Nicolas Randazzo

My research aims to develop a detailed facies model to predict the heterogeneity and origin of thin-bedded sandstones and mudstones which formed in shallow marine prodelta, medial and distal shelf, and offshore environments and quantitatively analyze the processes which formed them.  These models may then be utilized to assist petroleum companies with both exploration and acquisition of non-conventional petroleum resources. The project seeks to examine the Mancos Shale in the San Juan Basin, New Mexico, USA, which is not only of interest to companies such as British Petroleum, but also has an analog for Canadian exploration targets such as the Oil Sands in Alberta, Canada.  Chemostratigraphic analysis of core samples from the area will be performed using a state-of-the-art I-Trax XRF core scanner at McMaster University, which can examine the abundance of major, trace and rare earth elements in sedimentary layers at the millimeter scale. There are a number of potential avenues that this project aims to explore, mainly whether elemental geochemistry can be used to determine the provenance of the various sedimentary beds, correlate extensive volcanic ash layers which are used as a datum for sedimentological correlation of the area (e.g., Asquith, 1970; Bhattacharya, 2011), and examine whether laminae and bed scale event beds show a unique and diagnostic geochemical signature. Previous work in the Tununk Shale, a part of the Mancos Shale, showed that marine shales from highstand environments had a higher MgO/Al2O3 and Na2O/Al2O3 values, compared to shales from forced regressive floodplain shales and signifies a higher proportion of volcanically-derived clays in the marine sections (Wright et al., 2010).  It is already known that the Mancos Shale contains carbonate-bearing shales, bentonitic shales, as well as prodelta shales derived from fluvial systems and this study will aim to continue the work of Wright et al. (2010) by distinguishing volcanic, marine and fluvial clays. This will also be supplemented through a stable isotope analysis of the organic carbon within the sedimentary cores (provided by New Mexico Tech and USGS) as well as innovative sedimentological examination of the cores and their corresponding outcrops through a study of mudstone sections at the millimeter scale, which has not been done before in previous studies. Dr. Fred Longstaffe from the University of Western Canada will consult by sharing his knowledge and experience with clay minerals.  All of this will enable us to characterize the processes which formed each distinctive bed which will help us to understand sediment delivery and transport mechanisms for the purpose of predicting prospective zones containing hydrocarbons of economic interest. Additionally, all of the sedimentary layers examined in this research were deposited during the Cretaceous Period where the atmospheric carbon dioxide levels were among the highest in earth’s history and therefore have applications in understanding the current changes in earth’s climate.