The Use of Chemostratigraphy to Refine Ambiguous Sequence Stratigraphic Correlations in Marine Shales: An Example From the Woodford Shale, Oklahoma

Comparative geochemistry of Early Carboniferous marine red beds (MRBs) and their significance for deep time paleoceanographic reconstructions

“…Clusters have been generated using Ward Jr's (1963) method of minimum variance and Euclidean distance (the direct distance between two centroids). This along with Principal Component Analysis (PCA) are typically the most widely used statistical approach for subdividing units in chemostratigraphic studies (Kirschvink, 1980;Güler et al, 2002;Montero-Serrano et al, 2010;Alassane et al, 2015;Heij et al, 2016;Turner et al, 2015;Turner et al, 2016;Rowe et al, 2017;Driskill et al, 2018). Organizing the calibrated XRF-dataset in this manner enabled the definition of sub-lithofaciesscale associations and provided a transparent basis for the comparison to MRB datasets published in the existing literature.…”

“…Dendrogram illustrating the subdivision of the XRF-derived geochemical dataset (145 samples) into 13 chemofacies using Ward Jr's (1963) Hierarchical Clustering Analysis method (HCA). The width of a cluster on the x-axis represents the number of data points within that cluster; clusters are defined by the Phenon line which has been set at a value of 10 % of the maximum distance value(Güler et al, 2002;Turner et al, 2015). A total of 14 normalized variables have been used to form the clusters (Mg, Al, Si, P, K, Ca, Ti, V, Cr, Mn, Fe, Sr, Zr, Mo).…”

Seismic to Simulation: Woodford Shale Case Study in Oklahoma, USA

“…This formation is from Upper Devonian-Lower Mississippian age, and its principal lithology has been described as an organic-rich black shale with intercalations of chert, siltstone, sandstone, dolostone, and light-colored shale (Slatt et al, 2011;Molinares, 2013;Turner, 2015). In addition, laminations of reddish-brown clay, greenish clay and organic matter with scattered siliceous concretions are also present in the formation (Kirkland et al, 1992;Comer, 2007).…”

Mineralogical assemblage of Cambay Shale of North Cambay Basin, Gujarat, India

“…Therefore, FTIR, XRD and SEM are the most commonly and frequently used characterization technique for mineralogical assessment (Buller et al 2014, Abouelresh et al 2016, Rodriguez et al 2015, Guerra et al 2017, Akbar et al (2017, Yang et al 2018). However, for the identification of elemental composition of shales, X-ray fluorescence or energy dispersive XRF is the most commonly used technique (Guerra et al 2017;Turner et al 2015;Abouelresh et al 2016;Rodriguez et al 2015). Following the most frequent and common use of FTIR and SEM characterization technique in shale samples, the same techniques are used in the Shale samples of Cambay Shale of Cambay Basin, India to understand the mineralogy, porosity and pore structure.…”