Mineralogical Diversity of Ca₂SiO₄-Bearing Combustion Metamorphic Rocks in the Hatrurim Basin: Implications for Storage and Partitioning of Elements in Oil Shale Clinkering

• Main Authors: Ella V. Sokol, Svetlana N. Kokh, Victor V. Sharygin, Victoria A. Danilovsky, Yurii V. Seryotkin, Ruslan Liferovich, Anna S. Deviatiiarova, Elena N. Nigmatulina, Nikolay S. Karmanov
• Format: Article
• Language: English
• Published: MDPI AG 2019-07-01
• Series: Minerals
• Subjects: cement clinker; Ca₂SiO₄ modifications; larnite; flamite; ye’elimite; mayenite; trace element partitioning; threshold limits; combustion metamorphism; Hatrurim Formation
• Online Access: https://www.mdpi.com/2075-163X/9/8/465

This is the first attempt to provide a general mineralogical and geochemical survey of natural Ca₂SiO₄-bearing combustion metamorphic (CM) rocks produced by annealing and decarbonation of bioproductive Maastrichtian oil shales in the Hatrurim Basin (Negev Desert, Israel). We present a synthesis of data collected for fifteen years on thirty nine minerals existing as fairly large grains suitable for analytical examination. The Hatrurim Ca₂SiO₄-bearing CM rocks, which are natural analogs of industrial cement clinker, have been studied comprehensively, with a focus on several key issues: major- and trace-element compositions of the rocks and their sedimentary precursors; mineral chemistry of rock-forming phases; accessory mineralogy; incorporation of heavy metals and other trace elements into different phases of clinker-like natural assemblages; role of trace elements in stabilization/destabilization of Ca₂SiO₄ polymorphic modifications; mineralogical diversity of Ca₂SiO₄-bearing CM rocks and trace element partitioning during high-temperature–low-pressure anhydrous sintering. The reported results have implications for mineral formation and element partitioning during high-temperature–low-pressure combustion metamorphism of trace element-loaded bituminous marine chalky sediments (“oil shales”) as well as for the joint effect of multiple elements on the properties and hydration behavior of crystalline phases in industrial cement clinkers.