basalt fine porphyritic

Basalt - Homestead

Basalt is a common extrusive volcanic rock. It is usually gray to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or ...

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Igneous Rock Texture - Georgia State University

Porphyritic Rock Porphyritic rock is igneous rock which is characterized by large crystals surrounded by a background of material with very small crystals. The scenario for the production of such rocks involves the formation of certain types of mineral crystals over a long period deep in the earth.

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Mafic - chemeurope.com

Basalt Fine grained and porphyritic Porphyritic basalt Pyroclastic Basalt tuff or breccia Vesicular Vesicular basalt Amygdaloidal Amygdaloidal basalt Many small vesicles Scoria Glassy Tachylyte, sideromelane, palagonite See also QAPF diagram List of List of ...

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Classification and Distribution Major Intrusions Granodiorite

Plate 6 - Porphyritic Fine-grained Grano-diorite Exposed at Tsing Yan (27802430) which underlies much of central and southern Hong Kong. The granodiorite is typically porphyritic with large euhedral phenocrysts of alkali feldspar set in a medium- to fine-grained

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Porphyritic | Definition of Porphyritic at Dictionary.com

Porphyritic definition, of, pertaining to, containing, or resembling porphyry, its texture, or its structure. See more. DICTIONARY.COM THESAURUS.COM MEANINGS MEANINGS Emoji Slang Acronyms ...

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Mafic and intermediate dykes - mnd - CEDD - Home

Mafic dykes intrude fine-grained granite at many localities; these were formerly well exposed in Junk Bay Road (842910 819450 mnd-52), where three prominent vertical dykes cut both the fine- and the fine- to medium-grained granite.

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Basalt: Fine-Grained Mafic Rock - University of Pittsburgh

23/6/2020· Note that the rock is so fine-grained that other crystals are not visible to the naked eye. This is a vesicular basalt with many small vesicles. Other basalt samples appear in the pages explaining the fine-grained, fine-grained porphyritic, and vesicular/amygdaloidal textures.

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basalt | Definition, Properties, & Facts | Britannica

Basalt, extrusive igneous (volcanic) rock that is low in silica content, dark in color, and comparatively rich in iron and magnesium. Basalts may be broadly classified on a chemical and petrographic basis into two main groups: the tholeiitic and the alkali basalts.

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ALEX STREKEISEN-Basalt-

Basalt A basalt is a fine-grained basic igneous rock containing essential calcic plagioclase feldspar and pyroxene (usually Augite), with or without olivine. Basalts can also contain quartz, hornblende, biotite, hypersthene (an orthopyroxene) and feldspathoids.

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L162 - porphyritic basalt · Igneous Rocks · 1A Collections

L110 - porphyritic rhyolite L102 - hornblende biotite granite L112 - banded rhyolite L113 - rhyolite, glassy (obsidian) L120 - granodiorite L130 - porphyritic andesite L141 - gabbro L161 - amygdaloidal basalt L162 - porphyritic basalt L172 - ultramafic cumulate

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Basalt Rock | Formation, Properties, Composition, Uses

Basalt is rich in iron and magnesium and is mainly composed of olivine, pyroxene, and plagioclase. Most specimens are compact, fine-grained, and glassy. They can also be porphyritic, with phenocrysts of olivine, augite, or plagioclase. Holes left by gas bubbles

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L110 - porphyritic rhyolite · Igneous Rocks · 1A Collections

Porphyritic texture indicates two-stage cooling. The phenocrysts grew slowly in a magma chamber; the fine-grained groundmass formed during rapid cooling at the Earth's surface. Late stage hydrothermal alteration to white mica and carbonate.

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What is Basalt? - Granite

Basalt is an extrusive igneous rock, sometimes porphyritic, and is often both fine-grained and dense. Basalt in the tops of subaerial lava flows and cinders will often be highly vesiculated, imparting a lightweight "frothy" texture to the rock. The term basalt is often ...

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Basalt Textures - Michigan Technological University

Basalt is mainly made of two minerals: Plagioclase feldspar and pyroxene. Basalt has several textural varieties such as glassy, massive, porphyritic, vesicular, scoriaceous. In the Keweenaw we can subdivide textures into three types, following Huber's example: Porphyrite, Trap and Ophite, applies ideally to Isle Royale, but works for the PLV on the Keweenaw too.

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Basalt Rock Properties and Uses - Science Struck

This property is common amongst most dense, fine-grained textured rocks, such as basalt. Density The density of basalt is quite high, which can be seen through the combination of the rocks porosity: 0.1 – 1%, and its bulk density: 2.8 – 3 Mg (megagram) per m 3, This is because, around 50 percent of basalt is made of silica.

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Basalt ~ Learning Geology

Basalt has a fine-grained mineral texture due to the molten rock cooling too quickly for large mineral crystals to grow; it is often porphyritic, containing larger crystals (phenocrysts) formed prior to the extrusion that brought the magma to the surface, embedded in

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Porphyritic - YouTube

16/9/2016· Porphyritic is an adjective used in geology, specifically for igneous rocks, for a rock that has a distinct difference in the size of the crystals, with at least one group of crystals obviously ...

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Phenocryst & Porphyritic Textures | Science Trends

One example of this type of porphyritic texture is a porphyry, an igneous rock with large-grained crystals interspersed with fine-grained usually silicates. "Imperial Porphyry – porphyritic metadacite to porphyritic meta-andesite" by James St. John via Flickr is licensed under CC-BY 2.0

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Basalt Fiber Reinforced Concrete

Basalt has a fine-grained mineral texture due to the molten rock cooling too quickly for large mineral crystals to grow, although itoften is porphyritic, containing the larger crystals formed prior to the extrusion that brought the lava to the surface, embedded Basalt ...

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Basalt Fibre - an overview | ScienceDirect Topics

Basalt is a common extrusive volcanic rock, which is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic, containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is

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Porphyritic - WikiMili, The Free Encyclopedia

Porphyritic rocks may be aphanites or extrusive rock, with large crystals or phenocrysts floating in a fine-grained groundmass of non-visible crystals, as in a porphyritic basalt, or phanerites or intrusive rock, with individual crystals of the groundmass easilygranite.

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4.1: Classification of Igneous Rocks - Geosciences LibreTexts

Basalt and gabbro are the extrusive and intrusive names for mafic igneous rocks, and peridotite is ultramafic, with komatiite as the fine-grained extrusive equivalent. Komatiite is a rare rock because volcanic material that comes directly from the mantle is not common, although some examples can be found in ancient Archean rocks [ 2 ].

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Basalt - an overview | ScienceDirect Topics

Tholeiitic basalt often represents a fine, glassy groundmass consisting of fine-grained quartz and other main constituent minerals. Tholeiitic basalt has fine-porphyritic texture, which is characterized by pyroxene/plagioclase phenocrysts (Fig. 4.39) in fine glassy

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Porphyritic - WikiMili, The Free Encyclopedia

Porphyritic rocks may be aphanites or extrusive rock, with large crystals or phenocrysts floating in a fine-grained groundmass of non-visible crystals, as in a porphyritic basalt, or phanerites or intrusive rock, with individual crystals of the groundmass easilygranite.

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