The Impact of an Abandoned Uranium Mining Area on the Contamination of Agricultural Land in its Surroundings

The Huangsha uranium mining area is located in the Qingzhangshan uranium-bearing complex granite of the Middle Nanling Range, Southeast China. This uranium mining area contains three uranium deposits (Liangsanzhai, Egongtang, and Shangjiao) and multiple uranium occurrences, showing favorable mineralization conditions and prospecting potential for uranium mineral resources. Chloritization is one of the most important alteration types and prospecting indicators in this mining area. This study aims to unravel the formation environment of chlorites and the relationship between chloritization and uranium mineralization, based on detailed field work and petrographic studies of the wallrock and ore samples from the Huangsha uranium mining area. An electron probe microanalyzer (EPMA) was used in this study to analyze the paragenetic association, morphology, and chemical compositions of chlorite, to classify chemical types and to calculate formation temperatures and n(Al)/n(Al + Mg + Fe) values of chlorite. The formation mechanism and the relationship with uranium mineralization of the uranium mining area are presented. Some conclusions from this study are: (1) There are five types of chlorites, including the chlorite formed by the alteration of biotite (type-I), by the metasomatism of feldspar with Fe–Mg hydrothermal fluids (type-II), chlorite vein/veinlet filling in fissures (type-III), chlorite closely associated with uranium minerals (type-IV), and chlorite transformed from clay minerals by adsorbing Mg- and Fe-components (type-V). (2) The chlorite in the Huangsha uranium mining area belongs to iron-rich chlorite and is mainly composed of chamosite, partly clinochlore, which are the products of multiple stages of hydrothermal action. The original rocks are derived from argillite, and their formation temperatures vary from 195.7 °C to 283.0 °C, with an average of 233.2 °C, suggesting they formed under a medium to low temperature conditions. (3) The chlorites were formed under reducing conditions with low oxygen fugacity and relatively high sulfur fugacity through two formation mechanisms: dissolution–precipitation and dissolution–migration–precipitation; (4) The chloritization provided the required environment for uranium mineralization, and promoted the activation, migration, and deposition of uranium.

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DAMPAK PERUBAHAN PENGGUNAAN LAHAN PERTANIAN TERHADAP SOSIAL EKONOMI PETANI SEKITAR LOKASI PERTAMBANGAN BANYU URIP KECAMATAN GAYAM KABUPATEN BOJONEGORO

Jurnal Tataloka ◽

10.14710/tataloka.20.1.50-64 ◽

2018 ◽

Vol 20 (1) ◽

pp. 50

Author(s):

Aziz Bahtiar Rifa’i ◽

Fadjar Hari Mardiansjah

Keyword(s):

Land Use ◽

Land Use Change ◽

Agricultural Land ◽

Positive Impact ◽

Arable Land ◽

Mining Area ◽

Agricultural Land Use ◽

Socioeconomic Conditions ◽

Qualitative Approaches ◽

The Impact

This study examines the impact of agricultural land use change into a petroleum mining area to farmers’ socioeconomic conditions around petroleum mining project area in Gayam District of Kabupaten Bojonegoro. The analyses used a mix method, using both quantitative and qualitative approaches. The quantitative approach is used to determine the impact of agricultural land use change on the social and economic aspects with the respondent farmers were supported with a scoring method to determine the condition of socioeconomic vulnerability of farmers, while the qualitative approach carried out through in-depth interviews to some informants who have been affected by the project. The results shows that the presence of the petroleum mining industry has not had a positive impact yet on the farmers’ socioeconomic conditions. By the 700 hectares of agricultural land conversion, the agricultural production capacity of the area tends to decrease, including by the decreasing of the productivity of some agricultural land in a radius of 500 m from the fenceof the mining area as they are affected by the fence’s spotlight. The farmers' income also tends to decrease because of the decreasing of their working hours as the big loss of agricultural land in the area. As a result, many farmers should work outside of the area to search replacement of the arable land. These situations lead to a moderate condition of social and economic vulnerability for the farmers, especially for those who still have sufficient assets to meet the needs of their economic.

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