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x ·OX REPUBLIC OF BOTSWANA
ANNUAL REPORT
OFTHE
GEOLOGICAL SURVEY DEPARTMENT
FOR THE YEAR
1983
PRICE: P3,OO
PRI"'TED BY THE GOVEIt.l'MEf\T PRlf\TER, GABORO"'E, BOTSWA"'A MINISTRY OF MINERAL RESOURCES AND WATER AFFAIRS DEPARTMENT OF GEOLOGICAL SURVEY
[ DIRECTOR '-___ PelSOoal I SecretaI'( [DEPUTY DIRECTOR J
I '",001Secretary
~-RECORDS FIElO GEOLOGY HYOROGEOlOGY GEOPHYSICS ADMINISTRATION LABORATORY ~OFFICE ~~-SECTION LABORATORY Assislant Principal Principal I -Princij,lal I Director Geologist Geolo9ist ChemISt I I MIN. EXPLORATION MAPPING I S I Principal Chfet Technical Sen~r Senmr emor Administration Officer Geologist Geologist GeologISt officel lCanogrnphy) rh I -'- .-l Senior Senior Senior1 Senior Geol3gisl Gelwgis, Gelgisl Geologist I tlectronics Chemist Chemist ChI!mtst Technical Technical Technical Technical (2) I . (3) (~) Engineer I Officer Officer, Officer Off~er. Technical ASSl Admin. Officer Admin_ Officer Admin. Officer Senior 1, Geologist Technical Chemist Officer"'." Officer r- I Publicaoon ~"',""' A"tffi ~C""I""I Technical TechrOCal Technical r- OffICer Officer Officer Officer I I °re.fJ._1 I STAlTA STA/TA STA/T.A STA/TA STA/TA TA $AA/A S"hand TYPISt SAA/AA SAA/AA STAlTA STLTA STA~TA TA TA STA/TA ~r (61 (31 (101 Typist (21 (21 ( I (21
RECORDS MANAGEMENT REGIDNAl GEOLOGICAL EOPHYSICAl SURVEYS CHEMICAL ANALYSIS PRODUCTION OF MAPS DRIlliNG fOR WE OF PUBLICATIONS MAPPING lECTRONIC EOUIPMENT OF ROCKS MINERALS DRAWINGS AND MINERAL EXPLORATION GEOTfCHNICAl SURVEYS DESIGN ANO NATURAL WATERS PHOTOGRAPHS FOR GROUNDWATER SAMPtE STOMGf GEOCHRONOLOGY MAINTENANCE PUBLJCATIONS AND STRAT!GRAPH!C SURVEYS MINERALOGY/PETROLOGY ~ INTERNAL REPORTS GtQTECHNICAl SURVEYS
ADMINISTRATION Of REGIONAL HYOROGtoLOGICAl STAFF ·ACCOUNTS STORES ROCK AND MINERAL I, PRIVATE SECTOR MAPPING WATER BOREHDlE TRANSPORT SAMPLE PREPARATION EXPl.ORATION RECORDS REGISTRY TYPING INDUSTRIAL DEPARTMENT EXPLORATION GROUNOWATER STLJ[)IES MINERALS TESTING --_.. 1. GENERAL
1.1 Introduction
The Geological Survey Department 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, miner~ deposi ts and groundwater resources of Botswana. The depart- '.c.:: mental organisation remained as in previous years and consists of the Directorate, three operational divisions of Field Geology, Hydrogeology, and Geophysics, plus an administrative and training division. Support to these divisions was provided by the Chemistry and Industrial Minerals laboratories, drawing office, library and records, and drilling sections.
The staffing position within the professional and technical cadres remained reasonably satisfactory, making 1983 a generally productive year in all the operational divisions. The posts of senior chemist and technical records officer remained vacant throughout the year, and following various staff changes seven professional vacancies existed at the year's end. Two long serving members of the department, Mr. R.J. Peart, geophysicist, and Mr. E. Milner, electronics engineer, returned to the U.K. on completion of their tours, both having served in the department for eight years. Mr. Milner's post was
1 filled by Mr. B. Tlhabologang whose appointment increased the number of localised professional posts to five. Dr. C. Mortimer, Assistant Director, left in November on completion of his tour of service and his post was occupied by Mr. M.P. Modisi on confirmation of his appointment to PR1 grade. The new Assistant Director represents the first stage of localising the Directorate, a localisation programme that will be completed in early 1984 when the Director and Deputy Director posts will be taken over by Mr. T.P. Machacha and Mr. M. Sekwale respectively, on completion of the present incumbents' tours of service
A generally satisfactory work programme was completed by the Field Geology division. The final reports of the field surveys conducted last year were completed and field mapping continued with the production of the first edition geological sheets of poorly exposed ground in southern
Bot~wana (QDS 2425D, 2525C, D). The division continued with its strong exploration activity in the field of industrial minerals and, to a much lesser extent, in base metal exploration. The Mineral Resource Report No. 6, describing the Carbonate deposits in Botswana, was published during the year. A close overview of the exploration work undertaken by the private exploration companies was main tained where the main thrust continued to be directed towards the search for diamondiferous kimberlites and the detailed evaluation of the known coalfields.
Both the Hydrogeology and Geophysics diviSions were
2 heavily involved in groundwater exploration and development projects. A considc?rable amount of the work undertaken was in direct response to the countrywide drought conditions, and to the serious water supply shortage to the Gaborone Lobatse area. In association with the Department of Water Affairs much effort has been directed to the search for groundwater in the eastern part of the country.
Despite the emergency drought relief projects, work continued on the production of the 1 :500,000 hydrogeological reconnaissance map sheets, and support on this programme is being provided through a research project being under taken jointly with the Department of Geology, University of Botswana. The geophysics division supported a research project by the University of Michigan, USA, whereby heat flow measurements were obtained from deep boreholes drilled at several localities throughout Botswana. One very important finding from this study was the identification of high rock temperatures within the Kgaswe coalfield. The principal geophysicist, Mr. D.G. Hutchins, was heavily involved in the organisation of a seminar entitled 'Mineral Exploration in the Kalahari'. The seminar, organised jointly with the Botswana Geoscientists Association, and which was chaired by Professor D. Pretorius of the University of Witwatersrand and attended by more than 120 delegates, was formally opened by the Minister for Mineral Resources and Water Affairs, Dr. G.K.T. Chiepe. A strong input to the seminar proceedings was provided by the department with
3 the release of the results of the various bilateral funded
mineral exploration projects undertaken in the Kalahari
within the last three years.
In the support section the Drawing Office had a very
'full work programme and towards the year's end much effort
was directed towards completion of the second edition of
the Geological Map of Botswana, to be published in early 1984. In the, chemistry laboratory Mr. Sutcliffe departed
in July on completion of his contract and for most of the second half of the year only one professional chemist was
in post, )who was, however, strongly supported by a full complement of technical staff. Mr. D. AlIen, diamond driller, joined the department in January, and the second driller post was occupied in May by Mr. R. Gagne, who is to take charge of a CIDA funded driller training project.
Two of the bilateral funded technical aid projects were completed during the year. The final phase of the
CIDA funded GS-12 project, Airborne Magnetic Survey, was completed with the preparation of a final report and accompanying maps. The project leader, Mr. H. Meixner, left Botswana in July. Within the GS-17 project, Mineral
Exploration in the Kalahari, that part of the project funded by the Republic of West Germany was completed in December and an interim report prepared, with the final published report becoming available in early 1984. The U.K. funded part of the GS-17 project, over the Molopo Farms area finalised all the required field work and the
4 final report will be completed in mid-1984.
Two new bilateral aid projects were initiated, both funded by CIDA. The diamond driller training project commenced in May, it will continue for two years and is designed to produce Batswana diamond drillers at the T3 level. The CIDA funded programme to localise the geophysics division commenced and four Batswana students have been sent to Canada for graduate training in geophysics. The project includes facility for technician training to diploma level and it is anticipated that in total six students will be sent for degree courses and eight for technical training, the total input by the project being some 52 student years.
Both the U.K. and the Republic of West Germany have expressed interest in financing and undertaking further mineral exploration projects. Subject to formal approval by Botswana and the donor governments it is anticipated that a mineral exploration project over the Vumba schist belt, Northeast District and funded by West Germany, will commence in 1984. The U.K. government are reviewing the possibility of undertaking a mineral exploration/mapping project over the Ghanzi ridge, although this project may not commence before 1985. It is also anticipated that other groundwater or mineral exploration studies, perhaps funded by Italy, France and Sweden, will be initiated in 1984.
5 HYOROGEOLOGICAL RECONNAISSANCE MAP OF THE REPUBLIC OF BOTSWANA AI SCAII. I bllll IIIH) PROGRESS IN M~.PP!NG AS AT 1.5.84
Published
I: :: Awaiting production J ~~~~j Under rovislon G_~: ;: in Dra\r\ling Office ---
19 5. HYDROGEOLOGY DIVISION
5.1 Introduction
During 1983 the Hydrogeology Division has been almost entirely engaged in groundwater exploration and development projects as a result of the drought and the water shortage crisis for Gaborone - Lobatse. Projects initiated to attempt to alleviate the serious water shortage, such as those at Ramotswa, Molepolole, Letlhakeng, Lobatse/Nuane, Lotlhakane, Palapye are not fully completed and will continue into 1984.
Progress on long term projects not directly related to an immediate water demand were either deferred or delayed and requests, largely from the agricultural secto~ for assessment of groundwater resources and professional advice on groundwater development projects could not be attended to.
The active involvement in groundwater exploration and development, however, has generated new hydrogeological information which will assist with the assessment and management of groundwater resources. It has also broadened the expertise of the Division and an important contribution towards securing a satisfactory water supply to Gaborone/ Lobatse and Mochudi has been made.
20 A co-operation agreement with the Department of
Geology, University of Botswana, has been established.
Under the agreement two projects have commenced with hydro geological mapping of southeast Botswana and monitoring plus modelling of a dolomite aquifer near Lobatse.
Groundwater monitoring networks have been set up at
three aquifers in southeast Botswana. Monitoring is essential to obtain data for the determination of ground water recharge and the assessment of groundwater resources.
To arrive at reliable calculations for recharge and resources observations over several years are required and
monitoring will therefore be an ongoing activity for some time to come.
Consulting for Government and public is an all year
round task and during 1983 major issues have been the
Domestic Water Law Consultancy, the Eastern Botswana Water Resources Study, the effluent disposal study for Morupule Power Station (BPC), the groundwater potential study for the IFPP area (Ministry of Agriculture), the reinstatement
of the wellfield in the Lobatse Estates Southern Basin (WUC), the operation of the Ramotswa wellfield (DWA, WUC).
Training of Technical Assistants continued throughout
1983. Results are very satisfactory and Assistants are assigned to carry out work without direct supervision.
21 5.2 Groundwater Exploration and Development Projects
Mochudi Water Supply
Staff: D. Buckley, hydrogeologist; J. Keakile, senior technical assistant work organisation, geophysical
surveying, supervision of drilling operations, test pumping; T.K. Ntesang, levelling of borehole heads; T. Kgole and L. Mogotsi in service training.
The project which commenced in March 1982 was completed in October 1983. After Phase I was completed in June 1982 work was suspended to November 1982 when a drilling rig was made available from the Department of Water Affairs.
A total of 38 boreholes was drilled, of which 12 were dry, 18 had low yields between 1 and 6m3 /h, one was abandoned because of a lost drill bit, and the remaining 7 boreholes had a yield of 8m 3 /h or more with one borehole yielding 58m3 /h and one 45m 3 /h. Boreholes with lower yields are in the granite basement southeast of Mochudi, whereas the higher yielding bore holes are in Waterberg rocks northwest of the village. The total resource / identified is 2000 m3 /day which will be enough to supply Mochudi for the next ten years at the current growth rate.
New hydrogeological findings from the study confirmed that the Masama Sandstone has more groundwater potential that the rest of the Waterberg sequence and future investi-
22 gations should concentrate on this stratigraphic unit within the Waterberg. Groundwater flow in the Waterberg rocks, as well as in the granites, occurs along discrete zones associated with fracturing and dolerite intrusions. Inclined boreholes have a greater chance of intersecting
vertical/subvertical fracture zones which are easily missed by a vertical hole.
Palapye Water Supply
Staff: Dr. Neumann-Redlin, hydrogeologist; T. Kgole and L. Mogotsi in service training.
