Igneous Rocks Igneous rocks are composed of interlocking _________ Igneous rocks have textures (crystal size), which inform us of their rate of cooling. crystals
Large crystals= __________ cooling slow
Small crystals= _________ cooling fast
Glassy (no crystals)= _____________ cooling very rapid
3. Igneous rock can be used to infer mineral composition
_______= mafic (magnesium & iron) Dark Dunite Gabbro
__________= felsic (aluminum & silicon) Light Rhyolite Pegmatite
4.Upon cooling, gases can become trapped in igneous rocks forming a vesicular or porous texture
Sedimentary Rocks 1. Classified based up ____________ composition
Clastic = composed of rock fragments
Chemical = composed of 1 mineral Limestone Rock salt
Bioclastic = formed from plant and animal products Coal Limestone (coquina)
2. Clastic sedimentary rocks are classified according to their _____________ sediments Sandstone Shale
3. Chemical sedimentary rocks are classified according to their __________ composition mineral Rocks Gypsum Dolostone
4. Sedimentary rocks can contain _________ fossils
Metamorphic Rocks crystals 1. Metamorphic rocks are composed of interlocking __________ (which are often elongated or flattened) crystals
2. Metamorphic rocks are classified on the basis of their __________ foliation
____________ = minerals are not layered nonfoliated _________= minerals are layered or aligned foliated
3. Foliated metamorphic rocks are classified according to their mineral size and composition.
4. Non-foliated metamorphic rocks are classified according to their _________ composition mineral Quartzite
Igneous rocks form when molten rock, or magma, _________ and ____________. __________ originate in the mantle and crust as a result of partial melting of the solid rock due to tectonic forces. Magma works its way to the surface because it is ___________ or (less/more) dense than the surrounding rocks. cools solidifies Magma lighter
4. Igneous rocks that form when lava (molten rock on the surface of the earth) solidifies are classified as ________ or ________ igneous rocks. 5. Most magma never reaches the surface of the Earth. Rather it crystallizes at depth to produce _________ or ________ igneous rocks. 6. Although _______ rocks form at depth, __________ and _________ often expose them at the surface extrusive volcanic intrusive plutonic igneous weathering erosion
Igneous Rock Texture The rate of cooling affect both the size and the arrangement of crystals, a property called ___________. Rapid cooling produces _________ crystals (fine-grained texture) and slower cooling allow time for __________ crystals to form texture small larger
3. Many of the fine-grained, quickly cooling rocks contain voids left behind by gas bubbles trapped as lava solidifies. These rocks are said to exhibit a ___________ texture. 4. Slow cooling magma produces igneous rocks with _______ crystals and a _________ grained texture. vesicular large coarse
6. Rapidly cooling silica-rich lava may produce rocks without a crystalline structure and a _________ texture 7. In addition to the igneous textures already considered, some igneous rocks have large crystals that are embedded in a matrix of smaller crystals. These rocks are said to have a _________ texture. glassy porphyritic
1.Sedimentary Rocks- ___________________________________________________________________________ 2. Compaction- __________________________________________________________________ Form from the accumulation of sediments derived from pre-existing rocks and/or organic material The pressure that forces out any water and air present and compacting the sediments into rock
3 Types of Sedimentary Rocks Cementation- ____________________________________________________________________________ 3 Types of Sedimentary Rocks Clastic- _________________________________________ Bioclastic-_________________________________________ Chemical-_____________________________________________________________________________________________________________________ Sediments or clasts are “glued” together by precipitating minerals Rocks composed of solid sediments, like sand, silt Rocks composed of living organisms or their materials Interconnected crystals of just one mineral that formed by evaporation and/or precipitation of dissolved minerals
4. Characteristics of Sedimentary Rocks The clasts or sediments are usually rounded, because they have been moved by _________________, ________ or ________________ wind running water ocean waves
Metamorphic Rocks more less foliation changed Pre-existing rock Metamorphic Rocks are usually: 1. __________ dense and _________ porous 2. ______________ (layered minerals) B. Formation of Metamorphic Rocks During metamorphism, the parent rock (or protolith) is ___________ What is the “parent rock”? more less foliation changed Pre-existing rock
___________ Metamorphism Contact
_____________ Metamorphism Regional
______________ Foliated
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_______- breaks easily into smooth layers with very small crystals phyllite
________- visible crystals, with a high mica content schist
_________- coarse grained crystal foliations (banding- alternating light and dark layers) Gneiss
___________ Nonfoliated
________________- appearance of crystallized “stretched-pebble” Metaconglomerate
___________- grainy single mineral rock that is harder than glass Quartzite
___________- grainy single mineral rock that react with dilute HCl acid Marble
___________- very fine-grained rock that breaks into small shards Hornfels