belongs to Wasson's chemical group I‐An3 and is structurally unusual, being best described as a heat‐altered granular coarse octahedrite. It is chemically and structurally very similar to the Mount Dooling iron, found in 1909 about 400 km away, and has a fracture surface which fits the Mount Dooling mass very closely. The Gosnells fragment was probably transported by human agency, though it is not known when or by w

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00127.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Niobian rutile was found in a KREEP lithic fragment of basaltic texture. The niobian rutile contains 85.3% TiO2, 7.1% Nb2O5, 2.65% Cr2O3, 0.70% ZrO2, 0.61% SiO2, 0.82% Al2O30.61% FeO, 0.52% CaO, 0.22% V2O3in addition to minor amounts of MnO, MgO, and CeO2. Rare earth elements were not detected, in contrast with lunar niobian rutile of Marvin (1971). Coexisting minerals in the KREEP fragment are major amounts of plagioclase and orthopyroxene, and minor amounts of olivine, ilmenite, augite, barian K‐feldspar, whitlockite, troilite, Ni‐Fe, zirkelite and chro

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00128.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

A potentiostat was used to study the electrolytic corrosion of iron meteorites in a neutral solution. Low current densities were chosen so that the observed potentials would more closely approximate the theoretical Nernst values. Iron, nickel, and cobalt ions, the products of corrosion, were soluble in the electrolyte solution, and were determined after each electrolysis by atomic absorption spectrophotometry. Kamacite and taenite dissolved as individual phases, with kamacite dissolving preferentially. Cobalt dissolved along with iron and nickel from each phase. There is a direct relationship between nickel content and the potential at which a meteorite first starts to dissolve; the higher the nickel content, the more resistant the meteorite is to corrosion. None of the six meteorites observed started to dissolve at a lower potential than pure iron, nor at a higher potential than pure nickel

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00129.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The Oro Grande, New Mexico, U.S.A., chondrite was found in 1971. Electron microprobe analyses and microscopic examination show the following mineralogy: olivine (Fa 19.3 mole percent), orthopyroxene (Fs 16.2 mole percent), diopside, feldspar (An 13.6 mole percent), chlorapatite, whitlockite, kamacite, taenite, troilite, chromite, and an iron‐bearing terrestrial weathering product. A bulk chemical analysis of the meteorite shows the following results (weight percent): Fe 0.84, Ni 1.46, Co 0.07, FeS 3.62, SiO234.18, TiO20.14, Al2O31.83, Cr2O30.55, Fe2O321.25, FeO 9.13, MnO 0.31, MgO 21.52, CaO 1.72, Na2O 0.70, K2O 0.08, P2O50.25, H2O+ 2.14, H2O‐0.40, C 0.22, Sum 100.41. On the basis of composition and texture, the Oro Grande meteorite is classified as an H5 chondrite. A large lithic fragment (∼5 mm long) with a very fine‐grained texture different from that of the host meteorite was analyzed for bulk composition using the broad beam of an electron microprobe, and was found to be enriched in Ca, Al, Na, and K, and depleted in Mg and Fe relative to the bulk composition of the host meteorite. Its mineral compositions, however, are very similar to those of the host. It is suggested that the fragment is not a xenolith of a previously undescribed type of achondrite, but is probably an impact‐produced partial melt of the host chondrite or a fragment of an unusually large

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00130.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

A number of stony meteorite specimens, presumably from a single fall, have been recovered from an area about 5–6 miles north of Ransom, Kansas. This paper presents a map of discovery locations, so far as known. Megascopic appearance, external and internal, of a typical (?) specimen is described. The Ransom meteorite has already been classified as an olivine‐bronzite chondrite — chemical group H of Van Schmus and Wood. Features observed in thin section are characteristic of petrologic

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00131.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The Haverö ureilite fell on August 2, 1971 on the Island of Haverö, Finland, lat 22° 03‘ 43“ E., long 60° 14’ 44” N. The meteorite contains curved open fractures partly filled with kamacite foils or drops, clusters of olivine mosaic with preferred orientation, very fine‐lamellar polysynthetic twinned clino‐***bronzite and carbonaceous matter as laths up to 4 mm in length. The carbon laths are in preferred orientation and contain in addition to graphite, kamacite, chromite and diamonds. The petrology, textural features and origi

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1972.tb00132.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY