What describes a texture containing bubble shaped cavities?
Which of the following describes a texture containing bubble-shaped cavities? Vesicular. Pegmatitic. Igneous rock that forms from anonymously large crystals.
What does an igneous rock with a pyroclastic texture indicate?
What does an igneous rock with a pyroclastic texture tell a geologist? The rock was likely formed by a violent volcanic eruption.
Which of the following textures indicates two stages of cooling and crystallization quizlet?
The rock was likely formed by a violent volcanic eruption. Which of the following textures indicates two stages of cooling and crystallization? Porphyritic.
What is phaneritic and aphanitic?
APHANITIC TEXTURE – Igneous rocks that form on the earth's surface have very fine-grained texture because the crystals are too small to see without magnification. PHANERITIC TEXTURE – Igneous rocks with large, visible crystals because the rock formed slowly in an underground magma chamber.
What is pyroclastic texture?
Pyroclastic texture results from the explosive fragmentation of volcanic material, including magma (commonly the light, frothy pumice variety and glass fragments called shards), country rock, and phenocrysts.
What is porphyritic texture?
Porphyritic – This texture describes a rock that has well-formed crystals visible to the naked eye, called phenocrysts, set in a very fine grained or glassy matrix, called the groundmass.
What are the cavity texture of igneous rock?
Vesicular texture is a volcanic rock texture characterized by a rock being pitted with many cavities (known as vesicles) at its surface and inside. This texture is common in aphanitic, or glassy, igneous rocks that have come to the surface of the earth, a process known as extrusion.
How do porphyritic textures form?
A porphyritic texture is developed when magma that has been slowly cooling and crystallising within the Earth's crust is suddenly erupted at the surface, causing the remaining uncrystallised magma to cool rapidly. This texture is characteristic of most volcanic rocks.
What does an Aphanitic texture indicate?
Extrusive igneous rocks have a fine-grained or aphanitic texture, in which the grains are too small to see with the unaided eye. The fine-grained texture indicates the quickly cooling lava did not have time to grow large crystals. These tiny crystals can be viewed under a petrographic microscope (1).
What is fragmental texture?
A texture of sedimentary rocks, characterized by broken, abraded, or irregular particles in surface contact, and resulting from the physical transport and deposition of such particles; the texture of a clastic rock. The term is used in distinction to a crystalline texture. Ref: AGI.
What is an aphanitic texture?
Aphanitic – This texture describes very fine grained rock where individual crystals can be seen only with the aid of a microscope, i.e. the rock is mostly groundmass. An aphanitic texture is developed when magma is erupted at the Earth's surface and cools too quickly for large crystals to grow.
What is Trachytic texture?
Trachytic is a texture of extrusive rocks in which the groundmass contains little volcanic glass and consists predominantly of minute tabular crystals, namely, sanidine microlites. The microlites are parallel, forming flow lines along the directions of lava flow and around inclusions.
What is aphanitic texture?
Aphanitic – This texture describes very fine grained rock where individual crystals can be seen only with the aid of a microscope, i.e. the rock is mostly groundmass. An aphanitic texture is developed when magma is erupted at the Earth's surface and cools too quickly for large crystals to grow.
What type of rock has gas bubbles?
Pumice is a type of extrusive volcanic rock, produced when lava with a very high content of water and gases is discharged from a volcano. As the gas bubbles escape, the lava becomes frothy. When this lava cools and hardens, the result is a very light rock material filled with tiny bubbles of gas.
What is coarse grained texture?
(a) Said of a crystalline rock, and of its texture, in which the individual minerals are relatively large; specif. said of an igneous rock whose particles have an average diameter greater than 5 mm (0.2 in.).
What are the cavity texture of igneous rocks?
Vesicular texture is a volcanic rock texture characterized by a rock being pitted with many cavities (known as vesicles) at its surface and inside. This texture is common in aphanitic, or glassy, igneous rocks that have come to the surface of the earth, a process known as extrusion.
What is a clastic texture?
Clastic texture: grains or clasts do not interlock but rather are piled together and cemented. Boundaries of individual grains may be another grain, cement or empty pore space. Overall rock is generally porous and not very dense.
What is foliated texture?
Foliated Textures A foliated texture is caused by pressure. Mineral grains from pre-existing rocks are oriented parallel to each other or organized into distinctive bands during metamorphosis. Examples of foliated textures include slaty, phyllitic, schistose, and gneissic. Slaty Texture.
What is Aphyric texture?
An igneous rock texture characterized by a fine-grained aphanitic groundmass and by an absence of any phenocrysts.
What is Holocrystalline texture?
Said of the texture of an igneous rock composed entirely of crystals, i.e., having no glassy part. Also, said of a rock with such a texture.
What is Amygdaloidal texture?
A related texture is amygdaloidal in which the volcanic rock, usually basalt or andesite, has cavities, or vesicles, that are filled with secondary minerals, such as zeolites, calcite, quartz, or chalcedony. Individual cavity fillings are termed amygdules (American usage) or amygdales (British usage).
Can igneous rocks have air bubbles?
Quick cooling means that mineral crystals don't have much time to grow, so these rocks have a very fine-grained or even glassy texture. Hot gas bubbles are often trapped in the quenched lava, forming a bubbly, vesicular texture.
What is fine-grained texture?
Fine-grained textures generally indicate magmas that rapidly cooled at or near the Earth's surface. Fast cooling prevents crystals from growing very large. The cutoff between fine- and coarse-grained textures is about 1 mm. All four photos below are of the mafic rock basalt.
What is sedimentary texture?
Sedimentary texture encompasses three fundamental properties of sedimentary rocks: grain size, grain shape (form, roundness, and surface texture (microrelief) of grains), and fabric (grain packing and orientation). Grain size and shape are properties of individual grains. Fabric is a property of grain aggregates.
What is a crystalline texture?
Crystalline textures include phaneritic, foliated, and porphyritic. Phaneritic textures are where interlocking crystals of igneous rock are visible to the unaided eye. Foliated texture is where metamorphic rock is made of layers of materials.
What is Nonfoliated texture?
Non-foliated textures do not have lineations, foliations, or other alignments of mineral grains. Non-foliated metamorphic rocks are typically composed of just one mineral and, therefore, usually show the effects of metamorphism with recrystallization in which crystals grow together, but with no preferred direction.
What is Aphanitic texture?
Aphanitic – This texture describes very fine grained rock where individual crystals can be seen only with the aid of a microscope, i.e. the rock is mostly groundmass. An aphanitic texture is developed when magma is erupted at the Earth's surface and cools too quickly for large crystals to grow.
What is seriate texture?
Seriate is textural term applied to crystalline rocks that describes crystal sizes that vary continuous from the smallest to largest. Seriate is an inequigranular texture.
What type of rocks have bubbles?
Scoria is a dark-colored igneous rock with abundant round bubble-like cavities known as vesicles.
What type of rock contains air bubbles?
Extrusive Igneous Rocks: Quick cooling means that mineral crystals don't have much time to grow, so these rocks have a very fine-grained or even glassy texture. Hot gas bubbles are often trapped in the quenched lava, forming a bubbly, vesicular texture.