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Between 1976 and 1982, the Overseas Directorate of the British Geological Survey, United Kingdom and the Geological Survey of Bolivia, Santa Cruz, carried out a major reconnaissance geological mapping, geochemical sampling and mineral exploration programme of that part of the Precambrian Brazilian Shield lying within eastern Bolivia. Previous geological work had been undertaken in the area, but this was the first time that a systematic and fully integrated survey had been attempted. The Project area is approximately 220,000 square kilometres and regional geochemical samples were collected from 8185 sites producing an overall sampling density of 1 sample per 27 square kilometres. Because of logistic problems it was impossible to sample certain inaccessible areas so the actual sampling density was 1 sample per 16 square kilometres for the 130,000 square kilometres effectively sampled. The geochemical samples were analysed in the Project laboratories in Santa Cruz and in the GEOBOL geochemical laboratories in La Paz. Uranium analyses were carried out by a commercial laboratory in the UK. The results of the Project are incorporated in 21 comprehensive reports in both English and Spanish. Twelve describe the geology, geochemistry and mineral potential of the individual 1:250,000 map areas and the remainder are devoted to the geology and mineral potential of areas of special geological or economic interest. The stream sediments were determined for: Ag, Co, Cu, Fe, Mn, Ni, Pb, Zn, As, U, B, Ba, Be, Cr, La, Li, Mo, Nb, Sn, Sr, Y, and Zr. These results are presented in an atlas as 22 single element 1:1 million scale, classed proportional symbol, point source data maps in which the symbols are overprinted on a simplified geological base map in order to facilitate rapid data interpretation. A 1:4 million scale moving average map based on a 4 x 4 km cell size and a 10 km search radius, printed alongside the symbol map, identifies the major regional variations. Raw data is available from the Geological Survey of Bolivia, Santa Cruz along with copies of the reports.
Microfossil samples submitted to the BGS are currently registered using the prefix 'MPA'. Samples include rock, residues from sample preparations, and slides of mounted specimens. Rock, residues and slides from the same sample all bear the same unique identifying sample number. The numbers MPA 1 to 51000 have been used, but this grows steadily. There are currently 21 volumes of registered samples.
All type and figured calcareous microfossils and palynmorphs held in the BGS collections are registered using the prefix 'MPK'. To date MPK1 to 13400 have been used. Information includes name, locality, geological details and journal details.
Microfossil samples submitted to the BGS biostratigraphy laboratory are currently registered using the prefix 'MPA'. Samples include rock, residues from sample preparations, and slides of mounted specimens. Rock, residues and slides from the same sample all bear the same unique identifying sample number. The numbers MPA 1 to 54400 have been used, but this grows steadily. There are currently 21 volumes of registered samples. The value added dataset comprises data for each sample held in the sample register, including collectors' symbols and numbers, 1:10k (or 6") OS quarter sheet, NGR, 1:50k (or 1") geological sheet, borehole name and depth (if relevant), locality, geological formation and report numbers. The value added dataset also includes identifications of specimens on each slide, which are listed on logging sheets and are held separately.
Two geochemical surveys were undertaken in the Solomon Islands between 1976 and 1983 as part of a combined geological mapping and mineral exploration project. The survey of Choiseul and the Shortland Islands was carried out between 1976 and 1979 by the Institute of Geological Sciences (now the British Geological Survey) with support from staff of the Geology Division of the Ministry of Land, Energy and Natural Resources, Solomon Islands. The project produced 12 geological maps at 1:50,000 scale as well as a series of unpublished reports. The survey of the New Georgia Group of islands was undertaken between 1979 and 1983. The project produced 7 geological maps at a scale of 1:100,000 and a regional map of the entire island group at a scale of 1:250,000. A series of multielement geochemical anomaly maps were produced at a scale of 1:100,000 to accompany each of the published geological maps. Master copies of these are held at the Geological Survey in Honiara. Full descriptions of the methods used are described in the margins of the anomaly maps. A total of 8848 stream sediment samples were collected from Choiseul and 7441 from the New Georgia Group, resulting in an average sampling density for the two areas of 2.68 samples per km2 and 1.47 samples per km2 respectively. Sampling in the Shortland Islands was confined to the larger islands, 187 were collected from the Fauro Island group, 148 from Alu and 69 from Mono. The samples were dry sieved and the fraction passing -80 mesh B.S. (177 microns) was analysed. A hot concentrated nitric acid digestion was used prior to analysis by atomic absorbtion spectrophotometry (AAS) for Co, Cu, Pb, Zn, Ni, Ag, and Mn. Samples from the vicinity of the Siruka Ultramafic Complex were determined for Cr by AAS after digestion by a bisulphate fusion technique. Raw data can be obtained from the Geology Division, Ministry of Mines and Energy, PO Box G37, Honiara, Solomon Islands.