Greg Kallemeyn

• PhD Geochemistry, UCLA
• Researcher (retired) at University of California, Los Angeles

We used instrumental neutron activation analysis and petrography to determine bulk and phase compositions and textural characteristics of 15 carbonaceous chondrites of uncertain classification: Acfer 094 (type 3.0, ungrouped CM-related); Belgica-7904 (mildly metamorphosed, anomalous, CM-like chondrite, possibly a member of a new grouplet that inclu...

We have used neutron activation and electron-probe fused-bead techniques to analyze the bulk major and trace-element compositions of 104 named HED meteorites (about 100–102 distinct meteorites, depending upon pairings), including 32 polymict eucrites, 30 howardites and six diogenites. Most were not previously analyzed for siderophile trace elements...

The CK chondrites are the most oxidized carbonaceous chondrites; most of the Fe is present as magnetite or FeO-rich mafic silicates. Their textures and refractory lithophile abundances indicate that their nearest relatives are the CV chondrites. There are two observed CK falls, Karoonda and Kobe. These and several other relatively unweathered CK fi...

CK chondrites constitute the most oxidized anhydrous carbonaceous chondrite group; most of the Fe occurs in magnetite and in FeO-rich mafic silicates. The two observed CK falls (Karoonda and Kobe), along with thirteen relatively unweathered CK finds, have unfractionated siderophile-element abundance patterns. In contrast, a sizable fraction of CK f...

New bulk-compositional data, including trace siderophile elements such as Ir, Os, Au, and Ni, are presented for 25 ureilites. Without exception, ureilites have siderophile abundances too high to plausibly have formed as cumulates. Ureilites undoubtedly underwent a variety of “smelting,” by which C was oxidized to CO gas while olivine FeO was reduce...

Impacts have been important in the evolution of the Moon's crust and regolith, and impact melt products (breccias, glasses, and "highland basalts") account for a huge fraction of all sampled nonmare materials. As we endeavor to unravel the history of the Moon using these materials, it is important to understand that three fundamentally distinct typ...

Chondritic clast PV1 from the Plainview H-chondrite regolith breccia is a subrounded, 5-mm-diameter unequilibrated chondritic fragment that contains 13 wt% C occurring mainly within irregularly shaped 30–400-μm-size opaque patches. The clast formed from H3 chondrite material as indicated by the mean apparent chondrule diameter (310 μm vs. ∼300 μm i...

Abstract— We have analyzed nine highland lunar meteorites (lunaites) using mainly INAA. Several of these rocks are difficult to classify. Dhofar 081 is basically a fragmental breccia, but much of its groundmass features a glassy-fluidized texture that is indicative of localized shock melting. Also, much of the matrix glass is swirly-brown, suggesti...

We present much new data for ureilites. The average ureilite composition can be modeled by assuming that the major yet not exhaustive siderophile depletions of typical ureilites formed by down-seepage of small proportions of S-rich metallic melt.

Carbon-rich chondritic clast PV1 from the Plainview H-chondrite regolith breccia formed from a normal H3 chondrite by impact melting, fracturing, aqueous alteration, C-enrichment (possibly from a cometary impact) and faulting.

Gujba is a coarse-grained meteorite fall composed of 41 vol% large kamacite globules, 20 vol% large light-colored silicate globules with cryptocrystalline, barred pyroxene and barred olivine textures, 39 vol% dark-colored, silicate-rich matrix, and rare refractory inclusions. Gujba resembles Bencubbin and Weatherford in texture, oxygen-isotopic com...

Northwest Africa 468 (NWA 468) is a new ungrouped, silicate-rich member of the IAB complex of nonmagmatic iron meteorites. The silicates contain relatively coarse (∼300 μm) grains of low-Ca clinopyroxene with polysynthetic twinning and inclined extinction. Low-Ca clinopyroxene is indicative of quenching from high temperatures (either from protoenst...

