Masters Thesis
Quaternary faulting of Deschutes County, Oregon
Sixty-one normal faults were identified in a 53-kilometer long by 21-kilometer wide northwest-trending zone in central and northern Deschutes County, Oregon. The faults are within the Tumalo and Sisters fault zones and the Northwest Rift Zone, and extend from Newberry Volcano to Black Butte. Faults are identified in and near the population centers of Bend, Redmond, Sisters, and Tumalo. The investigation identified displacement of volcanic flows dated at 24 ± 14 ka using K/Ar and 39 ± 6 ka using 40Ar/ 39Ar, displacement of several prominent pyroclastic deposits, displacement of multiple undated volcanic flows, and displacement of undated sedimentary deposits; 7,000-year-old Mazama ash is unfaulted. Displacement of deposits in the southern portion of the study area relative to displacement in the northern portion is interpreted having occurred more recently and is generally of greater magnitude. Evidence of fault reactivation over time was found, as older rock units are displaced more than younger ones along the same segment of a fault.
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Quaternary_Faulting_of_Deschutes_County__Oregon.pdf | 2020-08-06 | Public | Download |
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Plate_1.pdf | 2020-08-06 | Public | Download |
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Plate_2.pdf | 2020-08-06 | Public | Download |
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