Geos 240 Study Guide Exam 1
Covers Chapters 1-3 in Miall and labs 1-3
1. Know the definition and usage of: groups, formations, members and beds in
stratigraphy.
2. What are the main methods of describing and analyzing stratigraphy?
3. What kinds of minerals or materials make up the grains in clastic sediments?
4. What kinds of minerals make up the cements in sedimentary rocks?
5. How, why and where do sediments undergo chemical and physical changes?
6. Are any particular minerals acid generating or basic or are all minerals
environmentally neutral?
7. What does rounding tell you concerning sedimentary particles?
8. What does sorting tell you concerning sedimentary particles?
9. What is the difference between chemical and biochemical sediments?
10. What kinds of sediments can be considered exclusively chemical in origin?
11. What, where and when does the “carbonate factory” operate?
12. What is the “dolomite problem”? (Hey Buddy! I’m a dolomite! You gotta
problem?)
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13. What is the difference between a sandstone, a wacke and a mudstone?
14. What is the principal difference between a quartz arenite, an arkose and a lithic
sandstone?
15. How does the provenance differ for a lithic wacke and a fossiliferous bio-pelmicrite?
16. How do we measure provenance and what can provenance tell us about clastic
sediments?
17. If reef building organisms differ in time and space (rudists, bryzoans,
brachiopods, corals, sponges…), what is the fundamental thing that makes a reef, a
reef?
18. How do the porosities and permeabilities differ between sands and muds?
19. What 3 processes transform sediment into sedimentary rocks?
20. What types of sedimentary rocks are most likely to become compacted versus
cemented?
21. Earth’s climate system depends only on the solar constant (output) and the
atmosphere and oceans, right?
22. What is mass wasting and where and when does it occur?
23. What is the difference between a rudstone and a sedimentary breccia?
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24. Where and when would you expect to find rock flour produced and deposited?
25. Is sea level constant throughout geological time; why or why not?
26. What is a sedimentary basin and what kinds of places do they occur?
27. What kinds of agents are responsible for transporting sediments and are they all
of equal importance?
28. What particular resources occur mainly in sedimentary rocks or are restricted
to sedimentary environments?
29. What are sedimentary structures and what are they useful for?
30. Is the rate of sedimentation always uniform or is there missing time in a stack of
rocks and how could we tell?
31. How can marine sedimentary rocks come to be deposited on continental areas?
32. How would you draw a column of alternating sandstones and shales so that I
could tell the difference between them from across the room?
33. What is the basis for the Wentworth size scale and what are the breaks for claysilt-sand-gravel?
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34. Other than trying to hurt its feelings why would I call a sedimentary rock
immature?
35. What is a hardground, where does it occur and what does it signify?
36. Congratulations! You have just been hired as my exploration manager for a new
frontier basin! I want to know the ages and thicknesses and geometries of the
sedimentary formations and which are prone to holding oil and natural gas. Your
budget is $10M. What kinds of information do you need and how will you get it?
37. If you only have downhole logging tools how do you distinguish coal from shale
or limestone from salt? What logging tools do you need and why?
38. If you have lots of reflection seismic data in a region why do you still need
borehole data like a sonic and density logs?
39. Suppose you are a geologist working for the exploration manager in question 36.
Why do you need to convince him that you need real rocks from surface or borehole
samples and not just geophysical information? You had better make this good or
He’ll spend all the budget on fancy whiz-bang high tech toys!
40. Can petrophysical logs tell you about anything other than the lithologies? If so
how does this work?
41. What is diagenesis, why does it occur and what kinds of physical evidence is
there that this happens?
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42. Why do we examine, measure, describe or sample sedimentary rocks on
different intervals from seismic wavelengths down to millimetres and how does the
information we obtain differ in usefulness?
Terms:
Allochem
Alluvium
Aquifer
Aragonite
Arenite
Argillaceous
Arkose
Banded iron formation
Beachrock
Bed
Benthic
Bitumen
Breccia
Brine
Calcareous
Calcite
Caliper
Carbonaceous
Concretion
Continental shelf
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Clay (particle size versus minerals)
Chemical weathering
Craton
Crossbed
Density (grain versus formation)
Diamict
Diapir
Diatom
Dolomite
Dropstone
Eustatic sea level change
Euxinic/Eutrophic
Evaporites
Facies
Fecal pellet
Foraminifera
Foreland basin
Formation
Formation microscanner
Fossilization
Gamma ray (natural count)
Gradient
Grainstone
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Greywacke
Grit
Groundwater
Heavy minerals
Hinterland
Interval velocity
Isostasy
Jacob’s staff/pogo stick
Kelly table
Karst
Lithology
Laminae
Lagoon
Loess
Lutite
Matrix
Micrite
Mud
Natural gas
Neutron log
Ocean basin
Oolite
Orthochem
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Pelagic
Permeability
Petroleum
Placer
Planktonic
Pore fluid
Porosity (Different types?)
Provenance
Reef
Reflection seismic section
Regression
Resistivity
Rift
Rudite
Salinity
Saltation
Settling
Shale
Shoal
Sparite
Spontaneous potential
Stokes law
Stromatolite
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Stylolite
Terrane
Tectonic
Till
Trace fossil
Transgression
Two way time
Type section
Uniformitarian
Vug
Wacke
Well log
Whiting
Wilson cycle
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