Northwest Africa 468 (NWA 468) is a new ungrouped, silicate-rich member of the IAB complex of nonmagmatic iron meteorites. The silicates contain relatively coarse (∼300 μm) grains of low-Ca clinopyroxene with polysynthetic twinning and inclined extinction. Low-Ca clinopyroxene is indicative of quenching from high temperatures (either from protoenst...

We present new data for iron meteorites that are members of group IAB or are closely related to this large group, and we have also reevaluated some of our earlier data for these irons. In the past it was not possible to distinguish IAB and IIICD irons on the basis of their positions on element-Ni diagrams, but we now show that plotting the new and...

Northwest Africa 468 (NWA 468) is a new ungrouped, silicate-rich member of the IAB complex of nonmagmatic iron meteorites. The silicates contain relatively coarse (approximately 300 micron-size) grains of low-Ca clinopyroxene with polysynthetic twinning and inclined extinction. Low-Ca clinopyroxene is indicative of quenching from high temperatures...

We report the first bulk compositional data for a new eucrite with the proposed name of Bluewing 001 [1]. A 0.174 g fragment was powdered for bulk analysis by a combination of INAA and fused bead electron-probe analysis. Our study only commenced at the end of November, so unfortunately our data are still somewhat preliminary. Results for diagnos-ti...

New compositional analyses of Bencubbin and Gujba host materials and an OC clast from Bencubbin are presented. Their relationship to other meteorites and their origin by condensation processes in the solar nebular or an impact plume are discussed.

On element-Au diagrams IAB irons form a main group and parallel clusters called subgroups (S). IIIC (S2) and IIID (S3) are resolved from each other. S1 is intermediate between main group and S2. These may have formed in impact events on an asteroid.

Gujba is a new Bencubbin-like meteorite fall enriched in N-15 and consisting (in vol.%) of 41% metal nodules, 20% large light-colored silicate nodules and 39% dark-colored, C- and silicate-rich matrix.

The bulk chemistry of three new lunar meteorites is presented and placed within the context of each meteorite's petrographic texture. Unusual PGEs for D-26 is not explainable by contamination, but may reflect the presence of siderophile-rich nuggets.

Abstract— The carbonaceous chondrite MacAlpine Hills (MAC) 88107 has bulk composition and mineralogy that are intermediate between those of CO and CM chondrites. This meteorite experienced minor alteration and a low degree of thermal metamorphism (petrologic type 3.1) and escaped post-accretional brecciation. The alteration resulted in the formatio...

We studied 14 chondrules separated from LEW85332, an ungrouped type-3 carbonaceous chondrite related to CR chondrites; 23 elements were determined by neutron activation and the chondrules were characterized petrographically. Oxygen isotopic compositions were determined by R. N. Clayton and T. K. Mayeda for seven chondrules. Chondrule abundance rati...

The Chaunskij meteorite, which was found in 1985 in northeastern Russia, consists of ∼90 vol % metal and ∼10% phosphate-silicate inclusions and sulfide nodules. Metallographic structures of the metal are consistent with a typical mesosiderite cooling history. The metal is unusually rich in Ni and depleted in W, Ir and Pt, and has been subjected to...

We present new bulk compositional data for 6 martian meteorites, including highly siderophile elements Ni, Re, Os, Ir and Au. These and literature data are utilized for comparison versus the siderophile systematics of igneous rocks from Earth, the Moon, and the HED asteroid. The siderophile composition of ALH84001 is clearly anomalous. Whether this...

Neutron-induced prompt gamma-ray analysis (PGA) was applied to seven meteorite samples (Allende, Zagami, Acfer 209, ALH77005, ALH84001, EET79001 and Neagari). Samples were irradiated in both the thermal neutron and the cold neutron guided beams of JRR-3M at JAERI. Multiple samples of an Allende standard powder were analyzed for Si using two differe...

The ungrouped carbonaceous chondrite MAC88107 contains secondary fayalite (Fa90-100), hedenbergite (~Fs50Wo50), phyllosilicates, magnetite, and Ni-bearing sulfides. Fayalite and hedenbergite formed during aqueous alteration in an asteroidal environment.

