Keys to gully formation processes on Mars: Relation to climate cycles and sources of meltwater

0019-1035/$ see front matter 2011 Elsevier Inc. A doi:10.1016/j.icarus.2011.02.020 ⇑ Corresponding author. Address: Department of University, Box 1846, Providence, RI 02912, USA. Fax E-mail address: [email protected] (S.C. Sc Advances in dating gullies on Mars using superposition relationships and a stratigraphic marker horizon link gully chronostratigraphy to recent climate cycles. New observations of gully morphology show the close association of gully source regions, channels, and fan deposits with well-documented ice-rich latitude-dependent mantle deposits, the deposition of which is interpreted to be coincident with recent ice ages. On the basis of these close correlations, we interpret the formative processes for mid-latitude gullies to involve melting of these ice-rich mantling deposits and the generation of an aqueous phase leading to fluvial activity. Continued monitoring of gullies by spacecraft in the current ‘‘interglacial’’ climate period ( 0.4 Ma to the present) will permit assessment of changing rates and styles of gully activity in the now largely depleted source areas. 2011 Elsevier Inc. All rights reserved.