Fine fraction in quartz arenite sandstones from Lower Cretaceous Hatira formation in Israel was observed by Transmission electron microscope (TEM). Samples were collected from Hatira and Ramon craters located in southern part of Israel and from Manara cliff from the northern part of Israel. The additional phases cause yellow, red, dark red and dark violet colors of the layered sandstones. The motivation was to identify the minerals of the fine factions that cause the variations in the colors. The minerals observed were clay minerals, mainly kaolinite (Al4Si4O20(OH)8), some illite (K0.65Al2.0[Al0.65Si3.35O10](OH)2) and smectite. Iron oxides were goethite (FeOOH) and hematite (Fe2O3), Titanium-iron oxides observed was ilmenite (FeTiO3), and Titanium-oxides were rutile (TiO2), and anatase (TiO2). Sulphates observed were jarosite (KFe3(SO4)2(OH)6) and alunite (KAl3(SO4)2(OH)6). Some of the hematite was formed by recrystallization of goethite. Ilmenite disintegrated into small iron oxides mainly hematite. Euhedral to sub-hedral rutile (TiO2) and anatase (TiO2) were preserved in clay-minerals. Crystals of alunite and jarosite were observed in sandstones in both craters. They probably crystallized due to some transgression of the Thetis Sea.
Part of the book: Materials at the Nanoscale