Science Crossword

3. A dark fine grained volcanic rock
5. The name of the single landmass that began to break apart 200 million years ago and gave rise to today’s continent.
6. The hypothesis that the continents slowly move across Earth’s surface.
7. An undersea mountain chain where new ocean floor is produced; a divergent plate boundary.
10. The preserved remains or traces of an organism that lived in the past.
11. A system for the detection for objects underwater and for measuring the waters depth by emmiting sound pulses and detecting or measuring their return of being reflected.
12. the processes that build up the Earth's surface to deposit sediments and create new land forms.
14. Earth’s innermost part
15. Composed of a great variety of igneous, metamorphic, and sedimentary rocks.
18. two tectonic plates that are moving away from each other
19. A deep valley that forms where two plates move apart.
20. the movement caused within a fluid

1. Rift valleys that have been stretched or
2. The theory that pieces of Earth’s lithosphere are in constant motion, driven by convection currents in the mantle.
4. The process by which molten material adds new oceanic crust
8. A plate boundary where two plates move toward eachother.
9. A plate boundary where two plates move past eachother in opposite directions.
13. A very hard granular crystalline igneous rock.
16. all the waters on the earth's surface, such as lakes and seas, and sometimes including water over the earth's surface, such as clouds.
17. a deep valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle.