2. Large, ancient landmass that was composed of all the continents joined together

3. Theory that the Earth’s crust and upper mantle are broken into plates that float and move around on a plastic- like layer of the mantle

5. Wegener’s hypothesis that all continents were once connected in a single, large land mass that broke apart about 200 million years ago and drifted slowly to their current positions

7. Hess’s theory that new seafloor is formed when magma is forced upwards toward the surface at the mid-oceanic ridge

9. Currents in Earth’s mantle that transfers heat in Earth’s interior and is the driving force for plate tectonics

11. Motion of the Earth’s surface as it shifts downward relative to a datum such as sea=level

13. Indicates a border

14. PLATE BOUNDARIES

15. Formed when two sections of Earth’s crust is colliding – coming together

17. Forms where lithospheric plates are moving away from each other.

19. Boundary between two lithospheric plates where the plates are sliding past each other.

21. Long crack that forms between tectonic plates moving apart at plate boundaries

23. Fracture that occurs when rocks change their shape by breaking can form as a result of compression, being pulled apart by shear

25. Area in which one lithospheric plate slides under another, occurs at converging plate boundaries

27. A chain of mountains or hills that form as continuous elevated crest for some distance

29. Depression in the ground, generally defined by being deeper than they are wide.

31. Plastic-like layer of the Earth on which the lithospheric plates float and move around

33. Rigid layer of Earth about 100 km thick, plates moving apart at plate boundaries

35. A physical map showing vertical features with a drawing such as shaded mountains

37. Features of a land area caused by differences in elevation.

39. A map that shows the shape and elevation of the land surface using contour lines, and shows other land features using symbols and colors

41. On a map, lines that connect point of equal elevation above sea level.

43. Height above average sea level

45. Distance between contour lines on a topographic map

47. A permanently affixed mark that establishes the exact elevation of a place; used by surveyors in measuring site elevations