Analysis of Gully Systems in Two High-Northern Latitude Craters on Mars
Abstract
Gullies on Mars are usually defined by a source alcove and a channel that shallows into a debris apron. This holds true for a vast majority of gullies, especially those in southern latitudes. However, several gullies in northern high-latitudes (>50° N) show complex forms with more than one prominent channel. These gullies have not undergone detailed morphologic and morphometric analysis, so we have studied such gullies in two northern high-latitude craters to facilitate comparison with other well-studied gullies. Morphometric comparison of gully morphologies and their spatially associated landforms can give insight to different gully forming processes and provide clues to past environmental conditions.
Crater 1 (63.8°N 292.3°E), northeast of Tantalus Fossae, is ~16.3 km in diameter and contains numerous gullies on its eastern and western interior slopes. On its east side, gullies are poorly developed, except for one gully, which is deeply incised. This gully shows a braided morphology with several deep channels which incise the entire thin, light-toned apron. This morphology may be due to the unconsolidated sediment composing the crater slopes. At the deepest part of one alcove is an intriguing, elongated 12-m high mound, which is eroded along its downslope trend and from which a gully emanates. We interpret this to be a dust-covered snowpack. Crater 2 (53.6°N 26.3°E) is ~4.5 km across, and is located on the northern ejecta blanket of Lyot Crater. It contains gullies on all its slopes with well-defined alcoves, but most of their aprons blend together. Only two gullies have distinct aprons. The first has several indistinct, broad, shallow, discontinuous channel-like forms on its thick, dusty apron. Its alcove is sharply-defined with four branches and escarpments suggesting episodic flow. The latter consists of several gullies merging into a lobate apron. Pitted features on the apron's surface, consistent with those formed by sublimation processes, suggest high-volatile subsurface volumes within the crater. We have mapped these gully systems and have delineated their drainage basin areas. Currently, we are analyzing their detailed morphologies, slopes, and morphometrics to compare these systems with other martian gully systems. Funding provided by SETI Inst. REU Intern Program and NAI Grant #NNX15BB01- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMEP21E2197H
- Keywords:
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- 6225 Mars;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 5415 Erosion and weathering;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS;
- 5419 Hydrology and fluvial processes;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS;
- 5494 Instruments and techniques;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS