Fusion crust and the measurement of surface ages of Antarctic ordinary chondrites

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National Aeronautics and Space Administration, National Technical Information Service, distributor , [Washington, D.C, Springfield, Va
Crusts., Thermoluminescence., Radioactive isotopes., Atmospheric temperature., Chondrites., Radioactivity., Galactic cosmic
StatementJannette M.C. Akridge, Paul H. Benoit, and Derek W.G. Sears.
Series[NASA contractor report] -- NASA/CR-97-207735., NASA contractor report -- NASA CR-207735.
ContributionsBenoit, Paul H., Sears, Derek W. G., United States. National Aeronautics and Space Administration.
The Physical Object
FormatMicroform
Pagination1 v.
ID Numbers
Open LibraryOL15507737M

Conclusions The equivalent doses collected by our lab are consistent with meteorite surface temperatures between 10 - 15 0C. This comparatively high temperature range limits the use of fusion crust for dating purposes.

It seems that fusion crust can only be used to date meteorites with surface ages. Get this from a library. Fusion crust and the measurement of surface ages of Antarctic ordinary chondrites.

[Jannette M C Akridge; Paul H Benoit; Derek W G Sears; United States. National Aeronautics and Space Administration.]. Fusion Crust and the Measurement of Surface Ages of Antarctic Ordinary Chondrites. in the first mm of material under the fusion crust.

We therefore refer to this surface layer as "fusion crust" although it does include some unmelted material just below the crust. When the meteorite lands on earth this drained layer will begin to build up. The equivalent doses exhibited by a suite of Antarctic meteorites, studied in our laboratory, seem to suggest that the surface of the meteorites reached temperatures on the order of C.

This temperature range limits the use of fusion crust to those meteorites with surface ages 20 ka. Terrestrial age measurements using natural thermoluminscence of a drained zone under the fusion crust of Antarctic ordinary chondrites Article July with 9 Reads How we measure 'reads'.

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SAO/NASA Astrophysics Data System (ADS) Title: Fusion crust and the measurement of surface ages of Antarctic ordinary chondrites Authors: Akridge, J. C., Benoit, P. Terrestrial age measurements using natural thermoluminescence of a drained zone under the fusion crust of Antarctic ordinary chondrites.

Meteoritics and Planetary Science, 35, – CrossRef Google Scholar. Terrestrial Ages of Antarctic Meteorites Based on the Thermoluminescence Levels Induced in the Fusion Crust.

Sengupta 1, N. Bhandari 2 and S. Watanabe 3 1 Institute of Physics, University of São Paulo, São Paulo, Brazil and IIT Kharagpur, West Bengal, India 2 Physical Research Laboratory, Ahmedabad, India.

About Cookies, including instructions on how to turn off cookies if you wish to do so. By continuing to browse this site you agree to us using cookies as described in. The terrestrial ages of Antarctic meteorites were estimated from the thermoluminescence (TL) intensity of the fusion crust.

It was found that there is a good correlation between the TL intensities and terrestrial ages which had been previously determined by cosmogenic radionuclide : Akio Nakanishi.

We acquired nine Antarctic equilibrated ordinary chondrites with fusion crust from the Johnson Space Center and the Smithsonian. Table 1 lists our samples, the lending institution, and the measured equivalent dose.

The fusion crust of ALHAALHAand ALHA was removed in approximately mm cuts using a diamond blade saw. We analyzed 16 carbonaceous chondrites (CM, CO3, CV3, CR2, CK and CH3) and 28 ordinary chondrites covering petrological types 3– 6 and chemical groups H, L, and LL.

We observed significant K isotope (δ 41 K) variations (− to ‰) among the carbonaceous and ordinary chondrites. In general, the two major chondrite groups are.

In a study investigating non-destructive classification approaches for equilibrated ordinary chondri 31 out of four groups of ten ordinary chondrites Cited by: 4. Curation of Antarctic meteorites at the National Institute of Polar Research.

Yamaguchi1, N. Imae1, H. Kojima1, S. Ozawa1, fusion crust, evaporates etc. Samples that seem to ordinary and E, R chondrites are determined by Fa in olivine and Fs in pyroxene.

As seen at the terrestrial meteorites collected over the entire Antarctic ice sheet (Losiak and Velbel, ) even small amounts of liquid water, present once or twice a season, are sufficient to. [1] Akridge JMC Benoit PH and Sears DWG Terrestrial age measurements using natural thermoluminescence of a drained zone under the fusion crust of Antarctic ordinary : Derek W.

