Term
| What are the steps of the scientific method |
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Definition
| question>research>hypothesis>experiment>analyze>results. |
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Term
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Definition
| a procisional explanation for observations that is subject to continual testing and midification if necessary; if well supported by evidence, hypotheses may become theories |
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Definition
| an explanation for some ntural phenoenon with a large body of supporting evidence; theories must be testable by experiments and or observations, as is the case with plate tectonic theory |
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Term
| What are the three main themes of historical geology |
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Definition
| Plate tectonics, time, evoluionary theory |
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Definition
| gerbil is what happens when things die |
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Term
| What is the definition of a mineral |
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Definition
| A naturally ocurring, inorganic, crystalline solid having characteristic physical properties and a narrowl defined chemical composition. |
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Term
| What is the classification system for minerals? |
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Definition
| 1. Naturally occuring 2. inorganic solid 3. crystalline structure 4. narrowly defined chemical comp. 5. with particular physical properties. |
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Term
| What are the non-silicate types of minerals? |
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Definition
| Oxides, Carbonates, Sulfides, Sulfates. |
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Term
| What are the silicate types of minerals? |
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Definition
| Halides, Phosphates, Hudroxides, Native elements. |
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Term
| What are some of the most important mineral groups for historical geology? |
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Definition
| Silica minerals (quartz), Feldspars, Clays, Calcite, Gypsum, Halite, Iron-oxide minerals (ferromagnesian minerals) |
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Term
| What are characteristics of Quartz? |
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Definition
| (almost) pure silica, macrocrystalline structure = quartz (large crystals), Microcrystalline structure = Chalcedony (micro), Conchoidal fracture, very hard (7ish) Very stable, Nearly isotropic. |
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Term
| What is the most common MINERAL in the earth's CRUST? |
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Definition
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Term
| Feldspars characteristics |
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Definition
| Similar to quartz but with a bit of metal, most common mineral in crust, two clevage planes, unstable at surface (weather to clays) |
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Term
| What are the most abundant minerals at the SURFACE |
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Definition
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Term
| Characteristics of clay minerals? |
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Definition
| Sheet silicates, Most abundant at surface, Stacks of sheets, Floculate (form clumps) microscopic, soft, form mud. |
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Term
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Definition
| Calcium carbonate, effervesses, soft, three clevage planes, secreated by organisms to make shells, polymorph: aragonite. Similar to dolomite. |
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Term
| Gypsum, what's it all about? |
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Definition
| Calcium sulfate, highly soluble, usually formed by concentration of water, very very soft, three clevage planes, used in drywall, sand at white sands beach. |
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Definition
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Term
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Definition
| commonly the cement in sedimentary rocks, often distinctly colored. |
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Term
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Definition
| silicates, rich in iron and magnesium, unstable at earths surface, bulk of earths mantle, dark colored. |
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Term
| What kind of information can you get from minerals? |
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Definition
Molecular chemistry = enviroment and conditions of formation.
Nuclear chemistry = radiometric dating
Thermodynamic stability = related to their chemistry and crustalline structure. temperature and pressure. |
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Term
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Definition
| A solid aggregate of minerals |
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Term
| How are rocks classified? |
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Definition
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Term
| What are the three basic types of rocks? |
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Definition
| Igneous, metamorphic, sedimentary |
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Term
| How are rocks classified within each group? |
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Definition
| Texture: side and arrangement of grains, compisition: minerology |
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Term
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Definition
| Rocks formed by solidification of magma |
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Term
| What are intrusive igneous rocks? |
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Definition
| formed below earths surface (plutonic) |
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Term
| what are extrusive rocks? |
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Definition
| formed above earths crust (volcanic) |
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Term
| What do igneous rocks tell us? |
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Definition
| Chemistry of magma source, temperature and pressure history of magma, large scale tectonic events. |
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Term
| What is ultramafic compisition |
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Definition
| composition of the mantle, high ferromagnesian content, very dense, dark, low magma viscocity, never extruded. (peridotite) |
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Term
| What is mafic composition? |
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Definition
| composition of oceanic crust, high ferromagnesian content, dense, dark, low magma viscosity, associated with crustal divergence. (Gabbro, Basalt) |
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Term
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Definition
| Often found as mixed mafic/felsic rock, reasonable ferromagnesian content, not very dense, medium grey, moderate to high magma viscosity, associated with crustal convergence. Diorite, Andesite. (salt and peppery?) |
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Term
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Definition
| Igneous rock, Often found as mixed mafic/felsic rock, Low ferromagnesian content (mostly feldspar and quartz) Low density, Light colored, High magma viscosity, bulk composition of continental crust. (granite, rhyolite, Erock) |
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Term
| What type of rock is granite? |
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Definition
| Felsic INTRUSIVE rock. Formed underground! Enchanted rock! |
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Term
| What type of rock is basalt? |
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Definition
| Mafic EXTRUSIVE rock. Formed underwater, above crust! |
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Term
| What type of information can you get from igneous rocks? |
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Definition
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Term
| Definition of Metamorphic rock |
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Definition
