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Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly?

Rodriguez JA, Kargel JS, Baker VR, Gulick VC, Berman DC, Fairén AG, Linares R, Zarroca M, Yan J, Miyamoto H, Glines N - Sci Rep (2015)

Bottom Line: Using more recent mission data, we argue that during the Late Noachian fluvial and glacial sediments were deposited into a clastic wedge within a paleo-basin located in the southern circum-Chryse region, which at the time was completely submerged under a primordial northern plains ocean [corrected].Subsequent Late Hesperian outflow channels were sourced from within these geologic materials and formed by gigantic groundwater outbursts driven by an elevated hydraulic head from the Valles Marineris region.Thus, our findings link the formation of the southern circum-Chryse outflow channels to ancient marine, glacial, and fluvial erosion and sedimentation.

View Article: PubMed Central - PubMed

Affiliation: Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ 85719-2395, USA.

ABSTRACT
Catastrophic floods generated ~3.2 Ga by rapid groundwater evacuation scoured the Solar System's most voluminous channels, the southern circum-Chryse outflow channels. Based on Viking Orbiter data analysis, it was hypothesized that these outflows emanated from a global Hesperian cryosphere-confined aquifer that was infused by south polar meltwater infiltration into the planet's upper crust. In this model, the outflow channels formed along zones of superlithostatic pressure generated by pronounced elevation differences around the Highland-Lowland Dichotomy Boundary. However, the restricted geographic location of the channels indicates that these conditions were not uniform. Furthermore, some outflow channel sources are too high to have been fed by south polar basal melting. Using more recent mission data, we argue that during the Late Noachian fluvial and glacial sediments were deposited into a clastic wedge within a paleo-basin located in the southern circum-Chryse region, which at the time was completely submerged under a primordial northern plains ocean [corrected]. Subsequent Late Hesperian outflow channels were sourced from within these geologic materials and formed by gigantic groundwater outbursts driven by an elevated hydraulic head from the Valles Marineris region. Thus, our findings link the formation of the southern circum-Chryse outflow channels to ancient marine, glacial, and fluvial erosion and sedimentation.

No MeSH data available.


Related in: MedlinePlus

(a) Topographic view of circum-Chryse and western Arabia Terra showing the distribution of upland fluvial canyons (green), hybrid canyons (white) and subsided valleys (red). The black areas mark elevations ranging from −2050 to −1900, which mark the contact between the upland fluvial canyons and the subsided terrains (1), the dichotomy boundary west of the outflow channels (2), and the inter-crater plains of western Arabia Terra (3). (b) Reconstruction of coastal line at approximately −1900 m during the proposed stage of regional Late Noachian sedimentation. Question marks show the locations of uncertain paleoshoreline stretches. We produced the maps in this figure using Esri’s ArcGIS geographic information system.
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f3: (a) Topographic view of circum-Chryse and western Arabia Terra showing the distribution of upland fluvial canyons (green), hybrid canyons (white) and subsided valleys (red). The black areas mark elevations ranging from −2050 to −1900, which mark the contact between the upland fluvial canyons and the subsided terrains (1), the dichotomy boundary west of the outflow channels (2), and the inter-crater plains of western Arabia Terra (3). (b) Reconstruction of coastal line at approximately −1900 m during the proposed stage of regional Late Noachian sedimentation. Question marks show the locations of uncertain paleoshoreline stretches. We produced the maps in this figure using Esri’s ArcGIS geographic information system.

Mentions: The terrain contact between the upland and hybrid canyons is defined by elevations ranging between −2050 m and −1900 m (Fig. 3a, label 1), which also mark a section of the dichotomy boundary to the west (Fig. 3a, label 2). The dichotomy boundary corresponds approximately to the margins of water bodies (“Oceanus Borealis”24) that episodically covered the northern plains, most extensively during the Late Noachian2425262728 and Late Hesperian2526272829. The mean elevation of the Late Noachian ocean shoreline, which is the one of relevance to this study, has been estimated to be approximately −1680 m24. The elevation range also characterizes the inter-crater plains surfaces in western Arabia Terra (Fig. 3a, label 3), a region of the planet which has been interpreted as a frozen, buried remnant of the Late Noachian ocean30, where localized desiccation of the regional hydrosphere generated the widespread evaporite deposits detected by the Opportunity rover31.


Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly?

Rodriguez JA, Kargel JS, Baker VR, Gulick VC, Berman DC, Fairén AG, Linares R, Zarroca M, Yan J, Miyamoto H, Glines N - Sci Rep (2015)

(a) Topographic view of circum-Chryse and western Arabia Terra showing the distribution of upland fluvial canyons (green), hybrid canyons (white) and subsided valleys (red). The black areas mark elevations ranging from −2050 to −1900, which mark the contact between the upland fluvial canyons and the subsided terrains (1), the dichotomy boundary west of the outflow channels (2), and the inter-crater plains of western Arabia Terra (3). (b) Reconstruction of coastal line at approximately −1900 m during the proposed stage of regional Late Noachian sedimentation. Question marks show the locations of uncertain paleoshoreline stretches. We produced the maps in this figure using Esri’s ArcGIS geographic information system.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562069&req=5

f3: (a) Topographic view of circum-Chryse and western Arabia Terra showing the distribution of upland fluvial canyons (green), hybrid canyons (white) and subsided valleys (red). The black areas mark elevations ranging from −2050 to −1900, which mark the contact between the upland fluvial canyons and the subsided terrains (1), the dichotomy boundary west of the outflow channels (2), and the inter-crater plains of western Arabia Terra (3). (b) Reconstruction of coastal line at approximately −1900 m during the proposed stage of regional Late Noachian sedimentation. Question marks show the locations of uncertain paleoshoreline stretches. We produced the maps in this figure using Esri’s ArcGIS geographic information system.
Mentions: The terrain contact between the upland and hybrid canyons is defined by elevations ranging between −2050 m and −1900 m (Fig. 3a, label 1), which also mark a section of the dichotomy boundary to the west (Fig. 3a, label 2). The dichotomy boundary corresponds approximately to the margins of water bodies (“Oceanus Borealis”24) that episodically covered the northern plains, most extensively during the Late Noachian2425262728 and Late Hesperian2526272829. The mean elevation of the Late Noachian ocean shoreline, which is the one of relevance to this study, has been estimated to be approximately −1680 m24. The elevation range also characterizes the inter-crater plains surfaces in western Arabia Terra (Fig. 3a, label 3), a region of the planet which has been interpreted as a frozen, buried remnant of the Late Noachian ocean30, where localized desiccation of the regional hydrosphere generated the widespread evaporite deposits detected by the Opportunity rover31.

Bottom Line: Using more recent mission data, we argue that during the Late Noachian fluvial and glacial sediments were deposited into a clastic wedge within a paleo-basin located in the southern circum-Chryse region, which at the time was completely submerged under a primordial northern plains ocean [corrected].Subsequent Late Hesperian outflow channels were sourced from within these geologic materials and formed by gigantic groundwater outbursts driven by an elevated hydraulic head from the Valles Marineris region.Thus, our findings link the formation of the southern circum-Chryse outflow channels to ancient marine, glacial, and fluvial erosion and sedimentation.

View Article: PubMed Central - PubMed

Affiliation: Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ 85719-2395, USA.

ABSTRACT
Catastrophic floods generated ~3.2 Ga by rapid groundwater evacuation scoured the Solar System's most voluminous channels, the southern circum-Chryse outflow channels. Based on Viking Orbiter data analysis, it was hypothesized that these outflows emanated from a global Hesperian cryosphere-confined aquifer that was infused by south polar meltwater infiltration into the planet's upper crust. In this model, the outflow channels formed along zones of superlithostatic pressure generated by pronounced elevation differences around the Highland-Lowland Dichotomy Boundary. However, the restricted geographic location of the channels indicates that these conditions were not uniform. Furthermore, some outflow channel sources are too high to have been fed by south polar basal melting. Using more recent mission data, we argue that during the Late Noachian fluvial and glacial sediments were deposited into a clastic wedge within a paleo-basin located in the southern circum-Chryse region, which at the time was completely submerged under a primordial northern plains ocean [corrected]. Subsequent Late Hesperian outflow channels were sourced from within these geologic materials and formed by gigantic groundwater outbursts driven by an elevated hydraulic head from the Valles Marineris region. Thus, our findings link the formation of the southern circum-Chryse outflow channels to ancient marine, glacial, and fluvial erosion and sedimentation.

No MeSH data available.


Related in: MedlinePlus