1 Overnight temperatures are generally quite mild with an average low of 11.4 Â°C (52.5 Â°F). 2  The mean diurnal temperature variation/ range in July is 7.5 Â°C (13.5 Â°F).  The weather in July is slightly dry with rain periodically. Only 50mm (2in) of H2O is deposited across an average of 17 days.
Chemical sedimentary rock forms when mineral constituents in solution become supersaturated and inorganically precipitate. Common chemical sedimentary rocks include oolitic limestone and rocks composed of evaporite minerals such as halite (rock salt), sylvite, barite and gypsum.
Sedimentary rocks are divided into two broad classes, detrital sedimentary rocks and chemical sedimentary rocks as described below. Sedimentary rocks make up perhaps only five percent or so of the outer 16 kilometers (10 miles) of the Earth (Lutgens and Tarbuck), but the majority of surface rocks are sedimentary.