Sears. Akridge J.M.C., Benoit P.H., and Sears D.W.G. () Terrestrial age measurements using natural thermoluminscence of a drained zone under the fusion crust of Antarctic ordinary chondrites.

Figure 2. Terrestrial ages derived from natural TL of the fusion crust vs.

Details Fusion crust and the measurement of surface ages of Antarctic ordinary chondrites FB2

terrestrial age estimates fiom cosrnogenic Figure 1. Build up of natural TL as a function of time for radionuclide abundance's (14c and 36~1) for Antarctic the hion crust for meteorite finds in Antarctica.

meteorites. Terrestrial age measurements using natural thermoluminscence of a drained zone under the fusion crust of Antarctic ordinary chondrites. Meteoritics & Planetary Science − Batchelor J. and Sears D. Terrestrial age measurements using natural thermoluminescence of a drained zone under the fusion crust of Antarctic ordinary chondrites Terrestrial age measurements using natural thermoluminescence of a drained zone under the fusion.

years on the surface of the Earth. However, the TL of fusion crust potentially offers a better method for the measurement of terrestrial ages in the range of 40, toyears, a range in which _4C and 36C1bear large uncertainties. Each plot represents a section perpendicular to the fusion crust surface, which starts at the exterior and extends a distance of µm inward.

The spatial resolution is µm along the section line and is the average of a 2 by 2 array of 50 by 50 µm analyses, with each analysis spot being the summed average of 5 time-of-flight spectra. The meteorite surface albedos (fusion crust cover) were independently measured for this study (see the Acknowledgements section).

Surface heat budget of Antarctic Cited by: 7. Several Antarctic ordinary chondrites, measured by Scherer et al. (a, b) and Welten et al. (,), showed terrestrial ages in excess of Ma. We would expect that the terrestrial age would be related to the weathering rates of meteorites and their eventual by: beneath the fusion crust.

The carbonaceous chondrite (ALHA) has surface deposits of epsomite concentrated in and near polygonal cracks in the crust (see figure). The sources of the elements and processes leading to formation of the evaporites are problematical.

Description Fusion crust and the measurement of surface ages of Antarctic ordinary chondrites PDF

Some of the Evaporite deposit, on antarctic stony meteorites Weathering Class. Terrestrial age meas-urements using natural thermoluminescence of a drained zone un-der the fusion crust of Antarctic ordinary chondrites.

Meteoritics and Planetary Science 35(4):DOI /jtbx. Nearly every known stony meteorite type is included. The book is organized by classification and sub-type, from primitive chondrites LL, to planetary achondrites. The first section of the book is dedicated to the ordinary chondrites, followed by the enstatite, carbonaceous, K, and R chondrite classes.

Some lunar meteorites (the basalts) do not have such vesicular fusion crusts, however, and the fusion crust of most lunar meteorites found in hot deserts has been ablated away by the wind.

In the absence of a fusion crust, a lunar (or martian) meteorite is less likely to be recognized as a meteorite than is an asteroidal meteorite because it.

Looking For Meteorites in Antarctica. Press Release - Source: Michael Lucibella, Antarctic Sun Editor smooth fusion crust that's shows that a rock fell to Earth. Like taking a book out of.

Study of Chelyabinsk LL5 ordinary chondrite fragment with a light lithology and its fusion crust, fallen on Februin Russian Federation, was carried out using Mössbauer spectroscopy with a high velocity resolution. The textures of chondrites indicate that they have not melted since they formed by the accretion of their different constituents.

Chondrites are so numerous and so philosophically important that they will hold our attention throughout much of this book. We discuss their.

Fig. Ordinary chondrites: The most common type of meterorite.(The fusion crust is a glassy coating on meteorites that forms during passage of the meteorite through the atmosphere.) For many of the ordinary chondrites we find, the fusion crust is in about the same state of preservation, or put another way, they appear similarly "fresh.".Potassium Isotope Compositions of Carbonaceous and Ordinary Chondrites: Implications on the Origin of Volatile Depletion in the Early Solar System.

K abundance on the surface of the Earth e.g., continental crust ~( ppm; Rudnick chondrites and ordinary chondrites vs.

cosmic-ray exposure ages (A) or vs. cosmic-ray 5 exposure ages (T.