State of Science
A tale of two planets: geomorphology applied to Mars' surface, fluvio-deltaic processes and landforms
Article first published online: 27 JAN 2010
Copyright © 2010 John Wiley & Sons, Ltd.
Earth Surface Processes and Landforms
Volume 35, Issue 1, pages 102–117, January 2010
How to Cite
Kleinhans, M. G. (2010), A tale of two planets: geomorphology applied to Mars' surface, fluvio-deltaic processes and landforms. Earth Surf. Process. Landforms, 35: 102–117. doi: 10.1002/esp.1895
- Issue published online: 27 JAN 2010
- Article first published online: 27 JAN 2010
- Manuscript Accepted: 9 JUL 2009
- Manuscript Revised: 1 JUL 2009
- Manuscript Received: 14 OCT 2008
- lake deltas;
- alluvial fans;
- climate change
Deltas on planet Mars record past climate, but so far a wide range of hypotheses for their formation have been proposed. The objective of this paper is to understand martian fan deltas, their formative conditions, evolution and formative duration, and implications for the past climate.
As an introduction to Mars, physiographic provinces are described and unambiguous proof is listed for the presence of flowing water in the past, such as certain minerals, groundwater, catastrophic outflow channels, alluvial fans and fan deltas, distributary networks and glaciers. The climate history of Mars differs from that of Earth by having had much drier conditions than on Earth, extreme intermittency and extreme events, most of them billions of years ago.
Tens of fan deltas, unchannelized fan deltas and stepped fans have been found in impact crater and other lakes. The stepped fans were likely formed by backstepping under fast rising lake levels and have no known terrestrial equivalent. The fan deltas were formed once the lake overflowed. Alluvial fans are much more numerous and formed with less water.
The delta studies illustrate how major challenges of martian morphology and reconstruction of past conditions can be taken up most effectively by combinations of the available high-resolution images and digital elevation models, terrestrial analogues, laboratory experiments and physics-based models gleaned from geomorphology.
To resolve formative mechanisms and time scale of martian fans and deltas, morphological distinctions between dense debris flows and dilute fluvial flows must be identified for both source and sink areas. Furthermore, the properties of the martian surface material are very poorly constrained but can be explored by modelling various mass wasting, fluvial and glacial phenomena and hydrology, and by experimentation with slightly cohesive sediment. Finally, the highly debated role of groundwater sapping in valley and delta formation on Mars should be explored experimentally. Copyright © 2010 John Wiley & Sons, Ltd.