A turbidimetric test for barium and its geologic application in Arkansas

Sample is fused with carbonate flux, leached with hot sodium-carbonate solution; resulting barium carbonate is dissolved in dilute HCl and precipitated as sulfate. Turbidity of solution, measured against standards, gives useful results in the range 500-10,000 ppm barium. This simple, rapid, and inexpensive geochemical-prospecting method has been used to study barite deposits in Arkansas. 'Deposits in the commonly steeply dipping Stanley Shale tend to be uniform in grade and are surrounded by thin halos of outwardly decreasing barium content, rarely more than 150 feet thick'. In this gently dipping Trinity Group, deposits and haloes are irregular in shape and barium content.