A sedimentary origin for intercrater plains north of the Hellas basin: Implications for climate conditions and erosion rates on early Mars

 

Press Release ESA : "New evidence for a warmer and wetter early Mars" - 6th December 2016

A sedimentary origin for intercrater plains north of the Hellas basin: Implications for climate conditions and erosion rates on early Mars, F. Salese, V. Ansan, N. Mangold, J. Carter, A. Ody, F. Poulet, and G. G. Ori (2016), Journal of Geophysical Research, doi:10.1002/2016JE005039.

Understanding the origin (volcanic or sedimentary) and timing of intercrater plains is crucial for deciphering the geological evolution of Mars. We have produced a detailed geological map of the intercrater plains north of the Hellas basin, based on images from the Mars Express High-Resolution Stereo Camera, the Mars Reconnaissance High-Resolution Imaging Science Experiment, and Context. Erosional windows and fresh impact craters provide a way of studying the lithology of intercrater plain units. They are composed predominantly of light-toned sedimentary rocks with subhorizontal bedding over a broad extent (greater than tens of kilometers), showing cross-bedding stratifications locally. The broad extent, geometry, and flat topography of these sediments favor a formation by aqueous processes (alluvial and lacustrine) rather than airfall (eolian and volcaniclastic). The Late Noachian (~3.7 Ga) sedimentary plains are locally covered by dark-toned, rough-textured lava flows of Late Hesperian age (~3.3 Ga)... Read more

 

 

Figure 15 Crism Sed web

 

© NASA/ASU/HiRISE/CRISM/IAS.

Partially eroded sedimentary strata.In red (false color), the detection of clay minerals (or phyllosilicates) by the spectrometer CRISM.


 

 

Contacts :

> Laboratoire de planétologie et géodynamique de Nantes (CNRS/Université de Nantes/Université d'Angers):
Researcher CNRS/Université de Nantes, Nicolas Mangold, Phone 002 51 12 53 40 l nicolas.mangold@univ-nantes.fr
Francesco Salese, Phone 0039 32 91 77 25 69, francesco.salese@univ-nantes.fr

> Presse CNRS: Martin Koppe, Phone 001 44 96 43 09, koppe.martin@cnrs-dir.fr