REPUBLIC OF BOTSWANA
;".
ANNUAL REPORT
OFTHE
GEOLOGICAL SURVEY DEPARTMENT
FOR THE YEAR
199J-;
PRICE: P3,OO
Printed by the Government Printer, Gaborone Botswana GEOLOGICAL SURVEY DEPARTMENT
(Director: T. P. Machacha)
ANNUAL REPORT
OF THE
GEOLOGICAL SURVEY DEPARTMENT
FOR THE YEAR
1992
PUblished by
The Director Geological Survey Department Private Bag 14, Lobatse, Botswana.
With the authority of The Ministry of Mineral Resources and Water Affairs Republic of Botswana 1. GENERAL
The Geological Survey remained within the Ministry of Mineral Resources and Water Affairs and continued with its main functions of gathering, assessing and disseminating all data related to the rocks, mineral deposits and grouhdwater resources of Botswana. The departmental organisational structure continued to consist of the Directorate, four operational divisions of Regional Geology, Economic Geology, Hydrogeology and Geophysics together with an Administrative Division. Support to the main divisions was provided by the Drawing Office, Technical Records and Library, Chemistry and Mineral Dressing Laboratories. During the year the staffing position within the Department was consolidated with a full establishment of professional staff. There were no changes in the Directorate although the Deputy Director spent much of the year in Canada completing his PhD studies. The Principal Regional Geologist, Mr D P Piper, returned to the U K in July and was replaced by Dr R M Key who arrived from the U K in October. Within the Economic Division the evaluation of industrial minerals continued to be given priority with extensive investigations in the Dukwe-Matsitama, Selibe-Phikwe and Palapye areas. The writing of the gold monograph continued, as did the exploration for base and precious metals in the Maitengwe Schist Belt. Mineral exploration by the Private Sector continued at a high level throughout the year despite the global recession. At the beginning of the year there were 295 prospecting licences in force which increased to 297 licences by the year's end. 222 of the licences were for precious stones (diamonds), 56 for base and precious metals and 19 for other minerals. Within the Hydrogeology Division much of the activity was involved with the implimentation or monitoring of six major groundwater projects throughout Botswana. Five of the projects involve consulting companies and one (the TGLP Ghanzi/Makunda Groundwater Project) is being undertaken· completely by Department staff. Additionally there were a number of on-going groundwater research programmes which will eventually lead to a better understanding of the groundwater resources of Botswana as well as improving the techniques used to find this precious resource. The Division continues to monitor the groundwater resources which are presently being utilized; there is a National Monitoring Network established in the Department which is being fully computerised. Professional advice on groundwater was given to other public bodies throughout Government. The Geophysics Division continued to assist the Hydrogeology Division and Department of Water Affairs in groundwater resource evaluation and development projects. A groundwater methodology handbook was produced which will s'erve as a reference text for geophysical exploration for groundwater. The National Gravity Survey Database is being continuously upgraded, and there were over 19 000 records on the database by the end of the year. This represents a coverage of one station per 33 km 2. A seismological station became fully operational within Botswana during the year. This station is part of a global telemetry seismograph network which wil/ monitor seismicity in Botswana and neighbouring countries. An important role of the Regional Mapping Division continued to be 'the production of geological maps of quarter degree sheets of the better exposed parts of the country. Work continued on a number of these maps, with some geologists using their field information as the basis for post-graduate studies in the U K. At the end of the year it was also decide to produce geological maps of the poorly exposed parts of Botswana where there is a lot of mineral exploration. These maps wil/ be at a scale of 1 :250 000 in contrast to the 1 :125 000 quarter degree sheets. The Division also undertook some investigations in urban areas in order to identify geological features which may affect construction projects. Col/aboration continued with other National Geological Surveys on matters of regional importance and with various university geology departments on specific projects within Botswana. In addition to providing various rock, mineral and other chemical analyses for the various Divisions within the Department, the Chemistry Laboratory undertook Similar work for a number of outside institutions including the pOlice and the Department of Water Affairs. Similarly the Mineral Dressing Laboratory provided thin sections and polished samples to staff within the Department and to a number of outside institutions. A wide range of technical services were also provided by the Laboratory to customers which included the University of Botswana and a number of consulting firms. The Drawing Office continued to prepare all the geological maps produced by the Department for
Page 1 printing at the Government Printer. All the diagrams for the Department's publications are also completed in the Drawing Office. The Department's library acquired a number of new technical books as well as receiving a large number of consultancy reports related to work in Botswana. Over 30 international periodicals are regularly received. There were six operational drilling rigs within the Drilling Section although many of these machines are old and need replacing. Nevertheless a number of boreholes were completed on behalf of the various Divisions in various parts of the country. The Department's use of computers has increased steadily over the past few years and all Divisions received new computing equipment during the year. Data processing and handling is increasingly being undertaken on computers. Eventually it is intended that datasets from different Divisions can be merged and analysed using sophisticated techniques such as Geographic Informatiop Systems (GIS).
Page 2 5. HYDROGEOLOGY DIVISION
5.1 Introduction The Hydrogeology Division of the Geological Survey Department has the responsibility for investigating and exploring for groundwater r"sources of a regional nature as well as promoting the advancement of applied groundwater research in Botswana. The exploration of groundwater resources involves the assessment of their potential for development and utilisation with water quality being an important factor. The Division also has the responsibility of gathering data on groundwater levels from our established monitoring network, water abstractions, monitoring of water quality evolution and the receival of borehole data and water samples from government as well as privately drilled boreholes. All this information is stored in the National Borehole Records Archive and Groundwater Computer Data Banks as well as in the Drill Sample Store. The National database now contains 15400 records. The research project, Groundwater Recharge Evaluation Study (GRES PHASE 11) was approved and started in November, 1992. This project is being executed as a cooperation research programme between the Geological Survey Department, the University of Botswana and the Free University Amsterdam. Within the Division's internal programmes, limi.ted research continued with the assessment of groundwater resources of Seleka and Kanyenorthern wellfields by Messrs Nkala and Mokokwe who left for Australia early in 1992 to pursue MSc. Hydrogeology programmes. The "Geophysical Methodology Handbook" research project was continued in Canada by G. Shields under the supervision of Professor J. Wright of Memorial University of Newfoundland. This programme is scheduled for completion during the first quarter of 1993. Another research programme was initiated during the year in the Middlepits/Makopong area. This project which is being carried out by our junior hydrogeologist, Mr Molebatsi, investigates hydrochemical and recharge phenomena within the area. Training as usual constituted an important aspect of the Division's activities. Messrs Nkala and Mokokwe left for Australia to pursue their MSc. studies in Hydrogeology at the University of New South Wales. They have now transferred to the University of Technology, Sydney in order to complete their programmes. Mr. Molebatsi left for the United Kingdom in September, 1992 to undertake an MSc. study programme at the University College London. Two junior hydrogeologists, Messrs I. Mabua and M. Magowe, joined the Department on the 1st June, 1992 while a technical trainee, Mr. L. Mutukwa joined the Division on the 29th July, 1992. Mr. J. Marks left the Department on the transfer to Botswana Savings Bank. During the course of the year the Hydrogeology Division continued to suffer from lack of experienced manpower for the planning and implementation of regional groundwater projects. Hence some of the "priority" groundwater exploration projects have been shifted to the Department of Water Affairs for immediate implementation while others still await the recrul.trnent of project hydrogeologists for their planning and implementation.
