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Tualatin Basin

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Journal Article
Published: 01 April 2003
Environmental and Engineering Geoscience (2003) 9 (4): 327–338.
...DOYLE C. WILSON Abstract Hydrogeologic properties of the Neogene Hillsboro Formation and Willamette Silt in the Tualatin basin are evaluated to provide a foundation for future groundwater use in the Portland, Oregon, metropolitan area, and are then compared to hydrogeological conditions...
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Journal Article
Journal: Geosphere
Published: 01 April 2014
Geosphere (2014) 10 (2): 264–275.
...D.K. McPhee; V.E. Langenheim; R.E. Wells; R.J. Blakely Abstract The Tualatin basin, west of Portland (Oregon, USA), coincides with a 110 mGal gravity low along the Puget-Willamette lowland. New gravity measurements (n = 3000) reveal a three-dimensional (3-D) subsurface geometry suggesting early...
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Journal Article
Published: 01 January 2000
Journal of Sedimentary Research (2000) 70 (1): 117–126.
... basins. The northwest-trending Tualatin Mountains-Portland Hills (TMPH) faulted anticline presently separates fine-grained sediments of the Hillsboro Formation in the Tualatin Basin from coarse-grained sediments of the Troutdale Formation in the Portland Basin. Augite-hornblende-hypersthene relative...
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Journal Article
Published: 04 May 2021
Bulletin of the Seismological Society of America (2021)
...Ian Stone; Erin A. Wirth; Arthur D. Frankel ABSTRACT We use converted body‐wave phases from local earthquakes to constrain depth to basement and average attenuation relations for the Seattle basin in Washington and the Tualatin basin in Oregon. P ‐, P‐to‐S ‐( Ps ), S‐to‐P‐ ( Sp ), and S ‐wave...
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Journal Article
Journal: Geosphere
Published: 21 April 2021
Geosphere (2021)
...Darby P. Scanlon; John Bershaw; Ray E. Wells; Ashley R. Streig The Portland and Tualatin basins are part of the Salish-Puget-Willamette Lowland, a 900-km-long, forearc depression lying between the volcanic arc and the Coast Ranges of the Cascadia convergent margin. Such inland seaways...
Journal Article
Published: 15 December 2020
Bulletin of the Seismological Society of America (2021) 111 (2): 671–685.
... outside the Portland and Tualatin basins. Sites on artificial fill and Holocene alluvium show strong amplification peaks (factor of 5) around 1–2 Hz. Sites on the Portland Hills, consisting of thin soil over basalt, display spectral peaks at 4–5 Hz (factor of 4). Spectral peaks at both sites are similar...
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Estimated depths of interfaces beneath stations in the <b>Tualatin</b> <b>basin</b>. The ...
Published: 04 May 2021
Figure 5. Estimated depths of interfaces beneath stations in the Tualatin basin. The stations are listed in an approximately northwest‐to‐southeast order. The solid blue line represents the depth to basement values calculated in this study, whereas the dotted blue line represents the depth
Image
Isostatic gravity map of the <b>Tualatin</b> <b>basin</b> and surrounding area with major...
in > Geosphere
Published: 01 April 2014
Figure 2. Isostatic gravity map of the Tualatin basin and surrounding area with major faults (from Fig. 1 ). Contour interval is 4 mGal. White dots—gravity measurements; black dots—gravity measurements on basement; white squares—cities.
Image
(A) Depth to basement map of the <b>Tualatin</b> <b>basin</b> and surrounding area with m...
in > Geosphere
Published: 01 April 2014
Figure 3. (A) Depth to basement map of the Tualatin basin and surrounding area with major faults from Figure 1B . Contour interval is 300 m. Wells are shown as white circles ( Table 1 ) and black circles ( Table 3 ). (B) Basement gravity field calculated from the gravity inversion (color scale
Journal Article
Published: 01 August 2004
Bulletin of the Seismological Society of America (2004) 94 (4): 1402–1409.