The project commenced in June. After compilation and evaluation of existing data a target area southeast of
Palapye was selected for geophysical surveying. Six sites were selected for a phase one drilling programme to start January 1984. Sites are in contact zones of dolerite dykes and on north-south trending lineations believed to be tension fractures.
Molepolole Groundwater Project
Staff: D. Buckley, hydrogeologist.
The department provides professional supervision to this project which has been contracted out to Steffen Robertson and Kirsten, Consulting Engineers. The project forms part of a regional investigation of groundwater
23 resources for the future water supply of Gaborone and Lobatse. The consultant commenced work in October evaluating the potential of the Waterberg rocks and an interim report on the siting of boreholes is being awaited.
Letlhakeng Groundwater Project
Staff: M. Sekwale, hydrogeologist, and D. Buckley,
hydrogeologist.
This is a further project for regional investigation of groundwater resources for the future water supply of
Gaborone and Lobatse. Work commenced in June with compila tion of existing data, followed by geophysical investigations in two identified target areas. These investigations aim at delineating the contours of the basement and major structural features developed in the Karoo succession. Geophysical field work under a first phase were completed in December. Data interpretation followed. Major structural features could be detected and with a second phase of geophysical investigations the location and nature of these features are to be determined in detail. Drilling will be undertaken by the Department of Water Affairs in February 1984.
All geophysical work in this project is carried out by the Geophysics DiviSion.
24 Ramotswa Project
Staff: Dr. M. von Hoyer, hydrogeologist; J. Phiri in service training; T.K. Ntesang, levelling of borehole heads. Drilling by Department of Water Affairs.
This project was initiated to identify an alternative source for the Gaborone water supply. Work commenced in June with a study of the hydrogeology of a karst aquifer developed in Transvaal dolomites and investigations were then extended into shale/quartzite formations of the same succession. By the end of the year a total number of 13 boreholes had been drilled, 3 in shale/quartzite formations and the remaining ten in dolomite. Two boreholes were dry, three had low yields in the range of 1 to 3m3 /h and eight had yields between 20 and 150 m3 /h. Drilling operations are not completed and will continue in 1984 with the drill ing of two more sites in dolomite.
Although the total resource developed has not as yet been assessed in detail it is obvious that a groundwater resource of considerable volume has been located. Since end of November three production boreholes have been in operation delivering between 4500 to 7000 m3 /day to Gaborone through a recently constructed pipeline.
New hydrogeological findings from this project indicate that karstified dolomites have good groundwater
25 potential as, to a lesser extent, have Transvaal shales. Karst is developed along structural features which fall into a regional tectonic stress pattern. Tension fissures in the area are north-south oriented. A shallow and a deep karst zone is developed. Borehole siting by geolo gical, geomorphological and karsthydrogeological methods as well as structural analysis generate good success rates. It has been found that geophysical input can be reduced to detailed investigation of selected small size target areas.
Drilling in karst formation can be extremely difficult and may therefore be time consuming and costly.
Lobatse Project
staff: Dr. M. von Hoyer and M. Sekwale, hydrogeologists.
This project was developed to locate more groundwater supplies as an alternative to the surface water supply to Lobatse from the Nuane Dam. The project investigated the possibility for locating an extension of the existing Nuane wellfield. The contract for siting was awarded to Wellfield Consulting Services. The department provided the profession al supervision for the client the Department of water Affairs. Boreholes were drilled on 10 sites. Three potential production boreholes were identified each of which are estimated to have a yield of approximately 60m3 /h. Drilling in karstified dolomites caused great difficulties. The project is not fully completed as there are plans to
26 ream the three boreholes to a larger diameter.
As part of the same contract the dolomite area south east of Lobatse was investigated. Four boreholes were drilled of which only one could be a potential production borehole.
Lotlhakane Project
Staff: Dr. M. von Hoyer, M. Sekwale, hydrogeologists.
This is another project to identify additional ground water resources in Transvaal dolomites for the future water supply of Lobatse and Gaborone. The contract for siting was awarded to Wellfield Consulting Services. Under the professional supervision of the Geological Survey boreholes were sited by the consultant. Under a first drilling phase
5 boreholes were drilled of which one borehole appears to have a good yield. Seven additional sites have been selected but further drilling has been deferred to 1984.
5.3 Groundwater Monitoring
Staff: Dr. M. von Hoyer, hydrogeologist.
Monitoring of groundwater quality continued in the area of the Lobatse Sewage Treatment Ponds. Monitoring systems were installed at Nuane wellfield (Lobatse) and at
Ramotswa wellfield. In both areas do10mt te aqu..i.f"rs are
27 under observation. The monitoring and evaluation of data for the Nuane wellfield is carried out in co-operation with
the University of Botswana. An aquifer model has been produced which is continuously updated as new data are collected.
5.4 Hydrogeological Mapping
Staff: S.A. Bruno, hydrogeologist and Dr. J. de Vries of
University of Botswana.
Work on this long term programme was much reduced because of the heavy involvement of the Division in ground water exploration under the current drought conditions.
Map sheet No. 7 has reached 75% completion. Map sheet
No. 11 which is being compiled under the co-operation agree ment between University of Botswana and the Geological Survey has reached 50% completion.
5.5 Other groundwater studies
Study on Groundwater Potential in the Integrated Farming Pilot Project (IFPPh West of Lobatse
This desk top study assessed the groundwater potential in the IFPP area and sets out recommendations for the
28 development and utilisation of the groundwater resources.
Borehole Reconnaissance of Paje Wellfield for Botswana
Power Corporation (BPC)
A borehole reconnaissance in the greater Paje wellfield area was undertaken in preparation for a planned bore hole census. With the census to be carried out by BPC, the present state of the groundwater table conditions should be recorded prior to planned abstraction from the wellfield. The census is to establish base line conditions along which possible future claims for compensation from private borehole owners would be assessed.
Lobatse Borehole Inventory
On request of Water Utilities Corporation and the
Lobatse Town Council boreholes within Lobatse township area presently unused werp identified in the field, their present
status recorded and their yield potential assessed from records. With this inventory 24 potential supply boreholes for non potable water have been identified. During drought periods and periods of water restrictions the boreholes could supply water for non-potable use, such as construction works.
BPC Morupule Power Station, Effluent Disposal
Water Apportionment Board and Ministry of Mineral
29 r
Resources and Water Affairs were assisted with the investi gation of a possible threat of groundwater pollution from effluents of the planned power plant. A desk study was
prepared.
Eastern Botswana Water Resources Study
This study was prepared by VIAK Consultants. The department contributed towards the hydrogeological part of the study through meetings and discussions with the Consultant and arranged access to data, records and publications. At advanced stages of the study comments were submitted on hydrogeological issues.
Study for possibility to Develop Fresh Groundwater for
Nata Water SUpplY
On request of the Department of Water Affairs an area of 50km radius around Nata was studied and an aquifer with
fresh water was identified within 30km distance of the village. Existing data and hydrogeological maps were used for this desk top study.
5.5 Borehole Records Archive
Work on up-grading and updating of borehole location maps and transfer of data on computer storage continued.
It did not, however, proceed with the speed desired due to
30 activities under the drought and water supply crisis
demanding priority.
Data for boreholes north of the 20th lateral were updated and stored on computer and borehole location maps
compiled.
An increasing number of members of the public make use of the data archive and seek advice on drilling and general
groundwater aspects.
5.6 Research Projects in Co-operation with Outside Institutions
A co-operation has been established with the University of Botswana by which University staff will undertake research
studies on recharge processes in dolomite aquifers in south~ east Botswana. Finance for the studies will be provided by the Netherlands government through the Free University of
Amsterdam. University students will be involved with~ this research work where possible. A further project to be completed by the University will be the compilation of the hydrogeological map. Sheet number 11, on the scale of
1 :500,000. For the cooperative projects the Geological Survey provides equipment, labour, office space, laboratory services and professional back-up where required.
Professor Verhage, University of Witwatersrand is undertaking investigations on groundwater age in Cave Sand-
31 stone and Ecca aquifers. BGR assisted with setting up of a new computer programme for the storing of boreholes data. The new programme is a modified and somewhat enlarged version of the established programme.
