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Iron meteorites from antarctica: more specimens, still 40% ungrouped
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Wasson, J. T. |
| Copyright Year | 1999 |
| Description | Clarke was the first to recognize that ungrouped irons are more common in Antarctica than in the regions where most irons have been collected; his conclusion was based on the first 21 irons collected in Antarctica. Wasson et al. reported compositional data for 24 Antarctic irons and reported that eight were ungrouped; the ungrouped fraction of 0.33 was found to be about twice that (0.153) observed in irons from the remainder of the world. Wasson reported data for seven additional Antarctic irons, and reported that 12 of 31 were ungrouped, a fraction of 0.39. I summarize the data obtained to date on independent Antarctic iron meteorites by our UCLA neutron-activation laboratory. With about five exceptions, the listed values are the means of duplicate determinations. We have now analyzed 40 independent iron meteorites; I list eight other irons that proved to be paired with meteorites listed. Because of the close relationship between pallasites and iron meteorites, I also list our data for two Antarctic pallasites that were studied at UCLA. Our new results confirm the previously reached conclusion about the abundance of ungrouped irons. In fact, the ungrouped fraction has increased slightly; of the 40 irons 16 are ungrouped, a fraction of 0.40. The two meteorites with pallasite structures are both small (= 50 g); one is ungrouped, the other a high-Ir anomalous member of the main-group pallasites (PMG). |
| File Size | 323647 |
| Page Count | 6 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20010071787 |
| Archival Resource Key | ark:/13960/t5k984c5k |
| Language | English |
| Publisher Date | 1999-01-13 |
| Access Restriction | Open |
| Subject Keyword | Astrophysics Iron Meteorites Chemical Composition Antarctic Regions Taxonomy Stony-iron Meteorites Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
