Mackie, James, authorEgenhoff, Sven, advisorSchutt, Derek, committee memberRocca, Monique, committee member2007-01-032007-01-032013http://hdl.handle.net/10217/79106The Scallion and overlying False Bakken intervals represent the lowermost portion of the Mississippian Lodgepole Formation, a predominantly carbonate unit located in the Williston Basin of North Dakota (ND) and Montana (MT) in the US, and Saskatchewan and Manitoba in southern Canada. Macroscopic and microscopic observations allow a subdivision of these mostly fine-grained sediments into five carbonate and two siliciclastic facies. These facies form distinct stratigraphic units that can be traced through western ND and easternmost MT with nodular skeletal wackestones and packstones of the Scallion interval at the base showing a distinct coarsening-upward trend, overlain by between one and three black siliciclastic mudstones with interbedded carbonate mudstones of the False Bakken unit. This lowermost part of the Lodgepole Formation represents mid-ramp to basinal settings of a low-inclination carbonate platform system within the half-enclosed intracratonic Williston Basin. The observed stacking patterns reflect relative sea-level changes that influenced facies distribution within the basin throughout its evolution: the coarsening-upward observed within the Scallion interval shows a general shoaling of the setting during progradation, representing a lowstand systems tract. The False Bakken interval consisting of up to three shale beds with intercalated carbonate mudstones shows a significant fining within the lower Lodgepole Formation depositional system and is interpreted as representing the transgressive systems tract. The subdivision into a maximum of three mudstone units reflects three backstepping parasequences during relative sea-level rise. The subsequent renewed onset of fine-grained carbonate deposition on top of the False Bakken interval reflects deposition during highstand conditions. During burial, the Lodgepole Formation experienced a complex series of diagenetic events with nodule formation, dolomitization, and pressure dissolution being the most prominent. The results of these processes are irregularly distributed both stratigraphically and geographically and play a significant role in reservoir quality of the formation.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Text