Pelch Geology Exam 2 Questions With Detailed Correct Answers| Graded A+

mineral - correct answers a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition -anything that is not grown or from a living animal is made from this rocks - correct answers made up of one or more minerals igneous - correct answers rock formed from cooled magma or lava metamorphic - correct answers A type of rock that forms from an existing rock that is changed by heat, pressure, or chemical reactions. *fluids, temp, pressure* sedimentary - correct answers forms when particles from other rocks or the remains of plants and animals are pressed and cemented together; weather, erosion, deposit 3 main phases of mining - correct answers exploration, extraction, and reclamation/remediation exploration - correct answers estimate of the average composition of the Earth's crust can be a misleading indicator towards locating and mining an ore -geologically and economically complicated -expensive -important process to gain data extraction - correct answers underground and surface mining (open pit or mountain top removal) surface mining - correct answers open pit and mountain top removal mining; largest mines -PROS: efficient and high profit -CONS: bad for environment, expensive, permanent feature underground mining - correct answers tunnels and/or vertical shafts cut directly into the ground -usually smaller operations but still expensive tailings - correct answers piles of gangue, which is the waste material that results from mining. -highly contaminated benefication - correct answers separates and concentrates the valuable minerals -starts with crushing, then milling (adding water) into fine powder, then flotation (separation), and smelting (concentrating) slag - correct answers waste from smelting during benefication reclamation - correct answers the process of returning land to its original condition after mining is completed remediation - correct answers return a contaminated area to its original state -fixing, removing, or counteracting environmental hazards after mining conflict minerals - correct answers extracted in conflict zones; profits support wars, genocides, violence, and more -suppliers and buyers often leverage regional tensions to get them at low prices -*most come from central Africa* (including 70% of diamonds) 70% of diamonds come from - correct answers central Africa coltan - correct answers a dull metallic mineral composed of columbite and tantalite, and refined to produce tantalum. --sourced mainly from Congo tantalum - correct answers comes from coltan; primary component in all cellular devices and a lot of other tech -80% of it lies in the Democratic Republic of Congo coltan mining - correct answers 80% of mining is in pits worked by unpaid/underpaid Congo locals -make ~$80 USD/year Lasedi La Rona - correct answers 1,109 carat diamond sold for $53M i . 2017 -Swahili for "Our Light" diamonds - correct answers C - chemical formula -unstable; graphite is the stable form -hardest naturally occurring substance -most successful marketing/advertising campaign in history diamond mining: Kimberlites and Lamporites - correct answers come from ancient explosive volcanic structures that brought them up from the mantle high viscosity - correct answers lots of resistance (flows slowly) like honey low viscosity - correct answers flows easily like water pressure - correct answers decreases as magma rises through the lithosphere gas released - correct answers increases as magma rises through the lithosphere T or F: as pressure decreases in magma, gas escaping increases - correct answers true Volcanoes and Plate Boundaries - correct answers we find active volcanoes at plate boundaries, especially divergent boundaries -subduction zones have flux melting and intermediate types of rock and magma magma and gas - correct answers volcanic eruptions are driven by pressure explosive vs non-explosive eruptions - correct answers determined by how fast gas escapes from magma felsic/intermediate magma - correct answers -explosive -high viscosity -high silica -a lot of ash produced -lower temp basaltic magma - correct answers -nonexplosive -low viscosity -low silica -higher temp silica - correct answers a material found in magma that is formed from the elements oxygen and silicon... makes rocks stick together high= high viscosity low= low viscosity T or F: high temp= low viscosity and high silica= high viscosity - correct answers true composite and strato volcanoes - correct answers tall, steep slopes -high silica -convergent plate boundaries -explosive eruptions scoria/cinder cone volcanoes - correct answers most common type; small with intermediate slopes -gas rich, basaltic magma -created from several eruptions of small rock called tephra tephra - correct answers rock fragments and particles ejected by a volcanic eruption shield volcanoes - correct answers gently sloping; common in Hawaii -low viscosity -largest volcanoes in solar system Olympus Mons - correct answers largest volcano in the solar system found on Mars; it is a shield volcano supervolcanoes - correct answers volcanoes that have very large and explosive eruptions Yellowstone - correct answers sits on top of the world's largest supervolcano -eruption would blow the lithosphere apart -half of all earthly hydrothermal features are found here in its caldera T or F: a lot of Earth's population lives far away from plate boundaries - correct answers false sulfur dioxide - correct answers gas erupted from volcanoes that causes global cooling -combines with water to block/reflect sunlight volcanic hazards - correct answers pyroclastic flows, lahar, flank collapse, ash fall/clouds, gas, tsunami, climate change, acid rain hazard - correct answers something that has the potential to cause harm (ex: car crash) risk - correct answers the likelihood that something will cause harm (ex: chances of you being hurt in a car crash) Mt. Rainer - correct answers Composite Cone (Strato) Volcano in Washington State, has alternating layers of ash-lava-ash -convergent boundary pyroclastic flow - correct answers the flow of dense and fast-moving ash, cinders, bombs, and gases down the side of a volcano during an explosive eruption -ex: Pompeii -100-110 MPH lahars and mudflows - correct answers water mixes with ash to form a "milkshake" of fast-moving rocks, boulders, trees, and other debris -caused by flash melting on slopes -deposits fine-grained, thick layers of sediments -*hazards that reach the farthest distance wise* Mt St Helens - correct answers composite volcano that exploded explosively -landslide happened seconds before eruption because of the earthquake that pushed the magma to the surface -swelled 30% before eruption landslide on Mt St Helens - correct answers -caused by earthquake pushing magma to surface -decreased pressure and allowed gases to escape -acted as a cap on a shaken soda: once it was opened, everything exploded David Johnston - correct answers geologist who urged state and government to close down national parks surrounding Mt St Helens b/c he had a feeling that it was about to erupt -died in eruption but saved thousands of lives Mt Pelee - correct answers Composite Martinique (French island in Caribbean) -subduction zone--- flux melting -Erupted and killed 30,000 in the town of St. Pierre by Pyroclastic flow almost immediately one survived in a jail cell signs of pre-eruption on Mt Pelee - correct answers -snakes and insects came down to town because of increasing temps on the mountain -bulging/swelling mountain -earthquakes -giant lake in caldera -fish died from gases seismic noise - correct answers generated from increased pressure creating magma movement in the lithosphere... moves rocks, magma, landslides, etc. -anything that moves can create this, such as waves at the beach flux melting - correct answers melting due to addition of volatiles such as water -causes volcanoes at subduction zones hanging and foot wall - correct answers foot wall is stationary hanging wall moves