123°45' 40' 35' 30' 25' 20' 15' 10' 05' 123°00' 55' 50' 45' 40' 35' 30' 25' 20' 15' 122°10'

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Themes visible in this map are: STRUCTURE POINTS, LATITUDE/LONGITUDE, COASTLINE and LAND.

Tertiary and Quaternary structures of the eastern Juan de Fuca Strait: point map
Samuel Y. Johnson, David C. Mosher, Shawn V. Dadisman, Jon R. Childs and Susan B. Rhea, 2000.

The scatter points on this map sheet show locations where Quaternary and pre-Quaternary faulting and folding were interpreted from seismic reflection profiles, the tracks and many examples of which are presented in this atlas
(follow the hotspot links on Figure 2 and the various tracks pages). Faults are recognized on the basis of truncated reflections and (or) abrupt changes in reflection dip or seismic facies, such as amplitude, frequency, continuity, and geometry. Fault identification was greatly facilitated by the availability of diverse and complementary seismic-reflection data sets with variable depth imaging and resolution. There are a significant number of relatively high-angle contacts bounding reflections or sets of reflections within the Quaternary section (see depth to base of Quaternary Map) in the upper ~ 1 s TWT that could be interpreted either as faults (e.g., Figures 3, 6, 9, and 13) or as steep depositional contacts associated with glaciofluvial erosion and deposition (Figure 1). Differentiating between tectonic and nontectonic origins is possible with the benefit of deeper seismic data such as from the SHIPS program or the INDUSTRY lines that reveal whether potential structures are "rooted" within the basement and are faults or, in contrast, are confined to the Quaternary section and are sedimentary features.

 

Reference citation:
Johnson, S.Y., Mosher, D.C., Dadisman, S.V., Childs, J.R., and Rhea, S.B., 2000. Tertiary and Quaternary structures of the eastern Juan de Fuca Strait: point map, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Sediment Deformation Features Map
Structure Map
48°30'
25'
20'
15'
10'
05'
48°00'

Structure Point Map (Quaternary and pre-Quaternary faults and folds)

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