Mineralogy of sea-bottom sediments from the Strait of Magellan

A mineralogical investigation (\"powder\" X-ray diffractometry) was carried out on the < 62 μm fraction of sea-bottom sediments from the Strait of Magellan (Southern Chile). Our data have been integrated with the results of the analyses previously carried out by Setti and Veniale (1991) on the samples from other areas of the Strait of Magellan, in order to achieve a complete description of the mineralogical characteristics of the sea-bottom sediments. The recognized minerals are quartz, feldspars, amphiboles, calcite, aragonite, mica, chlorite and the clay minerals smectite and mixed-layers. The variations in composition are related to the different physiographic characteristics of the basin, the lithology of the outcropping rocks and the climate and vegetation. The distribution of the mineral phases allowed for a better understanding of the sources of the sediments and the means terrigenous supplies occurring in the Strait of Magellan.