Multi-data integration of exploration criteria and selection of prospecting targets: An example in Shengyuan Uranium producing basin
Liu Dechang, Zou Jingke, Sun Maorong, Wang Guojuan
Beijing Research Institute of Uranium Geology
Abstract
Based on the analysis of the exploration criteria for ShengYuan Basin a uranium ore field, the multi-data integration and information extraction of exploration criteria are carried out on computer and image processing system so that the areas with best combinations of exploration criteria are directly displayed on the screen. Six prospecting targets are selected through the field examination.
Shengyuan basin in Jiangxi province is a uranium-producing, Jurassic-Cretaceous volcanic sedimentary basin with an area of about 400 sq. km . Its basement consists of Sinian-Cambrian rocks with Caledonian granites intruded. Several uranium deposits, occurrences and anomalies have been discovered over the basin region which, therefore, becomes a very important uranium ore field China.
Geologic analysis of exploraiton criteria for Uranium deposit
Through the comprehensive research of remote sensing, geologic, geophysical and geochemical data in Shengyuan basin, eight basic criteria were proposed: 1. favourability of lithology, 2. crustal fracture intensity. 3. metallogenic fault, 4. airborne radiometric anomaly of uranium, 5. Th/U radio, 6. hydrogeochemical anomaly of uranium, 7. absolute elevation of relief, and 8. topographic low. Furthermore, these eight criteria were converted into three combined criteria: 1. enrichment conditions, 2. enrichment indicators ,and 3. ore preservation conditions (Table 1)
When the uranium source exists, it is very important to consider the presence of enrichment conditions which are referred to the concentration environments or places of ore-forming solution. However, the places with enrichment conditions will not always show the uranium concentration therefore, enrichment indicators must be the ore preservation conditions which prevent uranium deposits from being eroded. So, the most prospective areas for exploration should be those with both favorable metallogenic conditions and good ore preservation conditions.
The above-mentioned enrichment conditions, enrichment indicators and ore preservation conditions belong to geologic, geophysical and morphological criteria, respectively. Their combinations reflect the multi-data integration of exploration criteria.
Table 1 Classfication of Exploration Criteria for Shengyuan Basin
| Classification of Criteria |
Criteria |
| Enrichment Conditions |
Favorability of Lithology : J3d, J3e, Z, G, J2s, K1, r, K2
Crustal fracture intensity : Total number of faults per unit area Metallogenic
fault : SN, EW, NE-trending faults |
| Enrichment Indicators |
Airborne radiometric anomalies of uranium, Th/U ratio <3,
Hydrogeochemical anomalies of uranium |
| Ore preservation conditions |
Absolute elevation of relief : 0-100m, 100-200m, 200-300 m Topographic low
|
