EESA06H3 Lecture 7: EESA06 Lecture 7.pdf
Document Summary
Hotspot trails old dead volcanoes, flat tops (from erosion), below seas level, dead volcano. Relative ages of islands: the youngest island above the hotspot, eventually go under sea level, systematic aging of the rocks as you go down the trail. Islands after 3 million years become completely submerged. Phreatomagmatic water + volcanic activity, violent releases. Geologists like this area because there is no vegetation = young landscape, still actively evolving. Pyroclastic layers of ash that falls on the land that blows out underwater, think of a. Snow avalanche" that happens under water - laminated sediments. Scoria large pieces of burnt rock found around cinder cones. Trace fossil track of organism, like footprints, turtle tracks to lay eggs. Lithification to turn a sediment into rock. Compaction to squeeze water and air out of something. Rock is a naturally formed consolidated material, composed of grains of one or more minerals.
