Introduction: The OMEGA instrument on Mars Express has recently detected the largest gypsum deposit on Mars within the north polar sand sea [1]. Here we discuss the unique geologic context and origin of this evaporite deposit. Gypsum on Earth and Mars: Gypsum is a hydrated Ca-sulfate (2H 2 O • CaSO 4). Though gypsum can be formed, for example, as a hydrothermal deposit [e.g., 2] or as an altera...

The research aims to study Sabkha mineralogy determine the mineral types, nature of precipitation, and patterns salt crystallization. Two Sabkhas in Abu Ghraib, west Baghdad, were studied. It was found that formed flat ponds from saturated solutions a semi-arid arid climate. Halite predominates, followed by anhydrite gypsum as evaporite minerals. As for minerals soil, it consisted feldspar, cal...

Abstract The origins of Kiruna-type magnetite(-apatite) [Mt(-Ap)] deposits are contentious, with existing models ranging from purely hydrothermal to orthomagmatic end members. Here, we evaluate the compositions fluids that formed classic yet enigmatic Mt(-Ap) deposit at El Laco, northern Chile. We report evidence ore-stage minerals crystallized an Fe-rich (6–17 wt% Fe) sulfate melt. suggest a m...

This volume grew out of the various oral and poster presentations given during the ‘Evaporite’ session at the International Geological Union conference (2004) in Florence, Italy. It was clear that only a few of the participants or attendees, coming from many countries and various distant parts of the world, were well informed about evaporites outside their immediate area of study, apart from da...