A comparative study of the trace element distribution in limestones, dolostones, and breccias in the upper Knox Group of the Copper Ridge Zinc District, East Tennessee

The trace element contents of the limestones, dolostones, and breccias were investigated in the Lower Ordovician Upper Knox Group of the Copper Ridge District, East Tennessee. Part of the Upper Knox consists of the Kingsport and Mascot Formations, which consist of four recognizable lithofacies: limestone, fine-grained dolostone, medium-grained dolostone, and coarse-grained dolostone.

Textural and trace element data suggest that the neomorphism of the limestones occurred in the presence of meteoric water. Trace element distributions suggest that the dolostones formed in a solution more saline than normal marine water and at a correspondingly higher salinity for the coarser grain sizes (medium- and coarse-grained dolostones).

A comparison of trace element contents for the Coarser-grained dolostones from a mineralized and an unmineralized section does not reveal a recognizable difference between them and thus suggests that the formation of the coarser-grained dolostones was not a result of limestones dolomitized by mineralizing fluids. Field evidence also does not suggest such a correlation between coarser-grained dolostones and mineralization.

The dolomite matrices of the various breccia types (coarse-rock matrix, ore matrix, and barren matrix) are not well differentiated as to breccia type by the trace elements analyzed under the present study.