The Wallula fault and tectonic framework of south-central Washington, as interpreted from magnetic and gravity anomalies

Quaternary Rupture of a Crustal Fault beneath Victoria, British Columbia, Canada

“…Within a zone up to 1 km wide, we observe near vertical faults, variable scarp facing directions, laterally discontinuous surface scarps, and field evidence for strike-slip and reverse faulting. These characteristics are typical of strike slip systems and are similar to features observed along active oblique-reverse faults in the adjacent Pacific Northwest (e.g., Johnson et al, 2001;Sherrod et al, 2008Sherrod et al, , 2016Kelsey et al, 2012;Personius et al, 2014;Blakely et al, 2014).…”

“…Both the Darrington-Devil's Mountain fault and the Southern Whidbey Island fault systems of Washington state (Fig. 1) are likewise near-vertical fault zones with oblique slip histories similar to many of the crustal fault systems throughout the Puget Sound region (e.g., McCaffrey and Goldfinger, 1995;ten Brink et al, 2006;Blakely et al, 2014;Nelson et al, 2014;Sherrod et al, 2016). Considering these similarities in orientation and slip sense, we suggest that the Leech River fault is part of this regional active forearc fault system.…”

“…trenching, and geophysical studies have proven successful at highlighting a network of oblique reverse forearc faults, both on-and offshore of Washington and Oregon, that can produce earthquakes up to 7.5 in magnitude (McCaffrey and Goldfinger, 1995;ten Brink et al, 2006;Blakely et al, 2014;Sherrod et al, 2016). In particular, LiDAR, seismic, and aeromagnetic data have been paramount in the recognition of the Seattle fault as a significant seismic hazard source within the greater Seattle region (SF, Fig.…”

Crustal framework of the northwest Paraná Basin, Brazil: Insights from joint modeling of magnetic and gravity data

“…In general, in the analysis and interpretation of gravity signatures of extensional and cratonic sedimentary basins, anomalies are related to the following geological features: (i) negative anomalies are caused by low-density sediments that fill the depocenters; (ii) positive anomalies around the basin are associated with structural highs and basement rocks; and, (iii) positive anomalies at or near the depocenters are commonly related to intrusions and/or high density volcanic rocks in the crust or upper mantle (Gunn, 1997;Vidotti et al, 1998;Blakely et al, 2014). In some cases, isostatic compensation may cause crustal thinning, resulting in broad gravity highs superimposed on the shorter-wavelength depocenter anomaly (Karner et al, 2005).…”

O lineamento transbrasiliano na Bacia do Paraná : compartimentação crustal do embasamento e reativações fanerozóicas

“…In general, in the analysis and interpretation of gravity signatures of extensional and cratonic sedimentary basins, anomalies are related to the following geological features: (i) negative anomalies are caused by low-density sediments that fill the depocenters; (ii) positive anomalies around the basin are associated with structural highs and basement rocks; and, (iii) positive anomalies at or near the depocenters are commonly related to intrusions and/or high density volcanic rocks in the crust or upper mantle (Gunn, 1997;Blakely et al, 2014). In some cases, isostatic compensation may cause crustal thinning, resulting in broad gravity highs superimposed on the shorter-wavelength depocenter anomaly (Karner et al, 2005).…”