A thesis submitted in partial fulfillment of the
requirements for the degree of
MASTER OF SCIENCE
in
GEOLOGY
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 | Table 1. A summary by section of bed thickness and sandstone to shale ratios. |
| Table 2. Summary of fold form by section (Figure 8). |
| Table 3. A summary of bed thickness and sandstone to shale ratios by folding unit. |
| Table 4. Results of applying the model relating multilayer thickness, number of structural units, and viscosity contrast in a multilayer with free slip. |
| Figure 1. Location of study area. |
| Figure 2. Location of study area in Sutherlin subbasin. |
| Figure 3. Stratigraphic nomenclature for the region containing the study area. |
| Figure 4. Schematic fence diagram of wells and measured sections surrounding the study area (after Ryu and others, 1992). |
| Figure 5. Paleogeographic reconstruction of the Pacific Northwest at 55±5 Ma (after Heller and others, 1987, Fig. 5). |
| Figure 6. Cross-section of Sutherlin subbasin through study area. |
| Figure 7. Estimated thickness of Umpqua Group units in the study area. |
| Figure 8. N-S cross-section of folds with axial survey points, and map view of axial survey points. |
| Figure 9. Schematic showing thickness of measured fold limbs from north to south. |
| Figure 10. Bed deformed into low-amplitude sine wave with wavelength of about two meters. |
| Figure 11. Duplex-like feature. |
| Figure 12. Asymmetry of folds defined. |
| Figure 13. Section I folds. |
| Figure 14. Folds 3 and 4 of Section I. |
| Figure 15. Envelopes of a bed traced through the folds of Section I. |
| Figure 16. Bedding thrusts and sub-horizontal faults in the concentric-like fold of Section I. |
| Figure 17. Section I folds and faults not at low angle to bedding. |
| Figure 18. Section II and Section III folds. |
| Figure 19. Idealized kink form imposed on schematic drawing of kink-like fold. |
| Figure 20. Fractures and contacts in kink-like fold. |
| Figure 21. Tan siltstone and associated calcareous nodule at base of kink-like fold of Section III. |
| Figure 22. Thrust fault zone immediately north of (stratigraphically below) the kink-like fold. |
| Figure 23. Section IV and Section V folds. |
| Figure 24. Jointed hinge of fold 14 in Section IV. |
| Figure 25. Section VI asymmetric chevron-like folds. |
| Figure 26. Schematic folding of conjugate fault zones in layers of Section VI. |
| Figure 27. Anticlinal fold 21 in Section VI. |
| Figure 28. Duplication of layers in south anticline of Section VI. |
| Figure 29. Boudin layer in curve of drag fold in fold 21, Section VI. |
| Figure 30. Model of folding units in the study outcrop. |
| Figure 31. Theoretical multilayer folds. |
| Figure 32. Fold form of Section I. |
| Figure 33. Parameters for multilayer folding models. |
| Figure 34. Opposite sense of asymmetry of monoclinal kink and drag folds. |
| Figure 35. Sense of fold asymmetry for the outcrop setting in a thrust sheet. |
| Figure 36. Chart of layer to average media viscosity. |
| Figure 37. Chart of initial thickness as a function of layer to average media viscosity contrast. |
| Figure 38. Relation of the wavelength to thickness ratio in rigid and soft media, for various ratios of media to normal viscosity of the multilayer. |
| Figure 39. Order of deformation. |
