Attempted integration of geologic and geophysical data from the Idaho National Engineering Laboratory area, Eastern Snake River Plain

Conference · Thu Apr 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5095550

Josten, N E; Hackett, W R; Smith, R P ^[1]

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1. EG G Idaho, Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.

The Eastern Snake River Plain (ESRP) is a late-Cenozoic, bimodal volcanic province that developed synchronously with basin-and-range extension in the surrounding tectonic province. Strong geologic and geophysical contrasts exist between these two provinces. The Basin and Range is composed of northwest-trending, carbonate-bedrock ranges and alluvium-filled valleys. The ESRP is a bimodal volcanic province, with Tertiary silicic-volcanic rocks overlain by Quaternary mafic lavas. Patterns of ESRP volcanism and associated dike-induced surface deformation suggest that Quaternary crustal extension on the ESRP is accommodated by intrusion of basaltic dikes along northwest-trending volcanic-rift zones. This contrasts with recurrent seismogenic slip along northwest-trending, segmented normal faults in the adjacent Basin and Range tectonic province. The authors present new geophysical compilations, and they attempt to correlate these data with the surface distribution of volcanic-rift zones and other mapped geologic features near the Idaho National Engineering Laboratory. Numerous, northwest-trending aeromagnetic anomalies do not always correspond with mapped volcanic-rift zones, which are expected to be underlain by mafic-dike swarms. Northwest-trending gravity anomalies also cross the ESRP, but their widths suggest broadly distributed masses rather than narrow rift zones. The spatial and temporal distribution of volcanic-rift zones on the ESRP has important implications for regional tectonics and seismicity, as well as the assessment of seismic- and volcanic hazards at the Idaho National Engineering Laboratory. Discrepancies among the data sets suggest that older, buried volcanic-rift zones may have existed in a different configuration than is currently indicated by surficial geology. Alternatively, the geophysical signatures of non-rift-zone features may be indistinguishable from those of volcanic-rift zones.

• OSTI ID: 5095550
• Report Number(s): CONF-9305259--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540250 -- Environment
Terrestrial-- Site Resource & Use Studies-- (1990-)
58 GEOSCIENCES
580000* -- Geosciences
DEVELOPED COUNTRIES
GEOLOGIC STRUCTURES
GEOLOGY
GEOPHYSICAL SURVEYS
GEOPHYSICS
IDAHO
IDAHO NATIONAL ENGINEERING LABORATORY
IGNEOUS ROCKS
MAGNETIC SURVEYS
NATIONAL ORGANIZATIONS
NORTH AMERICA
RIFT ZONES
ROCKS
SITE CHARACTERIZATION
SNAKE RIVER PLAIN
SURVEYS
US DOE
US ERDA
US ORGANIZATIONS
USA
VOLCANIC ROCKS
VOLCANISM