Global Map of Martian Fluvial Systems: Age and Total Eroded Volume Estimations

Abstract

The study of the fluvial systems present on the Martian surface is a key in the investigation of the paleoclimate of the planet: Various indications suggest that these features could have formed under climatic conditions very different from the present one. For this reason, it seems necessary to update the previous maps of Martian valleys using newer mosaics and data at higher resolution. In this work we present a detailed global map of Martian valleys classified according to their morphology. Our data set includes all the valleys longer than 20 km mapped within the QGIS (Quantum Geographic Information System) software. With respect to previous global maps, the coupling of topographic information with data of higher image quality allowed us a better mapping of these structures at a fine scale: New small valleys and more tributaries for several systems have been observed. We mapped valleys of various typologies for a global total length of 773,559 km. The mapped valley networks cover the 69% of this total length. Moreover, a rough estimation of the valleys' age spatial distribution was performed. We found that the 94% of the mapped valleys have a maximum age consistent with an origin in the Noachian period; the 4% have a Hesperian maximum age, while the remaining 2% have a maximum age consistent with an origin in the Amazonian period. Finally, we also estimated the total eroded volume of the mapped valley networks finding a value in the order of 3 × 1014 m3 in good agreement with what found in literature.

Paleolakes in the Northwest Hellas Region, Mars: Implications for the Regional Geologic History and Paleoclimate

“…A similar distribution has also been observed at global scales, in which open‐basin lakes are extensively distributed near the dichotomy of Mars (Fassett & Head, ; Goudge, Head, et al, ). The density distribution of the paleolakes exhibits a relatively large difference between the “highland region” and the southeast “slope region.” The lower density of paleolakes in the “slope region,” combined with the sparse distributed valleys based on previous maps (e.g., Alemanno et al, ; Luo & Stepinski, ), may indicate that the “slope region” may have been partially covered by water due to the existence of a large lake or ocean in the Hellas basin that has been proposed by previous studies (Figure ) (e.g., Bernhardt et al, ; Crown et al, ; Moore & Wilhelms, ; Salese et al, ; Wilson et al, ). The “Hellas Ocean” could have formed after the formation of the Hellas basin in a warm and wet climate, and then the water level decreased when the climate became drier.…”

“…based on previous maps (e.g., Alemanno et al, 2018;Luo & Stepinski, 2009), may indicate that the "slope region" may have been partially covered by water due to the existence of a large lake or ocean in the Hellas basin that has been proposed by previous studies (Figure 14) (e.g., Bernhardt et al, 2016;Crown et al, 2005;Moore & Wilhelms, 2001;Salese et al, 2016;Wilson et al, 2007). The "Hellas Ocean" could have formed after the formation of the Hellas basin in a warm and wet climate, and then the water level decreased when the climate became drier.…”

“…Liquid water has played a significant role in shaping the Martian surface and a variety of landforms that could be related to fluvial activity are present on Mars (Baker, ; McSween, ), for example, valley networks (Alemanno et al, ; Carr, ; Fassett & Head, ; Gulick & Baker, ), outflow channels (Baker, ; Rodriguez et al, ), paleolakes (De Hon, ; Fassett & Head, ; Goudge, Head, et al, ; Goudge, Aureli, et al, ), and deltas (Fassett & Head, ; Goudge et al, , ; Kraal et al, ; Rivera‐Hernández & Palucis, ). Among them, paleolakes have received much attention.…”

Diverse Polygonal Patterned Grounds in the Northern Eridania Basin, Mars: Possible Origins and Implications

“…The basaltic layers and overlying light‐toned clay‐rich deposits on each of them may respectively correspond to volcanic eruption events and subsequent aqueous alteration of basaltic materials. Ponding and flooding of liquid water would have densely occurred resulting in the formation of a series of paleolakes (e.g., Goudge et al., 2015; Irwin et al., 2002) and numerous valley/fluvial network systems (e.g., Alemanno et al., 2018; Howard et al., 2005; Hynek et al., 2010; Irwin et al., 2005; Phillips et al., 2001). Local‐scale precipitation and groundwater flow may also have caused runoff, ponding, cementation or diagenesis (Andrews‐Hanna et al., 2007).…”

“…A set of aqueous minerals (e.g., clay‐rich, sulfate and chloride‐bearing deposits) have been detected in the northern Eridania basin and they are exposed in the local stratigraphy (Adeli et al., 2015; Carter et al., 2013; Ehlmann et al., 2011; Michalski et al., 2017; Osterloo et al., 2010; Pajola et al., 2016). Widespread ancient valley networks in the martian southern highlands (Alemanno et al., 2018) and those on the Eridania basin floor suggest that the duration of regional fluvial activity is extended from Late Noachian to Late Hesperian (Baker & Head, 2012; Fassett & Head, 2008). The starting point of the Ma'adim Vallis is connected to a breach in the northern perimeter of the Eridania palaeolake system, exactly adjacent to the northwest of our study area: the northern Eridania basin (Figure 1).…”