... 5.2 Development ProJects
5.2.1 Groundwater Studies and Protection 5.2.1.1 Letlhakeng/Botlhapatlou Groundwater Investigation Project Project duration: 15th February, 1990 to 30th August, 1991 (not completed by this date) Total project cost: P6161992 Consultant: Bureau de Recherches Geologiques et Minieres (BRGM), Orleans, France. Drilling Contractor: Geotest (Pty) Ltd., Gaborone. This project started on the 15th February, 1990 and was scheduled for completion by the 15th September, 1991. The draft final reports were submitted to the Geological Survey on the 12th August, 1991 and were reviewed and commented upon. After scrutiny of these reports it was agreed by DGS and DWA that the chapters dealing with modelling and calculation of potential groundwater resources
Page 8 in the area were inadequate and in some cases the concepts concerning hydraulic parameter calculations were dubious and hence confusing. The Consultant BRGM has since been working on these amendments and corrections. A meeting was convened on the 22nd September, 1992 between the Consultant, DGS and DWA where additional modelling scenarios as carried out by BRGM were discussed. At this meeting it was still felt that further improvements were necessary before DGS could approve the final reports which in essence have cost the government of Botswana about P6.2 million (as total project costs). The submission of the final reports is anticipated by the end of 1992 which is' more than one year late! This situation does not reflect very well on the performance of this French Consultant, particularly concerning the Letlhakeng/Botlhapatlou Groundwater Projectl
5.2.1.2 Mmamabula Groundwater Resources Investigation Project Phase 11, Khurutshe Area Project Duration: 25.5 months Total Project Cost: P10 000 000 Consultants: Bureau de Recherches Geologique et Minieres (BRGM), Orleans, France. Drilling Contractor: Pula Groundwater Developers (Pty) LTD.,Gaborone. Botswana. Commencement of Project: October, 1991 . The contract for the consultancy works was awarded to BRGM and the contract agreement was signed on the 6th September, 1991. Data processing and interpretation of the aeromagnetic data has been completed by CGG and BRGM in France and the aeromagnetic interpretation draft report was submitted to the client in August, 1992. A technical meeting was convened to discuss this report, and consequently corrections were made. The final report will be submitted during 1993. Geological, structural, hydrogeological compilation and interrelation of the data have been carried out. However the report will be compiled towards the end of the project because at present, data are still being compiled and interpreted, as new data are being collected from geophysical investigations and drilling works. A draft report of the geological study was submitted in April, 1992. The final report will be prepared towards the end· of the project. Geophysical borehole siting work started in April, 1992 and is still on-going. A total of 28 drilling sites had already been identified by the end of November, 1992, out of which 7 are in the Waterberg, while 21 are in the Karoo. The preparation of tender documents for the drilling and test pumping work was completed two months later than originally planned, but this delay did not result in any additional costs. In fact the drilling works were rescheduled to start the beginning of July, 1992. However the award of the contract was delayed by 2.5 months. These 2.5 month's delay has resulted in cost overrun which is to be paid to the consultant. The Contract Agreement for drilling and test pumping works was signed on the 14th August, 1992 between the Botswana Government, reprElsented by the Director of Geological Survey, and Pula Groundwater Developers, and the field activities officially commenced on the 14th September, 1992. Drilling activities since then have been progreSSing well and on schedule. By the end of November, 1992, 9 boreholes had been drilled. Preliminary indications are that the Karoo Ntane Sandstone Formation, is a promising aquifer, while groundwater potential of the Waterberg is low. Climatological, hydrological and groundwater monitoring activities were on-going towards the end of the year.
5.2.1.3 Matsheng Area Groundwater Investigation The planning and implementation of this project has been delayed for quite sometime now due to the difficulty in securing an experienced hydrogeologist through SIDA for its initiation and Implementation. However on the 10th September, 1992 the Geological Survey submitted a project memorandum to MIRWA requesting SIDA to fund the recruitment of a project hydrogeologist through a consultancy arrangement rather than the normal direct employment procedure. The latter has so far proven ineffective because of the supposedly low and unattractive salaries associated with It. The revised project memorandum for Matsheng was submitted for the 24th September, 1992 MFDP tranche. The Terms of Reference will be revised whenever time becomes available because at the moment, all the Geological Survey hydrogeologists are fully engaged in on-going projects.
Page 9 5.2.1.4 TGLP Toteng/Sehitwa Groundwater Potential Survey Project duration: May, 1991 to December, 1992 Total project cost: P 3 500 000 Consultant: Geoflux (Pty) Gaborone. Drilling Contractor: Dewet Drilling, Gaborone Project commencement: 29 May 1991 The objectives of this project are to identify areas with groundwater resources of suitable quality and sufficient quantity in, or near, demarcated TGLP ranches. Vital information for demarcation of the TGLP ranches is sought. The aim of the project is to minimise the capital expenditure for the farmer on borehole drilling by reducing the risk for unsuccessful drilling. All data collected during the first phase of the project were analysed during the early months of this year, and borehole sites were selected. In all fifteen sites were selected for further ground geophysical investigations, in order to pinpoint the actual drill sites. The siting aimed at specific geological features which are potentially water yielding, while at the same time a regional distribution of information was targeted. Drilling started in early April, 1992 when the fifteen sites had been identified. By the end of August, 1992 fifteen boreholes had been completed and well hydraulic tests performed in them. Two types of water yielding formations were encountered; a tight quartzite of the Ghanzi Group and a loose sand of the Kalahari Group. Preliminary estimates of the water yields, from the Kalahari sand boreholes range from 30 to 40 m3/h. These boreholes are confined to the easternmost part of the project area where difficulties were encountered during drilling. A greater spread of borehole yields is found in the quartzite formation. Here the range encountered is o to 80 m3/h. This great spread is due to the fact that yields in these boreholes are completely controlled by fractures, contrary to the boreholes drilled in the Kalahari sands. Another important objective of the project is to study the water quality and its distribution in the area. As an indication of its general suitability for cattle the water salinity is measured. It proved that no clearcut regional distribution can be discerned at this preliminary stage of the data analysis. However, the range of salinities is from 1 500 to more than 20 000 mg/1.
