Book Description

The purpose of this study was the acqui ition of data concerning factors affecting quantitative analysis of calcite and aragonite in deep-sea cores by use of X-ray diffraction. Factors to be controlled in the preparation of the powdered samples include the amount of mineral grains, their surface condition, size, shape, and orientation on the target area. Pressure and grinding effects are discussed. Experiments were made to establish a standard curve for percentage estimation of calcite in sediment samples, based on he r lation between the percentage of calcite and the calcite/fluorite intensity ratio. Two different relations were obtained between the content of calcite and the calcite/fluorite intensity ratio. Two different relations were obtained between the content of calcite and the calcite/fluorite intensity ratio; for example, for a fraction 4 - 8 microns and intensity ratio of 0.8, the percentage of calcite could be assumed to vary from 30 to 50%, dependent upon whether the coccolith or the foram curve is used. In deep-sea carbonate oozes, the coccolithophoridae/foraminifera ratio changes from area to area and from time to time.