We present new bulk compositional data for six martian meteorites, including the highly siderophile elements Ni, Re, Os, Ir, and Au. These and literature data are compared with the siderophile systematics of igneous rocks from Earth, the Moon, and the HED asteroid. The composition of ALH 84001 is anomalously siderophile-poor. Whether this reflects...

The strongest evidence for the lunar magmasphere hypothesis is still the pronounced geochemical bimodality among pristine nonmare rocks. Magnesium-suite (MgS) rocks have a distinctly higher mg ratio than ferroan anorthositic suite (FAS) cumulates of otherwise similar geochemistry (e.g., Na/Ca, REE, and especially Eu/AI). Well-sampled FAS rocks are...

New bulk compositional data for six martian meteorites, including highly siderophile elements Ni, Re, Os, Ir, and Au [ I ], are utilized along with literature data for comparison with the siderophile systematics of igneous rocks from Earth, the Moon, and the HED asteroid. Queen Alexandra Range 94201 and EET 79001-B are both depleted in the "noblest...

The high-Al mare basalts from Apollo 14 include most of the oldest individual mare samples known, with Rb-Sr ages in several cases between 4.1 and 4.3 Ga. However, the Nd isotopic systematics for the same samples are generally disturbed, even though under most circumstances Nd isotopes probably tend to be more resistant to disturbance than Sr isoto...

The Kakangari, LEW 87232, and Lea Co. 002 chondrites have a similar set of petrologic and oxygen isotopic characteristics that distinguishes them from other chondrite groups. They are here established to constitute a single chondrite grouplet—the K (after Kakangari) chondrites. The K chondrites have (1) high matrix abundances (33–77 vol%) as do car...

Bulk compositional and petrographic data clearly define the new R (Rumuruti) group of chondrites consisting of Rumuruti (the only fall), ALH85151, Acfer 217, Carlisle Lakes, Dar al Gani 013, PCA91002, PCA91241, Y-75302, Y-793575, and Y-82002. Compositional, petrographic, rare-gas, and 0-isotopic data strongly suggest that PCA91002 and PCA91241 are...

QUE94281 is a spherule-poor regolith breccia composed mainly of mineral fragments of pyroxene and plagioclase. Its overall texture is roughly intermediate between those of Y793274 and EET87521. About 2/3 of the pyroxene fragments larger than 100 mm contain pyroxene exsolution lamellae of order 1 mm in width, a remarkable similarity with Y793274 and...

The Ningqiang chondrite, which fell in China in 1983, was initially classified as a CV3 chondrite. Citing important petrographic and compositional differences between Ningqiang and typical CV chondrites, Rubin et al reclassified Ningqiang as an anomalous member of the CV group (CV3-an). Among the differences were a lower refractory inclusion abunda...

A 6 mm-diameter dark spherule, 15434,28, from the regolith on the Apennine Front at the Apollo 15 landing site has a homogeneous glass interior with a 200 μm-thick rind of devitrified or crystallized melt. The rind contains abundant small fragments of Apollo 15 olivine-normative mare basalt and rare volcanic Apollo 15 green glass. The glass interio...

We have studied bulk compositions and mineralogy of several unusual eucrites. Bulk compositions were determined using standard UCLA methods: Instrumental Neutron Activation Analysis (INAA), RNAA (Ni, Zn, Ge, Cd, Re, Os, Ir, and Au), and fused-bead Electron Probe Microanalysis (EPMA) (major elements + Ti). Mineral compositions were studied using EPM...

Among several eucrites we have been studying by our usual methods, two stand out as extraordinary cumulates: Asuka 881394, a volatile-depleted cumulate eucrite, and EET 87548, an extraordinarily pyroxene- and chromite-rich cumulate eucrite. The medium-grained granular texture of Asuka 881394 is possibly altered from the original igneous texture, an...

We report neutron activation analyses, including radiochemical determination of trace siderophile elements (Au, Ge, Ir, Ni, Os and Re), for three SNC/martian meteorites, and Os and Re results for numerous eucrites. Ratios such as Ga/Al in the SNC orthopyroxenite ALH84001 confirm its martian affinity—its many distinctive characteristics, most notabl...