5.2.1.5 Middlepits/Makopong TGLP Groundwater Potential Survey Project Duration: 1st September, 1992 to 1st October, 1993. Total Project Cost: Pula 4 850 000.00 Consultant: Water Surveys Botswana (Pty) Ltd. Consulting Hydrogeologists. Gaborone. Drilling Contractor: TGB and Pula Groundwater Developers. Gaborone. Project commencement: 1st September, 1992. Preparation of the terms of reference for the consultancy, the subsequent invitation of tender and the tender evaluation were completed by the 18th June, 1992 with the award of the contract to Water Surveys Botswana, a locally registered groundwater conSUltancy. Post-award negotiation and mobilisation preceeded actual survey implementation and commenced on the 1st September, 1992. The main areas for investigation are the presently demarcated TGLP blocks to the north and north west of both Middlepits and Makopong. However, for accurate assessment, the geology and hydrogeology has to be comprehended in a broader, more regional sense and thus the actual survey boundaries lie well outside the TGLP block boundaries. This allows scope for possible TGLP block relocation if more promising and potential areas become apparent during the course of the study. This groundwater potential survey covers approximately 17000 km2 of the southern Kgalagadi District, bounded by the Molopo River in the south, Mabuasehube and Gemsbok Parks and latitude 24° 55' S in the north and longitudes 21 ° 45' and 22° 55' E in the west and east respectively.
Page 10 In a sub-regional cont'lxt the geology, and hence the hydrogeology of the area, is in the process of being re-modelled by the integration of existing borehole geological data, re-interpretation of existing airborne magnetic and electromagnetic data and satellite imagery and the implementation and interpretation of a relatively detailed ground regional gravity survey. Inventory and technical reports covering these topics were produced late 1992. Problems have been encountered due to the absence of borehole information in the north and north west of the defined areas as well as information on aquifer characteristics lying at the base of the sedimentary basin throughout the entire area. Groundwater potential in this respect is unknown. Phase I which consists of planning and siting of 16 boreholes will investigate and help develop geological and hydrogeological models for the area. Boreholes sites were finalised in December, 1992 and the drilling programme will commence early 1993. Phase II drilling programme will concentrate on specific and varied target areas, where appropriate techniques will be applied in some considerable details. These will be designed to prove or disprove the potential of such areas to produce groundwater of potable quality and yield.
5.2.1.6 TGLP GhanzilMakunda Groundwater Potential Survey Project duration: 22 months from fund-release date. Project cost: P 5 600000 (as estimated in April, 1992) Consultant: The project will be carried out in-house, by the DGS. Drilling contractor: Not yet selected. Date of commencement: As soon as funds are made available. The Tribal Grazing Land Policy (TGLP) was established in 1975 under the guidance of the Ministry of Agriculture (MOA) with the aim of conserving range resources, promoting greater equality of income and fostering greater productivity and commercialisation within the livestock industry. The Policy encourages farmers to acquire 50 year ranch-land leases in areas especially assigned for cattle rearing purposes. The advancement of the TGLP objectives requires the development of groundwater resources in the TGLP areas. Therefore, during the mid 1980's, funds were allocated to the MOA to be .used in groundwater investigations. These investigations will reduce risks of losing capital by drilling unsuccessful boreholes; promote the discovery of livestock-water supplies and, in general, stimulate the cattle industry. As a result of this fund allocation, TGLP groundwater investigations are now in progress in two areas: Toteng/Sehitwa and Middlepits/Makopong. The present project will extend the investigations to a third area, and will further enhance the development of TGLP ranches. Mr Gabriel Salas, a hydrogeologist working for the Australian New South Wales Department of Water Resources, arrived in Botswana on a two-year contract basis to carry out the GhanzilMakunda project under the supervision of the Department of the Geological Survey. He commenced work on the 7th February, 1992. Contacts with the Ministry of Agriculture were established soon after the arrival of Mr Salas. The aims and objectives of this particular TGLP project were further discussed and defined. It was decided the groundwater investigation would centre not only on the Ghanzi/Makunda TGLP areas, but also incorporate surrounding areas. So, its total area will approximately extend from the boundary with Namibia to the longitude of Ghanzi, and from Ghanzi's latitude to the latitude of Ncojane Ranches, enclosing a surface of some 18 600 km 2 which is the largest area covered by a TGLP project to date. In .March 1992, a Project Memorandum was written. The document defined the methodology of the TGLP investigation and its costs. It proposed two options: the option of having the Department of Geological Survey carrying out the investigation - and use the TGLP project to provide training and fieldwork experience to its own geological and geophysical staff; and the option of handing out the project to a consulting company, which is the usual procedure. The costs of the two options were estimated. The DGS option will cost approximately 60% of the cost of the conSUltants option where the latter requires a minimum expenditure of P 8 400 000. The Project Memorandum with the two proposed options was submitted to the Ministry of Mineral Resources and Water Affairs (MIRWA) in early April, 1992. It was to be reviewed and approved for funding during the April, 1992 tranche. Unfortunately such a review was not carried out until the end of September, 1992, causing delays of
Page 11 over seven months. These delays affected the project's immediate implementation. During early November, 1992 the situation of the GhanzilMakunda TGLP project has still not been completely defined. It is understood the project's implementation by the DGS was approved - even though no written confirmation has been received yet - and funds will be made available sometime "soon", In spite of not having access to funds, the DGS in the meantime has continued advancing, up to a limited extent, the project. A large amount of geological, geophysical and groundwater information has been collected from mineral exploration records and from groundwater consultants' investigations. This information is being reviewed, collated and assessed with the intention of producing a comprehensive technical literature review, which will back-up the execution of the project. In addition, the DGS Geophysics Division has advanced the first stage of the project's fieldwork programme. Using funds destined to train the Division's staff, DGS geophysicists and technicians completed a four month gravity survey by the beginning of December, 1992.
5.2.2 Groundwater Research Programmes 5.2.2.1 Groundwater Exploration - Geophysical Methods The final report on this project was still incomplete towards the end of the year and is currently being compiled at Memorial University of Newfoundland, Canada by Professor J. Wright and G. Shields. However towards the end of the year the Geophysics and Hydrogeology Divisions were reviewing some of the chapters which definitely will be continued during 1993.
5.2.2.2 An Evaluation of Groundwater Resources within the Kanye Wellfield
Groundwater monitoring in the wellfield was do~e routinely on a monthly basis to collect data for Mr Mokokwe who Is currently doing an 18th months MSc. Hydrogeology at the University of Technology, Sydney, Australia. Mr Mokokwe was in Botswana from November, 1992 to February, 1993 to collect further information for his MSc. thesis. He reported a change of plans in that he has now decided to investigate a problem in environmental hydrogeology using data from Australia. It is nevertheless recommended that he should bring the Kanye project to completion after his MSc. studies.
5.2.2.3 An Evaluation of the Groundwater Resources within Seleka Farm Wellfield Routine groundwater monitoring of the BDC Seleka wellfield continues. The data are being collected for Mr Nkala who is currently on an 18 months MSc. programme at the University of Technology, Sydney in Australia. Mr Nkala was also in Botswana from November, 1992 to February, 1993 for collection of further data and information for his MSc. thesis.
