Earth Science Reviewer PDF

REVIEWER IN EARTH SCIENCE Weathering is the term applied to the combined action of all physical and chemical processes that disintegrate and decompose rocks near the Earth’s surface. Freeze-thaw weathering o Water collects in a rock crack o Water freezer and co...

REVIEWER IN EARTH SCIENCE Weathering is the term applied to the combined action of all physical and chemical processes that disintegrate and decompose rocks near the Earth’s surface. Freeze-thaw weathering o Water collects in a rock crack o Water freezer and contracts, forcing cracks to widen. o Repeated expansion and contraction cause further cracks till rock splits. Unloading is the removal of great weights or rock or ice that lie on the surface. Source of Heat on Earth o Heat from the decay of radioactive elements o Heat from the accretion of Earth during its formation o Frictional heating caused by the sinking of core materials to the center of the planet. How does convection occur in the mantle? o Molten rock is less dense due to its hot temperature resulting to rising of the hot material and sinking of cooler rock establishing a circular motion. Heat transfer mechanisms o Conduction o Convection o Radiation o Advection Magmatism happens when mantle rock melts due to increased in temperature or decreased in pressure. June 15, 1991 – Mt. Pinatubo eruption Consideration in Magma generation o Addition of heat o Addition of volatiles o Decrease in pressure through convective uplifting Regional metamorphism – Its increased in pressure & temperature are due to some processes known as plate tectonic and causes the formation of mountains. Changes that occur during the metamorphism o Changes in minerals o Polymorphic phase transformations o Folding and bending of rocks causing change in its shape How do temperature and pressure affect metamorphism? o The deeper the rock depth, the higher the pressure and temperature. Agents of metamorphism – heat, fluid/chemical activity, pressure Anticline – upward fold of the plate Syncline – downward fold of the plate San Andreas Fault is an example of a transform boundary. Compression – rocks push or squeeze against one another where stress produced is directed toward the center. Rocks respond differently to the same stress because of their different characteristics and origin of formation. Importance of Seafloor Spreading – It causes folding of rock layers into mountains that spreads on the Earth’s surface. The heat from radioactive processes within the planet’s interior causes the plates to move. Formation of Ocean Basins o When there was an increase in available water or fall of landmass. o Due to seafloor spreading and the movement of tectonic plates o When water has covered a large portion of the Earth’s crust Oceanic ridges are continuous mountain chains located under the surface of the sea.  Ocean trenches are long-narrow, steep-sided depressions found on the ocean floor. Ocean basins are regions that are below sea level. SONAR – instrument that uses sound waves to measure distance underwater. Guyot is a submerged volcanic mountain with a flat top. Strike-slip – the rocks above the fault plane moving downward relative to the rocks below the fault plane. Divergent boundary occurs when two tectonic plates move away from each other. Deformation refers to any change in the shape or size of a rock as a response to stress. Principle of Superposition – older layer (bottom); Younger layer (top) Stratification – refers to the crustal movement, displacement of soils and distortion of terrains that lead to layering of rocks. Principle of Faunal Succession – shows the same vertical changes in fossils that are embedded in rocks occurred in different places. Law of Inclusion – If a sandstone in contact with a granite contains fragments of the granite, granite is older that sandstone. Absolute dating – the age of rock is determined by radiometric dating. Relative dating – does not provide actual numerical dates for the rocks but all are just estimates based on the profile of strata. Zircon – a crystal discovered in Australia and is believed to be 4.375 billion years old. Half-life of Carbon-14 is 5,730 years. Half-life is the amount of time it takes for the proton to decay into a stable atom. When a radioactive carbon atom decays, it turns into a more active isotope. Index fossils – used by the scientist to define and identify the subdivision of GTS. These are useful because the tell the relative age of the rock layers. They existed for a short period of time over large areas. Fossils are remnants, impressions or traces of plants and animals. Trace fossils are preserved wastes products and worm burrows. Hadean eon – first rocks, first atmosphere and oceans were formed. Epochs under Cenozoic Era – Tertiary Period o Oligocene, Paleocene, Pliocene Ediacaran fauna – soft-bodied organism found in Australia. 4.6 Billion years old – age of Earth according to the paleontologists. Major Divisions of GTS – Eon, Era, Period, Epoch Era o Precambrian - oldest o Paleozoic - old o Mesozoic - middle o Cenozoic - present God bless on your exams! -Ma’am Niña