BRITISH GEOLOGICAL SURVEY -LIBRARY SERVICES Serial No. l/v, <: t~:'::O 93 &an /' ._ .. Dispia Xemx / Geo~y. Map Lib ~ ;<.. Min . ;tjm=.s..P.- ..~ ..· .....- ...-. -;z:~.-==-- Cat. /' Mill. S~~,!~~F~~= Cmulate In: RelOID to ~ Library
REPUBLIC OF BOTSWANA
,> (.:' ,:' .:-)
ANNUAL REPORT
OFTHE
GEOLOGICAL SURVEY DEPARTMENT
FOR THE YEAR
1984
PRICE: P3,OO
PRI1\"TED BY THE GOYEIlI'\MENT PRll'\TER, GABOROI'\E, BOTSW,\l\'\ 1. GENERAL 1.1 Introduction
The Geologicfll Survey Department remained within the Ministry of Mineral Resources and Water Affairs and continued wi·~h its main funct.ions of gathering, assessing, and disseminating all data related to the rocks, mineral deposits and groundwater resources of Botswana. The departmental organisation remained as in previous years and consists of the Directorate, three operational divisions of Field Geology, Hydrogeology and Geophysics, plus an administrative division. Support to these divisions was provided by the Chemistry and Industrial Minerals laboratorLes, Drawing Office, Library and Records and Drilling sections.
The staffing position within the professional and technical cadres remained "reasonably satisfactory, though the Geophysics and Hydrogeology Divisions were understaffed, mainly because of the recruitment freeze imposed following the water restrictions introduced in the Gaborone-Lobatse area. The posts of Senior Chemist and Technical Records Officer were both filled in 1984.
A long serving local officer, Mr. R.J. Malejane, retired from the Civil Service after working for more than 20 year's at the Survey. Mr. D. Buckley, Hydrogeologist, returned to the UK on completion of his tour, having served in the Survey for three years, while Dr. Chr. Neumann-f((,dlin, Senior Hydrogeologist, returned to BGI!, Hannover, after serving for
5 1/2 years with the Geological Survey Dl?parCrnent.
1 Mr. C. Black, Deputy Director, left the Survey in early
1984, when his post was localised by the appointment of Mr.
M. Sek,"ale.
Thus 1984 saw the completion of the localisation process
initiated in late 1983 with the appointmen: of IVJr. M.P. Modisi
as Assistant Director. On the 1st of January, 1984, Mr. T.P.
Machacha and IVJr. M. Sekvvale were appointed Director and
Deputy Director respectively, while Dr. G.C. Clark, former
Director, \Vas appointed adviser to the new incumbents for a period of six months. Dr. Clark finally left the Survey in
July, 1984, after serving with the Department for a period of nine years.
A satisfactory work programme was completed by the
Field Geology division. Final reports of surveys conducted in the previous year were completed. Field ~llapping of the poorly exposed parts of Southern Botswana, (ODS 2421+D and
2525C,D) was completed. Mapping of the Foley quarter degree sheet (ODS 2127C) was completed and the accompanying map and bulletin were to be compiled in 1985. Field mapping of the
Letlhakeng Sheet (ODS 2425A), was started this year while preparations for mapping the Kanye Sheet (OD:,) 21+25C) were underway.
The division also continued with its strong exploration activity in the field of industrial minerals and a limited amount of work in base metal and coal exploration. The
Mineral Resource Report No. 7, on the potential for quick lime production, was published during the year.
2 A close overview of the explorat.Lort work undertaken by the private exploration companies was maintained, where the mal n thrust continued to be directed toward,; the '.leuI'ch for diamondiferous kimberlites and detailed evaluation of the known coalfields. This year also saw a lot of interest being shown in base metals and platinum group metals in the Molopo
Farms Complex.
Both the Hydrogeology and Geophysics divisions continued to be heavily involved in groundwater exploration and development projects. However their work was slowed down by the recruitment freeze imposed during the year because of the water restrictions. The two divisions continued to do work in response to the country wide drought conditions and to the serious water supply shortage in the Gaborone-Lobatse area. The Department, in conjunction with the Department of
Water Affairs, continued the search for water in parts of eastern Botswana. All groundwater explorat.ion and development projects introduced in the work programme in 1984 under the drought and the Gaboroile-Lobatse water supply crisis were completed during the year.
Work on the production of the 1:500 000 hydrogeological reconnaissance map sheets was continued during 1985. Map
Sheet No. 11 was compiled and completed, while the compilation of map sheet No. 8 was started. This m~pping programme was a joint research project with the 'Department of Geology at the
University of Botswana.
The Geophysics division conti nued to ,mppo[' t Cl reBearch project by the University of Michigan, USA, whereby heat
flow measurements were obtained from deep boreholes drilled
at several localities throughout Botswana. The final measure
ments were made in July, 1984.
In the support section the Drawing Office completed the
second edition of the geological map of Botswana, which was
finally published in early 1984. The Chemistry Laboratory
was for the first time fully staffed, with four pro1fessional
chemists. In late 1984, however, most the technical staff
had left the Survey for overseas courses. The drilling unit
continued to be staffed by two expatriate drillers.
One bilateral technical aid project funded by the UK
as part of the GS-17 project over the Molopo Farms area was completed in 1984 and the project leader, Dr. David Gould, left Botswana in September.
The two new aid projects initiated by CIDA in 1983 continued to run smoothly in 1984. ThesE' ... are the driller training project which started in May, 1983 and is due to end .in May, 1986, and the CIDA funded prq,gramme to localise the geophysics unit. DUTing this year three more students were sent to Canada for training as geophysicists and electronic engineers. Two other students were also sent to
Canada to train as geological technicians.
The German government started another technical aid project as a continuation of the GS-17 programme. The project is for mineral exploration over the Vumba Schist belt, North east District. The project started in September, 1984 and is
4 due for completion in August, 1986.
The UK government carried out a feasibility study on the possibility of undertaking a mineral exploration/mapping project on the Ghanzi-Chobe foldbelt. Their conclusions were positive, so that if funding is available this project is expected to take off in late 1986/early 1987.
5 5. HYDROGEOLOGY DIVISION
5.1 Introduction
The year 1984 saw the completion of all groundwater
exploration and development projects which had been introduced in the work programme in 1984, under the drought and water
shortage crisis in Gaborone and Lobatse.
As the year progressed the division was increasingly affected by the recruitment freeze imposed by government early in 1984, following the introduction of water supply restrictions for Gaborone and Lobatse. Posts falling vac8nt during the year could not be filled in time to maintain continuity in the divisional work. After May, 1984 no new projects were accepted. The shortage of experienced hydrogeologists hampered the training progr~mme for local hydrogeologists and severely reduced the capacity of the division as consultants for
Government and public.
As hydrogeologists left and projects were completed all remaining resources were concentrated on the training of local hydrogeologists as well as technical assistants. The ground water monitoring programme, largely operated by technical assistants, was expanded and further efforts concentrated on the up-grading of the borehole records archives.
Mr. Marobela and Mr. Selaolo, both BSc graduates in geology, joined the division in January as Assistant Hydro geologists. They received training in hydrogeology. Mr. J.
Sethono joined the division in July, 1984 as a trainee
17 Technical Assistant.
5.2 Groundwater Exploration and Development
Projects
Letlhakeng Groundwater Study
The first phase of this study, which had been commenced in June, 1983 was completed in August, 1984. The objective was to investigate the hydrogeolbkyof the Karoo succession in ., . the area between Molepolole and Letlhakeng and to assess its groundwater potential for possible regional water supply.
An underlying objective had been to investigate the possible . , existence of a groundwater resource of the magnitude similar to the one developed in the Jwaneng wellfield. The conclusions derived from the first phase of the study can be summarised as follows:
The area between Molepolole and Letlhakeng is underlain by geological formations unfavourable for large ground\vater storage. The exceptionally favourable aquifer characteristic~ of Jwaneng probably exist in a delta with sands developed on the margin of the Karoo basin. Geophysical investigation techniques and data interpretation methods applied with this first approach did not produce the information expected. In a follow-up, the search for delta sediments along the Karoo basin margin will be continued. A largely geological approach will be taken. Simultaneously geophysical investigation techniques and data interpretation methods are to be reviewed with the aim of developing techniques suitable for the detectim of lineaments under Kalahari cover and the tracing
18 of basement structure under Kalahari!Karoo over-burden.
Experimental geophysical investigations in the Letlhakeng area
and the Jwaneng wellfield were carried out in November and
December.
