Noachian–Hesperian geologic history of the Echus Chasma and Kasei Valles system on Mars: New data and interpretations

Abstract

New high-resolution datasets have prompted a mapping-based study of the 2500-km-long Echus Chasma and Kasei Valles system that utilizes geomorphic details, stratigraphic relations, and cratering statistics derived from the new datasets. Our results suggest that between the Hesperian and Amazonian Epochs on Mars (3.7 Ga to Recent) the study area was affected by at least 4 episodes of widespread volcanic activity and 4 periods of episodic fluvio-glacial activity. This paper discusses the Noachian to Hesperian (N2.6 Ga) history of the study area, during which time in the Hesperian three of the volcanic episodes took place along with the first two episodes of fluvioglacial activity. Highlights of our new findings and refinements from this time period include (1) two ancient western floods sourced from Tharsis that occurred around 3.61 and 3.4 Ga and carved the east-trending path of north Kasei Valles; (2) Uranius Dorsum with 58 aligned cones along its length that was emplaced in north Kasei around 3.6 Ga between these periods of early flooding; (3) possible ash deposits surrounding Echus Chasma, one of which contains narrow dendritic valley systems that may have been carved over a period of about 10,000 yr; and (4) evidence that suggests glaciers and near-surface ice may have contributed to erosion of local units.

Episodes of fluvial and volcanic activity in Mangala Valles, Mars

“…7A, B, 12B, 13A and B). Compared to Ast, smooth plains units have relatively few flow features, the exceptions being sinuous channels and aggradational streamlined features similar to those observed in Kasei Valles (Chapman et al, 2010) (Fig. 10D).…”

“…This intimate relationship between tectonic, volcanic, and aqueous activity augments current ideas about complexity of the Memnonia Fossae region and its relationship to Tharsis-related volcanism and tectonics. Ares Valles and the Kasei Valles and Echus Chasma system have been suggested to share this episodic behavior, but at a much earlier time in martian history (Warner et al, 2009;Chapman et al, 2010), indicating that Mangala Valles represents a younger expression of what may be a similar subsurface process. Detailed comparative studies of other more recently active fluvial-volcanic systems, such as Athabasca Valles (Jaeger et al, 2007(Jaeger et al, , 2010, may aid in determining the extent to which repeated fluvial and volcanic activity has extended into the Amazonian Period.…”

“…In particular, there are challenges associated with generating the substantial volumes of water required to erode and transport material out of these systems, which has prompted a wide range of alternative formation hypotheses including aqueous flooding (e.g., Baker and Milton, 1974;Sharp and Malin, 1975), volcanism (e.g., Leverington, 2004), glacial erosion (e.g., Lucchitta, 1982), eolian erosion (e.g., Cutts and Blasius, 1981), debris flows (e.g., Nummedal and Prior, 1981), or a combination of these processes (e.g., Chapman et al, 2003Chapman et al, , 2010Warner et al, 2009;McEwen et al, 2012). While lack of terrestrial analogs of comparable scale and complexity renders geomorphic comparison of large landscape features in these regions difficult (Mars Channel Working Group, 1983), new high-resolution images allow us to identify smaller surface features that provide clues about the processes that have influenced their overall surface geomorphology, allowing for reconstruction of their activity history.…”

Quantifying geological processes on Mars—Results of the high resolution stereo camera (HRSC) on Mars express

“…Studying the Echus Chasma and Kasei Valles system, Chapman et al (2010a) found closely interspersed episodes of volcanic and fluvio-glacial activity, with flood basalt emplacement in Kasei occurring at 3.7 Ga, the formation of Echus Chasma at 3.6 Ga with early flooding sourced from the west. A cycle lasting from 1.8-1.0 Ga began with fluvial erosion of a narrow channel in the Tharsis Montes formation in north Kasei Valles followed by episodic catastrophic floods sourced from Echus Chasma.…”

“…(1) The large areal extent of single HRSC nadir images (minimum width of 62.5 km at 12.5 m/pixel and variable lengths up to several 1000 km) are particularly favorable for mapping of volcanic deposits and edifices at scales of about 1:40,000 (e.g., Bleacher et al, 2007aBleacher et al, , 2007bChapman et al, 2010aChapman et al, , 2010bPlatz and Michael, 2011;Hauber, 2012, 2013). Colored views of the Martian surface based on the red, green, blue, and near-infrared channels also deliver additional information that assist in distinguishing surface domains, and when combined with OMEGA data in particular and provide information on the composition of volcanic materials.…”