SUSTech《地球科学概论》Ch01Ch09复习题及要点解析.docx

SUSTech地球科学概论Ch01Ch09复习题及要点解析 Fill-in-the-Blank 1. The science of geology is divided into two broad areas_physical_ geology and _historical_ geology. 2. C12 has 6 protons. How many protons does C13 have? _6_ How many neutrons does C13 have? _7_ Nitrogen-14 (N14) has 6 protons and 8 neutrons: true or false? _false_ 3.When basalt lava is chilled rapidly in an ocean or lake, it forms bulbous structures called _pillow lava_. 4. The type of metamorphism that occurs over large areas, commonly at convergent plate margins, and is responsible for the production of most metamorphic rocks is _regional_. 5. The most accurate radiometric dates are obtained from _igneous_ rocks. Only in very unusual circumstances can _sedimentary/metamorphic_ rocks be radiometrically dated. 6. The principle of original horizontality states that _sedimentary_ rocks were deposited in horizontal layers. Thus, if rock layers are now _tilted/dipping_, they must have been disturbed after lithification. 7. The _magnitude_ of an earthquake on the Richter Scale is determined by measuring the _amplitude_ of the largest recorded seismic wave. 8. The velocities of P- and S-waves are determined by these two properties of the material they are passing through: _density_ and _elasticity_. 9. Strike-slip faults are caused by _shearing_ forces. 10. A flat-topped seamount is called a(n) _guyot_. Short Answer Question 1. What is the difference between an active volcano and a dormant volcano? An active volcano has erupted during historic time; a dormant volcano has not erupted recently but may do so in the future. 2. What does a porphyritic texture tell about the history of an igneous rock? The magma cooled at two rates, first slowly, probably underground, then more rapidly 3. Briefly explain why the study of sedimentary environments is important in the study of historical geology. Historical geology is concerned with understanding what events have taken place in thehistory of the Earth and in what order. By using sedimentary rocks and the study of their depositional environments, geologists can determine what processes have occurred on the surface of the Earth and when they occurred. 4. What is the difference between slate and phyllite? Grain size. Phyllite grains are larger, although they are still too small to be seen. The grains give the rock a glossy or lustrous sheen. 5. What kind of rocks (igneous, sedimentary, metamorphic) have been most important in determining absolute age dates for the geologic time scale? Explain why. Igneous rocks because they can be radiometrically dated. 6. What are the six fundamental geologic principles which are used in relative dating? superposition, original horizontality, lateral continuity, cross-cutting relationships, inclusions, fossil succession. 7. Explain the differences between the magnitude and the intensity of an earthquake, in terms of how each is measured or observed. Magnitude is measured by instruments (seismographs), while intensity is measured by people's reactions and observations. 8. What is the difference between elastic and plastic deformation? After elastic deformation, the material returns to its original shape; after plastic deformation, the material stays deformed. 9. What does compression stress result from? Compression stress results from external forces directed toward one another. 10. What causes submarine hydrothermal vents? Seawater seeps into cracks in the oceanic crust, is heated by hot rock at depth, and rises to the seafloor to be discharged as hot springs. Short Answer Essay Questions 1. How do a rock and a mineral differ? A rock is a naturally occurring aggregate of minerals, while minerals are naturally occurring, inorganic crystalline solids. Rocks are made up of minerals, not vice versa. 2. When looking at a hand sample of an igneous rock, how would you tell if it is plutonic or volcanic? If the texture is phaneritic, the magma cooled slowly, and the rock is plutonic. If the texture is aphanitic, the magma cooled rapidly, and the rock is volcanic. 3. How does elastic rebound theory explain when earthquakes occur? Where the rocks on the opposite side of a fault are on pieces of crust that are moving in different directions, the rocks are initially locked in place by their strength and friction. The rocks do not move but they do deform. As the pressure builds, the strength of the rocks is eventually exceeded. They rebound to their original shape, but the crust on either side of the fault has moved to a new location. 4. What are some uses of metamorphic rocks such as marble, slate, sulfide ore, talc, graphite, and clay? Marble is used as a building stone; some of the worlds most beautiful sculptures have been carved from it. Slate is also used as a building stone; in some regions where it is commonly found, it makes up the roofs of all the buildings. Sulfide ore minerals are some of the most important metals that we use in modern society. In addition, we use talc for talcum powder, graphite for pencils, garnets and corundum for gemstones or abrasives, some high temperature clay minerals for ceramics, and some temperature-resistant minerals for sparkplugs and other hot jobs. 5. Briefly explain why, according to the principle of isostasy, continental crust should be thicker than oceanic crust. A mass such as the continental crust that “floats” on an underlying mass, should do so at an equilibrium level, such that it extends at least as far beneath the upper level of the underlying material as it does above the surface of that material. Earth is a dynamic and evolving planet. Plate tectonic theory: The lithosphere is composed of rigid plates that diverge, converge, orslide sideways past one another as they move over the asthenosphere. Volcanoes and earthquakes occur at the boundaries between the plates. The rock cycleillustrates theinteractions betweenEarths internal andexternal processesandhow the threerock groups areinterrelated. Geology is the study of the Earth Physical geology is concernedwith the materials and processes whichcompose and operate onthe surface of,and within, Earth. Historical geology is concernedwith the origin and evolution of Earth'scontinents, oceans, atmosphere, and life. The principal subsystems of the earth:Atmosphere / Biosphere / Hydrosphere / Lithosphere / Mantle / Core. 十大环境问题：气候变暖、臭氧层破坏、生物多样性减少、酸雨蔓延、森林锐减、土地荒漠化、大气污染、水体污染、海洋污染、固体废物污染。 A rock is a solid aggregate of one or more minerals, as well asnon-crystalline matter such as natural glass or organic materiallike coal.由固体颗粒天然地紧密 结合所形成的固体。 Minerals are naturally occurring, inorganic,crystallinesolids that have definite chemical composition and characteristic physicalproperties. 矿物是自然产出的均匀无机质固体，具有可以用化学方程式表示的化学成分，而且内部的原子、离子或分子以某种固定的几何图案有规律地排列。 Rock group: 火成岩(igneousrock) / 沉积岩(sedimentary rock) / 变质岩(metamorphic rock). Isotope 同位 / proton 质子 / neutron 中子 地壳中元素含量：氧硅铝铁钙硫磷镁。 Bonding: Ionic bounding / Covalent Bonding / Metallic / Van der Waals Bonds Polymorphism: 物质能以两种或两种以上晶体结构存在。 Mineral groups: 1.Native elements minerals (Ag、Pt) 2.硅酸盐矿物(silicates，Most common as measured by rock volume)、碳酸盐矿物(carbonates)、氧化物矿物(oxides)、硫化物矿物(sulfides)、硫酸盐矿物(sulfates)、卤化物矿物(halides) Ferromagnesian silicates: Dark in color and dense(稠密). Non-: Light colored. Carbonate minerals(碳酸盐岩): Are found mostly in the sedimentary rocks limestone and dolostone / Carbonates are derived from the shells and hard parts of marine organisms or areprecipitated from seawater as evaporites. Sulfides minerals(硫化盐矿):Are found in all types of rocks. They commonly form along mid-oceanic ridges. Sulfates minerals(硫酸盐矿):Sulfate minerals are common in deserts, forming from evaporation of water. Identify bases: Shape(Single crystal / aggregate), Optical properties(color and streak / luster / transparency), Mechanical properties(hardness / cleavage / fracture), Other physical properties(specific gravity / magnetism). Transparency:矿物透过可见光的能力。广义讲，所有非金属矿物都是透明矿物，所有金属矿物都是不透明矿物。 Luster:矿物对可见光的反射能力。可分为金属光泽、半金属光泽和非金属光泽。 Color:矿物吸收了白光中某种波长的色光后所表现出来的互补色。包括自色、他色、假色。 Striation:矿物粉末的颜色。对于某些金属矿物具有重要鉴定意义，如赤铁矿可呈赤红、铁黑或钢灰等色，但它的条痕总为樱红色。 Cleavage：是晶体受到外力打击时能够沿着一定结晶方向分裂成为平面的能力，受内部结构特征的制约。解理面总是代表内部质点排列而成的平面之间联结力最弱的方向。不同矿物产生解理的能力不同，故解理的特征是识别矿物的重要标志。 fracuture：矿物受外力打击后不沿固定的结晶方向断开时所形成的断裂面。断裂面方向任意，端口不规则。 鉴别：Density 轻重 / Feel-滑石(talc) / Taste 石盐(halite) / Magnetism-磁铁矿(magnetite) / Double refraction 方解石(calcite) / React to dilute hydrochloric acid 方解,白云石(dolomite). A resource is a concentration of naturally occurring solid, liquid, or gaseousmaterials in or on Earths curst in such form and amount that economicextraction of a commodity from the concentration is currently or potentiallyfeasible. Natural resources: Metallic resources (copper, iron ore, etc) / Nonmetallic resources (sand, gravel, salt, sulfur, etc) / Energy resources (petroleum, natural gas, coal and uranium). resource: the total amount of a commodity, whether discovered orundiscovered. reserve: only that part of the resource base that is known and can beeconomically recovered. Ch 03 Magma: Molten rock material below the Earths surface. Lava flows: Magma reaches the surface. Igneous rock(火成岩): intrusive rock(侵入岩) and volcanic rock(火山岩). Destructive&Constructive:Volcanism may destroy housesand farmland and cause injuries and fatalities. & It isresponsible for the origin of manyoceanic islands and oceanic crustas well as critical atmosphericgases. Distribution: 60% Circum-Pacific belt / 20%Mediterranean belt / 20% Mid-oceanic ridges. Type: Convergent(挤压) / Divergent(发散) / Intraplate(版块内). Volcanic material喷出物包括Gas、Pyroclastic materials和melting body(凝结形成lava). Volcanic Gas: Water vapor / carbon dioxide, nitrogen, sulfur dioxide, hydrogen sulfide / carbon