5.2.2.4 Hydrogeochemistry of the Satured Zone in Selected Areas of the Kalahari, south-west Botswana The project area stretches from west of Middlepits to Tshabong, along the Molopo River and northwards, for approximately 40 km in the Kgalagadi District of south-west Botswana. A hydrochemical study of the saturated zone in this area, where much of the solid geology and hydrogeology is obscured due to a mantle of soft and dry Kalahari sand, and where very little previous investigation has occurred, is obviously a worthwhile MSc. research topic. This is emphasised when it is viewed as an integral (but independently managed) part of the groundwater potential survey of the Middlepits/Makopong TGLP Areas. This study has been tailored to a suitable size and content so that it is manageable within the 2 year MSc. Hydrogeology course offered by the University of London in England, where Mr Molebatsi is currently studying. A full hydrochemical analysis on a water sample gives a unique signature, or a fingerprint whereby a number of deductions can be made. The proportions and concentrations of the major ions tell us how long the water has been in contact with the rock matrix (depending on the type of rock matrix), whether mixing between differing sources of water has occurred and whether the aquifer is regularly flushed by recharge waters. Various elements and isotopes can indicate the age of the water and thereby demonstrate when the water table last received fresh water recharge - i.e. recently or
Page 12 historically. When analyses for several boreholes in the same area are compared various other 3-dimensional phenomena such as direction of groundivater flow can be tackled and even modelled. Two or more different hydrochemical data sets within a single area usually indicate separately evolved systems or isolated aquifers. Previous similar studies within Botswana have concentrated on regional hydrochemical trends. Marobela (1987) looked at the hydrochemical facies of groundwater in south-eastern Botswana (very thin or absent Kal.,hari) whilst Phofuetsile (1988) studied the hydrochemistry of the eastern Kgalagadi District. The latter in particular examined the traits of water lying within various rock strata below relatively thick Kalahari sand cover. Neither of these studies have concentrated on the details of small localised areas, primarily because concentrated groupings of boreholes from which samples can be taken and analysed are seldom found in the field.
5.2.2.5 Groundwater Resources Monitoring and Recharge Studies in Botswana (GRES - PHASE 11) This four year research programme is a technical cooperation project which involves the participation of three institutions, namely the Geological Survey, the University of Botswana and the Free University Amsterdam. The project is fully funded by both the Botswana and the Netherlands Governments and officially started on the 1st November, 1992. Hydrogeological research during GRES - PHASE 11 will essentially concentrate on groundwater recharge in the Kalahari semi-desert, recharge here being defined as aquifer replenishment. From a scientific point of view the objective is to examine recharge processes in both present and past times. Four pilot study areas have been selected representing the different hydrogeologic conditions for aquifer replenishment i.e. where movement of soil moisture through the unsaturated zone to the saturated zone takes place down to the perched watertable andlor through leakage to a confined aquifer. While research during GRES - PHASE I (Gieske, 1991) focused on detailed meteorological measurements and moisture transport in the unsaturated zone, GRES - PHASE 11 research will essentially focus on moisture transport from the unsaturated zone to the saturated zone in both time and space. Isotope-physical and hydrochemical tracer techniques will play a key role in examining flow patterns and transport processes. Within the framework of GRES - PHASE 11 a PhD study will be carried out by Mr E. Selaolo whose main objective will be tQ evaluate recharge processes with reference to specific areas such as the Jwaneng - Letlhakeng/Botlhapatlou area, the Matsheng area and a few Kalahari pans with differing morphological features.
5.2.2.6 Pollution Protection of Water Resources and Solid Waste Disposal The initial idea to implement a project focusing on the prevention and control of water pollution through proper identification and planning of waste disposal sites emerged from the Department of Geological Survey (DGS), under the Ministry of Mineral Resources and Water Affairs (MMRWA). A project memorandum was agreed upon in October, 1989 and was the subject of the Botswana German government negotiations in August, 1990. Both sides considered the project to be potentially a very important contribution to the forthcoming National Conservation Strategy (NCS). The Government of Botswana submitted a request to be jointly appraised by the German Agency for Technical Cooperation (GTZ) and the Bundesanstalt fur Geowissenschaften und Rohstoffe (BGR). An appraisal mission was conducted in Botswana from the 10th April until 22nd of April, 1991. Subsequently, a planning workshop (ZOPP 3) took place from 23rd until 26th of April, 1991. The participants were from the Department of Geological Survey (DGS), the Department of Water Affairs (DWA), the Ministry of Local Government and Lands (MLGL), the Ministry of Finance and Development Planning (MFDP), the Ministry of Health (MOH), and from different Town and District Councils. The overall goal of the project is to reduce the risks of environmental pollution caused by uncontrolled disposal of wastes. Special emphasis shall be placed on the. protection of the groundwater resources thus supporting the efforts of the Government of Botswana in the protection of the environment and the conservation of natural resources. In this context, the project contributes to the National Conservation Strategy (NCS) objectives. For dealing with the protection of groundwater resources the responsible institution shall be the
Page 13 Department of Geological Survey (DGS). The DGS with its Hydrogeological Division shall carry out geological and hydrogeological investigations necessary for the elaboration of groundwater vulnerability maps and will be actively involved in the identification of sanitary landfill sites at selected locations in close cooperation with the local authorities. The DGS shall carry out the relevant programmes in cooperation with the German experts. For the provision of required counterpart staff by the DGS, Mr. Mabua will be fully seconded to this project which is scheduled to commence during the first half of 1993. His training and MSc. preparations will focus on environmental and engineering hydrogeology - a subject which is currently receiving attention throughout the world. The German experts with the assistance of Mr. Phofuetsile will supervise Mr. Mabua during his early days of training before pursuing his MSc. studies.
5.2.3 Groundwater Resources and Basin Monitoring. Monitoring has continued as previously throughout the year. The Division commenced monitoring of the Seleka Farm boreholes. Our National Monitoring Network is as follows: Serowe: 37 boreholes + 2 wells. Includes 7 production boreholes, 3 automatic recorders, 3 boreholes are to be cleaned and one has been abandoned. Palapye: 12 boreholes. Includes 6 production boreholes, 2 recorders, 1 dry/blocked borehole. Ramotswa: 43 boreholes + 1 well. Includes 10 production boreholes, 4 automatic recorders, 11 blocked/dry boreholes. Mochudi: 13 boreholes. Includes 4 production boreholes, 3 automatic recorders, 1 dry/blocked hole. Malotwana: 10 boreholes. Includes 2 production boreholes, 2 automatic recorders. Molepolole: 20 boreholes + 1 well. Includes 7 production boreholes, 2 automatic recorders. 1 borehole is blocked. Metsemotlhaba: 14 boreholes. Includes 3 production boreholes, 2 recorders, dry/blocked borehole. Pitsanyane/Nnywane: 34 boreholes. Includes 2 production boreholes, 4 automatic recorders, 1 locked shelter, 2 dry boreholes. Lobatse Treatment Ponds/Lobatse Estates: 7 boreholes. Includes 2 which are blocked and are to be cleaned.
Kanye: 70 boreholes + 3 wells. Includes 7 production hole, 6 automatic recorders, 1 dry borehole. Letlhakeng/Botlhapatlou: 30 bore holes. Includes 10 automatic recorders. Seleka Farm: 26 boreholes The National Monitoring Network now comprises 316 boreholes and will increase with the completion of the Molepolole/Mochudi project and with the incorporation of the bore holes drilled under the TGLP projects which will increase our information on the aquifer conditions in the Kgalagadi and Ghanzi regions. A computer database using dBase 111 + has been designed and installed for the monitoring and rainfall data. It consists of the wellfield and borehole location details, the water level measurements plus data and time of reading for each borehole and the rainfall amount, date and duration. Data for Molepolole, Mochudi, Malotwana, Metsemotlhaba, Palapye and part of Serowe have been input on the computer so far. Basic hydrographs will be produced in future along with rainfall histograms as soon as the groundwater databank is fully completed where additional software for data processinQ will be utilised as well.
5.2.4 National Borehole Records Archive and Computer Data Bank After the completion o/the Borehole records Archive Project by Knight Piesold consultants in July,
Page 14 1991, the remaining work fell into the hands of Hydrogeology Technicians. Not a lot of records were entered on the computer. The main area of concern was to ensure the completion of updating of borehole data for Serowe, Palapye, Lephephe, Mahalapye, Gaborone and Lobatse sheets. At least one third of this work has been accomplished on the printouts to be edited. This edited work is ready for input on the computer. Updating here concerns fields such as village., location of project, owner, purpose of the borehole, mapsheet number, elevation accuracy, coordinates accuracy, completion date, drilling method, development method, development duration, estimated yield, driller, drilling details, casing details and screen details. Editing and adding borehole data was facilitated by the availability of water point survey reports in areas where the survey has been conducted. The best report being that submitted by Kweneng District Water Point Survey (Geological and Geodetic Services Botswana/Ground Water Development Services). This report contains most of the above required fields to be updated. Little progress has been achieved in data input after the completion of the project by Knight Plesold consultants. Few pumping tests data, as well as the new boreholes included in various consultants reports, have been entered on the computer. OthelWise progress in computerisation of borehole records remains unchanged. As concerns the mapping progress, some new boreholes with exact locations mainly from consultants reports were plotted. These reports also provided exact localities of some old boreholes. They were also corrected on water sources location maps. The coordinates, elevations and aquifer units were also corrected. The 538 duplicated boreholes outlined in Knight Piesold's final report were also attended to. More than 500 of these boreholes have been corrected on maps. No attempt has been made to correct the data for these boreholes on the computer. The Geological Survey has registered 320 privately owned boreholes this year (Z6992-Z7311). Out of the 320 boreholes, 226 were drilled in 1992 and the rest in previous years. A list of new boreholes for both government and private organisations has steadily increased after the completion of the Borehole Archive Project. These boreholes are to be plotted and entered on the computer. Another area of concern is the computerisation of north-eastern Botswana sheets. This area was not included in the study area by Knight Piesold consultants as it was thought the Geological Survey technicians could complete this work. However, due to much more borehole information and manpower constraints this has not been achieved. The boreholes for the Nata sheet have not all been plotted. Mapsheets 2026B, 2026C4 and 2026D1-D3 need to be updated. These sheets were not available at the Department of Surveys and Lands during the updating of the Nata sheet, but can now be obtained. Despite the problems outlined above the National Borehole Archive Database storage capacity has increased from 12,561 records in 1991 to more than 15,400 records at the end of 1992.
5.2.5 Drill Sample Store There are 28 and 29 full pallet boxes of sludge samples for government and private boreholes in the coreshed respectively. A full pallet box holds 36 trays and each tray contains approximately 112 standard size bottles of sludge samples. In the first week of November 1992 the Department had a total of 163 328 sludge samples for government boreholes and 122 723 samples for private bore holes. If the sludge samples are continued to be received at this current rate, it is predicted that the space allocated for the drill samples in the coreshed would be full by the end of 1993.
5.3 Consulting Service for Government & the Public Membership on Committees and Boards. Professional advice to the public, as in the previous years, formed an important part of the Division's activities. Consultation with the various Districts in connection with setting up databases for water point surveys continued. A number of Consultants made extensive use of our National Borehole Records Archive Database during implementation of groundwater exploration projects throughout the
Page 15 country. Assistance was given to the Department of Water Affairs in connection with the supervision of the Molepolole-Mochudi Groundwater Exploration Project. Hydrogeological investigations were carried out on behalf of the Ministry of Local Government, Lands and Housing with regard to the Self-Help Environmental and Sanitation Project - Pit Latrines Construction. The study assesses the chances of pollution to groundwater resources which may result from the construction of non-sealed pit latrines and recommends the type of pit latrines that should be constructed. However it was not possible to achieve much progress because of heavy Divisional workload and commitments. Whenever time permits the Geological Survey will continue to carry out these investigations until the planned "Solid Waste Disposal Study" is implemented, which is scheduled for the first half of 1993. The Geological Survey continued to support, and participate on the Committee from the Ministry of Commerce and Industry, where a consultancy is being conducted to investigate geological and hydrogeological factors related to the possibility for underground storage of mineral oil near Gaborone. Technical advice was also provided to the Water Apportionment Board of the Department of Water Affairs in connection with the control of monitoring of wellfields in Orapa, Jwaneng, Paje, Seleka and Ramotswa. Further technical advice was given to the Department of Water Affairs In connection with the following project - "Protection zones and guidelines for major wellfields, aquifers and dams in Botswana", "Tran"S-Kalahari Highway groundwater investigations", "IUCN review of the Okavango Delta Project", WUC Ramotswa aquifer test programme "and" Evaluation of Palla Road and Dukwi wellfield extension groundwater projects". The Department also continued to be represented on the "Interministrial Water Supply and Sanitation Committee" as well as the Debswana Water Supply Committee".