Palapye Groundwater Exploration
It \Jas the aim of this project to develop groundwater resources for the augmentation of the Palapye water sup~ly
3 where about 14 000 m /day will be required by the year 2 000.
Seven production boreholes were drilled, capable of supplying
3 900 m3 ! day. The groundwater occurs in frac (;ur'ed quartzites and sendstones of the Palapye Group. With a success rate of
58% and high borehole yi.elds, the project proved that with a systematic approach and detailed geological investigations, groundwater resources can be found and developed. As the most appropriate method for siting in this geological environment, a comb~nation of geological and hydrogeologlcal investigations, supported by interpretation of satellite imagery and air photography, has been applied. The analysis of the regional, tectonic stress pattern had a key role in the geological studies. The borehole water is of good quality and can be used to replace the s~line and polluted water presently in supply in Palapye. The groundwater resource is replenishable with a calculated recharge rate of 2 200 m3 !day in years with average rainfall.
Ramotswa Groundwacer Exploration Drilling of production boreholes continued into 1984, supervised hydrogeologically by the Geological Surve~.
19 After completion of all ten production boreholes and
construction of the pumping systems a three months pumping test
of the well field was carried out from the end of June to the
beginning of September. The pumping peeiod was followed by a
recovery period of one month. The resource abstractable within 6 the existing wellfield is estimated at 18.5 x 10 m'. With
high water levels the wellfield is capable of produCing an
average of 20 000 m3 /day, while peak abstractions of up to
23 000 m3 /day may be reached. It is expected that the well-
field can sustain this abstraction rate for a period of one
year. Aft.er one year of pumping at 20 000 m3 /day, assuming no
recharge, aquifer depletion would reach a state I"hen la.rge
draw downs would diminish the discharge rate from individual
boreholes. Periods of recovery in rotation across the well field
would become necessary. An abstraction in the range of 10 000
to 12 000 m3 /day may be the result. Storage would last another
two and a half years with abstraction at 12 000 m3 /day.
A mathematical aquifer model has been established which
is to serve as a management tool. Monitoring of abstraction;
water levels and rainfall is to continue for several years.
Data collected will be used to improve and refine the model
and particularly to study recharge processes.
/ Terms of reference have been prepared for siting boreholes
in a northern and southern extension area of the wellfield.
Pollution of the aquifer from the village has been observed and
the need for the protection of the important groundwater
resource has ~een realised. Tbus a consult8ncy is to study the
situation and design protection areas and stipulate protection
20 requirements. Terms of reference have been written for the consultancy.
Consultancy by ERGJVI "Water sup,£ly for Maun and HydrogeQ logical studies in the Kanye and 11010polole/Mochudi areD s"
The client in this project is the Ministry of Mineral Resources and Water Affairs, represented by the Geological Survey, which ac.so carries the control and professional supervision of the project. Work commenced at Maun, near tt,e confluence of the Shashe and ThamalakE.ne rivers. An aquifer with fresh water in fluviatile sands has been discovered. Six production boreholes were completed and test pumped by the beginning of December. Drilling \vorks were executed by the Department of Water Affairs. The capacity of the wellfield has
3 been determined at 4 800 m / day. With this additional supply, Maun has its water supply secured at least up to 1995. The aquifer receives recharge from the Shashe River. Groundwater monitoring will be carried out for a period of two years and data collected will be incorporated in a:-1 aquifer model. There is polential for extension of the wellfield as the sandy deposi.ts extend further upstream along the Shashe.
In the Kanye area, BRG11 has selected 11, sites for driD.llII!, to investigate the groundwater potential of the Transvaal dolomites. Borehol.e siting in the area between Mole~olo]e and I'JocY.udi underlain by \Vaterberg forr:mti.ons was :\ I.LI J J rI profJ'ess at the end of Decerrber.
5.3 Groun:l\on Ler ~[().!:.l.L~.!..'E
Moni.toring ccnti.nued 'tlil..1i (',;I"ill[ i:,[,,'d 11(' Lwu}'[,:, ,ti, LI,o
?J j'
Lobatse Treatment Plant, the Nywane and Ramotswa dolomite
aquifers, and on a number of boreholes at Mochudi and near
Letlhakeng. New networks were designed and installed at
Serowe to monitor recharge processes in the Cave Sandstone
under Kalahari overburden, in the Cave Sandstone under a
cover of basalt and in the Cave Sandstone without any covering
layers. With this network also the response of the aquifer
to water abstraction from the new wellfield is observed.
To install the observation station two new observation bore
holes were drilled by the Drilling Section of the Departme~t
and five existing boreholes were refurbished.
Another new network vias established near Palapye. Here
the quartzite sandstone/shale aquifer of the Tswapong Hills
is monitored with the aim of determining recharge rates. Two
technical assistants are permanently engaged in the monitoring
programme.
5.4 Hydrogeological Mapping
Good progress was achieved with this programme during
1984. Map sheet No. 11 was compiled and completed by Dr. J.
de Vries of the University of Botswana. First proof prints
were available for editing in December.
Under the guidance of Dr. de Vries, work on map sheet
No. 8 was started by Mr. C. Marobela. At the end of the year
about 50% had been completed.
5.5 Borehole Records Archives
With more trained technical assistants in the Division
2? Figure 4
HYDROGEOLOGICAL RECONNAISSANCE MAP OF THE REPUBLIC OF BOTSWANA AT SCALE 1 : 500 000 PROGRESS IN MAPPING AS AT 31.12.1984
Under production Published in Drawiflg Office
FTSl Under preparation tiilSJ AI press Awaiting production Fl ~.-- Under revision U in Drawing Office ~
23 the up-grading and up-dating of borehole records and water
location maps made good progress. Two borehole location maps
at a scale of 1:250 000 - Gaborone and Lobatse - have been
completed.
The programme for a computerised data base introduced
for the GSIO project and later amended by BGR has been
replaced by a new data filing and retrieval prcgramme which has
been developed in the Department from the commercial programme,
Hewlett Packard 'Query 45'. This new programme is more user
friendly', it provides larger storage capacity and more
facilities for link-up with parallel data bases (such as hydro
chemistry data). Borehole data will be filed according to
borehole number and location and the GS-numbering system, which
filed data by quarter degree sheets,has become obsolete. All
data filed on the old programme have been transferred to the
new programme, GS-HI.
5.6 Consulting for Governmen~ and the public
Membership on committees
The provision of professional advice is an all year round task. Major issues have been the installation of the
Ramotswa wellfield, the preparation of project memoranda
for future projects under the National' Development Plan VI and the preparations for a conjunctive U8e of water resources in southeast Botswana. Drilling companies as well as the owners of water boreholes are supplied with hydrogeological data on request. The Geological Survey is a member of the Water Apportion ment Board and besides providing technical advice to the Board is charged with the control of wellfield monitoring to which large scale groundwater users are obliged under the grant of water rights. These control measures ensure the proper management of the country's water resources. The Geological Survey is also represented on the Gaborone/Lobatse Water Crisis Task Force which co-ordinates all activities related to securing an adequate water supply for the Gaborone/Lobatse c;J.uster.
5.7 Co-operation with national and international institutions in hydrogeological research Co-operation serves the furthering of research in ground water science in Botswana by combining the resources of the Geological Survey and universities and other institutions specialising in hydrogeological research.
The co-operati~n with the University of Botswana, established in 1983, continued in a most fruitful way. University staff provided professional guidance for geology graduates undergoing specialised training in hydrogeology. Founded on the close relations between the University of Botswana and the Free University of Amsterdam a research project commenced in 1984 whic}1 is inves tigeting the process of ground"lBter recharge in dol o:"li te aquifers of southeast Botswana. Two students cf the Free University of Amsterdam conducted a study of the dolomite aquifer basins in the Nywane area north of Loba tse which supply a lar'ge proportion of Lobatse's water consumption. Preliminary results were made available to the Geological
Survey and the final reports are expected in March, 1985.
Further, uDder this co-operation the Hydrogeological Reconna.i,s-
~3aDce ,1ap, sheet No. 11, '"as compiled by a member of the
University of Botswana. For the assessment of the groundwai.er
resources developed at the Ramotswa wellfield the University
of BotE'~ana provided prcfessional advice with the design of a
mathematical computer simulation model.
