Across
- 7. Core innermost geologic layer of planet Earth. It is primarily a solid ball with a radius of about 1,220 km (760 mi), which is about 20% of Earth's radius
- 9. soil that dominates the deserts and xeric shrublands, which occupy about one third of the Earth's land surface.
- 10. Rock types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation.
- 11. a soil of an order rich in aluminum oxide and organic matter, typically characterized by low fertility, and including most podzols.
- 13. also called hard coal, the most highly metamorphosed form of coal. It contains more fixed carbon (86 percent or greater on a dry, ash-free basis) than any other form of coal
- 14. a soil type which has deep, high organic matter, nutrient-enriched surface soil (A horizon), typically between 60 and 80 cm in depth.
- 15. Cycle the pathway that chemical elements take in the surface and crust of the Earth. Encompasses the natural separation and concentration of elements and heat-assisted recombination processes.
- 16. a gray crystalline allotropic form of carbon which occurs as a mineral in some rocks and can be made from coke. It is used as a solid lubricant, in pencils, and as a moderator in nuclear reactors.
Down
- 1. Coal a type of coal containing a tar-like substance called bitumen or asphalt. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the seams
- 2. Rock one of the three main rock types. Formed through the cooling and solidification of magma or lava.
- 3. a layer inside a planetary body bounded below by a core and above by a crust
- 4. Coal a soft, brown, combustible, sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35%; is considered the lowest rank of coal due to its relatively low heat content.
- 5. the outermost layer of Earth’s lithosphere that makes up the planet’s continents and continental shelves and is formed near subduction zones at plate boundaries between continental and oceanic tectonic plates.
- 6. also called hard coal, the most highly metamorphosed form of coal. It contains more fixed carbon (86 percent or greater on a dry, ash-free basis) than any other form of coal
- 8. Cycle the pathway that chemical elements take in the surface and crust of the Earth. Encompasses the natural separation and concentration of elements and heat-assisted recombination processes.
- 12. a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Has the highest hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools.
- 13. a soil of an order comprising leached basic or slightly acid soils with a clay-enriched B horizon