Portal de Periódicos da CAPES

Geomorphic signatures of glacial activity in the Alba Patera volcanic province: Implications for recent frost accumulation on Mars

2013; Wiley; Volume: 118; Issue: 8 Linguagem: Inglês

10.1002/jgre.20113

2169-9100

Rishitosh K. Sinha, S. V. S. Murty,

Geology and Paleoclimatology Research

Abstract Glacial/periglacial landforms lying within impact craters on Mars have led to the identification of two mechanisms for their formation: (1) intermittent deposition of atmospherically emplaced snow/ice during past spin‐axis/orbital conditions and (2) flow of debris‐covered ice‐rich deposits. The maximum presence of the young ice/snow‐rich features (thermal contraction crack polygons, gullies, arcuate ridges, and lobate debris tongues) was observed on the pole‐facing slope, indicating that this slope was the preferred site for ice/snow accumulation (during the last 10 Ma). In this study, we investigated 30 craters lying in the Alba Patera volcanic province in the latitudinal bands between 45°N and 32.4°N. Morphological comparison of the younger ice/snow‐rich features in these craters led us to conclude that glacial/periglacial features in Alba Patera are mainly present within pole‐facing slopes of craters lying within 45°N–39°N. The craters lying within 40.2°N–40°N did not show any glacial/periglacial features. We suggest that the formation of these young ice/snow‐rich features follows the same orientation trends as those of other older (>10 Ma) glacial features (debris‐covered ice/snow‐rich large deposits at the base of the crater wall) in the region. The present work has revealed that the onset of physical processes that result in the formation of glacial/periglacial landforms is also dependent on the changes in elevation ranges of the investigated craters in Alba Patera. Our results confirm past inferences for accumulation of ice/snow on Mars and suggest that the period of ice/snow accumulation activity in Alba Patera occurred throughout the Amazonian and lasted until the recent past, i.e., 2.1–0.4 Ma.