Four of the magmatic IVA iron meteorites contain tridymite or clinobronzite-orthobronzitetridymite which are quite unlike silicate assemblages in other iron meteorites. The textures, the bulk chemistry, and the zoning preserved in the pyroxenes strongly suggest that they are igneous cumulates. The pyroxenes have extremely low Fe/Mn-ratios (less tha...

— We have determined the abundances of Ir and other elements by neutron activation analysis on annual dust samples from an ice core from Site B in the Crête region in central Greenland covering the years 1905–1914. Iridium was detected in all samples, but we found no excess Ir above the background in the years following the Tunguska event. The lack...

Angrites are commonly viewed as extremely volatile-depleted, and a related notion is that they formed by differentiation of a very CAI-rich material [e.g., 1]. Partial melting experiments reportedly reproduce the bulk compositions (although not fassaite-rich mineralogy) of angrites with Allende as starting material [2], but highly CAI-rich parent m...

We have employed neutron activation, including radiochemical NAA, to investigate SNC/martian meteorites ALH 77005, ALH 84001 and LEW 88516, along with 15 eucrites. Our data for 10 manifestly monomict eucrites confirm previous indications [e.g., 1] that compositionally pristine eucrites are generally extremely siderophile-poor, although for several...

The Bells and Essebi carbonaceous chondrites have long been associated with the CM group, although petrographic and isotopic observations have questioned that relationship. Samples of Bells and Essebi were obtained for bulk compositional study by neutron activation analysis (INAA) in an attempt to further fuel the debate on this issue. The current...

Petrographic and bulk compositional data suggest the existence of a new grouplet of carbonaceous chondrites consisting of Coolidge and Loongana 001. Coolidge is a carbonaceous chondrite find from Kansas, USA, previously considered a metamorphosed CV chondrite. Loongana 001 ia a recent find from Western Australia. It has a high matrix/chondrule moda...

A study of enstatite grains separated from EL6 chondrites shows ferrosilite contents to be ∼0.02–0.04 mol%, about an order of magnitude lower than reported in the literature. The higher values reported earlier can probably be attributed to the excitation of Fe atoms in Fe‐Ni and FeS, in part from μm‐sized blebs of FeS and Fe‐Ni commonly present in...

New analytical data combined with recent studies by other researchers allow the definition of a Renazzo (CR) group of carbonaceous chondrites. We analyzed nine CR chondrites (Acfer 187, Acfer 209, El Djouf 001, Elephant Moraine 87747, Elephant Moraine 87770, Elephant Moraine 87847, MacAlpine Hills 87320, PCA91082, and Yamato 793495) constituting at...

Mason and Wiik described the Kakangari meteorite, which fell in India in 1890, as probably a carbonaceous chondrite. Although it has affinities to carbonaceous (and ordinary) chondrite groups, it also has distinct differences that have led researchers to conclude that Kakangari belongs to its own grouplet. Recently, two other chondrites, Lea County...

Pecora Escarpment (PCA)91002 is a light/dark‐structured chondrite breccia related to Carlisle Lakes and Rumuruti; the meteorite contains ∼10–20 vol% equilibrated (type −5 and −6) clasts within a clastic groundmass, much of which was metamorphosed to type‐3.8 levels. The olivine compositional distribution forms a tight cluster that peaks at Fa 38–40...

Sioux County (SC) has long been classified as the most 'primitive' of the noncumulate eucrites. Stolper argued for genesis of most eucrites as little-differentiated parital melts, modified only by slight near-surface fractional crystallization. In this model, SC is the type example of a primary eucrite melt, where 'primary' denotes 'a liquid that h...

In a series of papers [e.g., 1,2], Lipschutz and co-workers compared trace- element RNAA data from Antarctic and non-Antarctic H4-6 chondrites and concluded that the two populations have significantly different concentrations of several trace elements including Co, Se, and Sb. They interpreted their data as indicating that these Antarctic H chondri...

