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 sedimentary rocks are identified by identifying the mineral from which they are composed. In this lab there are four minerals that need to be identified-quartz, halite, gypsum and calcite.Quartz has a hardness of 7 and is very difficult to scratch, even with a good quality knife blade.lastic sedimentary rocks contain clasts. These are fragments or pieces of rock or minerals. The composition of clastic sedimentary rocks is divided into three types-clay/silt, sand and gravel. Clay and silt are less than 1/16 mm. These are not visible to the unaided eye.