Sunday, 5 October 2008
George R. Brown Convention Center, Exhibit Hall E
The twin island Republic of Trinidad and Tobago lies in the southeast corner of the Caribbean Sea off the coast of Venezuela. Trinidad, the larger island is on the northern edge of the South American plate, but close to the southern boundary of the Caribbean plate. Tobago is located on the Caribbean plate. Trinidad is characterized by four unique coastlines demonstrating distinctive sedimentation. Tobago has two main coastlines. Sand samples were collected from the perimeter of the twin islands. These samples were then analyzed for mineral composition, including heavy mineral assemblages that were used to determine provenance. Traditional heavy mineral separation showed the presence of hornblende, zircon, epidote, pyrite, tourmaline, glauconite, magnetite and garnet. Such composition might indicate the provenance is in close proximity to a mixed igneous, metamorphic, and reworked sedimentary source. Studies of recent geological map data have shown that surficial terrain is of sedimentary origin. Based on this, one might discern that the provenance of these coastal deposits is from the South American continent via the Orinoco River. Determination of the transportation mechanisms through the study of regional oceanic currents has shown that the Guiana Current is the principle method by which Orinoco sediments are deposited to form the coastline of Trinidad and Tobago. Further studies on these patterns of sedimentation will determine the rate of deposition and percentages of the minerals that make up the sediments. Also how they affect the coastal and marine life that has been vital to these maritime islands.