Category
page 1Glacial deposits
till
thumb|right|Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as matrix support, is diagnostic of till.
thumb|right|Glacial till with tufts of grass
thumb|Till after avalanche, Norway
Till, or glacial till, is unsorted glacial sediment.
glacial sediment
material of glacial origin
quick clay
type of glaciomarine clay
dropstone
thumb|300px|A dropstone of quartzite in layered [[rhythmite at Itu, Brazil]]
Dropstones are isolated fragments of rock found within finer-grained water-deposited sedimentary rocks or pyroclastic beds. They range in size from small pebbles to boulders. The critical distinguishing feature is that there is evidence that they were not transported by normal water currents, but rather dropped in vertically through the air or water column, such as during a volcanic eruption.
Touchet Formation
geological formation