hanson et al. 2012 3d projection of the southern mid-continent basement-rock surface
TRANSCRIPT
New insights into the Early Cambrian igneous and sedimentary history of the Southern Oklahoma Aulacogen from basement well penetrations
Robert E. Puckett Jr., Richard E. Hanson, G. Randy Keller, Matthew E. Brueseke, Casey L. Bulen, Amy M. Eschberger, Stanley A. Mertzman
Hanson et al. 2012
3D Projection of the Southern Mid-Continent Basement-Rock Surface
Puckett et al., 2014
35 km
Washita Valley Fault and Overthrust Penetrations Western Arbuckle Mountains
42 overthrust drilling penetrations Accessible samples from 21 wells 26.6 km of uncorrelated igneous section
Oklahoma Geological SurveyGuidebook 38
2014
34
km N
on
-Co
rrel
ate
d C
ross
Se
ctio
n
Mafic Rock Photomicrographs
Mafic Rock Geochemistry
Pan Am Newberry Sec. 13-T1N-R3WPan Am Williams Sec. 20-T1N-R2WPan Am Jarman Sec. 19-T1N-R2W
Characterized as broadly transitional tholeiitic basalts to andesites from
multiple overlapping eruptive systems. Similar to OIB and other
continental flood basalts originating from an enriched mantle source.
Modified from Brueseke et al. 2014
Rhyolite Photomicrographs
Rhy
olite
Geo
chem
istr
y
Dominantly rhyolites and peralkaline rhyolites
Highly fractionated – Depleted Sr, P, Ti - Typical A-type signature
Typical within Plate, A-type, consistent with emplacement in alaucogen type setting
Outcrop-Based Generalized Cooling Unit DiagramSurface Exposures of the Carlton Rhyolite in the Wichita Mountains
From Puckett et al. 2011
Rhyolite Cooling Unit Pan American Oil Co. Moore #1-A Sec.20 T1N-R2W
Rhyolite Glassy Flow Margin Kaiser Francis/Westheimer-Neustadt Chapman #1 Sec.9-T2S-R2E
Rhyolite glassy flow
margin (Dark Brown
cuttings)
Flow interior 40 m below
glassy margin sample above
Well log interval from the COHO Resources Story #4 (18-1N-2W), showing gamma ray and induction logs and corresponding lithologic log.
Gamma Ray, Induction Log, and Lithologic LogCOHO Resources Story #4 Sec. 18-T1N-R2W
Phreatomagmatic Interval – Magma in Contact With Ground WaterPan American Oil Co. Whyte #1 Sec. 21-T1N-R1W
Clastic SectionPan Am Jar man #1Sec. 19-T1N-R2W
1.14
km
42
6 m
Puckett et al., 2014
35 km
Washita Valley Fault and Overthrust Penetrations Western Arbuckle Mountains
42 overthrust drilling penetrations Accessible samples from 21 wells 26.6 km of uncorrelated igneous section
1.2 km Cumulative Volcaniclastic Interval Intercalated with RhyoliteFrankfort Oil Co. Sparks Ranch #1 Sec. 32-T1S-R1W
Post Volcanic Sedimentation close to the Rift AxisFrankfort Oil Co. Sparks Ranch Sec. 32-T1S-R1W
Reagan Islands
• Positive relief features that resisted inundation until Latest Cambrian/Early Ordovician
• Identifiable by the absence of Reagan Sandstone resulting in Arbuckle Group carbonates unconformably overlying the Early Cambrian volcanic rocks.
• Also found in the Wichita Mountains at Balley Mountain and the Slick Hills
Modified from Campbell and Weber 2006
FAULT
POSSIBLE FAULT
SOHIO Traub #1-3Sec. 3-T6N-R14W6.8 km NNE of Bally Mountain
2.48 km beneath surface
6.19 km beneath surface
415 m thick basalt interval with 35 m rhyolite dike/sill
104 m thick basalt interval
229 m thick basalt interval
Helmerich & Payne McNutt Unit #1
Sec. 23-T9N-R26W
2.91 km
Surface
4.35 km
4.9 km(minimum)
Normal fault
5.48 km Total Depth
2.91 km ofPermian and Pennsylvanian sedimentary rocks including Granite Wash
1.44 km ofDiabase, Diorite, and Granite
850 m of Gabbro
3 m core of amphibolite and quartzo-feldspathic gneiss
Poss. Fault indicated on Caliper log
2.49 km
280 m of metamorphic rocks
5,436.5 m
5,467.8 mPhoto by OGS Core Facility Staff
Penetratively folded tonalitic gneiss
Amphibolite with migmatitic quartz-feldspar patch.
Hornblende Biotite
Light green areas on hornblende represent partial retrogression to actinolite. PPL Field width 5mm
Sericitized plagioclase
The Southern Oklahoma Aulacogen contains a minimum emplaced volume of 250,000 km3.
Igneous activity was voluminous, strongly bimodal, and intercalated. Coeval mafic and felsic volcanism phases overlap.
Felsic magmas were A-type, mafic magmas have an EMI-OIB signature. Eruption products are lava-dominated - Rhyolitic pyroclastic deposits are limited to thin beds between flows - Basalt pyroclastic deposits seem to be primarily sourced from phreatomagmatic eruptions.
Cratonic-sourced sedimentation into the rift was active during volcanism and defines a negative topographic profile after volcanism ceased.
Intercalated rhyolites and basalts are present in the subsurface throughout the aulacogen.
Summary