http://www.pr.nrcs.usda.gov/technical/soil_survey/vistsoil.htm

Soil

The Virgin Island’s soil is a complex tropical volcanic soil. The National Department of Agriculture classified it as victory soil. Victory soil forms on side slopes in volcanic areas in tropical climates and is considered an inceptisol. The O horizon is relatively shallow. The yellow and brown loamy A horizon extends about eleven inches underground before it hits the B Horizon extending nine inches further before it hits the weathered rock of the C horizon, which extends thirty inches to igneous parent rock. 
 
Victory soil of the Virgin Islands has the typical chemical properties for tropical islands. The soil has an acidic PH and a superactive CEC (Cation Exchange Capacity) meaning that plants can easily soak up nutrients due to a high amount of soil colloids that promote CEC.

The pedogenic process that seems to be occurring is Laterization. Since the soil content has a high percentage of sand and rock, the soil is very permeable allowing water to drain rapidly. This heavy drainage leads to eluviation and leaching that washes away nutrients. Plants suck up leftover nutrients that are not washed away. This leaching is what gives the soil its acidic PH, because the drainage washes away base cations (Pidwirny).

Santiago, Carmen. "VICTORY: the Representative Soil of the U.S. Virgin Islands." Natural Research Conservation Service. USDA, 12/16/2011. Web. 11 Oct 2012. <http://www.pr.nrcs.usda.gov/technical/soil_survey/vistsoil.htm>.

Pidwirny, Michael. "Soil." The Encyclopedia of Earth. Environmental Information Coalition, 07/5/2011. Web. 11 Oct 2012. <http://www.eoearth.org/article/Soil>.