Date of Award


Document Type


Degree Name

Master of Arts (MA)



First Advisor

H.J. Fischer


This study focused on the Frobisher-Alida interval, in particular, the Glenburn bed or the Mississippian Mission canyon Formation. Wireline logs and cores from closely spaced wells in, and adjacent to, the Wiley Field, Williston Basin, North Dakota were examined. Information derived from the wireline logs was used to construct several maps which show that there was little or no topographic relief or slope in the study area during deposition or the Glenburn bed. In addition, the maps show that structural derormation occurred subsequent to deposition or the Frobisher-Alida interval.

Six distinct lithoracies were recognized in cores or the Glenburn bed from the Wiley Field area: 1) fossilirerous grainy mudstone packstone (LF-1); 2) coated-grain wackestone-grainstone (LF-2); 3) peloidal/intraclastic wackestone-packstone (LF-3); 4) dolowacke stone-mudstone and nodular anhydrite (LF-4); 5) massive anhydrite (LF-5); and, 6) siliciclastic sandstone-siltstone (LF-6). or the six lithoracies, all but LF-6 were deposited in a low-energy, shallow sublittoral, marine setting. The siliciclastic sandstone-siltstone lithoracies {LF-6) was deposited by eolian processes as a silici clastic-dominated sabkha.

Facies within the Glenburn bed are stacked vertically rather than prograding either basinward or shoreward. Vertical stacking indicates that depositional processes were stable and did not shirt laterally by any significant amount, and that equilibrium conditions existed between sedimentation rates and rates or subsidence/sea level-change. Near the end or "Glenburn time," the most shoreward lithoracies prograded across the study area in a basinward direction, indicating a drop in sea level or an increase in sedimentation rate.

Within the study area, the distribution of fossils, dominant lithologies, and cement types indicate that lithofacies were formed in response to a horizontal salinity gradient in the water mass with salinities increasing to the northeast. The relative position of salinity values laterally across the area appears to have remained static during most of Glenburn bed deposition. Most of the sediments deposited in the study area are abiotic in origin, but may have formed due to, or in conjunction with, biochemical processes such as photosynthesis.

Marine water flowing into the study area to replace water lost by evaporation became increasingly saline as it evaporated along its flow path. A digitate pattern (in plane view) of carbonate and anhydrite deposition formed due to the shoreward flow of relatively fresh, marine-water plumes, and the laterally adjacent, basinward flow of dense, hypersaline brines respectively.

Diagenetic processes occurring due to the movement of surface or near surface hypersaline brines include dolomitization and calcite dissolution. Basinward-flowing, magnesium-rich brines derived from gypsum precipitating areas formed dolomite in a near surface, sublittoral setting. The same brines carried sulfide ions basinward where they were oxidized, creating an acid corrosive to carbonates that then caused vugular/enlarged fenestral porosity to develop in limestone lithofacies. The occurrence of plant megaspores (five new species) and fluorite in Mississippian rocks of the Williston Basin are reported for the first time in this report. Local hydrocarbon sourcing may have occurred.

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