Deposition, stratigraphy, provenance, and reservoir characterization of carbonate mudstones: the Three Forks Formation, Williston Basin
type: CreativeWork
description: This thesis uses a drill core database from a 250 square mile area of North Dakota and Montana to evaluate the depositional environment, stratigraphic development, provenance, and reservoir quality of the Famennian Three Forks carbonate mudstones. Depositional environments and lithofacies include the following. Schizohaline, storm dominated intrashelf deposits defined by disturbed claystone, dolomudstone, sandstone, laminated mudstone, and distorted to brecciated dolomudstone lithofacies. These lithofacies often contain syneresis cracks, desiccation cracks, high depositional rate features such as convolute bedding and load features, and many scours. Ichnofacies vary from fairweather mobile and sessile feeding traces, early post-storm event escape traces, post-event opportunistic colonizers, and a final return to fairweather colonies. Arid shallow shelf deposits form during times of minimal fluvial and resultant minimal siliciclastic input into the basin, as well as times of evaporation conducive to broad salina, evaporative gypsum deposits. Mudflats rim these two shelf environments. During arid times they commonly contain abundant syndepositional nodular anhydrites and during less arid times they are full of intraclasts that range in abundance and size. Significant autogenic organization of these deposits is inferred to result in high frequency facies variability due to geomorphologic buildups. A major allogenically controlled shift progresses upwards in the stratigraphy as the deposits decrease in evidence of aridity and increase in evidence of fluvial inputs. Detailed correlations and calibrations to regional biostratigraphic studies delineate seven third-order transgressive-regressive cycles within the formation. Calibration to the biostratigraphic timescale facilitates comparison of [superscript 87]Sr/[superscript 86]Sr data to eustatic trends. These data indicate freshwater inputs that also provide more radiogenic Sr than the well-mixed global curve. Additional…
abstract: This thesis uses a drill core database from a 250 square mile area of North Dakota and Montana to evaluate the depositional environment, stratigraphic development, provenance, and reservoir quality of the Famennian Three Forks carbonate mudstones. Depositional environments and lithofacies include the following. Schizohaline, storm dominated intrashelf deposits defined by disturbed claystone, dolomudstone, sandstone, laminated mudstone, and distorted to brecciated dolomudstone lithofacies. These lithofacies often contain syneresis cracks, desiccation cracks, high depositional rate features such as convolute bedding and load features, and many scours. Ichnofacies vary from fairweather mobile and sessile feeding traces, early post-storm event escape traces, post-event opportunistic colonizers, and a final return to fairweather colonies. Arid shallow shelf deposits form during times of minimal fluvial and resultant minimal siliciclastic input into the basin, as well as times of evaporation conducive to broad salina, evaporative gypsum deposits. Mudflats rim these two shelf environments. During arid times they commonly contain abundant syndepositional nodular anhydrites and during less arid times they are full of intraclasts that range in abundance and size. Significant autogenic organization of these deposits is inferred to result in high frequency facies variability due to geomorphologic buildups. A major allogenically controlled shift progresses upwards in the stratigraphy as the deposits decrease in evidence of aridity and increase in evidence of fluvial inputs. Detailed correlations and calibrations to regional biostratigraphic studies delineate seven third-order transgressive-regressive cycles within the formation. Calibration to the biostratigraphic timescale facilitates comparison of [superscript 87]Sr/[superscript 86]Sr data to eustatic trends. These data indicate freshwater inputs that also provide more radiogenic Sr than the well-mixed global curve. Additional…
author: Franklin Dykes, Alyssa
language: eng
language: English
keywords: Famennian, Williston Basin, Three Forks Formation, sedimentology, Epeiric sea, reservoir characterization
identifier: T 7676
date published: 2014
date modified: 2026-07-24T01:42:56Z
provider: Colorado School of Mines
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Colorado School of Mines. Arthur Lakes Library

PropertyValue
property ID: Handle
value: https://hdl.handle.net/11124/17031