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Photographs and information for a large collection of igneous, metamorphic and sedimentary rocks. Geology.com.
- Amphibolite
Amphibolite is a rock of convergent plate boundaries where...
- Peridotite
Peridotite is a generic name used for coarse-grained,...
- Basalt
What is Basalt? Basalt is a dark-colored, fine-grained,...
- Flint
These excavations began about 4000 BC and continued until...
- Amphibolite
9 Ιουλ 2023 · Igneous, sedimentary, and metamorphic rocks are the three types of rocks. Rocks fall into one of these categories depending on how they form and are then further subcategorized according to formation, composition, and other properties.
It explains how rocks of different types can be related and how geological forces such as plate tectonics, volcanic activity, erosion, and sedimentation play roles in shaping the Earth’s surface and changing its rock composition over geological time spans.
2 ημέρες πριν · Rock, in geology, naturally occurring and coherent aggregate of one or more minerals. Such aggregates constitute the basic unit of which the solid Earth is composed and typically form recognizable and mappable volumes. The three major classes of rock are igneous, sedimentary, and metamorphic rock.
Salt Lake Community College via OpenGeology. Igneous rocks are classified based on texture and composition. Texture describes the physical characteristics of the minerals, such as grain size. This relates to the cooling history of the molten magma from which it came. Composition refers to the rock’s specific mineralogy and chemical composition.
8 Αυγ 2023 · Chemical sedimentary rocks – such as rock salt, iron ore, chert, flint, some dolomites, and some limestones, form when dissolved minerals precipitate from solution. Organic sedimentary rocks – such as coal, some dolomites, and some limestones, form from the accumulation of plant or animal debris.
These rocks include: andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff. Pictures and brief descriptions of some common igneous rock types are shown on this page. Dacite is a fine-grained, extrusive igneous rock that is usually light in color. It has a composition that is intermediate between rhyolite and andesite.
