Abstract
We present a geomorphic map of the Hypanis Valles watershed and a
geomorphic map of the Hypanis deposit region at its terminus. We mapped
these two regions at different scales: 1:2,000,000 for the catchment map
(-5-10° N, 300-315° E) and 1:500,000 for the Hypanis deposit map
(10-13.0° N, 313-316.5° E). Our mapping provides new morphologic
insights beyond previous efforts which used lower spatial resolution
data. We defined units based on morphology, albedo, thermal inertia,
elevation, and spectral parameters. We propose that episodic volcanism
and aqueous activity filled the Chryse basin from the early Noachian.
Hypanis Valles was active during the Noachian, forming the Hypanis
terminal deposits in the southern Chryse region. Hundreds of
kilometer-sized mounds and cones stratigraphically post-date Hypanis
fluvial deposition as these features appear to have erupted or effused
through all other major map units. We propose sedimentary diapirism or
mud volcanism may be responsible for these features, a hypothesis
consistent with the compressional wrinkle ridge tectonism in a
sedimentary basin. Future work could further investigate the formation
of these cones and mounds and better assess their astrobiologic
importance.