1. Stratigraphy Principles of Stratigraphy Types of Stratigraphy Contacts Unconformities Text: Manual p. 29-35

2. Stratigraphy “Stratigraphy can be defined as the complete triumph of terminology over facts and common sense.” Attributed to P.D. Krynine by J. Ferm in Burton et al., 1987.

3. Stratigraphy Stratigraphy: the study of the 3-D spatial and temporal relationships among rocks

4. Stratigraphy Principles of Stratigraphy Types of Stratigraphy Contacts Unconformities Text: Manual p. 29-35

5. The oldest rocks are found on the bottom and the youngest rocks on the top. youngest oldest Principles of Stratigraphy 1. Superposition

6. youngest?oldest? Principles of Stratigraphy

7. older younger Principles of Stratigraphy

8. sediments are deposited at the earth’s surface in flat layers Principles of Stratigraphy 2. Original Horizontality

9. Principles of Stratigraphy

10. cross-bedding

11. a bed will extend laterally until: Principles of Stratigraphy 3. Lateral Continuity 1.Pinches out. 2.Abuts against older rock. 3.Truncated by erosion. 4.Cut by fault.

12. Principles of Stratigraphy

13. Rock that are cut by another geologic feature are older than the feature that cuts them. Principles of Stratigraphy 4. Cross-Cutting Relationships Fault Erosion Igneous Intrusion

14. If pieces of rock A are included in rock B, rock A formed before rock B. Principles of Stratigraphy 5. Rule of Inclusions A B

15. 6. Faunal Succession Systematic sequence of fossils with time. Extinct fossils do not reappear in younger rocks. Principles of Stratigraphy http://www.geo.utexas.edu/courses/401/

16. Stratigraphy Text: Manual p. 29-35 Principles of Stratigraphy Types of Stratigraphy Contacts Unconformities

17. Types of Stratigraphy LithostratigraphyLithostratigraphic UnitLithology PedostratigraphyPedostratigraphic UnitBuried Soils BiostratigraphyBio ZonesFossil Content ChronostratigraphyChronostratigraphic Units (Period, Epoch, Age) Time Relationships GeochronostratigraphyGeochronostratigraphic Unit (System, Series, Stage) Time Relationships MagnetostratigraphyMagnetic Reversals, ChronsMagnetic Polarity ChemostratigraphyIsotope ZonesChemical Characteristics Sequence StratigraphyAllostratigraphic Unitsunconformity-bounded packages TypeSubdivisionsProperty

18. Types of Stratigraphy - Allostratigraphy

19. Types of Stratigraphy LithostratigraphyLithostratigraphic UnitLithology PedostratigraphyPedostratigraphic UnitBuried Soils BiostratigraphyBio ZonesFossil Content ChronostratigraphyChronostratigraphic Units (Period, Epoch, Age) Time Relationships GeochronostratigraphyGeochronostratigraphic Unit (System, Series, Stage) Time Relationships MagnetostratigraphyMagnetic Reversals, ChronsMagnetic Polarity ChemostratigraphyIsotope ZonesChemical Characteristics Sequence StratigraphyAllostratigraphic Unitsunconformity-bounded packages TypeSubdivisionsProperty

20. Types of Stratigraphy - Lithostratigraphy Super Group Group *Formation Member / Tongue / Lentil Bed / Flow *Formation: distinct, mappable rock body with definable boundaries

21. Types of Stratigraphy Lithostratigraphic Units lens / lentil (E. McBride)

22. Stratigraphy Text: Manual p. 29-35 Principles of Stratigraphy Types of Stratigraphy Contacts Unconformities

23. Types of Contacts Intrusive Fault Depositional - Conformable Contact - Unconformity

24. Types of Contacts (Depositional) Vertical Contacts Lateral Contacts pinchout intertonguing gradation intercalated gradual abrupt (Boggs, p. 453)

25. Types of Contacts (Depositional) Lateral Contacts (E. McBride)

26. Stratigraphy Text: Manual p. 29-35 Principles of Stratigraphy Types of Stratigraphy Contacts Unconformities

27. Unconformity: buried surface of erosion; missing rock / time Hiatus: amount of missing time Diastem: small amount of missing rock / time vs

28. Uplift of Land Erosion – Mechanical, Chemical, Biological Drop in Sea Level Unconformities

29. Calvert Bluff / Alluvium Contact (Field Trip 1)

30. Unconformities Types: 1. Disconformity 2. Paraconformity 3. Nonconformity 4. Angular Unconformity

31. 1.Disconformity – sediments on sediments (same orientation) with obvious erosion Unconformities

32. Redwall Limestone Supai Group Muav Limestone 150 million years 20 million years Disconformity Unconformities

33. 2. Paraconformity – sediments on sediments (same orientation) no obvious erosion surface (Boggs, p. 456)

34. 3. Angular unconformity – sediments on sediments (different orientations) Unconformities

35. 250 million years Angular Unconformity Unconformities

36. Angular Unconformity Unconformities Wyoming

37. Angular Unconformity Unconformities (E. McBride)

38. 4. Nonconformity – sediments on crystalline igneous or metamorphic rocks Unconformities Erosional Surface Uplift, Erosion, Deposition

39. 1800 million years 550 million years Unconformities Nonconformity

40. Canadian Shield Nonconformity in Progress Enchanted Rock Unconformities