5.7 Conferences, Travelling Abroad
Mr. Sekwale attended the International Symposium in the Netherlands on Methods and Instrumentation for the Investigation of Groundwater Systems. Thereafter he paid a visit to BGR, Hannover, West Germany from 10.5.83 to 11.5.83. Mr. Sekwale also attended the International Groundwater Conference - Groundwater and Man in Sydney, Australia.
Dr. Neumann-Redlin visited the Satellite Remote Sensing Centre in Hartebeesthook, R.S.A. for purchase of processed satellite imagery and he held discussions with Professor Verhage, Witwatersrand University, on a study of groundwater age for some of Botswana's groundwaters.
32 bodies existed in close proximity to the project boreholes.
No obvious conductors were located.
6.3 Departmental Activities
6.3.1 Hydrogeophysical Surveys
As a result of the drought conditions prevailing in
Botswana during 1983 the geophysics division was engaged on numerous surveys for underground water. These surveys included major regional studies for township supplies and
smaller surveys for isolated village and farming requirements.
Mochudi Ground Water Project
Geophysical support to this project included recommend ations on survey procedure, the interpretation of the survey
data collected by the hydrogeology division and geophysical logging of selected boreholes. In addition a short geo physical survey was conducted to locate an additional borehole in an area where one very successful borehole had been drilled whilst subsequent nearby wells had proven dry. Eight kilometres of magnetic traversing and seventeen kilometres of Schlumberger soundings were conducted and located an anomalous resitivity zone some 200m wide extendJ.ng from the successful bore hole (No. 4284) in a westerly direction. This anomalous zone was interpreted as a weathered fault zone and a borehole sited to intersecL \;JJJll zone was successful.
35 Ramotswa Ground water Project
The Ramotswa area was selected as a possible ground
water source to supplement existing supplies to Gaborone and Lobatse, and Wellfield Services were contracted to undertake the geophysical investigations. The geophysics
division was responsible of the supervision and planning of the geophysical surveys, direct supervision of the contract ors in the field, and finally for the interpretation of the data leading to the selection of well sites, in consultation with the hydrogeology division.
Lobatse Ground Water Project
Wellfield Services were contracted by the Department of Water Affairs to review the groundwater potential in the Nuane area, north of Lobatse. The investigation was to include a review of existing data followed by selective drilling based on geophysical surveys over selected targets. The geophysics division was responsible for the supervision of the project and selection of the borehole sites in consultation with the contractor.
Letlhakeng Underground Water Project
An area northwest of Molepolole, to the south and west of Letlhakeng has been identified as a possible groundwater resource for the supplementation of the Gaborone and Lobatse water supply. The first phase in the evaluation of this resources, a ground geophysical survey leading to the
36 selection of test drill sites, commenced in June and the field work consisted of linecutting (116 kms), magnetic
traverses (154 kms) and electrical soundings (105 kms), and several areas of interest have been identified. Further work, principally VLF E.M., to locate fracture zones recognised from the geophysical survey, is planned prior to drilling selected targets in March 1984.
Palapye Groundwater Project
This project was commenced towards the end of 1983 by the hydrogeology division and advice was given on the geo physical aspects of the project as well as training of field personnel. Assistance, particularly regarding the interpre tation of the geophysical data, will continue into 1984.
Other hydrogeophysical surveys
Geophysical siting of boreholes was conducted over four ranches in the Nata area which are to be developed for the Group Ranch Scheme by the Animal Production Division, Ministry of Agriculture. The survey comprised some 16 kms of line-cutting, 45 electrical soundings and two test IP soundings.
Three sites were located on Farms Po-11, Po-10 and Po-14, where the electrical soundings inalcated a possible fresh water aquifer overlying conductive (saline) Kalahari deposits. On farm Po-15 electrical soundings indicated that saline conditions existed throughout the area Bnd
37 n !
consequently dril~ingwas not recommended. Drilling on the
other farms proved successful with satisfactory yields being / obtained.
A short geophysical survey was conducted over the Molokwe holding ground near Lobatse. Three survey lines
were prepared to intersect possible fracture zones and were geophysically surveyed using the following techniques:-
Magnetometrics
Pulse electromagnetics Spontaneous potential and electrical
resistivity (gradient array) !
Three borehole sites were s~lected showing the interpretation of the geophysical results.
A borehole for Ditlharapeng village was sited following
geophysical surveying over two survey lines oriented to
i~tersect possible fracture zones recognized from aerial
photography. The geophysical survey, magnetometrics, spontaneous potential and electrical resistivity (gradient
array) located two possible sites for the borehole.
6.3.2 Mineral Exploration
Kalahari Kaolinite deposit
A kaolinite deposit, some 4 metres thick, was intersec- ted by borehole CKP5 located in the vicinity of Mabuasehube and drilled as part of the Canadian Kalahari Project. The
38 orders were placed for parts and spares. While some class- room work is included in the course, emphasis is being
placed on practical on-the-job training.
7.2 Airborne Magnehc Survey: Ground-truth drilling (GS-12) (CIDA funded project)
Project leader: Mr. H. Meixner
Field work for this project was completed in 1982 and the on-going activity during the year was the preparation by the project leader of the final geological report.
Following a three month extension to his tour in Botswana, Mr. Meixner completed his input into the preparation of the
report and left Botswana in July. The report, with the accompanying full colour map of the Geological Framework of
western Botswana and adjacent areas will be published as a departmental bulletin. The preliminary results of the drilling programme were presented at the seminar on Mineral
Exploration in the Kalahari, held in Gaborone in October.
7.3 Okavango Groundwater Development Project (GS-13)
A revised project memorandum was prepared by the hydro geology division and submitted to the Ministry for approval. Copies were made available to prospective donors. By the
year's end two possible donors were identified and it is possible the project, now defined as groundwater resource
45 studies in two areas south of Maun, may be implemented in
1984.
7.4 Mineral Exploration of the Kalahari (GS-17)
7.4.1 Molopo Farms Project GS-17 (U.K.) (U.K. technical co-operation)
Project leader: Dr. D. Gould
Geologist: Dr. P.A. Rathbone
The core-drilling contract, employing Land & Marine Engineering (Overseas) Ltd. from U.K., and supervised by
the project geologists, which commenced in 1982, continued through to July 1983. Papers on the regional geology and
the gravity survey of the project area were presented at the Mineral Exploration in the Kalahari seminar in Gaborone. The remainder of the year was spent in petrographic description of thin sections of borehole core and revision of borehole logs.
A total of 5603 metres was dr illed dur i ng 1983, of which 3196 metres were cored, bringing the total for the contract up to 10 065 metres (4652 metres cored). The Halco D 1000 rig continued to drill the shallower holes using both open-hole and coring methods, as well as piloting the deeper holes for the Longyear 44 rig. Hydraulic problems on the Halco rig caused the loss of 10 days in February, but thereafter the Halco performed satisfactorily.
46 Final Report Volumes 1, 2 & 3
Report on Geophysical Borehole Wellfield Consulting
siting in Botswana Services
8.4.1 Publications
Aldiss, D.T. The Geology of the Semolale area. Bull. 25. Geol. Surv. Botswana
Gwosdz, W. and The Carbonate Resources of
Modisi, M.P. Botswana. Mineral Resources Report No. 6. Geol. Surv.
Botswana
McEwen, G. Annotated Bibliography and Index of the Geology of Botswana, 1971-
1976. Geol. Surv. Botswana
8.4.2 Internal Reports
The following internal reports were received by the library.
Aldiss, D.T. 1983 Notes on the photogeological interpretation of Tsetsejwe and Semolale areas. DTA/6/83
Cheney, C.S. 1982 A method for the determination of the effective porosity of rock
samples. CSC/1/82
64 Farr, J.L. and 1983 Bibliography of hydrogcology :Ln Neumann-Redlin, C. Botswana; unpubl-ir;hed reportB. JLF /3/es, CNn/'7/fl3
Gould, D. and 1982 The Geology of the Molopo FlU'Ill:3
Rathbone, P.A. project area. DGS/18/82
Gould D. and 1983 Lithological logs of boreholeB Rathbone, P.A. drilled -in the Molopo Farms project area. DGX/20/83, PAR/3/83
Gwosdz, W. 1983 Gypsum reserves at Bojanamane, Central Distr-ict, QDS 2227A. WG/44/83
Gwosdz, W. 1983 Remarks upon magnetite prospects in eastern Botswana. WG/45/83
Hutchins, D.G. 1983 Geophysical test survey in the Orapa area. Final Report. DGH/32/83
Hutchins, D.G. 1983 A short note on hydrogeophys-ical survey conducted for the Mochud-i underground water project. DGH/33/83
Hutchins, D.G. 1983 Apparent resistivity maps of Botswana. DGH/34/83
Kara, H. 1983 A report on samples from Brick
65 Earth deposits at Peleng (Lobatse) Letlhakeng and Maunatlala.
HK/7/83 Lock, N.P. and 1983 Moisture testwork on a coal Kara, H. sample from Morupule Colliery.
NPL/9/83, HK/8/83
Machacha, T.P. 1983 Evaluation of the economic potential of the Mmathethe granite
TPM/10/83
Modisi, M.P. and 1983 Moombo soil investigation. Kara, H. MPM/10/83, HK/4/83
Mukhopadhyay, S.K. 1983 Manual for routine analysis of water samples. SKM/1/83 Mukhopadhyay, S.K., 1983 Hydrogeochemical investigations
Malejane, R.J. and of the Molopo Farms. SKM/2/83,
Sutcliffe, H.S. RJM/2/83 and MHS/2/83
Mukhopadhyay, S.K. 1983 Analysis of three carbonate and Matlapeng, A.R. samples for use as reference material. SKM/3/83
Peart, R.J. 1983 A short note on a seismic refraction survey conducted in
the Palapye area to locate quarry
material. RJP/23/83
.~ Neumann-Redlin,C. 1983 Nata water supply, Desk Study.
CNR/6/83
66 Neumann-Redlin, C. 19133 j-t(-;-;pUf'L on ;1 />()]'(l)I()II' 1+('('I)!III/JI",~
":;:111' ' I' 11 J' 1 1", I' 11 ,'J " '11,' 1 1 I' 1" 11 1 •
Sekwale, M. CI'()UIIJIWIII,I'I' i'"II,"I.IIII ;',III'VI',Y, IJ
desk study 1'01' intogl'u LC'd .C.>I'III i 11/', pilot project, Southern DisLr'i(:1,. MS/12/83
Sekwale, M. 1983 Morupule Power Station grouncJ
wa ter pollution assessmen t; de:: k study, Central District. MS/13/83
Smith, R.A. 1983 Comments on the geology of the Mmamantswe area, subsequent to the relinquishment of BP Licence 5/82. RAS/5/E33
Von Hoyer, M. 19132 Report on borehole siting for integrated project (IFPP) Pelotshetlha and Diabo areas, Southern District. MVH/1/82
Von Hoyer, M. 1983 Lobatse Sewerage Scheme ground water monitoring network in the treatment plant area, Lobatse Estates. MVH/2/83
67 Zeil, P. 1983 Hydrogeophysical survey conducted over the proposed extensions to the Nata Ranches. PZ/1/83,
RJP/24/83
Zeil, P. 1983 PEM Borehole Survey at Ngami Area.
PZ/2/83
8.5 Drilling Section
Mr. D. Allen, on OSAS contract, was recruited in the first quarter of the year to fill one of the senior technical
officer (drilling) vacancies.
Drilling commenced in the Kgaswe coalfield with the
Hydreq-Gryphon drill and wire line equipment, the objective was to collect cores of the three main seams for petrographic analysis and capacity moisture determinations. The trailer mounted Boyles BBS 17A rig was employed for the Roads Depart ment to examine the potential of calcrete aggregate deposits
at Sekoma Pan, Kgalagadi District. Fifteen shallow core holes were drilled.
On completion of the boreholes at Kgaswe, the Hydreq
Gryphon rig was moved to Ramotswa to drill monitoring bore holes for the Ramotswa wellfield. The available down the hole tools were unsuitable for the rock formations
encountered, so the project was temporarily suspended pending acquisition of suitable equipment. The rig then
68 moved to Dinokwe, Central District, to explore the possible
coal development north of the Zoetfontein fault. This programme is presently in progress and will be completed in
early 1984.
On the job experience was provided for the trainees attached to the Driller Training Scheme. Mr. R. Gagne, the drilling instructor to the training scheme joined the department in May.
69