5.4 Staff and Staff Training
5.4.1 Staff Assignment and Staff Movements Mr E. Selaolo continued to head the Hydrogeology Division with assistance provided by Mr P. Phofuetsile especially in the administr Page 16 with the planning of the TGLP potential surveys near Middlepits and Makopong. A research project to Investigate the hydrochemistry/recharge within the Middlepits area was designed in order to prepare him for MSc. training. Mr T. Kgole was in charge of the Borehole Records Archive, Data Base and Drill Sample Store. Messrs A. Mogotsi, J. Marks, B. Mohamadi and T. Ntes;l.ng were also involved with the Borehole Records Archive and Drill Sample Store. The following technicians were also involved in the routine groundwater monitoring programme: J. Keakile, K. Phiri, J. Setlhomo, J. Marks and L. Mutukwa. Two junior hydrbgeologists, Messrs I. Mabua and M. Magowe, joined the Department after completion of their BSc. Geology programmes at the University of Botswana and were towards the end of the year involved and receiving training, with supervision provided by Mr Salas, under the GhanzilMakunda Groundwater Potential Survey. Mr J. Marks left the Department at the end of February, 1992 on transfer to the Botswana Savings Bank in Gaborone. 5.4.2 Staff Training During the course of the year a number of officers received training through short courses and seminarsiworkshopsimeetings/symposia. Others left for long-term training at overseas institutions. Mr Nkala attended a workshop on "Groundwater Modelling" which was held on the 1oth to 19th February, 1992 in Nairobi, Kenya. Both Messrs Nkala and Mokokwe left for Australia to pursue their MSc. studies in Hydrogeology towards the end of February, 1992 at the University of New South Wales, Sydney. They have now transferred to the University of Technology, Sydney where they are scheduled to complete their programmes by July, 1993. Mr Mabua attended a course on "Hydrogeology for Geophysicists" which was conducted by Dr Gieske of the University of Botswana from the 13th July to the 24th July, 1992. Mr Phofuetsile attended a course on "Water Resources Development and Management in Arid and Semi-Arid Regions" from the 10th April, 1992 to 7th June, 1992. This course was sponsored by SIDA and was conducted at the University of Lund in Sweden. Mr Molebatsi left for his MSc. studies at the University College London, United Kingdom, towards the end of September, 1992. This is a two year programme which he will hopefully complete by the end of September, 1994. Mr Selaolo attended advanced courses which were offered at the Jacob Blaustein Institute of Desert Research - Ben GurionUniversity of the Negev, Israel from the 14th July, 1992 to the end of August, 1992. These courses focused on "Hydrological Modelling of Flow and Pollution in Dry Regions" and were conducted by some of the world experts and lecturers in their various areas of specialisation and expertise. Mr Selaolo will also be involved in GRES-PHASE 11, a four year research programme between the Geological Survey Department, the University of Botswana and the Free University Amsterdam. This project officially started on the 1st November, 1992. As a research hydrogeologist he will investigate recharge processes within the Kalahari basin. It is also intended that some of the findings from this research project will be published as a PhD thesis by Mr Selaolo through the Free University of Amsterdam. 5.5 Reports and Publications Towards the end of the year many of the Division's groundwater exploration projects and research programmes were still on-going and as such there was very little reporting and only one publication was co-authored by Mr Selaolo through a round table meeting which he attended in Cairo, Egypt. The actual publication came out in 1992 although the meeting took place from the 5th to 9th October, 1991. Sekwale, M. and Selaolo, E.T., 1991. "An overview of the groundwater resources of Botswana as portrayed by the hydrogeological maps and the recently completed National Water Master Plan Study". In Planning for Groundwater Development in Arid and Semi-Arid Regions, edited by RIGW/IWACO, Cairo-Rotterdam. Page 17 6. GEOPHYSICS DIVISION 6.1 Staff The Canadian International Development Agency (CIDA) aid program to localize the Division continued. To date, all geophysicist posts are occupied by Batswana. The posts of Principal and Senior Geophysicists are still held by Canadians. Mr S.R. McMullan, Senior Geophysicist, left the Department at the end of 1992 and Mr P. Gledhill (Canadian) was promoted to fill the vacancy created. Mr T.H. Ngwisanyi and Mr 0.1. Koosimile completed their MSc studies in the Netherlands and resumed duty in late September 1992. Messrs H.M. Koketso, H. Holmes and Tarzan Kwadiba were promoted to Geophysicist level. Mr Chris Campbell (Canadian) continued to head the Division. Mr Charles Jaba was promoted to Senior Technical Officer while Meshack Ditlhogo advanced to Chief Technical Assistant. The two Batswana students at Cambrian College studying geological/geophysical technorogy (D. Moncho and M. Ramaselaga) continued well together with B. Tladi who is undertaking a course in electronic technology. All are expected to resume duty sometime in late 1994. 6.2 Development Projects 6.2.1 Groundwater Methodology handbook This handbook is meant to be used extensively as a reference text in groundwater exploration programs in Botswana and possibly neighbouring countries with similar geological/hydrogeological conditions as Botswana. It was a research project funded by CIDA and conducted by the Memorial University of Newfoundland through the Center for Earth Resources Research (CERR). During the reporting year, the Geophysics Division contribution was mainly editorial. The handbook (final report) is with the Department and will be printed soon for distribution to the public and private sector. 6.2.2 Ghan~/·Makunda TGLP project This is a joint Geophysics and Hydrogeology Divisions' project. The Ministry of Agriculture is the client. The aim of this project is to produce (primarily) hydrogeological and geological maps of the area as well as find the best geophysical techniques to site boreholes. To date, gravity data collection is in progress to increase station density and fill-in holes in the coverage. Over a thousand stations in addition to the NGS and Ncojane-Nossop basin hydrocarbon surveys have been occupied and several hundred more are planned in the next few months. 6.2.3 Petroleum Exploration There has been some renewed interest in the petroleum-gas potential of the Nossop-Ncojane and Passarge Basins. This year, two data sets have been sold to two international companies. However, no petroleum/gas prospecting licences have been issued as yet. 6.2.4 Geophysical Consultancy to the Hydrogeology Division and Department of Water Affairs. The Geophysics Division continued to assist the Hydrogeology Division and Department of Water Affairs in groundwater resource evaluation and development projects. The assistance was mainly in the monitoring of the geophysical output of the conSUltants as well as actually conducting surveys. Major ojects monitored are shown in the following table. Page 18 • Economic Geology Jnl of Petrology • Geobyte Jnl of Structural Geology • Geodrilling Mining Journal • Geoexploration Nature • Geological Magazine Precambrian Research • Jnl Geological Society Quarterly Jnl Engineering Geology • Geology Tectonophysics • Geophysical Prospecting Water Resources Research • Geophysics • Groundwater • Industrial Minerals Consultants reports received during the year were as follows: Aquatech Groundwater Consultants (Pty) Lld Borehole Surveying NNywane Basin. Proposal Nov, 1989. GC 1/716 Levelling of borehole in the Nnywane/Pitsanyane basin Nov. 1989. GC 1/717 Sir Alexander Gibb & Partners Letlhakane/Botlhapatlou Groundwater Project: Technical Proposal. Dec. 1988. GC4/17/1. Botswana National Water Master Plan: Technical Proposal. April 1989. GC4/18/1. Viak A.B. Consulting Engineer Evaluation of groundwater resources (GS10) Letlhakane - Botlhapatlou groundwater Project TB 10/2/16/88-89: Technical Proposal Dec. 1988. GC 9/9/1. Evaluation of groundwater resources (GS 10) Letlhakane . Botlhapatlou Groundwater Project TB 10/2/16/88-89: General experience and background of Tenderer. Dec. 1988. GC 9/9/2. Evaluation of groundwater resources (GS 10) Letlhakane - Botlhapatlou Groundwater Project TB 10/2/16/88-89: Financial Proposal Dec. 1988. GC 9/9/3 Wellfield Consulting Services Lld Pitsane BDF Camp groundwater investigation project. Final Report. March, 1992 GC 10/17/1 Trans Kalahari road groundwater investigation project: Inception Report. March, 1992 GC 10/18/1 Debswana (De Beers Botswana) Orapa Mine: Orapa Wellfields Assessment of computer modelling and groundwater resources projections: appendix to monitoring report no. 16. Technical note no. TN/005/92 May, 1992. GC 18/3/20 Jwaneng Mine Northern Wellfield Monitoring Report 23. July-December 1991. Data Compilation. GC 18/3/20. BRGM (Bureau de Recherches Geologiques et Minieres) Evaluation of groundwater resources (GS 10) Letlhakane-Botlhapatlou groundwater project. Inception report. GC 23/9/3. Evalu'ation of groundwater resources (GS10) Mmamabula groundwater resources investigation Phase 11 Khurutshe Area. CTB No.TB 10/2/3/90-9.1. August 1992. GC 23/9/4 Monthly reports of evaluation of groundwater resources (GS 10) Letlhakane -Botlhapatlou groundwater project: GC 23/9/2 a . q • Monthly progress report NO.1. Feb 15 - March 15, 1990. Monthly progress report No. 2. March 15 - April 15 1990 Monthly Report No .. 3 April 15 - May 15, 1990 Monthly Report No. 4 15 May - 15 June, 1990 Page 36 Monthly Report No. 5 15 June - 15 July, 1990 Monthly Report No. 6 13 July - 17 August, 1990 Monthly Report No. 7 17 Aug. - 14 Sept., 1990 Monthly Report No. 814 Se pt -12 October, 1990 Monthly Report No. 9 12 Oct. - 15 November, 1990 Monthly Report No. 10 15 Nov - 14 Dec. 1990 Monthly Report No. 1114 Dec -18 January, 1991 Monthly Report No. 12 18 Jan - 22 February, 1991 Monthly Report No. 13 22 Feb - 22 March, 1991 Monthly Report No. 1422 Mar - 19 April, 1991 Monthly Report No. 1519 Apr - 31 May, 1991 Monthly Report No. 16 1 June - 30 June, 1991 Monthly Report No. 17 1 July - 31 st July, 1991 Evaluation of groundwater resources (GS 10) Letlhakane - Botlhapatlou groundwater project. Inception Report. GC 23/9/3 Evaluation of groundwater resources (GS 10) Mmamabula groundwater Khurutshe Area CTB No TB/1 0/2/3/90-91. August 1992. GC 23/9/4 Mmamabula groundwater investigation Phase 11. Khurutshe Area TB 10/213190-91. Inception Report 1992. GC 23/1011 a. . Mmamabula groundwater investigation Phase 11 Khurutshe Area TB1 01213/90-91. Inception Report. Annexes. April, 1992. GC 23/10/1 b. WLPU (Watermeyer, Legge, Piesold and Uhlmann) Magnitude and sources of Water Pollution in Botswana.-Final Report August 1990. GC27/1312 Mahalapye Dam feasibilityl preliminary design study: Final Report on preliminary design Vol. 1 main report September, 1990. GC 271912. Mahalapye Dam feasibilityl preliminary design study: final report on preliminary design Vol. 11 appendices September 1990. GC 2719/3. Mahalapye Dam feasibilityl preliminary design study: final report on preliminary design Vol. III - drawings. September, 1990. GC 2719/4. Mahalapye Dam feasibility/ preliminary design study IV: final environmental report. September 1990. GC GC 2719/5. Swedish Geological Survey Evaluation of groundwater resources (GS10) Letlhakene-Botlhapatlou groundwater projectTB 10/2/16188-89. Financial Proposal. GC 30/11/2 SMEC (Snowy Mountain Engineering) Botswana National Water Master Plan Study. Final Report, VOI. 7 -Institutional Aspects. July, 1991. GC 351619. Botswana National Water Master Plan Study. Final Report Vol. 3 -Economics demography and water demands. January, 1991. GC 3516110 Botswana National Water Plan Study: Phase 2. Progress Report. December 1991. GC 3516111 Botswana National Water Master Plan Final Report Vol. 1. Summary. Study July 1991. GC 3516112 Sir M. Macdonald and Partners Motloutse Dam FeasibilitylPreliminary design study. Pollution Study. July, 1990. GC3713/1 Hydromin Consulting (Pty) Lld Page 37 Consolidated emergency water supply programme. Final Report. Vol. 1 relating to villages Pandamatenga BDF -Mabele and Kavimba. June 1991. GC 49/2/3 Consolidated emergency water supply programme. Final Report Vol. 2 relating to villages Pandamatenga - BDF - Mabele and Kavimba. June 1991. GC 49/2/4 Geophysical exploration of the Ncojane and Nosop sedimentary basin in Western Botswana. Annex-A November 1985. GC 49/4/1 Mmamabula groundwater resources investigation. Phase 11 - KhurutsheArea: Financial proposal for evaluation of groundwater resources (GS 10) TB 10/2/3/90-91. September 1990. GC 49/5/1 Water Resources Consultants Groundwater Development in five pilot ranches Hainaveld third development area, Ngamiland district. Final report, Vol. II February 1992. GC 53/4/2 Groundwater development in five pilot ranches Hainaveld third development area, Ngamiland district. Final report Vol. I., GC 53/4/1 Consolidated emergency village water supply programme: Final report Vol. 11990. GC 53/1/1a Groundwater development in Rooibrak area, Ghanzi district. GC 53/3/1 BGR Technical co-operation Project No. 78. 2250.5. Mineral exploration of the Kalahari (GS10) project. Geophysical, Geochemical and geological investigations in the Ngami and [ Page 38 Water Surveys Group Hydrogeological Exploration and Evaluation Project 15-13-23. Test pumping of boreholes 6500,6614, 6515,6516 and groundwater resource assessment of the aquifer along the Goatlhabogwe Valley. July, 1991. GC 69/2/1-3 Hydrogeological Exploration and evaluation groundwater investigation proposal: Final Report April - October 1991. GC 693/1-2. Hydrogeological Exploration and evaluation. Tobera Communal grazing. Final report. April, 1992. GC 69/4/1 Geoflux (Pty) Lld Groundwater Potential Survey: Toteng/Sehitwa TGLP area TB 10/2/5/90-91. GC 72/1/1-5b ZMCK Consulting Engineers Prequalification document for registration as an international groundwater consultant. GC 73/1/1 TIMM Consult Fifty five project proposals for Botswana in the fields of geology, groundwater, environment and industrial minerals. GC 74/1/1 Geragthy and Miller Inc. Environmental Services International Group 1989. GC 75/1/1 Halcrow National Water Master Plan. Consultancy Proposal Vol. 1 Technical Approach April 1989. GC 76/1/1 Tahal Consulting Engineers Qualifications in water resources management and development. GC 77/1/1 Lephephe - Mmamabula - Limpopo area preliminary proposal for the periormance of a feasibility study for the development of groundwater resources. May, 1986. GC 77/2/1 Knight Piesol.d Botswana Evaluation of underground water resources borehole records archive project (GS1 0). Final report. July 1991. GC 78/1/1 Morupule Power Station Pollution monitoring Annual Report. June 1992. GC 78/2/1. Poseidon Geophysics (Ply) Lld Operations report for the Khurutshe Aeromagnetic Survey. Mmamabula groundwater project - phase 11 on behalf of BRGM. March 1992. GC 79/1/1 B.R.G.M. Khurutshe Area Phase 11 Aeromagnetic Survey. October - November 1991. Survey 347,28 58 GC 79/1/2 Palla road area Aeromagnetic Survey. October - November 1991 Survey 347 28 58. GC 79/2/1 8.4.2 Reports and Publications The following Departmental reports were published during the year: Reports: • Annual Report for 1990 • Mineral Resources Report 11: The Aggregate and Building Stone Resources of Botswana by R. Kreimeyer, T.L. Siamisang and H. Kara. Maps: • Areas held under reconnaissance permits, prospecting licences and mining leases as at 1st January, 1992 (1 :2000 000). Areas held under reconnaissance permits, prospecting licences and mining leases as at 1st July, 1992 (1 :200000). Page 39 • Progress in Geological Mapping as at 31st December, 1991 (1 :2000 000). • Dibete 2326C • Mmamabula 23260 Sales of Departmental publications realised approximately P6 960.00 while about 700 publications were distributed free of charge and on exchange. The following internal reports were filed during the year: Aboneng, B G A report on chip samples recovered from seismic drilling operations in the Kalahari of South West Botswana. BGAll/89. Chatupa J C Description of Borehole OB 3(R) Core Section from the Letlhakane Mine Area. JCC/3192. Private Sector Mineral Exploration in Botswana. JCC 2/92. Gledhill, P A Borehole logging capabilities of the Geological Survey. PAGl/92. Koketso, H M Akiles Geophysical Survey. Final Report MHKl2/92. McMullan, S R Digital Vs Analogue EM - An African case history. SRM/1/92 Modie, B. N. Landslides in Botswana. BNM/1/92 Ntsimanyana, M The Geology of Molopo farms complex MN/6/92 The metal rich carbonaceous shales of Botswana. MN/5/92 Piper 0 P Report on lithostratigraphic drilling by De Beers Prospecting for the Geological Survey Department DPP/1192 Deep Sedimentary Basins in Western Botswana. DPP/2/92 Piper, 0 P and McMullan, S R Late Proterozoic and Basement Terrains in Botswana. DPP/3/92 SRM/2/92 Piper 0 P and Kreimeyer, R The Sengoma Quartzite formation and the upper part of the Sengoma argillite formation at Tsinane Hill, Lobatse. Results from stratigraphic borehole Les 1. DPP/4/92, RK 25192 Siamisang, T L Final Report on Matsiloje Limestone TLS/5/90. 8.5 Drilling Section 8.5.1. Introduction The Drilling and Mechanical Section of the Geological Survey has the main responsibility for providing drilling services to all field divisions of the Department. This Section's drilling production was once again severely hampered by the condition of the remaining department drilling fleet which consists of very old and obsolete rigs which are constantly under mechanical repairs. This problem resulted in most of the drilling projects not being completed within the expected time. Therefore a number of professional officers had to leave for their further studies without data for their MSc. theses. The new Edson 6000 w series rig, received in late 1989 from Australia, was expected to improve the drilling situation but due to the ever- increasing drilling work of the department, the rig did not cope with the work load. The second rig which could have improved production was expected in mid 1990, but due to some financial problems from the donor country - Australia (AIDAB), the rig has still not· arrived. At present, the drilling fleet of this Section comprises 6 machines. These are: Coring Rigs Soil test (augering) rigs Tone I Ranger 1 Tone II Proline Longyear 44 Page 40 Edson 6000 w series There is only one reliable rig amongst the 6 rigs, the Edson 6000 w series. The rest needs to be boarded and urgent replacement is required. 8.5.2 Staff The staff situation of the Drilling and Mechanical Section at the end of 1991 is as follows: Officer Post Vacant Chief Technical Officer C.K. Mpelege Senior Technical Officer T.B. Sekgopa Senior Technical Officer M. Ntloedibe Technical Officer M. Raditladi Technical Officer M. Molatlhegi Technical Officer K. Babitse Technical Assistant I. Ludick Technical Assistant It is hope that the vacant post of Chief Technical Officer will be filled in the near future to normalise the staffing situation. 8.5.3. Drilling Projects - 1991 A number of boreholes were sited at different places throughout the country. These boreholes were sited by various field divisions of this Department and were of different interest, ranging from mineral exploration, groundwater level/monitoring and recharge, field mapping and stratigraphy, and geophysical anomalies. No soil augering was carried out this year but a lot is expected next year when GRES PHASE 11 resumes project drilling. Projects carried out in 1991 as per rig were as follows. Longyear 44 Rig - Mabuasehube This drilling project was carried over from the 1989 annual drilling programme as it was not completed. This borehole is drilled for the interest of Geophysics Division on an anomaly 70 km south-east of Hukuntsi. This project should have been completed in 1990, but due to a considerable number of breakdowns, it was not completed as per estimated. Four to five months of work were lost in breakdowns. Another problems encountered was (still) lack of proper and good transport to suit that particular field area and camp water is fetched far from the drill site - Hukuntsi. By the end of the 1991 field season, (December) the borehole was down to 278 m. Edson 6000 w Series This rig started the field season late February 1991. The rig waited for a Rotary head drive shaft ordered from Australia. This head took too long to arrive so that we had to change to a coring head so as to carry on with other projects. The Kanye Hydrogeology project was suspended until the drive shaft arrived from Australia. The rig was then employed by Regional Geology Division at Ghanzi where a total of ten boreholes were drilled for field mapping purposes to the maximum of 100 m each. Two and half months's was lost due to lack of transport and water truck breakdowns. Tone Rig I & 11 These two rigs operate from one field area due to lack of transport. They were employed by two Divisions -Economic and Regional Geology. A total of fifteen boreholes of 30 - 70 m were drilled at Lepashe for the Regional Geology Division. This Division also proposed two more deep coring holes to be drilled by the Edson Rig in the same area depending on the availability of the rig. But this failed as the rig was fully employed by other Divisions. A total of ten coring boreholes were drilled at Mosetse/Matsitama as continuation of the above Regional Geology Division Project. These boreholes were not completed until the beginning of 1992 Page 41 February. These two rigs also experienced some breakdowns which resulted in a month and a half's work lost. By the end of 1991, only one tone rig (Tone I) was in operation while the other one was in Head Quarters for repairs. 8.5.4. Annual ProdUction a,s per Rig (estimated) Rig Total Meterage B/flushing Core D.T.H. Soil Test Tones 1&11 2200 Longyear 110 Edson 6000w 1000 Ranger 1 Proline 8.5.5 Outstanding Drilling Projects 1991 Longyear 44 Rig Two coring boreholes of unspecified depth and location were supposed to have been drilled at Dinokwe and Tsetseng for the Regional and Geophysics Divisions. Edson 6000w Series Two coring boreholes for Geophysics Division were to be drilled at Kraai Pan on some anomalies to the depth of about 125 m. Four D.T.H. bore holes for Hydrogeology Division were to be drilled at Pitsanyane for monitoring and recharge studies. Thirteen boreholes were to be flushed at various unspecified locations. One coring boreholes of 750 m was to be drilled at Passage for the Regional and Geophysics Divisions. Tones I & 11 Ten coring boreholes were to be drilled at Tlapana for Economic Geology Division - Industrial Minerals investigations. Each hole was estimated at 30 m. Twenty coring boreholes of 30 m were to be drilled at Selibe-Phikwe for industrial minerals - Economic Geology Division. Page 42