Sediment mineralogy in the Bay of Havana (Cuba): its relation to natural and anthropogenic processes

Abstract

The mineralogical analysis by means of X-ray diffraction of the surficial sediments from the Bay of Havana (Cuba) allows us to identify and quantify the presence of quartz, feldspars, calcite, magnesium calcite, aragonite and dolomite. The distribution of these minerals permits us to distinguish the occurrence of five sedimentary environments (coastal marine, transitional bay-marine, bay, prodelta and Luyano Drain environments) and relate them to the general trends of sedimentary dynamics in the bay. The mineralogy of the coastal marine sediments is dominated by the composition of the local calcareous substratum, i.e., by magnesium calcite and dolomite. These minerals are associated with aragonite in the transitional environment existing between the marine and the bay environments. The sediments in the bay show high contents of aragonite and calcite, while quartz and feldspars are in important quantities in the sediments from the prodelta environments. These mineralogical features are consistent with the natural processes occurring in the Bay of Havana, while the composition of the sediments from the Luyano Drain environment seem affected by the anthropogenic supply of this drain, showing very high contents of calcitic biogenic products.