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.
Clastic sedimentary rocks are composed of silicate minerals and rock fragments that were transported by moving fluids (as bed load, suspended load, or by sediment gravity flows) and were deposited when these fluids came to rest.ost sedimentary rocks contain either quartz (especially siliciclastic rocks) or calcite (especially carbonate rocks). In contrast to igneous and metamorphic rocks, a sedimentary rock usually contains very few different major minerals.