Abstract/Details

Determining the ages of impact events: Multidisciplinary studies using remote sensing and sample analysis techniques


1999 1999

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Abstract (summary)

The determination of the timing of impact events and the ages of cratered planetary surfaces is a complex and challenging undertaking. A powerful approach to this endeavor is a multidisciplinary study; understanding and using data from both rock samples and remote sensing.

Shocked material (especially melt material) found in meteorites like Orvinio provides critical material dating impact craters. Orvinio, in spite of a complex degassing history shows evidence for multiple impacts at 4.2 Ga, 7.5 Ma, and possibly 330 Ma. Correlating impact histories for inner solar system bodies and the asteroid belt will constrain the genesis of impactor populations. Determining the recent cratering history of the Earth, however, is complicated by surface processes which erode and destroy impact craters. The Gardnos impact structure, for example, while possessing samples suitable for dating, has suffered substantial post-impact degassing due to metamorphism in the Caledonian orogeny ∼385 Ma. We must therefore look to the Moon to unravel the recent cratering history of the Earth-Moon system The Clementine mission data set provides an excellent resource for research into the bright rayed craters on the lunar surface. Studies of large rayed craters using the OMAT (optical maturity parameter) technique of Lucey and colleagues has revealed much information on the maturation of the crater ejecta. Profiles of OMAT values for the ejecta of large craters as a group show no evidence for an increase in the cratering rate during the Copernican era as advocated by Shoemaker.

Future studies of both remote sensing and sample data will allow a better understanding of meteorite parent body impact histories and their implications for widespread epochs of increased impactor flux; the age-size correlation in lunar craters; the calibration of a large crater relative age scheme based on optical maturity with implications for the nature of the impactor flux in recent history; the nature of the recent small impactors on the lunar surface; implications for impact hazards on Earth today; and the best target sites for future landings and sample acquisition on the lunar surface.

Indexing (details)


Subject
Astronomy;
Astrophysics;
Remote sensing;
Mineralogy
Classification
0606: Astronomy
0606: Astrophysics
0799: Remote sensing
0411: Mineralogy
Identifier / keyword
Applied sciences; Pure sciences; Earth sciences; Ejecta; Impact events; Moon
Title
Determining the ages of impact events: Multidisciplinary studies using remote sensing and sample analysis techniques
Author
Grier, Jennifer Ann
Number of pages
230
Publication year
1999
Degree date
1999
School code
0009
Source
DAI-B 61/02, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
0599637781, 9780599637788
Advisor
McEwen, Alfred S.
University/institution
The University of Arizona
University location
United States -- Arizona
Degree
Ph.D.
Source type
Dissertations & Theses
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
9960259
ProQuest document ID
304501638
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
http://search.proquest.com/docview/304501638/fulltextPDF
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