Meteorites in Antarctica

The first meteorite discovered in Antarctica was found by a member of Douglas Mawson s expedition from 1911 to 1914 to the Adelie Coast (67°00 S, 139°00 E) of East Antarctica. The meteorite was collected in Commonwealth Bay about 43 km west of Cape Dennison 

Faure and T.M. Mensing, The Transantarctic Mountains Rocks, Ice, Meteorites and Water, DOI 10.1007/978-90-481-9390-5 18, Springer Science+Business Media B.V. 2010 

Starting with that inauspicious beginning, the Antarctic Search for Meteorites (ANSMET) has been spectacularly successful and has recovered well over 10,(XX) specimens or about 350 per year on average. Bill Cassidy led ANSMET until 1994 when he turned the operation over to Ralph P. Harvey of Case Western 

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Wasson J. T. (1990) Ungrouped iron meteorites in Antarctica Origin of anomalously high abundance. Science 249, 900-902. 

The cardinal rule of meteorite collecting in Antarctica and elsewhere is When in doubt, collect it and let the experts decide whether it is a meteorite. However, the scientific value of meteorites can be compromised if they are not collected properly. Therefore, ANSMET has recommended a simple procedure for collection meteorites in Antarctica and for documenting the collecting site ... 

The first evidence for the conversion of silicate minerals of stony meteorites in Antarctica was reported by Gooding (1986a) who detected the presence of clay mineraloids, gypsum, K-Fe sulfates (jarosite ), and rust on the surfaces and in cracks of achondrites and chondrites from Elephant Moraine (EET) and the Allan Hills. These weathering products had formed primarily from glass and plagioclase in the fusion crust and in cracks in the interiors of the meteorite specimens. 

The iron meteorites are of special interest because this group of meteorites is under-represented among Antarctic meteorites (Table 18.5). Several large fragments of the Derrick Peak iron meteorite (DRP 78001-78009) fell about 1 million years ago and have lain on a substrate of soil and rock fragments ever since. Therefore, these specimens were not transported in the ice of the polar plateau to their present location like most other meteorites in Antarctica, but they actually landed on rocks where they were found. 

The search for martian meteorites in Antarctica and in the hot deserts of the world continues because these meteorites are the only rocks from Mars that are presently available. The most recent information on the martian meteorites is contained in the books edited by Davis (2005) and by McFadden et al. (2006) and in the papers presented at a woikshop on the topic of unmixing of SNCs (Treiman 2003). 

This carefully worded conclusion aroused a great deal of public interest, which re-invigorated the exploration of the solar systan and vaUdated the collection of meteorites in Antarctica and elsewhere in the world. The paper by McKay et al. (1996) also started a debate among scientists whose comments were published under the heading Evaluating the evidence for past... 

When the search for meteorites in Antarctica started in 1976/77, few people expected that it would be successful because most of the continent is covered by an ice sheet of gigantic proportions. In retrospect, we now realize that meteorite specimens are concentrated on the bare-ice surfaces of the ablation zone adjacent to the Transantarctic Mountains where the flow of the ice is deflected upward by subglacial bedrock barriers. 

Zolensky ME, Gooding JL (1986) Aqueous alteration on carbonaceous-chondrite parent bodies as inferred from weathering of meteorites in Antarctica. Meteoritics 21 548-549... 

Meteorite ALH84001 was found in the Allan Hills in Antarctica in 1984 and was the subject of an extraordinary NASA press announcement in 1996. It weighed 1.93 kg when it was collected (Figure 6.10) and is probably the most extensively studied lump of rock of all time. It is 95 per cent orthopyroxene, the volcanic rock mineral that accumulated in a molten-lava-reducing environment on Mars some... 

ALH84001 A meteorite found in the Alan Hills in Antarctica in 1984. 

McSween HY, Taylor LA, Stolper EM (1979) Allan HrUs 77005 a new meteorite type found in Antarctica. Science 204 1201-1203... 

Biogenic magnetite may persist once the organism that produced it has died and may, therefore, contribute to the natural magnetic remanence of sediments (Stolz et al., 1986). The discovery in a calcareous Martian ( ) meteorite found in Antarctica, of magnetite crystals with properties very similar to these biogenic magnetites, sup-... 

