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.
Chemical Rocks. Chemical rocks precipitate from water. These include carbonates (limestone and dolomite), evaportites (halite, gypsum, anhydrite), and chert (SiO 2). Most sedimentary rocks are derived by processes of weathering, transportation, deposition, and diagenesis. The final texture (grain size, shape, sorting, mineralolgy, etc.) in a sediment or sedimentary rocks is dependent on process that occur during each stage.