Open AccessAncient oceans in the northern lowlands of Mars: Evidence from impact crater depth/diameter relationships
Author(s) -
Boyce Joseph M.,
MouginisMark Peter,
Garbeil Harold
Publication year - 2005
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2004je002328
Subject(s) - impact crater , amazonian , hesperian , geology , mars exploration program , noachian , martian , population , geomorphology , physical geography , geochemistry , earth science , archaeology , astrobiology , amazon rainforest , geography , ecology , physics , demography , sociology , biology
We present depth ( d ) and diameter ( D ) data for 2269 Martian impact craters in the diameter range 6–216 km, distributed over ∼11.52 × 10 6 km 2 of terrain that samples several geologic settings and the full range of latitudes and elevations throughout the northern lowlands of Mars. Our data indicate that there are three major crater types that fall into two major populations, those craters that contain Vastitis Borealis formation (VBF) and those that do not. The deepest type 1 craters comprise a Late Hesperian/Early Amazonian‐age population that does not contain VBF. Type 2, type 3, and subdued type 1 craters comprise a population of Hesperian‐age craters partially buried by the VBF. The unique d / D distribution of type 3 craters and photogeologic evidence suggest an erosional style for the VBF that requires sublimation processes, indicating that the VBF contained a substantial amount of ice. Type 3 craters occur throughout the northern lowland plains at elevations below −2400 m. If the VBF is a sedimentary deposit left by a large body of standing water in the northern lowlands of Mars, then the northern lowland plains contained a body of water with a volume of ∼6 × 10 7 km 3 or the equivalent of a 430 m global ocean during the Late Hesperian/Early Amazonian. This also implies that the VBF contains ∼4 × 10 6 km 3 of material, in agreement with the estimated amount of material eroded from the outflow channels surrounding Chryse basin and washed into the northern lowlands.