The impact of organic matter deposition and pre-oil window diagenetic transformation on commonly utilized thermal maturity indicators

Synnott, Dane Patrick

The impact of organic matter deposition and pre-oil window diagenetic transformation on commonly utilized thermal maturity indicators

dc.contributor.advisor	Pedersen, Per Kent
dc.contributor.advisor	Dewing, Keith
dc.contributor.author	Synnott, Dane Patrick
dc.contributor.committeemember	Fowler, Martin
dc.contributor.committeemember	Sanei, Hamed
dc.contributor.committeemember	Larter, Stephen
dc.contributor.committeemember	Curiale, Joseph
dc.date	2021-11
dc.date.accessioned	2021-08-26T18:07:04Z
dc.date.available	2021-08-26T18:07:04Z
dc.date.issued	2021-08-19
dc.description.abstract	Despite decades of research on organic matter deposition, alteration, and preservation, the processes affecting and altering organic matter at low maturity are relatively poorly understood. Processes that affect deposition of organic matter, such as wildfires, or influence its preservation after deposition, such as diagenetic clay catalyzed transformation, can reduce the reliability of commonly applied thermal maturity proxies. This thesis integrated organic geochemistry and petrographic examination of samples from the Upper Cretaceous in Western Canada and the Canadian Arctic Islands to better understand processes that altered organic matter during deposition and early diagenetic. Samples from the Upper Cretaceous Kanguk Formation of the Canadian Arctic Islands have abundances of pyrogenic polycyclic aromatic hydrocarbon compounds and combustion-related organic macerals that show a distinct trend of increasing wildfire influence from the Turonian to the Campanian. This trend corresponds with increasing amounts of terrigenous organic matter in the marine Sverdrup Basin, in addition to increasing angiosperm-derived biomarkers. High rates of terrigenous organic matter deposition, accelerated by wildfires, have an important impact on the preservation of organic matter in a marine basin, as observed through degradation trends correlated to elevated primary productivity. A stratigraphically-controlled thermal maturity transect of samples ranging from eogenesis up to the peak of catagenesis was collected from the Upper Cretaceous Western Canadian Sedimentary Basin and examined using integrated organic geochemistry and organic petrology. The diagenetic transformation of hopanoid and steroid compounds was investigated, and key chemical transformations were calibrated to a maturity level. This investigation demonstrated that early clay-catalyzed backbone rearrangement in both hopanoid and steroid compounds has a profound impact on the hopanoid and steroid composition at higher maturity levels as well as on commonly applied thermal maturity indicators. A detailed calibration was completed, producing a correlation between a wide variety of common geochemical and optical thermal maturity indicators. Although each indicator has drawbacks, thirteen proxies are found to be effective, and a multi-disciplinary approach is recommended.	en_US
dc.identifier.citation	Synnott, D. P. (2021). The impact of organic matter deposition and pre-oil window diagenetic transformation on commonly utilized thermal maturity indicators (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/39120
dc.identifier.uri	http://hdl.handle.net/1880/113766
dc.language.iso	eng	en_US
dc.publisher.faculty	Science	en_US
dc.publisher.institution	University of Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.	en_US
dc.subject	Organic Geochemistry	en_US
dc.subject	Diagenesis	en_US
dc.subject	Organic Petrology	en_US
dc.subject	Thermal Maturity	en_US
dc.subject.classification	Geochemistry	en_US
dc.subject.classification	Geology	en_US
dc.title	The impact of organic matter deposition and pre-oil window diagenetic transformation on commonly utilized thermal maturity indicators	en_US
dc.type	doctoral thesis	en_US
thesis.degree.discipline	Geoscience	en_US
thesis.degree.grantor	University of Calgary	en_US
thesis.degree.name	Doctor of Philosophy (PhD)	en_US
ucalgary.item.requestcopy	true	en_US