... the tunnel, which reflects the tunnel's location between low-density sedimentary deposits of the Tualatin basin to the west and high-density, mostly concealed Eocene basalt to the east. Superimposed on this gradient are several steplike anomalies that we interpret as evidence for faulted contacts between...
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Table 1.  Hydrogeologic characteristics in the Portland and <b>Tualatin</b> <b>basins</b>...
Published: 01 April 2003
Table 1. Hydrogeologic characteristics in the Portland and Tualatin basins. K x is horizontal hydraulic conductivity
Journal Article
Published: 01 January 1999
Environmental and Engineering Geoscience (1999) V (2): 189–197.
.... Observations in other borings from the central and western Tualatin Basin support the above hypothesis. Naturally large phosphate concentrations leaching from the Hillsboro Formation and into the Tualatin River drainage system will always keep the river at risk of accelerated seasonal algal growth...
Journal Article
Journal: Geosphere
Published: 06 February 2020
Geosphere (2020) 16 (2): 660–684.
...). Relative uplift of Eocene Coast Range basalt basement west of the fault zone is at least 5 km based on depth to basement under the Tualatin Basin from a recent inversion of gravity data. West of the city of Forest Grove, the fault consists of two subparallel strands ∼7 km apart. The westernmost, Parsons...
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Series: GSA Field Guide
Published: 01 January 2009
DOI: 10.1130/2009.fld015(31)
EISBN: 9780813756158
..., including high degree of confinement, low bulk permeability and limited recharge have led to overdraft conditions in many areas. Conversely, these characteristics create favorable conditions for aquifer storage and recovery system development in the central Willamette Valley and Tualatin Basin...
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Three‐component seismograms from Seattle <b>basin</b> station LAWT and <b>Tualatin</b> ba...
Published: 04 May 2021
Figure 2. Three‐component seismograms from Seattle basin station LAWT and Tualatin basin station KEEL showing the different converted phase arrival times. Z, R, and T labels correspond to the vertical, radial, and transverse components, respectively.
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(A) Elevation of the top of Columbia River Basalt Group (CRBG) in <b>Tualatin</b> ...
in > Geosphere
Published: 06 February 2020
Figure 15. (A) Elevation of the top of Columbia River Basalt Group (CRBG) in Tualatin Basin, in feet above mean sea level. CRBG is more than 1200 ft (366 m) below sea level in the center of the basin. Beaverton fault bounds Yakima-style fold belt across southern basin. (B) Location of Tualatin
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Physiographic and major structural features around the <b>Tualatin</b>, Portland, ...
Published: 01 January 2000
Figure 3 Physiographic and major structural features around the Tualatin, Portland, and Northern Willamette basins along with the locations of the HBD-1 and MTD-1 borings. Laterite and underlying lava flows of the Columbia River Basalt Group constitute the faulted anticlines of the Tualatin
Journal Article
Journal: GSA Bulletin
Published: 01 September 1995
GSA Bulletin (1995) 107 (9): 1051–1062.
... southwest of the Tualatin Mountains corresponds closely with another mapped fault and with mixed reverse and strike-slip faulting during a seismic swarm (M ≤ 3) in 1991. We believe these and other anomalies in the aeromagnetic data reflect the Portland Hills fault zone, believed to be the southwestern...
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Estimated depth to basement at stations in (a) the Seattle <b>basin</b> and (b) th...
Published: 04 May 2021
Figure 3. Estimated depth to basement at stations in (a) the Seattle basin and (b) the Tualatin basin based on this study (colored circles). Basement depth contours in the Seattle basin were taken from the Stephenson et al. (2017) CVM; Tualatin basin basement depth contours were taken from
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(A) Index map showing <b>basins</b> (tan) within the southern Puget-Willamette low...
in > Geosphere
Published: 01 April 2014
Figure 1. (A) Index map showing basins (tan) within the southern Puget-Willamette lowland. PB—Portland basin; TB—Tualatin basin; NWB—Northern Willamette basin. (B) Simplified geologic map of the Tualatin basin and surrounding area (modified from Blakely et al., 2000 ). Red line is profile