Browse Items (264 total)

Hand Specimen Dark grey rock, mainly fine sand.Does not react with acid, probably mainly quartz. Some glints of mica. Cement reacts with acid, so it is at least partially carbonate. Band of brown-grey material is due to…

Hand Specimen Mainly medium sand (to coarse sand in the case of L327a). Yellow-brown iron stained quartz, cemented by the same yellow brown oxide. A few larger quartz grains up to 5 mm long. Grains are angular to sub-rounded, and poorly…

Hand Specimen Reddish brown rock. Medium sand grade.Round to sub-round grains of quartz, often with a thin rim of red hematite. Mainly reddish and pink-brown grains, fewer white grains and very few black grains. Well sorted and well cemented.No…

Hand Specimen Pale grey rock, mainly medium to coarse grained quartz sand. Poorly sorted. Small amounts of lithic fragments up to 10 mm across, and shell fragments. Contains <15 vol% clay, making it an arenite.Pale grey cement fizzes…

Hand Specimen Reddish brown rock made up of pinkish feldspar, colourless quartz, and some dark grey grains. Medium to coarse sand. Moderately rounded. Fairly well sorted. Contains <15 vol% clay, so this is an arenite. No fizzing with…

Hand Specimen Pale yellow grey rock, almost entirely made up of medium sand quartz grains. These are sub-rounded, very well sorted, and are held together by a matrix of siliceous silt. Contains a significant amount of clay, but <15 vol%,…

Hand Specimen Poorly sorted. Rounded clasts up to ~15 mm long. Pale yellow matrix of quartz grains. Cement fizzes with acid, indicating that it contains carbonate. This conglomerate is just clast-supported. Thin-section Rounded clasts of very…

Hand Specimen Very poorly sorted.Angular to sub-angular clasts up to 30 mm long. Randomly orientated. Clasts mainly pale grey, some white, some red. Red-brown colour of the fine-grained matrix indicates iron staining. Matrix and some clasts…

Hand Specimen Six vials containing unlithified terrigenous sediments of different grain sizes. These are:   grain size (mm) grain size (phi) Very coarse sand 1-2 -1-0 Coarse sand 0.5-1 0-1 Medium sand 0.25-0.5 1-2 Fine sand 0.125-0.25 2-3 Very fine…

Hand Specimen Fine-grained, blue-green, sedimentary texture. Slaty cleavage. Some patches of lighter and finer-grained material. Thin-section Slaty cleavage due to the alignment of chlorite and muscovite. Cross-cut by the blobs of the…