During the past 15 yr, the global requirement for fertilizers has grown considerably, mainly due to demand by a larger and wealthier world population for more and higher-quality food. The demand and price for potash as a primary fertilizer ingredient have increased in tandem, because of the necessity to increase the quantity and quality of food production on the decreasing amount of available arable land. The primary sources of potash are evaporites, which occur mainly in marine salt basins and a few brine-bearing continental basins. World potash resources are large, but distribution is inequitable and not presently developed in countries where population and food requirements are large and increasing. There is no known substitute for potash in fertilizer, so knowledge of the world’s potash resources is critical for a sustainable future. The U.S. Geological Survey recently completed a global assessment of evaporite-hosted potash resources, which included a geographic information system–based inventory of known potash resources. This assessment included permissive areas or tracts for undiscovered resources at a scale of 1:1,000,000. Assessments of undiscovered potash resources were conducted for a number of the world’s evaporite-hosted potash basins. The data collected provide a major advance in our knowledge of global potash resources that did not exist prior to this study. The two databases include: (1) potash deposits and occurrences, and (2) potash tracts (basins that contain these deposits and occurrences and potentially undiscovered potash deposits). Data available include geology, mineralogy, grade, tonnage, depth, thickness, areal extent, and structure, as well as numerous pertinent references.

For hundreds of millions of years, nature has governed the biogeochemical cycles that have shaped the diverse geology and biology of Earth, but now, within a few kilometers of the surface, where the cycles are most complex, humans are mining and redistributing material at such a rapid rate that many elements of the periodic table are already in crucially short supply, or they are under threat to become so in the next few decades. It is not just water and fossil fuels that are affected by our consumption. Top-down and bottom-up analyses make clear that many of the accessible elemental resources of our future are now largely aboveground, stored in the familiar objects of our daily lives. In order to maintain supply lines to industry and to the dinner table, and to preserve our place in the biosphere, biogeochemical cycles must produce as much useful resource as they consume. Doing so will require cross-disciplinary scientists, designers, social communities, and visionary entrepreneurs working together to completely reframe our concepts of mining, consumption, human environments, and waste.

Abstract German potash and salt mines have pioneered underground isolation of chemotoxic wastes. Comprehensive site-specific safety assessments have validated short- and long-term performance for each facility. Adherence to strict site prerequisites and waste-acceptance criteria combined with the reliance on enclosure inside multiple barriers justify confidence in the retention capacity of the total system. Underground waste isolation has been proven to be a success in Germany. Application of the lessons learned here will help solve environmental problems worldwide.

Abstract Site-specific investigations of bedded evaporites began at the Waste Isolation Pilot Plant site in New Mexico (USA) in 1976, and the first waste was accepted in 1999. Here, we describe and discuss some lessons learned from personal experience. “Fatal flaws” may not be fatal. Features, events, or processes are sometimes useful exclusionary factors, especially during site selection. Solution chimneys discovered northwest of the site in 1975 were possible vertical pathways for radionuclide transport. Intensive field studies since then have indicated no solution chimneys at the Waste Isolation Pilot Plant site. Known chimneys are related to a geologic unit not found at the Waste Isolation Pilot Plant, and chimney fill is not very permeable. Normal fluid flow should be downward if subevaporite formations are connected to near-surface units. If a solution chimney had been found early at the pilot plant, there might have been pressure to relocate it. Timing is important. Potash resources were assessed in 1976 by drilling 21 boreholes; four were completed as shallow hydrology observation wells. Data from all boreholes would have provided a comprehensive picture of the hydrology early in the project history. Resource conflicts were considered more important at the time than hydraulic parameters. Critics will always be with you. the Waste Isolation Pilot Plant is recertified every five years, offering multiple opportunities for outside review and comment. Repeated comments about dissolution of some halite beds, for example, rely on conclusions reached before site-specific studies. Intensive studies since 1984 of shafts, cores, and geophysical logs have shown that halite is distributed mainly by depositional processes. Some critics remain well behind the curve of technical work; we still must respond.