POTASH

Abstract
Undiscovered potash resources in the Central Asia Salt Basin (CASB) of Turkmenistan, Uzbekistan, Tajikistan, and Afghanistan were assessed as part of a global mineral resource assessment led by the U.S. Geological Survey (USGS). The term “potash” refers to potassium-bearing, water-soluble salts derived from evaporite basins, where seawater dried up and precipitated various salt compounds; the word for the element “potassium” is derived from potash. Potash is produced worldwide at amounts exceeding 30 million metric tons per year, mostly for use in fertilizers. The term “potash” is used by industry to refer to potassium chloride, as well as potassium in sulfate, nitrate, and oxide forms (Neuendorf and others, 2005). For the purposes of this assessment, the term “potash” refers to potassium ores and minerals and potash ore grades. Resource and production values are usually expressed by industry in terms of K2O (potassium oxide) or muriate of potash (KCl, potassium chloride).
The CASB hosts significant discovered potash resources and originated in an inland sea during Late Jurassic time. Seawater flowed into the CASB, mostly from its extreme northwestern margin near the modern Caspian Sea, during several evaporation episodes that deposited at least five different packages of evaporites, with virtually all potash in the second and fourth packages. In this study, the CASB was subdivided into three tracts (permissive areas) for evaluation: the Amu Darya tract in the west, the Gissar tract in the center, and the Afghan-Tajik tract in the east. The Gissar and Amu Darya tracts were quantitatively assessed, whereas the Afghan‑Tajik tract was only qualitatively assessed because of the commonly extreme depth (as deep as 7 km) of the Jurassic salt, extensive deformation, and a lack of known potash deposits.
Two approaches were used to estimate amounts of undiscovered potash in the CASB. Stratabound evaporite deposits in the Amu Darya tract were evaluated using an Adaptive Geometric Estimation (AGE) approach, which estimates in-place potash volumes and tonnages. The Gissar tract was evaluated by using the AGE approach for stratabound deposits and the three-part form of assessment of Singer and Menzie (2005) for discrete halokinetic deposits. In the three-part form of assessment, numbers of undiscovered deposits were estimated and combined with grade and tonnage models to probabilistically forecast the amount of undiscovered potash. The Amu Darya tract is estimated to contain 38 billion metric tons (Bt) of undiscovered potash as K2O by using the AGE approach for stratabound deposits. The hybrid stratabound-halokinetic Gissar tract is estimated to contain between 1 and 16 Bt of undiscovered potash as K2O.
Chapter 1 of this report provides an overview of the history of the CASB and summarizes evaporite potash deposition, halokinesis, and dissolution processes that have affected the current distribution of potash-bearing salt in the CASB. Chapter 2 describes the Gissar tract, an uplifted region that contains a mix of stratabound and halokinetic potash deposits and all of the discovered and exploited potash deposits of the CASB. Chapter 3 describes the Amu Darya tract, where evaporite deposits remain flat-lying and undeformed since their original deposition. Chapter 4 describes the highly deformed and compressed Afghan‑Tajik tract and what is known of the deeply-buried Jurassic salt. Chapter 5 describes the spatial databases included with this report, which contain a collection of CASB potash information. Appendixes A and B summarize descriptive models for stratabound and halokinetic potash-bearing salt deposits, respectively. Appendix C summarizes the AGE method used to evaluate the Gissar and Amu Darya tracts. Appendixes D and E contain grade and thickness data for the Gissar and Amu Darya tracts. Appendix F provides the SYSTAT script used to estimate undiscovered K2O in a CASB tract. Appendix G provides a potash glossary, and

"As part of the U.S. Geological Survey’s Global Mineral Resource Assessment Project (GMRAP), an assessment of potash was undertaken. Two major components of this effort are a comprehensive database of over 950 potash deposits and occurrences and a tract database that identifies 84 areas that have some potential for undiscovered potash resources.
The database of potash deposits and occurrences contains more than 900 site records. This compilation of was a major part of our research effort and is based on collecting and translating well over 2,500 articles, books, and websites. The resulting potash database includes location, age, deposit geology, lithology, mineralogy, geologic setting, size and grade, and references.
Using the potash deposits and occurrences database and other geologic information compiled in the earlier stages of the potash assessment, tracts were delineated for more than 80 areas worldwide where undiscovered potash resources may occur. This study focused primarily on evaporite-hosted potash deposits; specifically stratabound potash-bearing salt and halokinetic potash-bearing salt deposits. Potash resources appear to be widely distributed, although potash does not occur in every salt-bearing basin. Fewer than half of the known salt basins have any reported potash based on this compilation of potash occurrences. Half of the potash-bearing salt basins may have any real potential for production of potash. Within the tracts delineated in this study, 40 may contain a potash deposit of sufficient size and grade to be of possible economic interest.
The databases developed for the GMRAP Potash Assessment have a continuing use beyond the assessment. In addition to demonstrating the widespread nature of potash mineralization, analysis of the compiled data could lead to a better understanding of potash deposits."

The Russian invasion of Ukraine is providing a new excuse for Amazon destruction. On 2 March (7 days after the invasion began), Brazilian President Jair Bolsonaro called on the National Congress to give urgency to approving bill PL 191/2020 to supply Brazil's agribusiness with the fertilizers the country normally imports from Russia (1). On 9 March, Bolsonaro's supporters in the Congress passed a motion granting "urgent" status to the bill, allowing it to bypass the normal committee process. The motion was approved but has not been finalized out of fear of international boycotts of Brazilian minerals. PL 191/2020 would open Indigenous lands to mining, hydroelectric dams, and logging, cattle ranching, and industrial agriculture by non-Indigenous entrepreneurs and companies (2). It was submitted to the National Congress in February 2020 by President Bolsonaro and gained priority in February 2021 when both houses of Congress were captured by the coalition of parties that supports Bolsonaro's anti-environmental agenda (3). However, it stalled until the invasion of Ukraine. Indigenous lands are essential to maintaining the environmental services of Brazil's Amazon Forest, given that these lands protect more forest than do federal "conservation units" (4). The supposed justification for approving the bill is the alleged need to extract potassium, a key component of fertilizers, from the Autazes mine in Brazil's state of Amazonas. However, Autazes is not located on officially recognized Indigenous land, making the passage of the bill irrelevant to this goal (5). Furthermore, Russia is not the world's only source of potassium: Other countries, led by Canada, are major international suppliers (6). Even within Brazil, mining Amazonia is not required to obtain potassium. The largest potassium deposits are in the state of Minas Gerais, and Brazil's deposits outside of Amazonia could supply the country with potassium until at least 2100 (7). Passing PL 191/2020 would not achieve the goals articulated by its supporters. Even if it affected the status of the planned mine in Autazes, the project would not be functional in time to solve Brazil's predicted fertilizer shortage for the coming year. Imports will have to supplement the supply. Major mining companies in Brazil are now opposing PL191/2020 (8). International actors, including the Canadian companies invested in Autazes (9), should not agree to initiate this project given the false pretenses under which the bill is being advanced. Moreover, if the bill goes into effect without changes, minerals importers should follow through with potential boycotts to make clear the irresponsible actions by Brazil have consequences.