A Geochemical Study of the North Coast Karst Belt Zone of Puerto Rico

Our study emphasizes the geochemical properties of the karst. Puerto Rico have three karst zones, we are interested in the north coast belt karst zone. This zone is very important because of its vast aquifers and problems with contamination because is heavily populated. This study will present three method using general chemistry techniques, which can be used to obtain the chemical components of the karst.  In the composition, we are looking to obtain the percentage of calcium carbonate in our samples. The karst rock sample was pulverized and weighted. After that, an acid bath of HCl was used to react with the CaCO₃ in the karst sample. Same samples were washed with NaOH after the HCL bath. After the reactions, the sample was washed and evaporated to eliminate any excess of water or acid. After the process, using a mass analysis of the initial karst sample mass and the precipitated salts mass, we can be obtain a percentage of calcium carbonate. This analysis was compared to standard calcium carbonate samples. The two other methods use similar techniques and are related to acidic reactions and how they affect the karst. Acidic solutions such as carbonic and sulfuric acid with different concentrations were used. The study of the reactions can explain the varied topography in the north coast. For this study, we want to quantify that effect. Understanding the composition and reactions effects, we can have an idea of the geochemical properties of karst.