Gypsum veins in Triassic Moenkopi mudrocks of southern Utah: Analogs to calcium sulfate veins on Mars

Abstract

Well‐exposed gypsum veins in the Triassic Moenkopi formation in southern Utah, USA, are similar to veins at Endeavour and Gale Craters on Mars. Both Moenkopi and Mars veins are hydrated calcium sulfate, have fibrous textures, and crosscut other diagenetic features. Moenkopi veins are stratigraphically localized with strontium and sulfur isotope ratios similar to primary Moenkopi sulfate beds and are thus interpreted to be sourced from within the unit. Endeavour veins seem to be distributed by lithology and may have a local source. Gale veins cut across multiple lithologies and appear to be sourced from another stratigraphic interval. Evaluation of vein network geometries indicates that horizontal Moenkopi veins are longer and thicker than vertical veins. Moenkopi veins are also generally oriented with the modern stress field, so are interpreted to have formed in the latest stages of exhumation. Endeavour veins appear to be generally vertical and oriented parallel to the margins of Cape York and are interpreted to have formed in response to topographic collapse of the crater rim. Gale horizontal veins appear to be slightly more continuous than vertical veins and may have formed during exhumation. Abrupt changes in orientation, complex crosscutting relationships, and fibrous (antitaxial) texture in Moenkopi and Mars veins suggest emplacement via hydraulic fracture at low temperatures. Moenkopi and Mars veins are interpreted as late‐stage diagenetic features that have experienced little alteration since emplacement. Moenkopi veins are useful terrestrial analogs for Mars veins because vein geometry, texture, and chemistry record information about crustal deformation and vein emplacement.

Multiscale and Multispectral Characterization of Mineralogy with the ExoMars 2022 Rover Remote Sensing Payload

“…From these it is clear that the veins are crosscutting secondary features, emplaced after the formation of the red and green mudstone units. The SWIR spectra of the high‐albedo veins (Figure e) are consistent with that of gypsum (Young & Chan, ) and the 950–1,000 nm VNIR slope is truly indicative of a sharp absorption feature around 1,000 nm in the ISEM‐E ground truth spectrum. The SWIR spectrum of the dry red coating material (Figure e) is also consistent with gypsum, showing that the mineral veins are weathering out and dispersing this material.…”

“…The Torrey gypsum veins and veins observed on Mars by Opportunity and Curiosity at Endeavour and Gale craters are late‐stage diagenetic features that have experienced little alteration since emplacement (Young & Chan, ). The absorption feature from 0.934 to 1.009 microns observed by the Opportunity Pancam showed a marked downturn in reflectance when gypsum veins were detected due to the H 2 O overtone from hydrated calcium sulfate (Farrand et al, ).…”

“…The Triassic Moenkopi formation in southern Utah, USA, is characterized by mudstone interbedded with siltstone, sandstone, and gypsum beds that represent tidal marginal marine and sabkha environments at the edge of the Early Triassic epeiric sea (Young & Chan, ). We deploy the ExoMars emulator suite at an exposure near 38° 18 05 N, 111° 29 11.7 W, just outside the towns of Torrey and Teasdale, UT (Figure b).…”

Geological Analysis of Martian Rover‐Derived Digital Outcrop Models Using the 3‐D Visualization Tool, Planetary Robotics 3‐D Viewer—PRo3D

“…The Curiosity rover science team has encountered many prominent diagenetic features in the form of nodules, raised ridges, dendritic/lenticular crystals, and veins or mineral filled fractures in almost all stratigraphic units encountered by the rover (Blaney et al, ; Grotzinger et al, , ; Kah et al, ; Kronyak et al, ; Léveillé et al, ; Mangold et al, ; Nachon et al, , ; Schieber et al, ; Siebach et al, ; Stack et al, ; Van Bommel et al, ; Young & Chan, ). One of the most striking examples of these features was a vein network observed at the Garden City target (see Figure c for location).…”

A terrestrial weathering and wind abrasion analog for mound and moat morphology of Gale crater, Mars

“…Areas of southern Utah are favorable for terrestrial comparisons to Mars due to the exceptional sedimentary rock exposure, lack of vegetation, and weathering features in the desert climate [e.g., Chan et al, 2011]. Analog eolian depositional environments and diagenetic products of southern Utah also inform interpretations of Mars geology [e.g., Ormö et al, 2004;Chan et al, 2004Chan et al, , 2005aChan et al, , 2011Potter et al, 2011;Young and Chan, 2017]. The focus of this study is a large weathering pit in Grand Staircase Escalante National Monument of Utah (Figure 2), informally dubbed "inselberg pit," German for "island mountain" [Netoff and Chan, 2008].…”