monoxide, hydrogen, Chlorine. Sulfur have widespread and significant effects on climate. Lava Flows: Aa lava is made up of angular blocks and fragments / Pahoehoe lava has a smooth surface much like taffy / Pressure ridges and spatter cones(高压脊和寄生熔岩锥) are typical of many flows. / Columnar Joints, formed in response to cooling and contraction of lava, formmost commonly in basalt and andesite lava flow. / Pillow lavas are bulbous, interconnecting masses that result fromunderwater eruption of basaltic lavas. Pyroclastic materials are solids, including ash, lapilli, blocks, bombs and cinder. Type:Shield Volcanoes 盾状火山、Cinder Cones 锥形火山、Composite Volcanoes (Stratovolcanoes) 复式火山、Lava Domes 熔岩丘、Supervolcano Eruptions 超级火山. Other Landforms: Fissure Eruptions and Basalt Plateaus / Crater/Calderas. Dangerous / Hazards: pyroclastic materials and gases, lahars(火山泥流). Ch 04 Magma composition: Si Fe Mg Ca Na K. relative proportions of silica,iron, and magnesium: Felsic (硅>65%，900) / Intermediate(53-65) / Mafic(45-52, 1200) / Ultramafic(硅<45). Si, sodium, potassium, aluminum / Calcium, Fe, Mg. Viscosity: composition, temperature, gasses(CO2), the presence of mineral crystals (crystallinity)friction from the surface over which lava flows (shearstress during movement). Magma Originate: Magma accumulates in reservoirs in the lower crust or upper mantle in magma chambers. Molten(熔融) rock is less dense than solid rock, and so it is buoyant and begins to rise thru the lithosphere. 高温低压有水，地表地下不宜，板块边界 断裂地下容易. Assimilation(同化): sometimes by stoping, can change a magma'scomposition, but usually only to a limited extent. Contamination(混染)，同过程不同侧面. Crystal setting: 结晶分异. Bowens Reaction Series:Discontinuous series(理想冷却条件) / Continuous series(钠代替钙). 先融化(后析出): quartz>muscovite>potassium feldspar>biotite=Na-rich plagioclase feldspar. Plutons: are bodies of igneous rock which have been intruded in country rockor have formed in place far beneath the surface. Concordant pluton include sills岩床,laccoliths盖/Discordant: dikes墙,batholiths基,stocks株. Dikes are discordant features (cut across layering in the country rock) Sills are concordant (parallel to the rock layers) Textures(斑状): Rapid cooling typifies volcanic rock and produces aphanitic(隐晶质) textures. / Slow cooling of plutonic magmas produces phaneritic(显晶质) textures with mineral grains that are easily visible without magnification. / Porphyritic textures are characteristic of rocks with complex cooling histories and contain mineral grains of different sizes. / Other igneous rock textures include vesicular, glassy, and pyroclastic. Phenocrysts(斑晶). Depending on whether magma erupts: plutonic (deep-seated)/ volcanic (eruptive) rocks. Based on the composition (SiO2) of Igneous Rock: Ultramafic rock (超基性岩) / Mafic (基性) / Intermediate (中性)/ Felsic (酸性). Peridotite is ultramafic rock, have olivine, rare at surface, composition close to mantle. Plutonic, Volcanic: Gabbro, basalt / Diorite, andesite / Granite, rhyolite. Tuff(volcanic ash),Obsidian(volcanic glass), Pumice & Scoria(volcanic glass, Vesicular). Ch05 火成Igneous rocks:67.4% . /沉积Sedimentary rocks:7.9% . /变质Metamorphic rocks:27.4% . External外力: Weathering, Erosion, Transportation, Sedimentation, solidification. Weathering风:the mechanical and chemical alteration of Earth materials at ornear the surface Erosion侵:involves removing weathered materials from their place of originbywater or wind. Mechanical Weathering: Frost action / Pressure release / Thermal expansion and contraction / Crystal growth / Activities of organisms. Result have chemically as parents. Chemical weathering: Solution / Oxidation / Hydrolysis Hydrolysis: During hydrolysis hydrogen ions react with and replace positive ions in potassium Feldspar. The result is clay minerals and substances in solution such as potassium and silica. Sediment Type: Detrital sediment consists of solid particles, products of mechanical Weathering. / Chemical sediments consist of minerals precipitated from solution by inorganic processes and by the activities of organisms thru chemical weathering. crack: When water freezes in cracks in rocks it expands and then it contracts when it thaws, thus exerting pressure and opening the cracks wider. Mud cracks: Depositional environment: Lagoons and mudflats. Ch 11 Evidence: Continental Fit, There is a close fit between the continents off the coast at a depth of about 2000 m. / Similarity of Rock Sequences, Marine, nonmarine, and glacial rock sequences of Pennsylvanian to Jurassic age are nearly identical on all the Gondwana continents / Similarity of Mountain Ranges, The trend of several major mountain ranges produces a continuous mountain range when the continents are positioned next to each other as they were during the formation of Pangea. / Glacial Evidence, Glacial tills and striations on the bedrock beneath the till provide evidence of glaciation