plastic-like part of the mantle on which the tectonic plates float

densest, hottest, solid, innermost layer

the crust and the upper mantle that is split into tectonic plates floating on the asthenosphere

thickest layer made of solid and melted rock

coolest, least dense, thinnest, outermost layer

completely liquid metal layer

two kinds of crust

solid layer due to the pressure it is under

Supporting evidence: fossils, continent shape, landforms

supporting evidence: discovery of Mid-Atlantic Ridge, rock samples show rocks are older the farther away they are from the ridge

Supporting evidence: Subduction, earthquakes, volcanoes, mid ocean ridges, previous theories

large pieces of lithosphere that move around on the Earth's surface

Theory states that all continents were once joined together in a large land mass that drifted apart

The name of the giant continent that Alfred Wegner proposed once existed

The process by which new oceanic lithosphere forms at mid ocean ridges

The theory that states that the Earth is broken up into plates that float and move around

most dense type of crust found under oceans

least dense type of crust found on Earth's continents

driving force behind tectonic plate movement caused by uneven heating of magma that sinks and rises in the mantle

method used to divide the Earth's long natural history into manageable parts

any method of determining whether an event or object is OLDER OR YOUNGER than other events or objects

a fossil found in the rock layers of only one geological age that is used to establish the age of the rock layers

any method of measuring the age of an event or object IN YEARS

layers of sedimentary rock; rock layers

the concept where the oldest layers are on the bottom and the youngest layers are on the top

the trace remains of an organism that lived long ago and is often preserved in sedimentary rock