What are the chemical characteristics of soils of the different geologic units on Vieques?
To compare and contrast the soils of Vieques, the soil samples were differentiated based on the underlying parent material (i.e., the rock formations or geologic units) on which they developed. ATSDR compared the constituent metals detected in the soil that developed on one geologic unit to the metals in the soil in the other geologic units. Comparisons were considered statistically significant (i.e., different) if there was less than 5% probability that the difference occurred by chance (i.e., p <0.05). Figure 3 illustrates the location of the generalized geologic units on Vieques used for this phase of the analysis (modified from Torres-Gonzalez 1989). • Undivided marine sedimentary rocks comprise most of the LIA, a small area near Mosquito Pier, and along the southern shore from Ensenada Sombre to Bahia Corcho. These rocks--largely soft limestone--are shown as the Tl geologic unit on Figure 3. The soil developed on the Tl geologic units have significantly higher concentrations of bo
