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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) Distribution of impact craters greater than 12 km in diameter. Measured impact craters include (1) collapsed craters, (2) buried craters, (3) flat-floored craters infilled up to their rims, and (4) degraded and pristine craters that retain significant topography. (b) Cumulative size-frequency distribution for all craters in study region. Calculated age includes craters with diameters larger than 12 km. Crater diameters were measured in ArcGIS software and cumulative size-frequency distributions were plotted using Craterstats2 software59. The Hartmann60 model production function and the Michael59 chronology function were used to calculate an overall age of 3.65 ± 0.01 Ga for the sedimentary wedge (i.e., Late Noachian60).
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f5: (a) Distribution of impact craters greater than 12 km in diameter. Measured impact craters include (1) collapsed craters, (2) buried craters, (3) flat-floored craters infilled up to their rims, and (4) degraded and pristine craters that retain significant topography. (b) Cumulative size-frequency distribution for all craters in study region. Calculated age includes craters with diameters larger than 12 km. Crater diameters were measured in ArcGIS software and cumulative size-frequency distributions were plotted using Craterstats2 software59. The Hartmann60 model production function and the Michael59 chronology function were used to calculate an overall age of 3.65 ± 0.01 Ga for the sedimentary wedge (i.e., Late Noachian60).

Mentions: We infer a relatively short-lasting duration for the conditions allowing deep upland erosion connected with the formation of the proposed massive clastic sedimentary wedge based on previous investigations that propose a major spike in erosional and sedimentation rates occurring near the Noachian-Hesperian boundary34353637383940414243. This geologic stage likely lasted just a few million years35. To establish a relative chronology for the proposed stage of large-scale sedimentation, we mapped the distribution of (1) collapsed craters, (2) buried craters, (3) flat-floored impact craters infilled up to their rims, and (4) impact craters that retain significant topography (Fig. 5a). Our mapping of buried craters is based on the identification of quasi-circular depressions distributed throughout the regional highlands. These features are thought to have formed by compaction of sediments overlying buried impact craters44. Impact crater statistics yield a Late Noachian age of 3.65 ± 0.01 Ga (Fig. 5b), and point to a major spike in impact cratering rates during this time period. This spike was likely the result of a late phase of the Late Heavy Bombardment thought to have affected Mars up to 3.6 Ga45. Increased global erosional and depositional rates associated with an active surface hydrosphere34353637383940414243 during the Late Heavy Bombardment are consistent with impact-induced climate change as proposed by Segura et al.46.


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) Distribution of impact craters greater than 12 km in diameter. Measured impact craters include (1) collapsed craters, (2) buried craters, (3) flat-floored craters infilled up to their rims, and (4) degraded and pristine craters that retain significant topography. (b) Cumulative size-frequency distribution for all craters in study region. Calculated age includes craters with diameters larger than 12 km. Crater diameters were measured in ArcGIS software and cumulative size-frequency distributions were plotted using Craterstats2 software59. The Hartmann60 model production function and the Michael59 chronology function were used to calculate an overall age of 3.65 ± 0.01 Ga for the sedimentary wedge (i.e., Late Noachian60).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f5: (a) Distribution of impact craters greater than 12 km in diameter. Measured impact craters include (1) collapsed craters, (2) buried craters, (3) flat-floored craters infilled up to their rims, and (4) degraded and pristine craters that retain significant topography. (b) Cumulative size-frequency distribution for all craters in study region. Calculated age includes craters with diameters larger than 12 km. Crater diameters were measured in ArcGIS software and cumulative size-frequency distributions were plotted using Craterstats2 software59. The Hartmann60 model production function and the Michael59 chronology function were used to calculate an overall age of 3.65 ± 0.01 Ga for the sedimentary wedge (i.e., Late Noachian60).
Mentions: We infer a relatively short-lasting duration for the conditions allowing deep upland erosion connected with the formation of the proposed massive clastic sedimentary wedge based on previous investigations that propose a major spike in erosional and sedimentation rates occurring near the Noachian-Hesperian boundary34353637383940414243. This geologic stage likely lasted just a few million years35. To establish a relative chronology for the proposed stage of large-scale sedimentation, we mapped the distribution of (1) collapsed craters, (2) buried craters, (3) flat-floored impact craters infilled up to their rims, and (4) impact craters that retain significant topography (Fig. 5a). Our mapping of buried craters is based on the identification of quasi-circular depressions distributed throughout the regional highlands. These features are thought to have formed by compaction of sediments overlying buried impact craters44. Impact crater statistics yield a Late Noachian age of 3.65 ± 0.01 Ga (Fig. 5b), and point to a major spike in impact cratering rates during this time period. This spike was likely the result of a late phase of the Late Heavy Bombardment thought to have affected Mars up to 3.6 Ga45. Increased global erosional and depositional rates associated with an active surface hydrosphere34353637383940414243 during the Late Heavy Bombardment are consistent with impact-induced climate change as proposed by Segura et al.46.

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