Geos 240 Final Exam Study Guide
Review Class Friday April 19 1:30-4:30 in F 300.
You are allowed a 1 page review sheet in the exam.
About 20 multiple choice to test vocabulary and understanding
About 20 Thoughtful (or annoying) matching terms and definitions or characteristics
4-5 essays to cover: It is always appropriate to include environmental, economical or
geohazard examples or aspects of any topic.
Chapter 1-7: review and sample vocabulary and concepts as tested on MT #1 and MT #2
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 & 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
within Basins (Nanaimo Group Cycles), Reciprocal sedimentation, Peter Vail and Global
Eustasy
Ch 13 Sedimentation & Plate Tectonics: Rift basins, Convergent Margins ForearcBackarc and Foreland basins, rollback, accretionary wedges and subduction complexes,
strike slip margin basins, pull aparts, positive and negative flower structures, Continent
collissional suture basins, remnant ocean crust, cratonic basins.
Possible essay topics and syntheses:
1. Cyclic stratigraphy, allosystems, boundaries, scales (time and bed thickness), causes,
setting, sedimentology. What can be learned from this type of analysis?
2. How complete is the stratigraphic record? It is the best we have but how good is it and
where are the holes? What are the challenges in trying to use stratigraphy and
sedimentology as a proxy for paleoclimate and paleooceanography?
3. Sediments occur in Basins. There are several types. Discuss a few of them, be able to
several different types on a map of N. Am or the world. How are rift basins and foreland
basins different in terms of tectonic causes, subsidence, sediment types, flexure, duration
and resources?
4. 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, 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?
5. Several events in Earth history are rather non-uniformitarian: evolution of
photosynthetic organisms, banded iron formations, Cambrian explosion of life,
subsequent massive extinctions. How can we use the tools and observations of
sedimentary geology to address this to draw more robust conclusions.
6. How does the supercontinent cycle affect the generation and preservation of sediments
and the correlation of the stratigraphic record between continents?
7. I will choose some questions from your paper presentations to award the diligent and
those who attended!