<p><strong>2448, RAFT RIVER MOUNTAINS FAULT </strong></p><p><strong>Structure number:&nbsp;</strong>2448. </p><p>Comments: Hecker's&nbsp;(1993) fault number 6-17. </p><p><strong>Structure name:&nbsp;</strong>Raft River Mountains fault. </p><p>Comments: <br><strong>Synopsis: </strong>Poorly understood middle to late Pleistocene(?) fault in the Raft River Mountains. The&nbsp;fault is in both Utah and Idaho. </p><p><strong>Date of compilation:&nbsp;</strong>10/99. <strong>Compiler and affiliation:&nbsp;</strong>Bill D. Black (Utah Geological Survey) and Suzanne Hecker </p><p>(U.S. Geological Survey). </p><p><strong>State: </strong>Utah. <strong>County: </strong>Box Elder. <strong>1° x 2° sheet:&nbsp;</strong>Brigham City. <strong>Province: </strong>Basin and Range. <strong>Reliability of location:&nbsp;</strong>Poor. </p><p>Comments: Mapped&nbsp;by Compton (1972) and Doelling (1980).&nbsp;Mapping from <br>Doelling (1980). <strong>Geologic setting:&nbsp;</strong>North-trending normal fault near the Utah-Idaho border along the northeast side of the Raft River Mountains.&nbsp;The Raft River Mountains have a core of Precambrian metamorphic rocks and trend east-west, similar to the Uinta Mountains. Northern slopes of the mountains drain into the Snake River and are considered part of the Snake River Plain, rather than the Great Basin. </p><p><strong>Sense of movement:&nbsp;</strong>N. </p><p>Comments: </p><p><strong>Dip: </strong>No data. </p><p>Comments: </p><p><strong>Dip direction:&nbsp;</strong>E. <strong>Geomorphic expression:&nbsp;</strong>Faulted alluvium. <strong>Age of faulted deposits:&nbsp;</strong>Middle to late Pleistocene(?). <strong>Paleoseismology studies: </strong>None. <strong>Timing of most recent paleoevent:&nbsp;</strong>(4) Middle and late Quaternary (&lt;750 ka). </p><p>Comments: </p><p><strong>Recurrence interval: </strong>No data. </p><p>Comments: </p><p><strong>Slip rate:&nbsp;</strong>Unknown, probably &lt;0.2 mm/yr. </p><p>Comments: </p><p><strong>Length: </strong>End to end (km):&nbsp;2 </p><p>Cumulative trace (km):&nbsp;2 </p><p><strong>Average strike </strong>(azimuth): N1°E </p><p><strong>REFERENCES </strong></p><p>Compton, R.R., 1972, Geologic map of the Yost quadrangle, Box Elder County, Utah and Cassia County, Idaho: U.S. Geological Survey Miscellaneous Investigations Series Map I-672, scale 1:31,680. </p><p>Doelling, H.H., 1980, Geology and mineral resources of Box Elder County, Utah: Utah <br>Geological and Mineral Survey Bulletin 115, 251 p., scale 1:125,000. </p><p>Hecker, Suzanne, 1993, Quaternary tectonics of Utah with emphasis on earthquakehazard characterization:&nbsp;Utah Geological Survey Bulletin 127, 2 plates, scale 1:500,000, 257 p. </p>