Search
Search results
Displaying 11 - 20
sediment
(Encyclopedia) sediment, mineral or organic particles that are deposited by the action of wind, water, or glacial ice. These sediments can eventually form sedimentary rocks (see rock). Sediments…clay
(Encyclopedia) clay, common name for a number of fine-grained, earthy materials that become plastic when wet. Chemically, clays are hydrous aluminum silicates, ordinarily containing impurities, e.g…natural gas
(Encyclopedia) natural gas, natural mixture of gaseous hydrocarbons found issuing from the ground or obtained from specially driven wells. The composition of natural gas varies in different…Oligocene epoch
(Encyclopedia) Oligocene epochOligocene epochŏlˈəgōsēnˌ [key], third epoch of the Tertiary period in the Cenozoic era of geologic time, lasting from 38 to 24 million years ago. More of North America…distillation
(Encyclopedia) distillation, process used to separate the substances composing a mixture. It involves a change of state, as of liquid to gas, and subsequent condensation. The process was probably…Ordovician period
(Encyclopedia) Ordovician periodOrdovician periodôrdəvĭshˈən [key] [from the Ordovices, ancient tribe of N Wales], second period of the Paleozoic era of geologic time (see Geologic Timescale,…sandstone
(Encyclopedia) sandstone, sedimentary rock formed by the cementing together of grains of sand. The usual cementing material in sandstone is calcium carbonate, iron oxides, or silica, and the hardness…Miocene epoch
(Encyclopedia) Miocene epochMiocene epochmīˈəsēn [key], fourth epoch of the Tertiary period in the Cenozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table), lasting from…Geology of the Grand Canyon: The Permian.
THE TEMPLES AND TOWERS OF THE VIRGEN.THE PERMIAN.The idea of a terrace is not so typically represented in the Permian as it is in the superior formations. In many parts of the great stairway…Geology of the Grand Canyon: The Cretaceous.
THE EOCENE.THE JURASSIC.THE CRETACEOUS.The platform immediately below the Pink Cliffs is picturesque rather than grand. Rough rolling ridges of yellow sandstone, long sloping hillsides and…Trending
Here are the facts and trivia that people are buzzing about.
