The geological significance of the boundary between the Fort Sill and Signal Mountain Formations in the lower Arbuckle Group (Cambrian)

Conference · Mon Feb 01 04:00:00 UTC 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:6002668

Hosey, R; Donovan, R N ^[1]

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1. Texas Christian Univ., Ft Worth, TX (United States). Geology Dept.

During the upper Cambrian, a transgression inundated the Southern Oklahoma aulacogen enveloping a landscape that consisted of hills of Cambrian-aged rhyolite up to 350 m in height. Initial deposits on this topography--the Reagan Formation--consist of siliciclastics that were deposited as alluvium and succeeding tidally-influenced marine sandstones and shales. The siliciclastics grains are made up of local rhyolite, quartz and authigenic glauconite. The overlying Honeycreek Formation is defined by the addition of carbonated detritus in the form of tidally-influenced pelmatozoan grainstones. The passage from the Honeycreek to the overlying Fort Sill Formation of the Arbuckle Group is marked by the incoming of beds of lime mudstone and the gradual disappearance of grainstones and siliciclastics. The contact between the Fort Sill and the overlying thinly-bedded dark grey bioclastic limestones of the Signal Mountain Formation is one of the most distinctive horizons in the Arbuckle Group. The contact evidently marks a substantial change in depositional environment. In detail the contact is sharp and shows evidence of minor erosion, although no karsting has been detected. The authors suggest that the contact surface records a regression, perhaps associated with dolomitization and followed by some erosion. A regression is also indicated by the local occurrence of a laminated tidal flat unit with traces of evaporites that outcrops in the far west of the Slick Hills immediately below the formation contact. They suggest that the Signal Mountains as a transgressive unit, incorporating siliciclastics transported into the area during the regression. It has been suggested that the unconformity reflects localized tectonism associated with the evolution of the Southern Oklahoma aulacogen. On the other hand the surface may correlate with a craton--wide Sauxian' hiatus.

• OSTI ID: 6002668
• Report Number(s): CONF-9303212--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:1
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ALLUVIAL DEPOSITS
CAMBRIAN PERIOD
CARBONATE ROCKS
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GEOLOGY
IGNEOUS ROCKS
NORTH AMERICA
OKLAHOMA
PALEOZOIC ERA
RHYOLITES
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SHALES
STRATIGRAPHY
USA
VOLCANIC ROCKS