| Pennsylvanian black shale samples from two cores (Oklahoma, C-TW-1 and Iowa, IRC) were analyzed for their organic and trace metal content. The objective was to determine organic matter preservation and trace metal concentration. Organic matter in shales had a first-order effect on trace metal concentration. Organic geochemical proxies' results indicated a terrestrial origin for samples from Iowa, and a marine origin for Oklahoma samples. C-TW-1 core shale samples consisted of almost 50% saturate hydrocarbon fraction in the bitumen and IRC core shale samples were greatly rich in resins and asphaltene fraction. Trace metal in extracted obtained after removal of the bitumen fraction showed lower metal concentration compared to bulk samples, indicating the presence of metals the organic fraction. This study suggests that differences in the shale samples resulted from different origin and redox conditions during preservation. |
