Data and code used in "Distinct Lithologies in Jezero Crater, Mars"

This repository contains the datasets and code used in the Zastrow and Glotch manuscript entitled "Distinct Lithologies in Jezero Crater, Mars".

Abstract

Jezero crater is the landing site for the Mars 2020 Perseverance rover. The Noachian-aged crater has undergone several periods of fluvial and lacustrine activity and many phyllosilicate- and carbonate-bearing rocks formed as a result. It also contains a large portion of the regional Nili Fossae olivine-carbonate unit. In this work, we performed spectral mixture analysis of visible/near-infrared hyperspectral imagery over Jezero. We modeled carbonate abundances up to ~35% and identified three distinct units containing different carbonate phases. Our work also suggests that the olivine in the regional unit is largely restricted to aeolian deposis overlying the carbonate-bearing rocks. The diversity of carbonate phases in Jezero points to multiple periods of carbonate formation under varying conditions.

Description of Repository Datasets

code_unmixing.zip:

• This folder contains the necessary files to unmix CRISM data using davinci's sma() function.  The model is run by launching davinci and entering source('ssa_unmixing_040ff').  To switch the CRISM image, edit line 10 in ssa_unmixing_040ff.
• Unmixing code:  ssa_unmixing_040ff
• Davinci functions:  unmixing_fxns.dvrc
• Spectral library:  n_k_jezeropaper.hdf

data_input.zip:

• This folder contains ENVI image files that have been DISORT-processed and are ready to be modeled using the unmixing code.  Each of the 3 CRISM images has two data files and ENVI headers:  1) the full uncut image cube and 2) the cut image cube.

data_models.zip:

• This folder contains NetCDF files with the output of the unmixing model that have been registered to the HiRISE base image.  Files contain the input CRISM measured spectra, output modeled spectra, normalized mineral concentration maps, and RMS error maps.  Data were written to file using the xarray Python package and can be read into python using the xarray.open_dataset() function.
• No Siderite, Added Kaolinite, Full Spectrum
  • These folders contain unregistered (but projected) model output for these three additional models.

data_roi.zip:

• This folder contains the shapefile for the ROI mapping.