The Rock Record of Mars: Structure, Sedimentology and Stratigraphy

This work combines several studies related to the sedimentary rock record of Mars. Data from several spacecraft are employed to ascertain the formation mechanisms and timescales of stratified outcrops exposed at the surface, In particular, high-resolution topographic data from stereo images are utilized to obtain quantitative estimates of geologic structure and stratigraphy. The first investigation focuses on a well-preserved fluvial distributary network exposed in Eberswalde crater. Geologic structure and basin topography are used to assess modes of formation and place limits on the deposition timescale. Chapter 3 describes an enigmatic feature studied by the Spirit rover, an 80 m diameter, intricately cross-bedded plateau known as Home Plate. Via combined analysis of the stratigraphy, structure, and sedimentology, a pyroclastic origin is proposed for the origin of this enigmatic sedimentary deposit. Finally, chapter 4 focuses on the occurrence of several rhythmically bedded sedimentary deposits across the surface of Mars. The strong quasiperiodicity seen in the stratigraphy at these locations is likely evidence of allogenic control on deposition from external climate cyclicity. Two scales of periodicity are demonstrated for one section at Becquerel crater. We propose a link to orbital forcing via the obliquity cycle of Mars