Formation of the Caribbean and the West Indies Flashcards
What is orogeny?
The tremendous series of earth’s movement which formed rocks into mountains.
Explain In-Situ theory
During the drifting of the continental land masses the earth’s crust folded in the Americas to form the west indies. The crust now occupied by the Caribbean and sections of the Atlantic ocean folded to form islands.
Explain the first episode of orogeny
Two mountains emerged as waves out of the maya mountains and extended eastwards. One went to form what is now Jamaica and the other travelled through Cuba, Hispanola and Puerto Rico to the virgin island.
What are islands?
The summits of mountains which rise from the seafloor
What are the upliftments in the Southern Caribbean?
Colombia, Venezuela, Trinidad and Barbados
What did the downfolds form? Give examples
The downfolds formed trenches.
The Cayman Trench (Between Jamaica and Cuba)
The Puerto Rican Trench (Between Puerto Rico and the Virgin Islands)
Explain the pacific plume theory
As continental lands masses and oceanic crust change positions magma extrudes at several locations to form volcanoes.
In which period was the Earth formed?
Pre-Cambrian Period
Explain the second episode of orogenisis
It was part of a worldwide geological upheavel which created mountain chains. The outburst of volcanic activities formed the lesser antilles from Saba in the north to Greneda in the South.
What are crustal plates?
The earth’s crust is broken up into segments which size. They are often called slabs and are in constant motion.
What are plates?
Segments of the earth’s crust which vary in size
What is a plate boundary?
A line of fracture in the crust that separates two plates.
In which plate boundary does seafloor spreading occurs?
Divergent boundary
Where is the divergent boundary near to?
The Cayman Trench
Why is the distance between the crust and the mantle in the divergent boundary short?
So that the seafloor gives way to pressure from the molten rocks.