For many years, cosmochemistry depended on the chance discovery of meteorites - either witnessed falls and serendipitous finds, or the dogged determination of a few private collectors who systematically searched for them. That changed in 1969, when Japanese explorers in Antarctica led by Masaru Yoshida stumbled onto meteorites exposed on bare ice. American geologist William Cassidy immediately recognized an opportunity, and with support from the National Science Foundation he mounted a joint expedition with the Japanese to the Allan Hills region of Antarctica in 1977 to recover meteorites. This was the first of many expeditions, sponsored by the National Science Foundation and headed first by Cassidy and later by Ralph Harvey, that have returned to Antarctica every year to collect meteorites (Fig. 1.11). The Japanese have operated a parallel field program in... 

About the same time that meteorites were found in Antarctica, an important collection of meteorites was being put together in Roosevelt County, New Mexico. Over a period from 1966 to 1972, several meteorite hunters collected 140 meteorite specimens representing about 100 separate fall events. This collection demonstrated another way for nature to concentrate meteorites. The meteorites in Roosevelt County were found in blowout areas where up to a meter of soil had been blown away by wind, leaving meteorites in plain view on the hardpan surface. Based on this experience, systematic and successful searches of desert areas in Western Australia have been carried out. Subsequently, the deserts of North Africa have turned out to be especially prolific sources of meteorites. The shifting desert sands expose meteorites that have accumulated over thousands of years. The meteorites are collected by nomads and sold to western collectors. Although most desert meteorites are weathered to some degree, new and rare meteorite classes have been discovered. 

The Apollo astronauts returned 382 kg of lunar sample to Earth, and this collection was supplemented by 326 g of soil samples collected by the Soviet Luna landers. The first lunar meteorite was found in 1982 in Antarctica. Since that time, over 120 lunar meteorites representing about 60 different fall events have been collected. The total mass of these meteorites is -48 kg. About one-third of these meteorites were recovered in Antarctica by American and Japanese teams, and most of the rest were recovered in the deserts of North Africa and Oman. The lunar meteorites have significantly expanded the areas of the Moon from which we have samples. 

Before leaving the aminoacids problem, it is interesting to note that aminoacids have been detected in carbonaceous chondrites found in Antarctica. The risk of contamination is much less important in Antarctica than in Australia and this is one of the reasons why these studies were undertaken. They fully confirm the results obtained on Murchison 54,55), even if in one CM carbonaceous chondrite the amino acid content was only 10% of what was observed in Murchison 56,57). The contamination is in fact lower than in Murchison the aminoacid content was very similar for samples taken near the surface of the Antarctica chondrites or from their bulk. On the other hand, all the significant analyses on Murchison were performed on samples from the interior of the meteoritic fragments due to the high degree of surface contamination. In the case of the Allende meteorite, which has the same terrestrial age as Murchison, contamination was found to extend to a depth of more than 5 mm below the surface 52). 

Many investigations about fluorine uptake are reported in literature. The goal of these examinations is to unravel the exposure duration of different materials to various environmental conditions. Here, the application of ion beam analysis in studies on terrestrial contamination of meteorites from Antarctica and diffusion profiles in bones from archaeological burial sites is presented. 

I have one final question for you, about your role in analyzing the Martian meteorite found in 1984 in Antarctica. Do you really believe that your work shows that primitive life forms existed on Mars lon apfo ... 

Solid bodies of extraterrestrial material that penetrate the atmosphere and reach the Earth s surface are called meteorites. Other extraterrestrial materials include micrometer-sized interplanetary dust particles (IDEs) collected in the lower stratosphere and polar ices. Most meteorites and IDEs are fragments of asteroids, but some IDEs may represent cometary material and some meteorites are fragments of the planets Mars and Earth s moon. Meteorites recovered following observed falls are called/a// those which cannot definitely be associated with observed falls are called finds. Meteorites are given names based on the location where they were recovered (e.g., the Allende meteorite fell in Allende, Mexico). Meteorites recovered in Antarctica and the deserts of Australia and northern Africa are given names and numbers, because numerous samples are found in the same locations. Fragments thought to be of the same meteorite fall, which, in Antarctica or hot deserts, may have different numbers or even names because they were found in different locations, are called... 

Eugster O. (1989) History of meteorites from the Moon collected in Antarctica. Science 245, 1197-1202. 

Geochemical cycle of I in Antarctica and its influence on I overabundances in Antarctic meteorites... 

The first Lunar meteorite, found in 1981 in Antarctica, was immediately identified as such by. its fusion crust and mineralogic and chemical resemblance to samples returned by the Apollo program. The properties of the 31 Lunar meteorites are more characteristic of the whole Moon, because they are random samples, than are the Apollo samples which derive from Lunar sites mainly selected for landing safety reasons 10). 

By far the most meteorites have been recovered in Antarctica during international expeditions dedicated to the search of meteorites (7). More than... 

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