Coal chemistry variations and extrinsic variables, Kaiparowits Plateau, Utah

Major and trace element analyses of coal and closely related interburden from core samples were examined using multivariate analysis techniques. Seventy-five samples from two drill cores, that have undergone extensive petrographic, sedimentological, and mineralogical analyses, and a selection of companion samples were used to determine principal components from the analysis of more than 65 major and trace elements and ash content. Cluster analysis of the principal component scores was used to relate the chemically-derived components to the extrinsic analyses. The major elements were treated separately from the trace elements because of a general lack of correlation between the two. Five major element components out of 12 analyzed species explain more than 86% of the variance of the major element dataset. The major element components appear to be largely related to the non-coal mineralogy, predominantly carbonate, silicate, and oxide components of the coal and interburden. All of the cluster distinguished by high SiO{sub 2} and high ash content were interburden samples. Six principal components from the trace element dataset explain approximately 71% of the variance of this dataset. The ash content, which was included with both the trace and major element examinations, did not correlate highly with any of the tracemore » elements. The trace elements show a secondary correlation with the mineral content of the coal but appear to be primarily related to plant diversity, marine influence, and the physical conditions of deposition. One cluster with moderate Sr values does contain samples from which carbonate minerals were separately identified. All of the samples that are distinguished by ash content in the trace element analysis are interburden samples.« less