Morphologic and mineralogic analysis of Nirgal and Her Desher Valles, Mars: Evidence of groundwater flow in northwest Noachis Terra

Dataset DOI

https://doi.org/10.48732/gzqc-0f53

Author(s)

Debra L. Buczkowski, Danielle Y. Wyrick, Cristina E. Viviano, Kim D. Seelos, Frank P. Seelos, and Scott L. Murchie

Journal

Journal of Geophysics, Planets

Publication DOI

n/a

Publication Year

2022

Description

A widespread phyllosilicate-bearing layer has been identified in a distinct region in northwest Noachis Terra. This layer is exposed along the length of two valley systems in the region, Nirgal and Her Desher Valles, as well as in nearby crater rims and walls. It has been suggested that the phyllosilicates were produced by pedogenic weathering fed by meteoric water or melted snow. However, the geomorphology and stratigraphy of the valley systems is more consistent with formation due to groundwater sapping, not fluvial erosion. Geomorphic analysis of the valleys shows that they are structurally controlled and are consistent with regions of groundwater trapping by fracture and fault systems on Earth. Identification of hematite/sulfate intermixed with the phyllosilicates in the Her Desher and Nirgal valleys, suggests that pre-existing phyllosilicates were altered as acidic, sulfur-rich groundwater sourced by the Tharsis uplift flowed through the region. While groundwater seepage is unlikely to be able to erode resistant bedrock, basalt previously altered into pedogenic soils would be more conducive to channel formation due to groundwater seepage.

Files

Preview Filename Description
sulfate_hematite_library.txt

Library spectra of sulfate and hematite, for comparison

137ad_kaolinite_spectra.txt

Kaolinite spectra from FRT137AD

137ad_smectite_spectra.txt

Smectite spectra from FRT137AD

137ad_spectra_complete.xlsx

Excel spreadsheet of spectra from FRT137AD

137ad_sulfate_spectra.txt

Sulfate spectra from FRT137AD

al_phyllo_library.txt

Library spectra of aluminum phyllosilicates, for comparison

fe_mg_phyllo_library.txt

Library spectra of nontronite and saponite, for comparison

c875_spectra.txt

Spectra from FRTC875

c9e2_spectra.txt

Spectra from FRTC9E2

8e5d_spectra.txt

Spectra from FRT8E5D

aa4a_spectra.txt

Spectra from FRTAA4A

14721_spectra.txt

Spectra from FRT14721

9b61_spectra.txt

Spectra from HRL9B61

ab96_spectra.txt

Spectra from HRLAB96

Uploaded by buczkdl1 on April 27, 2022, 4:07 p.m.
Last modified Oct. 11, 2022, 4:06 p.m.