Clay minerals, which totally make up 4-5% of the earth’s crust, are generally classified into three different phyllosilicate: illites, smectites and kaolins. Of these, kaolin generally has the lowest Fe content and illite the highest; however, smectite also has appreciable Fe contents (<30 wt %). In this editorial, the focus is restricted to the Fe-bearing smectites, since smectites are ubiquit...

The long-term safe storage of CO2 in geological reservoirs requires the understanding impact on clay-rich sealing cap rocks. reactivity mixed layer illite-smectite was investigated to determine reaction pathways under conditions supercritical (scCO2) context storage. A common clay (blue marl from Guadalquivir Tertiary basin, southern Spain) tested brine scCO2 (100 bar and 35 °C) for 120 240 h. ...

Introduction: Mineralogical studies have demonstrated that the nakhlite SNC meteorites have preserved the effects of water-rock interaction between a hydrothermal brine and the nakhlite parent rocks on Mars. Brittle fracturing and corrosion of olivine grains and mesostasis associated with the hydrothermal event have left veins of zoned Fe-carbonate, Fe-smectite (with minor serpentine), and an a...

Assemblages of clay minerals are routinely used as proxies for paleoclimatic change and paleoenvironmental conditions in Phanerozoic rocks. However, this tool is rarely applied in older sedimentary units. In this paper, the clay mineralogy of the Doushantuo Formation in South China is documented, providing constraints on depositional conditions of the Ediacaran Yangtze platform that host the ea...

Reflectance spectroscopy is a rapid and non-destructive method that can be used to detect organic compounds in geologic samples over a wide range of spatial scales that includes outcrops, hand samples, drill cores, and planetary surfaces. In order to assess the viability of this technique for quantification of organics and aliphatic compounds in particular, the present study examines how clay m...

This paper discusses the processes and mechanical factors that define the seismogenic zone and the updip transition from seismic to aseismic faulting. We review friction laws for granular and clay-rich fault zones and discuss them in the context of the mechanics of stick-slip and the requirements for instability. Seismogenic faulting is driven by the unstable release of stored elastic energy, a...

We present results from geomorphic mapping and visible to near-infrared spectral analyses of the Jezero crater paleolake basin and its associated watershed. The goal of this study is to understand the provenance of the sedimentary deposits within this open-basin lake using a source-to-sink approach. Two fan deposits located within the basin have distinct visible to near-infrared mineralogic sig...