Geos 240 Additional Review Material for Test 3 – Final Exam (cumulative)
Review Class Tuesday April 14 1:30-4:30 in F 300.
You are allowed a 1 page review sheet with you during the exam.
About 20 multiple choice to test vocabulary and understanding
About 20 Thoughtful (or annoying) matching terms and definitions or
characteristics
About 10 short multiple choice questions based on real practical materials, rocks
etc. There will be test kits or hand lenses provided. Example I might give you a
1) Conglomerate and ask about its grain size range, sorting, porosity, grain or
cement composition.
2) Chemical sedimentary rock and ask whether it is chalk, chert, gypsum etc.
3) A fossil and ask you if it is petrified wood or a pelecypod and what
sedimentary environment it indicates.
4-5 short essays to cover: It is always appropriate to include environmental,
economic or geohazard examples or aspects of any topic covered in lecture and lab.
Chapter 1-7: review and sample vocabulary and concepts as tested on MT #1 and
MT #2 or their study guides.
Chapter 8: Riverine, Deltaic, Littoral, Carbonate and Evaporite facies,
environments, climates, geographic settings, lithologies, biota, reefs, changes
throughout time, diagenesis. What are some environmental or economic reasons to
study these facies and successions?
Chapter 9: Sequence stratigraphy, accommodation and supply, Transgressive and
Regressive cycles, 4 stages for coastal/shelf clastic successions: high stand, falling
systems tract, low stand, transgressive systems tract.
Chapter 10: Sedimentary maps: isopach, structure contour (tops), isolith maps,
sand/shale ratio, facies, lithofacies, permeability, paleocurrent analyses from
sedimentary structures and transport directions from provenance (Sand/shale, QFL
or Heavy minerals)
Chapter 11: Tectonism and sedimentary basins, crustal stresses and styles of brittle
deformation, brittle-ductile transition, tectonic settings and basin styles, crustal
strength and subsidence, rifts, forearc, foreland, pull apart, glacio-isostatic loading,
steer’s head stages of rift basin, rift-flexure-subsidence, Foreland basins, load,
subsidence, orogenic pulses, sediment supply influence, geosynclinal cycle, flysch
and molasse, backstripping, subsidence curves and difference for rift versus
foreland basins, supercontinent break up fast spreading and sea level rise (Rodinia
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& Pangea), rate at >+20m/Ka, Increased subduction, ridge failure, supercontinent
assembly and sea level fall (Pangea), rate at -1cm/Ka to 110’s of m, epeirogeny &
cratonic basins, horizontal stresses and flexure or mantle convection?, reactivated
basement
Ch 12 Stratigraphic Cycles: 1st order - Supercontinent Cycle ~300 Ma, 2nd Order Sloss supercycles (eustasy + epeirogeny)10’s of Ma (TZAKTS), 3rd – 5th Order
Cycles Cyclothems and Epeirogeny, up to a few Ma, 4th -5th Order Milankovich
Cycles glacioeustasy and orbital forcing 10 Ka-2 Ma; Grenville Orogeny ~1 Ga
assembly of Rodinia, Permian assembly of Pangea, Western Canada Basin
Stratigraphy & cycles, Milankovitch: Eccentricity 95 Ka solar influx, Obliquity=tilt
40Ka seasonality and climactic belt widths, Precession 21 Ka seasonality, High
frequency tectonic pulses
Chs. 9, 12, 13: Stratigraphy, sequences and basin analysis
31. What is cyclic stratigraphy, how does it manifest and what can we tell from it?
1) Give 2 specific examples of the types of lithologies and stratigraphic processes
that repeat.
2) In each case what controls the lithology and bed thickness and what immediate
change in the sedimentary basin controls the cyclicity?
3) What is the overall forcing mechanism that drives the cyclic sedimentation
(seasonal, tidal, biological productivity, climate, tectonics, orbital, sea level etc.)
Discuss and give examples of sediment products and their variation. (10 points)
Chapters 3 and 8 Carbonate Rocks and Environments
32. Describe the general conditions required for or typical of carbonate sediment
formation, specifically: (10 pts total)
1) geographic location with respect to latitudes and continental margins
2) climactic conditions
3) seawater physical chemistry
4) physical oceanography and sediment supply
5) benthic biology
6) What is special about reef facies compared to adjacent carbonate environments?
7) How has reef formation varied during geological time?
8) What are the 2 principal carbonate components texturally and how are told
apart?
9) What is the “dolomite problem”, discussing what dolomite is and how it is
formed?
10) What are the sequence stratigraphic differences between carbonate and clastic
systems for TST & HST versus FSST and LST.
Chapters 6 and 8: Clastic facies and Depositional environments
33. What types of clastic facies might you expect to find along a short system in B.C.
as between the Coast Mountains and Tidewater. Sediment sources, types, maturity,
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sorting, transport processes, past versus present facies, etc. How would you
recognize this setting in the sedimentary record a hundred Ma hence from its
geometry, isopach, structure contour and physical sedimentology? How might
sequential facies come to be superposed in this restricted setting? (10 points)
Chapters 10, 11 and 13. Sedimentary Basins
35. Describe by comparison and contrast 2 distinct basin types and how you might tell
them apart using examples of tectonic location, geological age and setting, lateral and
vertical extent, geological time span, underlying crustal type, subsidence controls,
sediment types, possible resources that might be associated. Hint it would help to use
real basins for your examples. (10 points)
Da whole book especially Ch’s 11, 12 and 14
36. Discuss the uniqueness and importance of some particular geological process or
phenomenon that is not very uniformitarian, in that it only happened once or a very
few times in geological history. Pick a topic with sedimentary and environmental
consequences and discuss what happened, why this was unique and what the
consequences were. Eg. The appearance of photosynthetic organisms and iron
formations, Supercontinent breakup, Deglaciation, The Cambrian Explosion of life
and how this was fundamentally different than diversification following any
subsequent massive extinctions, The controls on Icehouse Earth and consequences
that feed back to other geological processes and environments. This is your chance to
expound on your own favorite big picture topic. (10 points)
37. Applications: Compare and contrast what you’d expect in terms of sediment
types, sedimentation rates, processes, basin formation mechanism, sediment
thicknesses and how you’d tell these apart if somehow the basins were preserved but
their tectonic context was lost to time. Near 2 different modern convergent margins:
(10 points)
1.) India against Asia (12 cm/yr) and
2.) The Atlantic against the Caribbean Plate by the Antilles Island Arc (6 cm/yr)
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