Laboratory Assignment Essay Example | Topics and Well Written Essays - 750 words

Laboratory Assignment - Essay Example The overlying volcanic islands (arcs) chains marks in the subduction zones. The ocean floor spreading is believed by geologist to result from the mantle convention and lower crust that results into less dense, hotter, and plastic material that move towards the surface. The cold dense rock sinks towards the mantle resulting into convective forces that tear the ocean crust within the midocenic ridge. This brings in the rift valley formation that is marked by high angle faults high heat flows and basaltic lavas. The mid oceanic ridges separates regions and comprises of foot tall mountain peaks that lie a mile below the ocean surface. Boundaries within the tectonic plate could be convergent divergent, or transform. In the divergent boundaries the extension of the crust within is thinned and mainly fractured by an upwelling hot mantle material. The relationship that exist between the islands can be explained in terms of divergent, convergent and transform boundaries. In the case of divergent boundaries, pulling of the adjacent plates is evident for example, at mid- Atlantic ridge separating North and South America plates from Africa and Eurasia. The ocean floor is formed as a result of the pulling apart forces. Another relationship exist under the context of convergent boundaries. In this case two plate’s moves towards one another where one is sub ducted and are typified by the Aleutian Trench. Good examples include; Mount St. Helens and Mount Fuji (Japan).Finally, the transform boundaries which results when a plate slides horizontally past another. For example, the earthquake-prone San Andreas Fault Zone in California. The labeled boundaries in this case represents the Earths shifting plates. Approximately all of the worlds renowned active volcanoes and earthquakes takes place along these plates, however, they are predominantly frequent within the