Eastern Bolivia Regional Drainage Geochemical Survey CD-ROM Version 2.0: September 2007

BGS research – International geochemistry CD-ROM series

Taken from Preface to the Geochemical Atlas of Eastern Bolivia.

Between 1976 and 1982, the Overseas Directorate of BGS, 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 km2 and regional geochemical samples were collected from 8185 sites producing an overall sampling density of one sample per 27 km2 . Because of logistic problems it was impossible to sample certain inaccessible areas so the actual sampling density was one sample per 16 km2 for the 130 000 km2 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. 12 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 geology and mineral potential of the whole of the project area are summarised in:

Litherland M et al. 1986. The geology and mineral resources of the Bolivian Precambrian. British Geological Survey Overseas Memoir No. 9, BGS Keyworth, Nottingham, UK

The results of the regional geochemical survey are presented in:

Appleton J D and Llanos A. 1985. Geochemical Atlas of Eastern Bolivia. British Geological Survey, Keyworth, Nottingham, UK.

These results are presented 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. This combination of maps permits the identification of regional related to major variations of bedrock composition as well as single or clusters of anomalously high values that may be indicative of mineralisation.

Fields in database:

  1. Samptype: Sample type:-   F = Stream Sediment,  S = Soil
  2. Sampno: Unique sample identifier
  3. UTMZone: Universal Transverse Mercator Projection Zone number
  4. Easting: x co-ordinates as read from 1:100,000 field maps (1 grid unit = 1 metre but read to nearest 100 m)
  5. Northing: y co-ordinates as read from 1:100 000 field maps (1 grid unit = 1 metre but read to nearest 100 m)
  6. Rockcode: Catchment area rock type code:

Codes for Rockcode in the Projecto Precambrico dataset

Period or Era Stratigraphic Unit Code
CretaceousEl Porton GroupCRE
Jurassic – CretaceousCarbonatite complexCAR
Jurassic – CretaceousAlkaline igneous complexesSYN, GTS
Silurian – DevonianSan José and Santiago GroupsDEV
Upper Proterozoic ? CambrianBoqui, Tucavaca and Murceilago GroupsBOQ, COA, COC
Upper Proterozoic ? CambrianHuanchaka Dolerite SuiteBAS
Middle ProterozoicSunsas Granites and granodioritesGTO
Middle Proterozoic: Rincón del TigréMafic RocksBAS
Igneous ComplexUltramafic RocksUMA
Middle ProterozoicSunsas and Vibosi GroupsSUN, TAB
San Ignacio Alkaline complex (nordmarkite)SYN
MiddleSan Ignacio Post-kinematic GranitePG, PGA, PGD, PGP, PGT, PGR
ProterozoicSan Ignacio Syn-kinematic GraniteGTA, PGA, PGC, PGJ, PGL, PGO, PGV
San Ignacio Granophyre ComplexesPGC, PGG, PGV
Middle ProterozoicBasic and ultramafic igneous rocks in the San Ignacio SupergroupBAS, PEB
Middle ProterozoicSan Ignacio SupergroupESQ, NAR, PAJ, PCA, PDE, PLB, PNC, PNH, PPE, PSS
Lower ProterozoicChiquitania Complex and Lomas Maneches ComplexCGC, GNS, PBE, PEN, PHG, PMG, PRP
  1. Cover: Nature of superficial cover:-  N = Not covered,   L = Laterite,  A = Alluvium and aeolian sands
  2. Area: Map sheet code for sample collection site
Area code 1:250k Sheet name Sheet number
1 Magdalena SD20-2 + SD20-6
2 Puerto Villazon SD20-3 + SD20-7
3 Huachi SD20-10
4 Perseverancia SD20-11
5 Huanchaca SD20-8 + SD20-12
6 Ascension SD20-14
7 Monte Verde SD20-15
8 Manomo SD20-18
17xxx Concepcion SE20-2 + SE20-3
4200x San Ignacio SE20-4
47xxx San Matias SE21-1 + SE21-2
402015-25 San Jose de Chiquitos SE20-7 + SE20-8
57xxx Santo Corazon SE21-5 + SE21-9
67xxx-68xxx Laguna Gaiba SE21-6 + SE21-10
77xx Velasco project area largely in SD20-18
  1. x: x UTM Co-ordinates calculated on UTM Zone 20
  2. y: x UTM Co-ordinates calculated on UTM Zone 20
  3. Element field: chemical symbol plus method of analysis
  • AAS atomic adsorption spectroscopy
  • OES optical emission spectroscopy
  • COL colorimetric
  • DNA delayed neutron activation
  • LOI % Loss of weight on ignition of sample at 450° C
  1.              Phase: Phase of project (1 or 2)

Values in ppm assigned to samples below the limit of detection are:


Absent data are indicated by -1.

All samples have UTM grid co-ordinates (UTM Zones 20 and 21) and have been standardised on the UTM Zone 20. The standardised data x/y co-ordinates are presented in the database as x and y.

Excel filename EBOLIVIA.XLS
Minimum Easting (x) (UTM20) 367800 Long. -64.3°
Maximum Easting (x) (UTM20) 1079300 Long. -57.7°
Minimum Northing (y) (UTM20) 7967100 Lat. -18.4°
Maximum Northing (y) (UTM20) 8624100 Lat.- 12.4°
Number of sites 8132 (6912 sedts and 1220 soils)
Average corrected sampling density 1 per 16 km²
Fraction used -150 micron
Elements by AAS (hot nitric acid extraction) Ag, Co, Cu, Fe, Mn, Ni, Pb, Zn
Elements determined colorimetrically (Gutzeit method) As
Elements determined by Delayed Neutron Activation (DNA) U
Elements by Optical Emission Spectroscopy (OES) B, Ba, Be, Cr, La, Li, Mo, Nb, Sn, Sr, Y, Zr

Reference to the CD-ROM should be as follows:

BGS (2007). Bolivia Regional Geochemical Survey CD-ROM: Proyecto Precàmbrico – Eastern Bolivia. Version 2.0. BGS International Regional Geochemistry CD-ROM Series, No. 3 Bolivia. British Geological Survey, Keyworth, Nottingham, UK

BGS work in Bolivia

Central enquiries
British Geological Survey
Keyworth Nottingham NG12 5GG
United Kingdom
Tel: +44 (0)115 936 3143
Fax: +44 (0)115 939 3276 Email: enquiries@bgs.ac.uk

Collaborating organisation: Bolivian Geological Survey

Director Ejecutivo
Servicio Nacional de Geologà­a y Minerà­a SerGeoMin
Calle Federico Zuazo 1673, Esquina Reyes Ortiz,
La Paz, Bolivia
Tel. (591-2) 2311373

readme.doc Information file (in MS Word 2003 format)
readme.pdf Information file (in PDF format)
ebolivia.csv Geochemical results and locational data for stream sediments and soils in comma separated variable format, first row contains field names
ebolivia.xls Geochemical results and locational data for stream sediments and soils in MS Excel 2003 format, first row contains field names
ebolivia.dbf Geochemical results and locational data for stream sediments and soils in dBase III+ format

Purchase information

You may also be interested in:


Applied geochemistry

Since the 1960s, the BGS has amassed considerable geochemical data holdings and developed significant expertise in applied geochemistry.

Show more

International geochemistry CD-ROM series

Regional geochemical data from a range of overseas countries are available on a series of CD-ROMS.

Show more

Was this page helpful?

  • How can we make this section better?*

  • Please select a reason*

  • How can we make this section better?*