Geosphere Unit Vocabulary 21 Words and Definitions

1. caldera – a large depression typically caused by collapse or ejection of the summit areas of a volcano 2. chemical weathering – the processes by which the internal structure of a mineral is altered by the removal and/or addition of elements 3. continental drift – a hypothesis that originally proposed that the continents had once been joined to form a single supercontinent

4. convergent boundary - plate boundary where two tectonic plates collide into one another; destroy Earth’s crust 5. deposition – the process by which an agent of erosion loses energy and drops the sediment it is carrying 6. divergent boundary – plate boundary where two tectonic plates move away from one another; create Earth’s crust

7. epicenter – the location on Earth’s surface directly above the focus, or origin, of an earthquake 8. erosion – the incorporation and transportation of material by a mobile agent, such as water, wind, or ice 9. fault – a fracture in Earth along which movement occurs

10. focus – the point within Earth where an earthquake originates 11 10. focus – the point within Earth where an earthquake originates 11. igneous rock – a type of rock that forms when magma or lava solidifies as it cools 12. magnitude – measure of the amount of energy released at the focus of an earthquake

13. mass movement – the downslope movement of rock, regolith and soil under the direct influence of gravity 14. mechanical weathering – the physical disintegration of rock, resulting in smaller fragments 15. metamorphic rock – a type of rock that forms when extreme heat and pressure change one kind of rock into another kind

16. plate boundary - the location where plates meet; three types: Divergent, Convergent, Transform 17. plate tectonics – the theory that proposes that Earth’s outer shell consists of individual plates that interact in various ways and thereby produce earthquakes, volcanoes, mountains, and the crust itself 18. rock cycle – a model that illustrates the origin of the three basic rock types and the interrelatedness of Earth materials and processes

19. sedimentary rock – a type of rock that forms when sediments are compacted and cemented together over time 20. transform boundary – plate boundary where two tectonic plates slide horizontally past each other; conserve Earth’s crust 21. viscosity – a measure of a fluid’s resistance to flow