The tendency for some minerals to break along smooth, flat surfaces is known as
Cleavage
The Earth is estimated to be ___ years old?
4.6 billion
Most abundant mineral group in the crust is...
Feldspar
Cooling of magma results in a fine-grained texture called...
Aphanitic
Igneous rocks that have a ___ texture have grains that can be seen with the naked eye
Phaneritic
A natural glass formed by rapid cooling of lava is called...
Obsidian
Basalt has the same mineral and chemical composition as...
Gabbro
The mineral assemblage of quarts, K-Feldspar, Na-Plagioclase, with minor biotite or hornblende, would be recognized readily by you as the minerals found in the rock known as...
Granite
Dark, rock-forming minerals are rich in...
Fe and Mg
The early-formed light colored mineral in a melt [magma] is...
Plagioclase
Pyroclastic rocks are formed by...
Violent, explosive volcanic eruptions
Phrenocrysts are evidence of...
Two periods of cooling
Vesicles (holes) form in igneous rock (such as scoria and vascular basalt) from...
Escaping gas
The common lava extruded from stratovolcanoes is...
Andesite
Shield volcanoes have low, angle slopes because they are composed of...
Fluid basaltic lava
Steep-sided, classic, "volcano-shaped" cones are called
Stratovolcanoes
Mt. St. Helen is an excellent example of a...
Explosive caldera
Rugged, blocky lava flows are called...
Aa
A volcanic rock that floats is...
Pumice
Which one of the following minerals can be scratched with your fingernail?
Gypsum
An igneous rock possessing a combination of mineral grains with markedly different grain sizes is...
A porphyry
Mt. Fuji (Fujiyama) in Japan and Mt. St. Etna on Sicily are classic examples of...
Stratovolcanoes
The mid-oceanic ridges are
Sites of new oceanic material
All plate margins are characterized by...
High earthquake activity
Mid-oceanic ridges are sites of ___ plate boundaries
Divergent
Rocks composed on only pyroxene and olivine may form by...
Crystal settling
Which one of the following groups do most minerals in the Earth's crust belong?
Silicates
Which one of the following groups do most minerals in the Earth's crust belong?
Silicates
Enchanted rock is...
An exposed portion of a granite batholiths
Dikes and sills are probably emplaced in the crust by...
Injection of magma into fractures
The first minerals of crystallize out of a magma are
Ca-Plagioclase and olivine
___ is composed of minerals found in the mid-range of Bowen's Reaction series
Diorite
What minerals are in the rock Diorite?
Augite, horneblende and plagioclase
The minerals in igneous rocks that is rich in aluminum are...
Mica and felspar
The rock cycle implies that...
Any rock type can form from any other rock type
The bright regions of the moon are made up of the rock ___
Anorthosite
Forty percent of the near side of the moon consists of smooth, dark plains made up of...
Basalt
If you had to find K-Feldspar where it occurs naturally in the state of Texas, one place that you would be certain to find it is...
Enchanted Rock
Plagioclase...
Glassy, clear or translucent grains
Amphibole (Horneblende)
Dark, brown to black grains with 60 - 120 degrees cleavage
Olivine
Glassy, green grains
Quartz
Glassy, clear or translucent grains
Biotite (mica)
Dark brown sheets
Abundant fossils begin to show up in rocks that are...
545 million years old
The recognition that the lithosphere is divided into rigid plates that move over the asthenosphere forms the foundation of the...
Plate tectonics theory
Rocks that form at the surface from materials originating in other rocks are...
Sedimentary
The principle that the various living organisms living at any particular period of time in the past are unique to that time is called
Faunal Succession
The outer core is ___ and it's made up of ___
Liquid,
Iron
Under most conditions, in a stack of sedimentary rocks, the older rocks are on the bottom of the stack
True
New material is formed at the ___ boundary
Divergent
The trench-volcanic arc association is indicative of a ___ plate margin
Convergent
The Japanese islands are an example of ___
An island arc at a convergent margin
The ocean crust is formed mostly of...
Basalt
Rubies and sapphires are gem quality varieties of...
Corundum
Corundum is what on the hardness scale?
9
Which of the following groups do most minerals in the earth's crust belong?
Silicates
Most common carbonate rock is...
Limestone
Quartz is composed of...
Silicon dioxide
Groups of Feldspars are...
Potassium Feldspar and Plagiclae Feldspar
Calcium Carbonate (CaCO3) is the mineral...
Calcite
What is important about galena?
Specific gravity
What's important about sphalerite?
An ore of zinc
What is the cleavage of Mica?
1 direction, Horizontal
What is the cleavage of calcite?
3 directions, not at right angles
What is the hardness of calcite?
3
What is the cleavage of horneblende?
2 directions - at 60 and 120 degrees
What is the general color of the ferromagnesium minerals?
Dark
Which minerals are alumno-silicates
Felspars
Which is softer, calcite or feldspar?
Calcite
Which is harder, calcite or gypsum?
Gypsum
Which is harder, topaz or feldspar?
Topaz
What properties distinguish gold from iron pyrite?
Gold has yellow streak, pyrite has black streak
What properties distinguish gypsum from calcite
You can scratch gypsum with your fingernail, you can't do that with calcite
