CEE 1030 1st Edition Exam 1 Study Guide Mid term Study Guide Earth Science Lecture 1 Terms Geology scientific study of planet earth Physical geology examines the materials composing earth and seeks to understand the many processes that operate beneath and on its surface Earth s resources Historical geology seeks an understanding of the origin of earth and its development through time including future predictions Relative dating place rocks in the proper order without knowing their age in years Absolute dating use radioactive decay of certain elements to date some rock types Igneous rocks cooling and solidification of magma Sedimentary rocks derived from weathering of preexisting rocks are accumulate in layers at earth s surface The rock cycle paths and processes by which rock types change at the earth s surface and interior Solid earth rock Atmosphere air Hydrosphere water Biosphere life Three types of plate boundaries transform fault divergent convergent Three basic rock types igneous rocks sedimentary rocks metamorphic rocks The earth as a system solid earth atmosphere hydrosphere biosphere Lecture 2 Terms Mineral ordered internal structure crystalline characteristic chemical composition inorganic naturally occurring distinct physical properties Rocks any solid mass of mineral or mineral like matter that occurs naturally Elements basic building blocks of minerals most minerals are a combination of two or more elements Atoms smallest unit of an element Nucleus contains most of the mass of the atom Protons positive charge Neutrons no charge neutral Electrons negative charge Atomic number number of protons Mass number number of protons and neutrons Electronic structure of atoms determines how atoms of elements bond together and with other elements Ionic solid electrostatic attraction between positive cations and negative anions Iconic bonding atoms gain or lose outermost valence electrons to form ions how minerals have sodium and chloride Covalent bonds atoms sharing electrons Polymorphs minerals with the same composition but different crystalline structures all the same mineral different structure physical properties color crystal form luster hardness streak color cleavage or fracture secondary physical properties reaction to hydrochloric acid double refraction magnetism taste fluorescence smell elasticity the silicates most important mineral group most rock forming minerals Lecture 3 Terms igneous rocks form by cooling and solidification of magma magma formed by rocks melting at the earth s surface extrusive or volcanic rocks rocks formed from lava at the earth s surface intrusive or plutonic rocks formed from magma at depth texture used to describe the overall appearance of a rock based on the size shape and arrangement of interlocking minerals magma consists of three components liquid solids gases igneous rocks classified name based on texture types of minerals chemical composition igneous textures aphanitic phaneritic porphyritic pegmatitic pyroclastic glassy pumice three ways that melt is generated in different places increase temperature thermal decrease pressure decompression add water fluid induced magma types in order of decreasing viscosity rhyolite andesite basaltic Lecture 4 Terms non explosive eruptions lava flows mainly basaltic and intermediate compositions explosive eruptions pyroclastic deposits mainly intermediate to rhyolitic compositions basaltic lava flows very fluid behavior can flow at rate typically 10 200 meters hour travel distances of several 100km rhyolitic lava flows very sticky pahoehoe ropy texture Aa rough jagged blocky texture very rocky Shield volcanoes large broad circular shape with gentle dipping slopes 3 to 5 degrees built by successive fluid lava flows from a central vent Cinder cones also known as scoria cones built from ejected gas rich lava fragments have steep angles Intermediate rhyolitic volcanoes composite cones or stratovolcanoes interbedded lava flows and pyroclastic debris potentially most dangerous volcano type complex histories Pyroclastic material rapid expansion of gas bubbles results in the obliteration and fragmentation of magma and rock Lahars volcanic mud flows Nature of volcanic eruptions these factors control viscosity of a magma this measures a material s resistance to flow temperature hotter magmas are less viscous more runny Lecture 5 Terms Weathering breakdown of rocks at the earth s surface Erosion physical removal of material by mobile agents Mechanical weathering disintegration breaking rocks into smaller pieces without changing their chemical composition Chemical weathering0 decomposition chemical reactions between rock minerals and air water Frost wedging exerts immense pressure occurs as the result of 9 expansion of water when it is converted to ice Root wedging rocks on tree roots tree will still grow but begin lean slowly fall Salt wedging evaporation of water rich in dissolved species will lead to growth of crystals in cracks exerts force Thermal expansion large daily temperature changes cause thermal strain Unloading uplift and erosion reduces pressure Dissolution promoted by acidic water Hydrolysis reaction of mineral with water Hydrogen ion attacks and replaces other ions Oxidation exposure to atmospheric oxygen Placer deposits resistant economic minerals Surface area same volume of rock but smaller particles have greater total surface area Rock type rocks containing calcite marble and limestone readily dissolve in weakly acid solutions Spheroidal weathering gradual rounding of edges and corners of angular fragments Regolith layer of weathering products at the earth s surface rock and mineral fragments Soil combination of mineral and organic matter plus water and air The portion of regolith that can support the growth of plants Humus decayed remains of animal and plant life organic matter essential part of soil Two types of weathering process mechanical and chemical Mechanical weathering frost wedging root wedging salt wedging thermal expansion unloading Chemical weathering dissolution hydrolysis oxidation Physical effects of chemical weathering spheroidal weathering regolith soil humus Factors controlling soil formation climate time plants and animals topography Lecture 6 Terms Sediments collection of loose solid particles Sedimentary rocks particles bound together to form a firm coherent rock Lithification unconsolidated sediment to rock Detrital sediment transported as solid particles Chemical type of