|
Editor's Highlight
Read Full Article (file size: 1276736 bytes) Cited by
GEOPHYSICAL RESEARCH LETTERS,
VOL. 33,
L08S02,
doi:10.1029/2005GL024484,
2006
Impact constraints on the age and origin of the lowlands of Mars
H. V. Frey
Planetary Geodynamics Laboratory, Goddard Space Flight Center, Greenbelt, Maryland, USA
Abstract
Visible and buried impact basins, seen as “Quasi-Circular Depressions” (QCDs) in MOLA data, provide important new constraints
on the age of the Martian lowlands. The buried lowlands are no younger than Early Noachian, at least as old as the oldest
exposed (visible) surface units in the highlands. A model absolute age for these buried lowlands is 4.04–4.11 GY (or earlier)
but similar model ages for the largest lowland basins are older yet, 4.08–4.18 GY. The lowland crust both formed and became
low no later than 500 million years after Mars formed, and likely even earlier. This constrains models for the origin of the
fundamental crustal topographic dichotomy on Mars. Mechanisms which operated both early and quickly during the earliest history
of Mars (e.g., large impacts) may be more likely than those requiring extended periods of time (i.e., endogenic models).
Received 25
August
2005;
accepted 15
December
2005;
published 4
March
2006.
Index Terms: 5420 Planetary Sciences: Solid Surface Planets: Impact phenomena, cratering (6022, 8136); 5455 Planetary Sciences: Solid Surface Planets: Origin and evolution; 5499 Planetary Sciences: Solid Surface Planets: General or miscellaneous.
Read Full Article (file size: 1276736 bytes) Cited by
Citation: Frey, H. V.
(2006),
Impact constraints on the age and origin of the lowlands of Mars,
Geophys. Res. Lett.,
33,
L08S02,
doi:10.1029/2005GL024484.
This paper is not subject to U.S. copyright. Published in 2006 by the
American Geophysical Union.
|