Knickpoints in Martian channels indicate past ocean levels.

ABSTRACT: On Mars, the presence of extensive networks of sinuous valleys and large channels provides evidence for a wetter and warmer environment where liquid water was more abundant than it is at present. We undertook an analysis of all major channel systems on Mars and detected sharp changes in elevation along the river long profiles associated with steep headwall theatre-like valleys and terraces left downstream by channel incision. These breaks in channel longitudinal slope, headwalls and terraces exhibit a striking resemblance with terrestrial fluvial features, commonly termed 'knickpoints'. On Earth, such knickpoints can be formed by more resistant bedrock or where changes in channel base-level have initiated erosion that migrates upstream (such as tectonic uplift or sea level change). We obse

SUBMITTER: Duran S 

PROVIDER: S-EPMC6805925 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature