MARGIN: 0cm 0cm 0pt; mso-pagination: widow-orphan; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto; mso-outline-level: 2" class=MsoNormal>man">Study of the Formation Mechanism of the mas-microsoft-com:office:smarttags" />Vientiane Potash Deposit Based on Phase Chemistrymas-microsoft-com:office:office" />

• 责任者：Cheng Huaide (Key Laboratory of Salt Lake Resources and Chemistry ; Qinghai Institute of Salt Lakes ; Chinese Academy of Sciences ; Xi’ning 810008 ; China) ; Ma Haizhou
• 刊名：Acta Geoscientica Sinica
• 出版年：2010
• 卷期：31(2)
• 关键词：钾盐矿床 ; potash deposit ; 老挝 ; Laos
• 页码：p.194-202
• 图表：6 illus., 35 refs.
• 分类号：1002
• issnNo：ISSN1006-3021
• isbnNo：CN11-3474/P

MARGIN: 0cm 0cm 0pt; mso-pagination: widow-orphan; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto" class=MsoNormal>man’; FONT-SIZE: 14pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang=EN-US>In this paper, the characteristics of ancient sea water during the formation of the potash deposit were studied, the physical-chemical peculiarities of potassium-forming brines were analyzed by using the phase diagram, the formation mechanism of this mineral deposit was investigated based on the chemical foundation of its formation conditions.  Based on the increasing Br content of basal halite since the Early Cretaceous, the authors deduced an extensive change in the composition of seawater: the period of “calcite seas” existed during the Late Cretaceous and the Early Tertiary. The above change in composition constituted the physical-chemical condition for the absence of sulfate and carbonate in the mas-microsoft-com:office:smarttags" />Vientiane potassium-magnesium salt deposit. As a result, the potassium chloride is rarely existent or virtually nonexistent in the potash deposit.