thumbnail

Geologic map of the Snoqualmie Pass 30 x 60 minute quadrangle, Washington

IMAP 2538

See also Data Series 186 (DS-186)
By:
, , , and

Links

Abstract

The Snoqualmie Pass quadrangle lies at the north edge of a Tertiary volcanic and sedimentary cover, where the regional structural uplift to the north elevated the older rocks to erosional levels. Much of the quadrangle is underlain by folded Eocene volcanic rocks and fluvial deposts of an extensional event, and these rocks are overlain by Cascade arc volcanic rocks: mildly deformed Oligocene-Miocene rocks and undeformed younger volcanic rocks. Melanges of Paleozoic and Mesozoic rocks are exposed in structural highs in the northern part of the quadrangle. The quadrangle is traversed north to south by the Straight Creek Fault, and the probably partially coincident Darringon-Devils Mountain Fault. A rich Quaternary stratigraphy reveals events of the Frazer glaciation.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Geologic map of the Snoqualmie Pass 30 x 60 minute quadrangle, Washington
Series title:
IMAP
Series number:
2538
Subseries
NONE
ISBN:
0607952598
Edition:
Version 1.0
Year Published:
2000
Language:
ENGLISH
Description:
1 map : col., 56 x 76 cm., on sheet 94 x 143 cm., folded in envelope 30 x 24 cm.; 1 pamphlet (57 cm. : ill., maps ; 28 cm.)
Scale:
100000
Online Only (Y/N):
N
Additional Online Files(Y/N):
Y