Sequence boundaries in Proterozoic successions: a comparison of the Brigham Group (Utah) and Wilpena Group (South Australia), with implications for sea-level change and global correlation

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6654629

Christie-Blick, N; Von der Borch, C C

Regional unconformities (sequence boundaries) have been identified in predominantly siliciclastic rocks of the Upper Proterozoic and Lower Cambrian Brigham Group (Utah), and Upper Proterozoic Wilpena Group (South Australia), on the basis of abrupt facies changes in stratigraphic logs, and, in places, of onlap and erosional truncation mapped on aerial photographs. The facies successions in both units can be interpreted qualitatively in terms of relative changes in sea level, using depositional models from seismic stratigraphy. Recent analysis of Early Paleozoic tectonic subsidence suggests that the Brigham Group was deposited in grabens prior to continental separation; the Wilpena Group also appears to have accumulated in grabens, and the inferred sea-level changes probably reflect significant changes in the rates of subsidence and sediment supply, as well as eustatic effects. As in the Phanerozoic some Proterozoic sequence boundaries may be of global extent. Given the tectonic setting and available age resolution, any correlation between the 4 or 5 sequence boundaries tentatively identified in the Brigham Group and the 2 or 3 in the Wilpena Group would be very speculative, but as more numerical ages become available, such boundaries may permit more precise time correlation between basins as well as within basins.

• Research Organization: Columbia Univ., Palisades, NY (USA)
• OSTI ID: 6654629
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
580201 -- Geophysics-- Seismology & Tectonics-- (1980-1989)
580203 -- Geophysics-- Geophysical Survey Methods-- (1980-1989)
AUSTRALASIA
AUSTRALIA
CAMBRIAN PERIOD
COMPARATIVE EVALUATIONS
CORRELATIONS
FEDERAL REGION VIII
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGIC MODELS
GEOLOGY
GEOPHYSICAL SURVEYS
LEVELS
MAPPING
NORTH AMERICA
PALEOZOIC ERA
PRECAMBRIAN ERA
ROCKS
SEA LEVEL
SEDIMENTARY ROCKS
SEISMIC SURVEYS
SOUTH AUSTRALIA
STRATIGRAPHY
SURVEYS
TECTONICS
USA
UTAH