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Pumice is an igneous rock with a foamy appearance. The name is derived from the Latin word pumex (meaning "pumice") [13] which is related to the Latin word spuma meaning "foam". [14] In former times, pumice was called "Spuma Maris", meaning "froth of the sea" in Latin because the frothy material was thought to be hardened sea foam.
The Siberian traps are underlain by the Tungus Syneclise, a large sedimentary basin containing thick sequences of Early-Mid-Paleozoic-aged carbonate and evaporite deposits, as well as Carboniferous-Permian-aged coal-bearing clastic rocks. When heated, such as by igneous intrusions, these rocks are capable of emitting large amounts of toxic and ...
Grain size in igneous rocks results from cooling time so porphyritic rocks are created when the magma has two distinct phases of cooling. [18] Igneous rocks are classified on the basis of texture and composition. Texture refers to the size, shape, and arrangement of the mineral grains or crystals of which the rock is composed. [citation needed]
Vesicular texture is a volcanic rock texture characterized by a rock being pitted with many cavities (known as vesicles) at its surface and inside. [1] This texture is common in aphanitic, or glassy, igneous rocks that have come to the surface of the Earth, a process known as extrusion. As magma rises to the surface the pressure on it decreases ...
When igneous rocks contain two distinct grain sizes, the texture is porphyritic, and the finer crystals are called the groundmass. [3] The extrusive rocks scoria and pumice have a vesicular, bubble-like, texture due to the presence of vapor bubbles trapped in the magma.
Trap rock, also known as either trapp or trap, is any dark-colored, fine-grained, non-granitic intrusive or extrusive igneous rock. Types of trap rock include basalt, peridotite, diabase, and gabbro. [1] Trap is also used to refer to flood (plateau) basalts, such as the Deccan Traps and Siberian Traps. [2]
Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock formed by ejection from a volcano as a molten blob and cooled in the air to form discrete grains called clasts. [ 1 ] [ 2 ] It is typically dark in color (brown, black or purplish-red), and basaltic or andesitic in composition.
The gas released at the surface has a composition that is a mass-flow average of the magma exsolved at various depths and is not representative of the magma conditions at any one depth. Molten rock (either magma or lava) near the atmosphere releases high-temperature volcanic gas (>400 °C).