| Rock formed through the alteration of other rocks by some combination of: Heat, Pressure, Hot aqueous fluids |
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Term
| What can metamorphic rock tell us? |
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Definition
| Local temperature/pressure, general geochemical history, information about the protolith. |
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Term
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Definition
| Changes in pressure, temperature and chemistry change mineral stability. |
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Term
| What are some ways minerals change |
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Definition
| Dissolution, recrystallization, growth. No change in bulk, loss of water. |
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Term
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Definition
| foliation is repetitive layering formed perpindicular to directional pressure and stress causes recrystallization or formation of new minerals in response to pressure. |
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Term
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Definition
| Usually made from a single predominant mineral, Usually very specific to protolith, tend to give less information. |
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Term
| What is contact metamorphism |
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Definition
| Local scale, contact aureole, significant increase in heat, may also involve hot fluids. May be indirect evidence for magmatic activity. |
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Term
| What is burial metamorphism |
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Definition
| basin-scale, generally along local geothermal gradient, Leads to info about tectonics and sedimentation. |
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Term
| what is regional metamorphism |
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Definition
| continental scale, inscreased directional pressure (predominant), often involves folding faulting. Closely tied to tectonics. |
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Term
| what is shock Metamorphism |
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Definition
| local scale, extreme pressure, relavant to hisory of life. Meteors! |
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Term
| what is metamorphic grade |
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Definition
| degree of alteration of protolith |
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Term
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Definition
| Distinct combinations of index minerals |
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Term
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Definition
| Changes in a sediment or sedimentary rock below 200C, compaction, cementation, minor minerological change, removes information. |
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Term
| What is clastic sedimentary rock? |
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Definition
| Made of pieces of other rocks, comes in grain sizes, grain minerology, info comes from sediment. |
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Term
| What are some types of sandstones? |
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Definition
| Quartz arenite, Arkose, Litharenite |
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Term
| What are chemical sedimentary rocks? |
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Definition
| Made of chemicals dissoled from other rocks, and reprecipated. Usually oen predominant mineral, information comes from sediment and diagenesis |
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Term
| What are some carbonate examples? |
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Definition
| Limestone (calcite or aragonite), Dolostone (diagenetic alteration of limestone)m Organic or evaporitic (fossils, aragonite, warm shallow seas) |
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Term
| What are some examples of evaporites? |
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Definition
| Limestone, gypsum, anhudrite, rock salt. |
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Term
| What are some other chemical sedimentary rocks? |
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Definition
| chert (silica), Coal, Glauconite |
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Term
| What are the basics of hyposemetric curve and stream gradient? |
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Definition
| The gradient shallows closer to deposition area, it is steep near soucce, grain size decreases closer to shore, further from source, glacial deposits are poorly sorted, wind deposits are very well sorted. |
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Term
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Definition
| roundness is further from source, sharp is closer to source, except for feldspars and their clevage. |
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Term
| what info can we get from sedimentary structures? |
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Definition
| depositional enviroment, climate, weather, currents, post burial history, biological activity. |
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Term
| what is a geopetal structure? |
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Definition
| Indicates which way was up |
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Term
| what does paleohorizontal mean? |
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Definition
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Term
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Definition
| unidirectional, bidirectional current indicators |
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Term
| What is an easy depositional environment? |
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Definition
| breccia, always near source, cave ins, mountains etc... Shale, Coal, black shale, limestone, |
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Term
| What is a not so easy depositional environment? |
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Definition
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Term
| What are sedimentary facies? |
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Definition
| associatons of sedimentary roccks and structures indicative of a particular depositional environment, also holographic |
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Term
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Definition
| change in absolute sea level. A rise is refferred to transgression, a fall is regression |
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Term
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Definition
| A change in land level, a tectonic uplift is regression and a subsidence is transgration. |
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Term
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Definition
| relative sea level change |
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Term
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Definition
| Increased sedimentation is regression, increased coastal erosion and subsidence is transgression |
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Term
| What does stratigraphy include? |
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Definition
| mapping, measuring stratigraphic columns, documenting facies, interpreting depositional history |
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Term
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Definition
| The description and interpretation of sequences of layered rocks |
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Term
| What is lithostratigraphy? |
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Definition
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Term
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Definition
| study of distriution of fossils in rocks |
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Term
| what is chronostratigraphy |
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Definition
| study of relationships of rocks and time |
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Term
| what is magnetostratigraphy |
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Definition
| study of magnetic history of rocks |
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Term
| what is a stratigraphic column? |
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Definition
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