volcanic+grit
1trap-tufa — n.; (also trap tuff) (Geol.) Volcanic tuff, volcanic grit …
2Lickey Hills — The hills had been a royal hunting reserve belonging to the Manor of Bromsgrove. Free public open access began in 1888 when Rednal Hill was bought by the Birmingham Society for the Preservation of Open Space. The Society then presented it to the… …
3Silurian Period — Interval of geologic time, 443–417 million years ago. The third period of the Paleozoic Era, the Silurian follows the Ordovician Period and precedes the Devonian. It marks the first appearance of land plants and jawed fishes. The continents were… …
4Geology of New Zealand — The continent of Zealandia The geology of New Zealand is noted for its volcanic activity, earthquakes and geothermal areas because of its position on the boundary of the Australian Plate and Pacific Plates. New Zealand was earlier part of the… …
5Achilles Point — (Te Pane o Horoiwi The head of Horoiwi ) is a rocky point on the headland at the eastern end of the small sandy beach named Ladies Bay, Auckland, New Zealand. The name Te Pane o Horoiwi can also sometimes refer to the whole headland between St… …
6Tuff — (from the Italian tufo ) is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff should not be confused with tufa , another type of rock. Volcanic ashThe products of a volcanic eruption are… …
7Diamond — This article is about the mineral. For the gemstone, see Diamond (gemstone). For other uses, including the shape ◊, see Diamond (disambiguation) …
8Geology of Yorkshire — In Yorkshire there is a very close relationship between the major topographical areas and the geological period in which they were formed. The Pennine chain of Hills in the west is of Carboniferous origin. The central vale is Permo Triassic. The… …
9Geology of Tasmania — Tasmania has a varied geological history, with the world s biggest exposure of diabase, or dolerite. Rocks from the Neoproterozoic, Paleozoic and Mesozoic time periods appear. It is one of the few southern hemisphere areas glaciated during the… …
10sedimentary rock — Rock formed at or near the Earth s surface by the accumulation and lithification of fragments of preexisting rocks or by precipitation from solution at normal surface temperatures. Sedimentary rocks can be formed only where sediments are… …