Geology FINAL exam reviewWhat are the causes of earthquakes?- *Plate tectonics*- Volcanism - Meteorite impact- Atomic Explosion - Dam Building - Injecting fluids into the ground What are the types of seismic waves?- Surface waves-travel along the surface of the earth, also called long waves- Primary waves (p)o Compress and pull thus changing both shape and volume of intervening materialo In granite approx., 6kmps (10 mph)o In water 1.5 kmps (2mph) - Faster are solids than liquids - Secondary Waves (s)o Only change shape of intervening materialo Granite 3.5 KmpsWhich wave cannot travel through water?Secondary (S)Which wave is the fastest?Primary waves (P)What is the epicenter?point on the Earth's surface directly above the focusWhat is the focus?The site below the surface of the Earth where the rupture startsWhere it occuresWhat is triangulation?Measuring from 2 permanent fixed points (reference points) to the evidence, forming an imaginary triangleHow is the Richter scale organized? And what does it measure? Organized on a scale of 1-9. Measure two things:1. Amplitude of wave: each increase in number results in an amplitude increase of ten. Ex: from 3 to 4 on the Richard scale results in a ten fold increase in amplitude 2. Increase in the energy released (each 30 times greater)Occurrences of earthquakes, where do they occur?Plate boundaries, divergent faults, transform faults, strike slip faults, and convergent plate boundaries.Most of them are shallowsWhat is a tsunami and what causes it?Seismic sea wave. Caused by underwater earthquakesWhat is isostacy?The concept that Earth's crust is floating in gravitational balance upon the material of the mantle. What is the asthenosphere?The upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection, which allows the plates slide aroundWhat is the lithosphere?The solid layer at the surface of the earth; made up of the crust and upper mantle. Two types of crust- continental and oceanic.Dr. SuessSaw that the shores of South America and Africa would have fit together in the past and could have once been conjoined. Looking at the fossils and plants. First one to suggest that some parts of the earth that were together Alfred WegenerCame up with the super continent Pangea, Continental Drift Concept, and Fossil Evidence.Sir Edward BullardMapped the continental shelf off south America and Africa then found that it was an even better match Harry Hess Discovered the mid oceanic ridge, sonar mapping, and subduction.Sea floor spreadingWhat are paleomagnetics?The study of the direction and intensity of the earth's magnetic field throughout geologic time. The magnetic field flip flops back and forth. To support continental drift and plate tectonics (16:40) where did we measure it? igneous RocksWhat are the three types of plate boundaries and where are they found?Divergent (Mid-Oceanic Ridge), Convergent (volcanoes), and transform (along the faults). Strike-slip . they are perpendicular to mid-oceanic ridge What are the driving mechanisms of plate tectonics?Gravity and convectionThe matching up of strata from different outcrops in different regions is called?correlationWho is known as the father of modern stratigraphy? William Strata SmithWhat is a disconformity? Deposition ceases.Period during which deposition ceased, erosion removed previously deposited rock and then deposition resumed Separate relatively flat-lying sedimentary rocks and are more difficult to identify, geologist must look for evidence of erosion on the surface of the underlying rock What is a nonconformity? Separates metamorphic or igneous rock form sedimentary rockThe break separates older metamorphic or intrusive igneous rocks from younger sedimentary strata(sedimentary rock layer) What is an angular unconformity? folded and faulted rocks eroded away and exposed on the surface and sedmintary rocks are deposited Consists of tilted or folded sedimentary rocks that are overlain by younger, more flatlying strata.Hutton’s Hiatus What is lateral continuity?Deposition continues across a large area until it thins out over the edges This implies that deposition extends laterally in all direction until it thins to zero How does C-14 work? What are the range of dates possible?Organic life; 40-40,000 yearsWhat is the difference between relative and absolute dating?Relative dating only provides use with the sequence in which chronological order of events is ordered (doesn't give exact time). While absolute dating is based on the rates of certain types of rocks; gives actual number of years that have passed.Relative Dating-sequence of geologic eventsAbsolute Dating- numerical ValueWhat is a half life?The amount of time it takes for half of the original amount of parent isotopes to decay into the daughter isotopesC-14- 5, 730 years. 40-40000K-Ar 200,000 all the way back to big bang years. Igneous rocksPotassium-40 with the stable Daughter product of Argon-40 has a half-life 1.3 billion years*There has been five major extinction that we have evidence for in sediments rocks with the fossils that were left behind What is Phanerozoic?"Evident life" physical lifeWhat is Paleozoic? Means old life; amphibians, reptiles, fish, and invertebratesWhat is Mesozoic? "Middle life"; Dinosaurs, birds, and flowering plantsWhat is Cenozoic? Recent life; age of mammalsLaw of Super positioning In a stratigraphic sequence, the lower layers are older than the upper layersLaw of Original Horizontality Sediments are deposited in nearly horizontal layers. Movements of the earth’s crust have displaced strata that do not retain their original horizontality Walther's Law of Lateral Continuity Facies change based on the depositional environment.Principle of Faunal Succession The fossils found in rock layers show time geological time sequencePrinciple of Floral SuccessionPlants help determine the temperature of the area they were growing inLaw of Cross Cutting The rock had to be there before the fault could cut into them.Relationships Principle of Inclusions (components) Rock containing another rock is the younger of the twoThe rock mass containing inclusions is the younger of the two