Recognition of unconformity-sourced aquifer cements and later burial cements, Mississippian Newman Limestone, Kentucky

Conference · Fri Feb 01 04:00:00 EST 1985 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:5866816

Niemann, J C; Read, J F

The Mississippian Newman Limestone in eastern Kentucky contains aquifer-related cements and deeper burial cements. These cements were differentiated by trace elements, cathodoluminescence, staining, and fluid inclusions. Aquifer cements are nonferroan and show a nonluminescent to dull to nonluminescent to bright cathodoluminescent zonation. They fill leached ooid and fossil molds, indicating that pore waters were initially undersaturated with calcium carbonate. Within a regional paleoaquifer, early nonluminescent cement (34 ppm Mn, 33 ppm Fe average) precipitated from oxidizing waters that later became reducing to form dull cement (average 181 ppm Mn, 565 ppm Fe). A second nonluminescent cement was formed following later recharge. Aquifer stagnation, prior to or during burial, was accompanied by bright cementation (2139 ppm Mn, 252 ppm Fe average). Waters were sourced from post-Newman unconformities. Aquifer cement, which decreases away from recharge areas, was determined by initially staining for late-burial calcite; image analysis was then used to determine the amount of early cement by substracting late-burial cement from total cement. Later, iron-rich burial cements (778 ppm Mn, 4295 ppm Fe average) filled the following pore space: (1) remnant intergranular, (2) fractures in compacted skeletal grains, (3) cavities caused by spalling ooid cortices and early cement rims, and (4) tectonic fractures, which are lined with saddle dolomite and pyrite. Secondary fluid inclusions suggest that late-stage fluids were chemically complex brines with temperatures that ranged from 50/sup 0/C to 160/sup 0/C and averaged 100/sup 0/C. These techniques may help to evaluate porosity loss by shallow cementation in paleoaquifers (potential pore plugging prior to hydrocarbon migration) vs. cementation by deeper burial processes.

• Research Organization: Virginia Polytechnic Institute and State Univ., Blacksburg
• OSTI ID: 5866816
• Report Number(s): CONF-850322-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 69:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
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03 NATURAL GAS
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ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATE ROCKS
CARBONATES
CHALCOGENIDES
DOLOMITE
FEDERAL REGION IV
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
IRON COMPOUNDS
IRON SULFIDES
KENTUCKY
LIMESTONE
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MINERAL RESOURCES
MINERALS
MISSISSIPPIAN PERIOD
NATURAL GAS DEPOSITS
NORTH AMERICA
OXYGEN COMPOUNDS
PALEOZOIC ERA
PETROLEUM DEPOSITS
POROSITY
PYRITE
RESERVOIR ROCK
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SOURCE ROCKS
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
USA