A major component of the moon's crust is fundamentally unrelated to the plagioclase flotation crust that is believed to have accumulated over the primordial magma ocean, as evidenced by the geochemical bimodality of pristine lunar rocks. This bimodality and the apparent ratio of ferroan-anorthositic suite rocks to non-ferroan-anorthositic suite roc...

Three type 3 chondrite finds, Willaroy, Suwahib (Buwah) and Moorabie, and one type 4 find, Cerro los Calvos, are ordinary chondrites (OC) in all respects except redox state: (a) they have OC abundances of refractory lithophiles (Cerro los Calvos data are ambiguous), Zn and other taxonomic elements, (b) they have OC matrix/chondrule abundance ratios...

Although the classificational group 'CR' was first put forth by McSween more than 10 years ago, it included only the Al Rais and Renazzo meteorites. It has only been the relatively recent discovery of several CR-related chondrites in Antarctica and the Sahara that has provided the necessary research material for an extensive group description and c...

Consortium studies on lunar meteorites Yamato 793169 and Asuka 881757 (formerly Asuka-31) were performed to characterize these new samples from unknown locations in the lunar mare. Both meteorites are coarse-grained mare rocks having low Mg/Fe ratios (bulk mg'=30-35) and low TiO2 (1.5-2.5 percent in homogenized bulk samples). They are intermediate...

Although chondrites are all solarlike in their abundances of nonvolatile elements, there are appreciable differences among chondrite groups in texture and mineralogical, chemical, and O-isotopic composition. There are now 12 chondrite groups, each containing at least five members: CI, CR, CM, CO, CV, and CK carbonaceous chondrites; H, L, and LL ord...

Alkalic suite pristine nonmare rocks are distinctly enriched in plagiophile elements such as Na and K, as well as generally incompatible elements, despite modes and textures more characteristic of typical crustal cumulates (most commonly anorthosites) than of the basaltic KREEP rocks that appear to account for the bulk of the lunar crust's total co...

The ∼39 ureilite meteorites are in many respects primitive objects. They are highly carbonaceous, averaging ∼3.0 wt% C, mostly as graphite. Yet their consistently coarse-grained textures and plagioclase-depleted compositions imply that they are igneous. Despite diverse mafic-silicate Mg/(Mg + Fe) and pyroxene/olivine ratios, plagioclase is totally...

Three carbonaceous chondrites from the MacAlpine Hills region of Antarctica (MAC87300, MAC87301, and MAC88107) are very similar compositionally and petrographically, and are somewhat more loosely related to Allan Hills A77307 and Colony. Mason (1988, 1989) described the three MacAlpine chondrites as petrographically similar to CM2 chondrites. Sears...

The IVA iron meteorites Steinbach (SB), Sao Joao Nepomuceno (SJN), Gibeon and Bishop Canyon are unusual in their contents of silicates. SB is particularly rich in silicates (ca. 50 wt%) and was long classified as a stony iron (Dorfler et al., 1965) but the metal fraction is typical of group IVA iron meteorites (Schaudy et al., 1972). The SB and SJN...

We have used INAA, RNAA, and fused-bead analysis to determine the bulk compositions of numerous Antarctic eucrites (and also the LEW88516 SNC meteorite). Only a few of the most unusual eucrites can be discussed in the limited space here. Takeda et al. (1988) noted that Y791195 is a slowly cooled eucrite, with an equant, medium-grained texture, and...

The Apollo highlands rock collection includes more than 100 'pristine' fragments that survived the intense meteoritic bombardment of the ancient lunar crust with unmixed, endogenously igneous compositions. The geochemical anomaly manifested by the 'ferroan-anorthositic suite' (FAS) appears to reflect a geochemical, and probably also a genetic, bimo...

INTRODUCTION. On April 7, 1990, a brecciated ordinary chondrite fell through the roof of a house near Glanerbrug in the Netherlands and was shattered to pieces. The total weight of the recovered fragments was about 800 g, the largest piece weighing 135 g. This main fragment clearly shows the inhomogeneous structure of the Glanerbrug: a dark-grey br...