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40)ar/(39)ar age of hornblende-bearing r chondrite lap 04840
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Cosca, M. Righter, K. |
| Copyright Year | 2015 |
| Description | Chondrites have a complex chronology due to several variables affecting and operating on chondritic parent bodies such as radiogenic heating, pressure and temperature variation with depth, aqueous alteration, and shock or impact heating. Unbrecciated chondrites can record ages from 4.56 to 4.4 Ga that represent cooling in small parent bodies. Some brecciated chondrites exhibit younger ages (much less than 4 to 4.4 Ga) that may reflect the age of brecciation, disturbance, or shock and impact events (much less than 4 Ga). A unique R chondrite was recently found in the LaPaz Icefield of Antarctica - LAP 04840. This chondrite contains approximately 15% hornblende and trace amounts of biotite, making it the first of its kind. Studies have revealed an equigranular texture, mineral equilibria yielding equilibration near 650-700 C and 250-500 bars, hornblende that is dominantly OH-bearing (very little Cl or F), and high D/H ratios. To help gain a better understanding of the origin of this unique sample, we have measured the (40)Ar/(39)Ar age (LAP 04840 split 39). |
| File Size | 221704 |
| Page Count | 2 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20150019421 |
| Archival Resource Key | ark:/13960/t3vt6nn5q |
| Language | English |
| Publisher Date | 2015-02-04 |
| Access Restriction | Open |
| Subject Keyword | Inorganic, Organic And Physical Chemistry Amphiboles Mass Spectrometers Swimming Pool Reactors Biotite Geochemistry Meteorite Parent Bodies Chondrites Chronology Antarctic Regions Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
