Untitled Flashcards Set

Q: What are the two main types of weathering? A: Mechanical (physical) weathering and chemical weathering.

Q: How does frost wedging contribute to mechanical weathering? A: Water enters cracks in rocks, freezes, expands, and breaks the rock apart.

Q: What is exfoliation in geology? A: The process where outer rock layers peel away due to pressure release.

Q: Why does chemical weathering occur more rapidly in warm, humid climates? A: Higher temperatures and moisture accelerate chemical reactions.

Q: What is the role of carbonic acid in weathering? A: It forms from CO₂ and water, dissolving minerals like limestone.

Q: What is the difference between residual soil and transported soil? A: Residual soil forms in place, while transported soil is moved by wind, water, or glaciers.

Q: What are the soil horizons in a typical soil profile? A: O (organic layer), A (topsoil), E (eluviation), B (subsoil), C (parent material), and R (bedrock).

Q: What are the three types of sediment transport? A: Traction (rolling), saltation (bouncing), and suspension (floating).

Q: What is the difference between well-sorted and poorly sorted sediment? A: Well-sorted sediment has uniform grain sizes; poorly sorted has mixed sizes.

Q: What is diagenesis? A: The chemical and physical changes that turn sediments into sedimentary rock.

Q: How do biochemical sedimentary rocks form? A: From the accumulation of organic material, such as shells or plant remains.

Q: What are examples of common chemical sedimentary rocks? A: Limestone, dolostone, chert, and evaporites (rock salt, gypsum).

Q: What type of sedimentary rock is coal? A: Organic sedimentary rock formed from compressed plant material.

Q: What is cross-bedding in sedimentary rocks? A: Angled layers formed by wind or water currents.

Q: What is regional metamorphism? A: Metamorphism caused by high pressure and temperature over large areas.

Q: What is the difference between low-grade and high-grade metamorphism? A: Low-grade metamorphism involves slight changes; high-grade results in major mineral transformation.

Q: What is a parent rock (protolith)? A: The original rock before metamorphism (e.g., limestone → marble).

Q: Name two non-foliated metamorphic rocks. A: Marble and quartzite.

Q: How does hydrothermal metamorphism occur? A: When hot, mineral-rich fluids alter the composition of surrounding rocks.

Q: What are index minerals? A: Minerals that indicate the temperature and pressure conditions of metamorphism (e.g., garnet, kyanite).

Q: What is the significance of a metamorphic aureole? A: It is a zone of altered rock surrounding an intrusive magma body.

Q: What is the principle of superposition? A: In undisturbed layers, the oldest rocks are at the bottom.

Q: What is the principle of original horizontality? A: Sedimentary layers are initially deposited in horizontal layers.

Q: How does the principle of cross-cutting relationships work? A: A fault or intrusion is younger than the rocks it cuts through.

Q: What is a fossil index? A: A fossil used to date and correlate rock layers.

Q: What is the difference between absolute and relative dating? A: Absolute dating gives a specific age, while relative dating determines order.

Q: What isotope is used for radiocarbon dating? A: Carbon-14.

Q: What is the significance of the geologic time scale? A: It organizes Earth's history into eons, eras, periods, and epochs.

Q: What are the two types of Earth's crust? A: Continental crust (thicker, granite) and oceanic crust (thinner, basalt).

Q: What are the main components of the mantle? A: Silicate minerals rich in iron and magnesium.

Q: What is the difference between the lithosphere and asthenosphere? A: The lithosphere is rigid, while the asthenosphere is semi-fluid.

Q: What is the S-wave shadow zone? A: A region where S-waves do not pass, indicating a liquid outer core.

Q: How do P-waves and S-waves differ? A: P-waves travel through solids and liquids; S-waves only travel through solids.

Q: Why is the outer core liquid while the inner core is solid? A: Differences in temperature and pressure cause the inner core to remain solid.

Q: What causes Earth's magnetic field? A: The movement of liquid iron in the outer core.

Q: What is metamorphism? A: The process by which existing rocks are transformed into metamorphic rocks due to changes in temperature, pressure, and chemically active fluids.

Q: What are the main agents of metamorphism? A: Heat, pressure (stress), and chemically active fluids.

Q: Define foliation in metamorphic rocks. A: A texture resulting from the parallel alignment of mineral grains, giving the rock a layered appearance.

Q: Name two common foliated metamorphic rocks. A: Schist and gneiss.

Q: What is contact metamorphism? A: Metamorphism occurring adjacent to igneous intrusions due to high temperatures.

Q: What is the principle of uniformitarianism? A: The concept that present geological processes have operated throughout Earth's history.

Q: Define relative dating. A: Determining the sequence of geological events without exact dates.

Q: What is an unconformity? A: A gap in the geological record indicating erosion or non-deposition.

Q: Describe radiometric dating. A: Determining absolute ages by measuring radioactive decay.

Q: What is the geologic time scale? A: A timeline dividing Earth's history into eons, eras, periods, and epochs.

Q: What is stress in geological terms? A: Force applied per unit area within rocks.

Q: Differentiate between compressional and tensional stress. A: Compressional stress squeezes rocks; tensional stress pulls them apart.

Q: What is a fold in geology? A: A bend in rock layers resulting from stress.

Q: Name the two main types of faults. A: Normal faults and reverse (thrust) faults.

Q: What is a joint in geological structures? A: A fracture in rock without significant movement.

Q: What causes earthquakes? A: Sudden release of energy due to fault movement.

Q: Define the focus of an earthquake. A: The point within Earth where seismic waves originate.

Q: What is the Richter scale? A: A scale measuring earthquake magnitude.

Q: Describe a seismic gap. A: An area along a fault with no recent earthquakes, indicating potential future activity.

Q: What is liquefaction? A: When saturated soil loses strength during shaking.

Q: What are the three main layers of Earth? A: Crust, mantle, and core.

Q: Differentiate between the lithosphere and asthenosphere. A: The lithosphere is rigid; the asthenosphere is semi-fluid.

Q: What is the Moho? A: The boundary between Earth's crust and mantle.

Q: Describe Earth's outer core. A: A liquid layer composed mainly of iron and nickel.

Q: What generates Earth's magnetic field? A: Movements within the liquid outer core.