Cross Word Puzzle

7. frequently the top layer of soil, a zone of organic material and minerals that have been mixed together
8. in resource management, the known quality of a resource that can be economically recovered
13. the breakdown of rocks and minerals by chemical reactions, the dissolving of chemical elements from rocks, or both
14. the organic horizon at the surface of many soils
15. the removal of strips of soil and rock to expose ore
16. an element with properties that allow it to conduct electricity and heat energy
19. the loss of some or all of a soil's ability to support plant growth
20. a horizontal layer in a soil defined by distinctive physical features such as texture and color
21. precipitation high in sulfuric acid and nitric acid from reactions between water vapor and sulfur and nitrogen oxides in the atmosphere
22. a mining technique that creates a large visible pit or hole in the ground
24. the most fully decomposed organic matter in the lowest section of the O horizon
25. the average concentration of an element in Earth's crust

1. the proportion of soil bases to soil acids, expressed as a percentage
2. the ability of a particular soil to absorb and release cations
3. a soil horizon composed primarily of mineral material with very little organic matter
4. unwanted waste material created during mining
5. a concentrated accumulation of minerals from which economically valuable materials can be extracted
6. the process of looking for minerals, metals, and precious stones in river sediments
9. a zone of leaching found in some acidic soils under the O horizon or sometimes the A horizon
10. mining techniques used when the desired resource is more than 100 m below the surface of the Earth
11. the underlying rock material from which the inorganic components of a soil are derived
12. the mechanical breakdown of rocks and minerals
17. the physical removal of rock fragments from a landscape or ecosystem
18. a mining technique in which the entire top of a mountain is removed with explosives
23. the least weathered soil horizon, which occurs beneath the B horizon