On the Potential to Apply Sequence Stratigraphic Concepts to Martian Strata

Schieber, Juergen¹ (1) Indiana University, Bloomington, IN

The Mars Orbiter Camera on the Mars Global Surveyor spacecraft has returned stunning images with a spatial resolution from 1.5 to 12 meters per pixel. These images show ample evidence for layered Martian bedrock, as well as evidence that the latter were at least in part deposited in an aqueous setting. Additionally, the Mars Exploration Rovers have produced close-up evidence that at least in one area these layers are sedimentary rocks that share many parallels with sedimentary rocks on Earth.

The up to 10 km deep Valles Marineris region of Mars is 6-7 times deeper than the Grand Canyon, and its exposures of layered strata constitute the sedimentary record of much of early Martian history. Well exposed sections show that this record consists of stacked stratal packages that can be distinguished on the basis of albedo, uniformity vs. variability of layer thickness, and erosion characteristics.

Analogous to stratigraphic partitioning of rock volumes on Earth, stratal packaging on Mars may well reflect the interplay between sediment flux, sedimentation rate, and base level change. On Earth, these packages or sequences are the building blocks of regional stratigraphic architecture. On the Colorado Plateau for example, first order sequences (Sloss sequences) range from less than 100 to several hundred meters in thickness. Stratigraphic packaging at that scale is visible on orbiter images from Valles Marineris. Unraveling stratigraphic architecture may help identification of regional depocenters, allow first order basin analysis, reveal processes of large scale sediment accumulation, and allow differentiation between volcanic and sedimentary successions.