Mappable units include, from youngest to oldest,
- Qtl- Quaternary terrace, low (Willamette gravels and other sediments)
- Qtm- Quaternary terrace, mid-level
- Qth- Quaternary terrace, high
- Ti- Tertiary intrusive (Mafic, mostly diabasic in texture)
- Ts- Spencer Formation (near-shore marine deposits)
- Tf- Now classified as Tyee, turbidite deposits called Flournoy Formation at the time.
- Tsr- Siletz River Volcanics
- The Corvallis Fault has uplifted older Tsr with respect to younger sedimentary units along the slash from upper right to lower middle
- Pediments are identified by diagonal cross-hatching
- Areas of particularly high slope (and thus high mass movement risk) are identified with dark gray shading
1 comment:
Nice idea to post a local map for map day. :)
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