Impact craters in the northern hemisphere of Mars: Layered ejecta and central pit characteristics
Citation
Barlow, N. G. (2006). Impact craters in the northern hemisphere of Mars: Layered ejecta and central pit characteristics. Meteoritics & Planetary Science, 41(10), 1425-1436.Publisher
The Meteoritical SocietyJournal
Meteoritics & Planetary ScienceDescription
From the proceedings of the Workshop on the Role of Volatiles and Atmospheres on Martian Impact Craters held on July 11-14, 2005, at the Johns Hopkins University Applied Physics Laboratory.Additional Links
https://meteoritical.org/Abstract
Mars Global Surveyor (MGS) and Mars Odyssey data are being used to revise the Catalog of Large Martian Impact Craters. Analysis of data in the revised catalog provides new details on the distribution and morphologic details of 6795 impact craters in the northern hemisphere of Mars. This report focuses on the ejecta morphologies and central pit characteristics of these craters. The results indicate that single-layer ejecta (SLE) morphology is most consistent with impact into an ice-rich target. Double-layer ejecta (DLE) and multiple-layer ejecta (MLE) craters also likely form in volatile-rich materials, but the interaction of the ejecta curtain and target-produced vapor with the thin Martian atmosphere may be responsible for the large runout distances of these ejecta. Pancake craters appear to be a modified form of double-layer craters where the thin outer layer has been destroyed or is unobservable at present resolutions. Pedestal craters are proposed to form in an ice-rich mantle deposited during high obliquity periods from which the ice has subsequently sublimated. Central pits likely form by the release of vapor produced by impact into ice-soil mixed targets. Therefore, results from the present study are consistent with target volatiles playing a dominant role in the formation of crater morphologies found in the Martian northern hemisphere.Type
Proceedingstext
Language
enISSN
1945-5100ae974a485f413a2113503eed53cd6c53
10.1111/j.1945-5100.2006.tb00427.x