...Anita M. Ho; Katharine V. Cashman Abstract This study provides the first quantitative estimate of heat loss for a Columbia River Basalt Group flow. A glass composition-based geothermometer was experimentally calibrated for a composition representative of the 500-km-long Ginkgo flow of the Columbia...

.... Dotted lines indicate magnetic lineaments. Dashed line is western extent of Columbia River basalt flows. Cross-hachured areas are magnetic lows discussed in text. CML—Canby-Molalla lineament; EL—Estacada lineament; W—anomaly across Willamette River dextrally offset along Canby-Molalla lineament. See...

.... Thickness packages <~1 km diameter are likely an interpolation artifact. Contour interval = 50 m. Location of the Columbia River shown for reference. BV—Beaverton fault; CM—Canby-Molalla fault; SOF—Sylvan-Oatfield fault; PH—Portland Hills fault; EB—East Bank fault; PHBL—Prune Hill/Blue Lake fault; LL...

.... Carver, and T. S. Yelin Woodburn rOD M.s~ Molalla 45.15N [] [] AGLDO [] CHR ~O / - Scotts Mills ~o o Mainshock '- Mount Angel~l. ANG MAQ .lOST [~O~i~ LA: ~ 0 WA1 N~ HOL ~ 1 : ~ , ~ , . u n ILG DIE ~ . ~ WIL 0 ~ 0 0 La [] SIV 0 LOM BYF0t I Salem ,OrOd "44.85N km IIiIII 0 10 Magnitude o 1.0- 2.2...

... near Woodburn, Oregon, to image the offset of the Miocene-age Columbia River Basalts ( CRB ) and overlying sediments at and northwest of the known mapped extent of the Mount Angel fault. The seismic data show a 100-200-m offset in the CRB reflector at depths from 300 to 700 m. Folded or offset...

...Michael H. Darin; John M. Armentrout; Rebecca J. Dorsey Abstract An extensive detrital zircon U-Pb data set ( n = 6324 dates) from Eocene to Miocene sandstones and modern river sands establishes the onset of arc magmatism and forearc uplift along the Cascadia convergent margin in southwestern...

...) and Pacific (PAC) plates are indicated by solid black arrows ( McCaffrey et al. , 2013 , 2016 ). The box shows area of this figure. BT, Bolton; BV, Beaverton; CM, Canby‐Molalla; CSZ, Cascadia subduction zone; DTC, Damascus‐Tickle Creek; EB, East Bank; GC, Gales Creek (shown in red); LL, Lackamas Lake; MA...

..., therefore 6 times deeper than the 1 km maximum depth of the Miocene Columba River Basalt Group (CRBG) in the basin, implying that the basin contains several kilometers of low-density pre-CRBG sediments and so formed primarily before the 15 Ma emplacement of the CRBG. The shape of the basin and the location...

... and Middle Forks of the Willamette River, the McKenzie River, the Santiam River, the Molalla River, and the Clackamas River, are predominantly alluvial with gravel beds in their downstream reaches. It is bed material from this lithologic province that has been primarily trapped by dams in the study area...

... about 21 km (GS. AZM = 2°; (N) VAL = 0.09, PLG = 0°, AZM = 92°; (P) VAL Numerous people were treated for minor injuries. Damage (VII) = - 3 . 4 7 , PLG = 55°, AZM = 182°. Best double couple: NPI: at Canby, Molalla, Mount Angel, and Newberg, Oregon. Slight strike = 91 °, dip = 10°, slip = - 9 0 °. NP2...

... with broken dishes, mirrors, clocks, etc., which had been thrown down by the earthquake. At the Elmo Buttle Ranch, about 10 miles northwest of Bradley, ground cracks appeared near the San Antonio River and showed splashes of silt and water through them. Aftershocks continued to be felt in this area...

...) is calculated in the N20°W direction, normal to the average N70°E trend of the age groups. It is important that the Gales Creek–Mount Angel, Canby-Molalla, Portland Hills–Clackamas River, and Sandy River faults also have northwestward trends, as shown by the dextral displacement of aeromagnetic anomalies...

... on the Willamette River north of Patterson ( Fig. 7J ) offers striking confirmation of its radiometric dating at 34.8 ± 0.2 Ma. Especially useful paleomagnetic observations include those of the Goshen flora overlying a reversal at 33.5 Ma ( Fig. 6I ) but which is estimated to be 33.4 Ma from radiometric...