Geol exam 1

what kind of volcano is known for lava flow?

shield volcanoes pour out in all different directions

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

what kind of bond is the weakest?

ionic bond

What are the eight most common elements in the earth's crust?

(Oxygen (O), Silicon (Si), Aluminum (Al), Calcium (Ca), Iron (Fe), Magnesium (Mg), Sodium (Na), and Potassium (K) .

how to classify igneous rocks

(see Figure 3.5 and Table 3.1 in text)

What is the net charge of an individual silicon-oxygen tetrahedron?

-2(Si^+4 and 4 O^-2

how can minerals be distinguished?

1) crystal form 2) hardness (know Mohs scale of hardness) 3) cleavage 4) specific gravity (density) 5) color 6) streak 7) luster 8) fracture

Basalt

A dark, dense, igneous rock with a fine texture, found in oceanic crust

Rhyolite

A light-brown to gray, fine-grained extrusive igneous rock with a felsic composition. The extrusive equivalent of granite.

Batholith

A mass of rock formed when a large body of magma cools inside the crust

What is a rock?

A naturally occurring solid mixture of one or more minerals or organic matter

what is an anion?

A negatively charged ion

What is a cation?

A positively charged ion

Dike

A slab of volcanic rock formed when magma forces itself across rock layers

Andesite

An intermediate colored rock, generally gray greenish-gray, also classed as an aphanite because of the small crystal or grain size.

Isotope

Atoms of the same element that have different numbers of neutrons

Diorite

Coarse-grained igneous rock of intermediate composition. Up to half of the rock is plagioclase feldspar and the rest is ferromagnesian minerals.

what kind of bond is the strongest?

Covalent Bonds

Peridotite

Dense, dark igneous rock that makes up the mantle.

What is a sheild volcano?

Flat and Wide Produces runny lava The layers of lava pile up but never create a point Low viscosity Low gas Not explosive Lava runs off the Volcano adding to the layers of rock

ionic bond

Formed when one or more electrons are transferred from one atom to another

Granite - Igneous

H: 6-7, S.G. 2.6-2.7, Streak: white, Luster: Dull to Grainy with Sporadic parts Pearly and Vitreous Color: Black, Grey, Orange, Pink, White Very hard, granular, crystalline igneous rock which consists mainly of quartz, mica, and feldspar and is often used as building stone

Gabbro (Igneous)

H: 7, S.G. 2.86-2.87, Streak: Black, Luster: shiny Color: Dark Grey to Black Intrusive igneous rock which is chemically equivalent to plutonic Basalt

What is the difference between intrusive and extrusive igneous rocks?

Intrusive igneous rocks cool from magma slowly in the crust. They have large crystals. Extrusive igneous rocks cool from lava rapidly at the surface. They have small crystals

What is lava?

Magma that reaches Earth's surface

What are native elements?

Minerals that are made of just one element. Like Silver (Ag) and sulfer (S)

What is magma?

Molten rock beneath the earth's surface

aphanitic

Rapid cooling at earth's surface results in tiny mineral crystals that can only be seen under a microscope.

metallic bond

a bond formed by the attraction between positively charged metal ions and the electrons around them

Laccolith

a mass of igneous rock, typically lens-shaped, that has been intruded between rock strata causing uplift in the shape of a dome.

pyroclastic flow

a mixture of gas and pyroclastic debris

what is a mineral?

a naturally occurring,inorgainc crystalline solid that has a specific chemical composition

Silica-oxygen tetrahedron

a silicon atom with four surrounding oxygen atoms arranged to define the corners of a tetrahedron; a fundamental component of most silicates in the Earth's crust.

Mohs scale of hardness

a simple relative hardness scale of 1-10 and scratch test to help tell the difference between minerals

sill

a slab of volcanic rock formed when magma squeezes between layers of rock

Van der Waals

a slight attraction that develops between the oppositely charged regions of nearby molecules

Phaneritic

coarse-grained, crystals are large enough to be seen w/out a microscope, formed by slow cooling (intrusive)

what is a composite volcano/stratovolcano

constructed of alternating layers of pyroclastic fragments and solidified lava flows (figure 4.17). The slopes are intermediate in steepness compared with cinder cones and shield volcanoes.

how to get glassy texture?

cool Very fast. like mid-air

what kind of bond holds together strongest materials

covalent bonds hold together things like diamonds

Pyroclasts are ______.

fragmented pieces of magma released during volcanic eruptions that create falls, flows, and surges

What is an ion?

groups of atoms with unequal numbers of protons and electronsm thus having a n non-zero charge

what has a more violent errution, high viscosity or low?

higher the viscosity the more violent the eruptive style

What does the texture of an igneous rock tell you about it's cooling history?

how fast it cooled. slow cooling allows for large crystals to form. fast yields small crystals

What are the general characteristics of mafic (basaltic) and silicic (felsic) magmas?

lower viscosity for mafic, and effusive eruptions. forms within upper mantle, much deeper than felsic magma and contains alof of iron and magnesium felsic magma more viscous than mafic and has more silicon minerals in it(most common felsic rock is grannite) common minerals include quartz, orthoclase

What are carbonates? give example

minerals that contain combinations of carbon and oxygen in their chemical structure.calcite

what basis are the three major rock groups subdivided?

sedimentary, igneous, metamorphic

Vesicles

small holes left behind after lava cools and turns into volcanic rock.

Vesicular

small holes left behind after lava cools and turns into volcanic rock.

What type of magma produces pyroclasts?

violent erruptiuons (small pieces of obsidian, ash, pumice, and cinders)

What is a cinder cone volcano?

volcano constructed of pyroclastic fragments ejected from a central vent (figure 4.16). Unlike a shield volcano, which is made up of lava flows, a cinder cone is formed exclusively of pyroclasts.

What are the principal gases dissolved in magma?

water vapor, carbon dioxide, and sulfur gases

What is the origin of an igneous rock and what two factors do we use to subdivide the igneous rocks?

when hot, molten rock crystallizes and solidifies and we differ by crystal size and rock texture