Assessing the interplay of tectonics, sedimentology and lithology in coastline development of Puerto Rico using a GIS

The authors used a GIS to characterize the coastline morphology of Puerto Rico at different length scales as a function of lithology, sedimentology, and tectonics in order to assess the contribution of each to coastline development. Independent variables considered include orientation and density of mapped onshore faults and geology. Puerto Rico was divided into four coastline segments: north, south, east, and west. A best-fit statistical approach was adopted to measure variations and isolate correlations for individual segments. A GIS (ArcInfo 3.0b, ArcView 7.1) was used to evaluate quantitatively and qualitatively the spatial relationships among variables. DOQ, 7.5 minute DEMs, and digitized geologic and topographic maps were provided by the USGS. Each parameter was analyzed statistically within areal grids of 5, 10, 15, and 20 km². Rose diagrams of mapped faults were compared with coastline orientations at the same scale. The observed high correlation implies significant tectonic imprint on coastline configuration