A Synopsis of the Geology, Geotectonic, and Geological History of Costa Rica

Costa Rica is a small territory but with a complex geological structure. The continental territory (51,179.92 km2) is predominantly made up of volcanic rocks, followed by low-grade metamorphic rocks and intrusive rocks. The oldest rocks date back about 200 million years (Ma). The maritime territory (589,683 km2) is much larger and is made up of volcanic and sedimentary rocks between 30 and 0 Ma old. However, there are minerals formed at other latitudes, transported by ancient rivers and/or by wind as old as 1000 Ma. Rocks older than 75 Ma were formed at other latitudes and below sea level. It is from 75 Ma that the volcanism of an island arc commenced, with multiple stages of formation and destruction, to finally begin to shape the current territory from about 40 Ma, and especially in the last 10 Ma. Costa Rica has volcanic, fluvial, coastal, tectonic, karstic, and mass removal landscapes with many transport and deposition processes, as well as resulting landform diversity. The glacial landscape is more restricted, but of great interest as it is in the tropics. Volcanism and active tectonics, in addition to a wide variability in rainfall (with extremes of up to 11,200 mm/year), and a high contrast of altitudinal relief over short distances and variable roughness, coupled with being surrounded by the Pacific OceanPacific Ocean and the Caribbean Sea, gives it a very particular local climates and a wide variety of landscapes.