Across
- 4. loose, fragmented material covering bedrock.
- 5. the layering of sedimentary rocks.
- 6. a rigid section of Earth's lithosphere that moves over the asthenosphere.
- 8. a solid mixture of minerals and other materials.
- 10. a soft, partially molten layer of the mantle beneath the lithosphere.
- 11. made from fragments of other rocks or minerals.
- 19. the study of past geographic and environmental conditions of Earth.
- 25. the liquid layer of Earth’s core that surrounds the inner core.
- 26. the movement of material caused by differences in temperature and density.
- 28. rock formed when magma cools slowly below the surface.
- 29. the boundary between two layers of sedimentary rock.
- 32. the rigid outer layer of Earth. Consists of the crust and upper mantle.
- 36. Earth’s innermost layer, composed mostly of iron and nickel.
- 41. the study of ancient magnetic fields recorded in rocks.
- 43. the outermost solid layer of Earth.
- 46. the horizontal sliding of tectonic plates past each other.
- 47. the idea that geologic processes have occurred at consistent rates over time.
- 48. the thin, dense crust beneath oceans.
- 49. molten rock beneath Earth’s surface.
- 53. molten rock that erupts onto Earth’s surface.
- 54. rock formed from compressed sediments.
- 57. the thick, less dense crust forming continents.
- 58. the theory that Earth’s surface is divided into moving plates.
- 59. the theory that continents move across Earth’s surface.
Down
- 1. solid rock beneath soil or loose surface materials.
- 2. rock formed when dissolved minerals precipitate from water.
- 3. a naturally occurring inorganic solid with a definite chemical composition and crystal structure.
- 5. layers of sediment or sedimentary rock.
- 7. exposed bedrock or ancient deposits visible at the surface.
- 9. a pattern of cracks that forms long, hexagonal columns in cooling lava.
- 12. the movement of tectonic plates away from each other.
- 13. a curved chain of volcanic islands formed at a subduction zone.
- 14. the alignment of minerals in metamorphic rock due to pressure.
- 15. formed from volcanic fragments ejected during eruptions.
- 16. a surface that represents a gap in the geologic record.
- 17. a switch in Earth’s magnetic field direction.
- 18. a large, stable area of exposed Precambrian rock.
- 20. rock a coarse-grained intrusive igneous rock formed deep underground.
- 21. a fixed area of volcanic activity in the mantle, not related to plate boundaries.
- 22. the meeting and compression of continental plates, forming mountains.
- 23. a small crustal fragment added to a continent through plate motion.
- 24. the idea that Earth's features were shaped by sudden, short-lived events.
- 27. rock formed from the remains of living organisms.
- 30. the movement of tectonic plates toward each other.
- 31. the boundary between Earth’s crust and mantle. Also known as Moho.
- 33. the solid, dense center of Earth.
- 34. rock formed from cooled magma or lava.
- 35. rock formed when lava cools quickly on Earth’s surface.
- 37. inclined layers within horizontal beds of rock.
- 38. a natural crack or fracture in rock with no movement along it.
- 39. rock changed by heat, pressure, or chemical processes.
- 40. the process of one plate sinking beneath another.
- 42. the addition of material to a tectonic plate, often at a plate boundary.
- 44. the process of new ocean crust forming at mid-ocean ridges and moving outward.
- 45. a supercontinent that existed about 300 million years ago.
- 50. a solid material that flows slowly under pressure.
- 51. an instrument that records vibrations from earthquakes.
- 52. the continuous transformation of rocks from one type to another.
- 55. the thick layer between Earth’s crust and core.
- 56. a mineral made of silicon and oxygen, often combined with other elements.