North polar trough formation due to in-situ erosion as a source of young ice in mid-latitudinal mantles on Mars.

ABSTRACT: The clockwise spiral of troughs marking the Martian north polar plateau forms one of the planet's youngest megastructures. One popular hypothesis posits that the spiral pattern resulted as troughs underwent poleward migration. Here, we show that the troughs are extensively segmented into enclosed depressions (or cells). Many cell interiors display concentric layers that connect pole- and equator-facing slopes, demonstrating in-situ trough erosion. The segmentation patterns indicate a history of gradual trough growth transversely to katabatic wind directions, whereby increases in trough intersections generated their spiral arrangement. The erosional event recorded in the truncated strata and trough segmentation may have supplied up to ~25% of the volume of the mid-latitude icy mantles. Topo

SUBMITTER: Rodriguez JAP 

PROVIDER: S-EPMC7994824 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature