Geology of the Caribbean Islands free essay sample

Geology of the Caribbean Islands Have you ever wondered how the famous tropical land masses located in Central America, known as the Caribbean Islands, came to existence? Well geologists have dated some of the rocks in the islands such as, Cuba and Trinidad, as far back as the Jurassic time period. This means the rocks formed about 145-200 million years ago, therefore the eldest islands from the Caribbean date way back to the time of dinosaurs. European countries such as Spain, France and England founded the islands approximately 500 years ago, and basically stole the lands from the original inhabitants. The islands were exploited for valuable resources such as lumber, precious minerals, and commodities like crude oil and copper. By definition geology is the study of the earth’s physical structure, substance, and it history, but we will be focusing on the geological features of solely the Caribbean. There exist about 100 permanently inhabited islands in the Caribbean with the most famous and main ones being St. Martin, Cayman Islands, Jamaica, Puerto Rico, the U. S Virgin Islands, Antigua and Barbuda, Bermuda, Barbados, and the Bahamas. The population of these islands is estimated to be around 45 million people. There are also 50 or so islets, which are purely composed of rock and cooled down volcanic eruption fragments. These islands however are not inhabited due to poor soil quality and most of them being too small to capacitate houses and buildings. According to Javier Viruete, â€Å"island arcs develop because of subduction of oceanic lithosphere beneath another oceanic plate†¦aqueous fluids and/or hydrous melts released from the subducting slab and their reaction with the overlying mantel wedge provide the prime control on arc magma genesis. † Basically this explains the formation of the islands as being caused by tectonic plates colliding against each other and releasing molten rock masses from the earth’s mantle up to the crust or lithosphere. This is known, as magma genesis in geology, and it’s the main reason of most island formations. Viruete also talks about how the islands are split up into three different regions geologically which date back to not only the Jurassic, but Early Cretaceous and Paleogene eras as well. The volcanically active Lesser Antilles islands are from the Cretaceous era, while the other islands do not possess active volcanic activity. Shockingly, many of the islands such as Cuba, Jamaica and Hispaniola (Dominican Republic, Honduras, Puerto Rico) were actually completely submerged under water during the Tertiary and Pleistocene periods. These islands went through phases of submergence and emergence throughout time, but have managed to stay above sea level till current day fortunately. Hispaniola contains various rocks such as sediments of gabbro, mudstone and massive layers of basaltic pillow lavas. Pillow lava is lava that has solidified after erupting under water and has round shaped characteristics. However, the most abundant rock on the islands is limestone, which is a sedimentary rock composed of the minerals calcite and aragonite. Limestone isn’t the best rock to grow produce and vegetation on, so inhabitants of the islands have very limited space to farm. The most common form of produce is the coral reef, which is found almost everywhere around the Caribbean Islands. Being located in extremely close proximity to the equator, if not on the equator, the Caribbean Islands are in a tropical climate zone. Warm maritime waters, with moist winds bring around 30 to 200 inches of rainfall annually with mountainous areas having the most precipitation. Dry periods with little to no rainfall at all are typically from the months of January to April. However, we lack accurate climatic rainfall data for the islands due to the inability to track rainfall at very high altitudes, such as the mountains of the Dominican Republic. The temperatures rarely reach 50 degrees Fahrenheit, being the lowest, and usually stay around 75-90 degrees Fahrenheit. Volcanic activity as mentioned earlier, exists in the Lesser Antilles islands, which are much smaller islands than the main ones also mentioned before. The Virgin Islands, Windward, and Leeward pretty much compose the Lesser Antilles, and these islands show most volcanic activity. There are about 30 active volcanoes in the Caribbean, most of them being shield volcanoes or lava domes. Guadeloupe, Martinique, and St. Vincent had the most recent eruptions, during the 20th century. Mont Pelee in Maritinique’s St. Pierre Harbor erupted in 1902 and brought devastating damage to the islands inhabitants and infrastructure. Another very important topic associated with the Caribbean, is the infamous â€Å"Caribbean Ring of Fire. † Geologists have mentioned the Caribbean being one of the most geologically active spots on the earth, which delightfully interest many world-renowned scientists and provides plenty of opportunity to conduct ongoing research. Many earthquakes, volcanic eruptions and natural disasters such as hurricanes, occur around this â€Å"ring. † It is called a â€Å"ring of fire,† because the islands composing the Caribbean, form a ring like shape when looked at on a map. The recent Haitian earthquake, which completely devastated the country, serves as a prime example why geologists chose to give such a name to the region. The reason behind such disastrous activity in the islands is that they are located right at the border of the Cocos, Nazca, South American, and North American tectonic plates. With three major tectonic plates meeting in one region, there is bound to be seismic activity as the plates undergo transformation from crashing into each other. The ring of fire, however does not only exist in the Caribbean, but expands across the border of the entire Pacific plate and touches counties such as the United States, Canada, Japan and the Philippines. Although the ring of fire seems very dangerous and intimidating, the Caribbean Islands are still one of the top tourist vacation spots, attracting over 20 million tourists every year from all across the globe. Geologists are still conducting research on many aspects of the Islands, especially the volcanic activity, as it is one of the few places in the world with active volcanoes. The population of the islands is expected to rise to about 60 million people by the year 2025. Conservation efforts have also arisen to protect the very few rain forests in countries like Barbados and Cuba, but seem to be weak due to very minimal support and funding by local governments. References 1. Adams, D. Caribbean Islands Regional Overview. Smithsonian Institution’s Department of Botany. Retrieved December 9, 2012, from http://botany. si. edu/projects/cpd/ma/ma-carib. htm 2. Ali, A. (2011, February 2). Record-breaking tourist arrivals.