COMPOSITION OF NOBLE GASES IN THE ABEE METEORITE, AND THE ORIGIN OF THE ENSTATITE CHONDRITES.
The Abee enstatite chondrite breccia was studied using two methods: measurement of noble gases, and, analyses of the clast size-distribution and the overall texture of Abee. These studies were made in order to understand the formation of the Abee breccia and the formation of the enstatite chondrites...
Main Author: | |
---|---|
Other Authors: | |
Format: | Thesis |
Language: | English |
Published: |
The University of Arizona.
1982
|
Subjects: | |
Online Access: | http://hdl.handle.net/10150/184938 |
id |
ftunivarizona:oai:repository.arizona.edu:10150/184938 |
---|---|
record_format |
openpolar |
spelling |
ftunivarizona:oai:repository.arizona.edu:10150/184938 2024-09-15T17:42:04+00:00 COMPOSITION OF NOBLE GASES IN THE ABEE METEORITE, AND THE ORIGIN OF THE ENSTATITE CHONDRITES. WACKER, JOHN FREDERICK. Wilkening, Laurel 1982 http://hdl.handle.net/10150/184938 en eng The University of Arizona. http://hdl.handle.net/10150/184938 683257738 8303395 Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Meteorites -- History Meteoritic hypothesis Chondrites (Meteorites) text Dissertation-Reproduction (electronic) 1982 ftunivarizona 2024-06-25T03:41:28Z The Abee enstatite chondrite breccia was studied using two methods: measurement of noble gases, and, analyses of the clast size-distribution and the overall texture of Abee. These studies were made in order to understand the formation of the Abee breccia and the formation of the enstatite chondrites. Noble gases were measured as a part of the consortium effort. Noble gases were measured in 17 samples from 10 regions within Abee. Radiogenic ages are 4.5 aeons. Cosmic ray exposure ages average 8 Myr. No evidence for pre-irradiation was found except for a chondrule which may have been neutron pre-irradiated. Abee has at least 2 iodine bearing minerals, both of which are silicate minerals. This suggests that iodine had refractory behavior in the E-chondrites. Two trapped components were found: one having planetary-type elemental and isotopic composition (termed "Kenna-type"), the second with a high argon to xenon ratio (termed "argon-rich") but isotopically similar to the first. Both components appear to be carried in silicate phases, probably enstatite. The Kenna-type component may be carried by small inclusions within silicate minerals. The argon-rich component may have originated from solar wind implantation before accretion of the E-chondrite parent body requiring an inner solar system origin or by noble gas trapping during high temperature mineral condensation requiring high nebular pressures. The clast size-distribution of Abee and 2 other meteorites from the Antarctic meteorite collection (BTNA 78004, ALHA 78113) were measured. The 3 meteorites appear to have formed during single, low energy impacts and that Abee was part of an ejecta blanket which mixed with surrounding regolith. From the textural study, a formation model for the Abee breccia is discussed. The breccia formed during a single impact. Clast metal rims were vapor deposited and partially metamorphosed during impact-generated heating. Greater heating formed dark and metal inclusions. Maximum temperatures were less than 1200 C and heating was ... Thesis Antarc* Antarctic The University of Arizona: UA Campus Repository |
institution |
Open Polar |
collection |
The University of Arizona: UA Campus Repository |
op_collection_id |
ftunivarizona |
language |
English |
topic |
Meteorites -- History Meteoritic hypothesis Chondrites (Meteorites) |
spellingShingle |
Meteorites -- History Meteoritic hypothesis Chondrites (Meteorites) WACKER, JOHN FREDERICK. COMPOSITION OF NOBLE GASES IN THE ABEE METEORITE, AND THE ORIGIN OF THE ENSTATITE CHONDRITES. |
topic_facet |
Meteorites -- History Meteoritic hypothesis Chondrites (Meteorites) |
description |
The Abee enstatite chondrite breccia was studied using two methods: measurement of noble gases, and, analyses of the clast size-distribution and the overall texture of Abee. These studies were made in order to understand the formation of the Abee breccia and the formation of the enstatite chondrites. Noble gases were measured as a part of the consortium effort. Noble gases were measured in 17 samples from 10 regions within Abee. Radiogenic ages are 4.5 aeons. Cosmic ray exposure ages average 8 Myr. No evidence for pre-irradiation was found except for a chondrule which may have been neutron pre-irradiated. Abee has at least 2 iodine bearing minerals, both of which are silicate minerals. This suggests that iodine had refractory behavior in the E-chondrites. Two trapped components were found: one having planetary-type elemental and isotopic composition (termed "Kenna-type"), the second with a high argon to xenon ratio (termed "argon-rich") but isotopically similar to the first. Both components appear to be carried in silicate phases, probably enstatite. The Kenna-type component may be carried by small inclusions within silicate minerals. The argon-rich component may have originated from solar wind implantation before accretion of the E-chondrite parent body requiring an inner solar system origin or by noble gas trapping during high temperature mineral condensation requiring high nebular pressures. The clast size-distribution of Abee and 2 other meteorites from the Antarctic meteorite collection (BTNA 78004, ALHA 78113) were measured. The 3 meteorites appear to have formed during single, low energy impacts and that Abee was part of an ejecta blanket which mixed with surrounding regolith. From the textural study, a formation model for the Abee breccia is discussed. The breccia formed during a single impact. Clast metal rims were vapor deposited and partially metamorphosed during impact-generated heating. Greater heating formed dark and metal inclusions. Maximum temperatures were less than 1200 C and heating was ... |
author2 |
Wilkening, Laurel |
format |
Thesis |
author |
WACKER, JOHN FREDERICK. |
author_facet |
WACKER, JOHN FREDERICK. |
author_sort |
WACKER, JOHN FREDERICK. |
title |
COMPOSITION OF NOBLE GASES IN THE ABEE METEORITE, AND THE ORIGIN OF THE ENSTATITE CHONDRITES. |
title_short |
COMPOSITION OF NOBLE GASES IN THE ABEE METEORITE, AND THE ORIGIN OF THE ENSTATITE CHONDRITES. |
title_full |
COMPOSITION OF NOBLE GASES IN THE ABEE METEORITE, AND THE ORIGIN OF THE ENSTATITE CHONDRITES. |
title_fullStr |
COMPOSITION OF NOBLE GASES IN THE ABEE METEORITE, AND THE ORIGIN OF THE ENSTATITE CHONDRITES. |
title_full_unstemmed |
COMPOSITION OF NOBLE GASES IN THE ABEE METEORITE, AND THE ORIGIN OF THE ENSTATITE CHONDRITES. |
title_sort |
composition of noble gases in the abee meteorite, and the origin of the enstatite chondrites. |
publisher |
The University of Arizona. |
publishDate |
1982 |
url |
http://hdl.handle.net/10150/184938 |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://hdl.handle.net/10150/184938 683257738 8303395 |
op_rights |
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
_version_ |
1810488440532238336 |