A world map shows nitrate mining locations marked by orange circles with "N." Key areas include the U S, Mexico, Chile, and Spain. Major clusters are in the U S (western states), Mexico, and northern Chile's Atacama Desert.
Nitrate Mines | Class | Rank | Percent | High Pressure | -2.0 to 0.0 | 0.0 to 1.9 | 2.0 to 3.9 | 4.0 to 5.9 | 6.0 to 7.9 | 8.0 to 9.9 | 10.0 to 11.9 | 12.0 to 13.9 | 14.0 to 15.9 | 18.0 to 19.9 | 20.0 to 21.9 | 22.0 to 23.9 | 24.0 to 25.9 | 26.0 to 27.9 | 28.0 to 29.9 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2.3636363636363638 | 1 | 1.06% | 0.769% | 0.553% | 0.725% | 0.603% | 0.825% | 0.239% | 0.135% | 0.206% | 0.342% | 0.126% | 0.317% | 1.60% | 0.778% | 4.46% | ||||
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