Ties were e~tablisl:ed with two universi'~ies in West ".,,' Germany. The Geology Department of the Uni Vel'S} ty of /11mich
has entered into an agreement for a joint research study
with the Geological Survey. The st~dy will be investigating
the possibility of using remote sensing data for grourldwater
resources explocc·tion. Data recorded by earth satel} ites will
fOI'm the major data input. Whlh;t' the actual research is
scheduled for 1985 the Geol.ogical Survey already had access to
highly sophisticated processed satellite imagery dur.·ng 1984.
The University of Tubingen .~s conducting a post-graduate
course for geology students which aims at, familiar2.sing the
young geolog.Uts vll.th the aspects of practicE} geo.! ogical work
in developing countries. One German studerlt spent three months
in Botswana as an assistant hydrogeologist in the Palapye
groundwater exploration project.
The Federal Institute for Geosciences and Natural
Resources (BGH) in Hannover, Wes"t Germany, had made recom- mendations for a remote sensing experiment covering parts of
northern and northwestern Botswana, in connection with the
26 shuttle flight Challenger. A side-looking irnaging radar
device (SIR-8) operated on board the Challenger during its
orbits bei~ween October 6th and October 13th. Three flight
paths covered the Nxai Pan, the Mababe Depn'ssi.on and the
southeas tern Okavango Delta. The experi.men L was undertaken
to investigate the potential of a radar scanner as a possible
tool for the detection of shallow groundwater bodies. A BGR
team, consisting of a soil SCientist, a hydrogeologist and 2
remote sensing experts, collected ground control data required
for the interpretation of the radar imagery. The Geological
Survey provided professional back-up and logistical support.
In~erpretation results are expected in April, 1985.
27 19B5 with fljing following shortly thereafter.
6.11 Groundwater Exploration
6.4.1 Letlhakeng Groundwater Project
An area to the northwest of Molepolole, to the south
and east of Letlhakeng, was ider1;jfied as a possible
groundwater resource for the supplemen:a~lon of the
Gaborone and Lobatse water supply. Following 8 desk study
of existing d8ta, geop:Clysical surveys were conducted
over two identifiable target areas. These reconnaissance
geophysical surveys were completed in Dece~l)er, 1983 and
a co~plete interpretation and reassessment of the field
.data iden~ified several areas warranting further investi
g~tion. Additional geophysics over these target areas,
primarily zones of falJlting, but also incl~ding areas of
relatively thick Karoo development, commenced in January
and continued until the end of February. Fllrther inter
pretation of this data (constant separation eler:trical
traverses and el ec Lri.cal soundings), formed the basi s for
final drill site selectien. Fourteen sites were recom
mended as potent.lal drill targetf:. The majori.ty of the
sites were selected from ~hegcophysical inte~pret2tion of
basenlent depth in order to locate the boreholes on the
flanks of basement ridges where coars," 1~'8.ndstones and
ktructures were anticipated.
Ten boreholes were drilled, five of which located
water with low y ielcls rangi ,cg frem 1 rn'/h to 6 rn 3 Ih, but
thC' ani,ici pated coarse sandstor,e,~ were not .in evicier,ce.
30 It was concluded that the deltaic conditions of the Jwaneng wellfield were not present in the Letlhakeng area (Buckley, 1984).
Towards the end of 1981+ electrical soundings were conducted at 21 borehole locations in the Jwaneng well field. The boreholes were selected to provide two traverses acrcss the wellfield; one north-south, the other east-west. The data will be interpreted with respect to
the borehole geology and compared 'Ni th the sounding data obtained in the Letlhakeng area with a view to identifying parameters c:hat typify the
6.4.2 Letlhakeng Test Survey
One bor-ehole dr.illed (No. 1+695) during the Letlhakeng underground water project was sited on a north-south lineament recognised from aerial photography and ERTS imagery. The borehole was rele.ti vely successful with a yield estimated at about 6 m3 /h. But there was little
eviden~e for any fracturing associated with the ERTS lineament.
Add i tional geophys.lcal ,Jurveys 'Nere conduch:d 1. n UlllI
detailed geophysic;s have included ITIi1!';rI<' L.L"", 1'C'Il.i.lltI.V LLy soundings, square array reli:Lliti.viLy, 1'"li.l.:;!;IvILy pr'uJ'LJLn!.", and electromagnetics (VLF, Slingram, SESS Genie) over a closely spaced survey grid consisting of 3 east west cut lines.
Geophysical anomalies (resistivity and electromagnetic) were detected, located some 100 metres west of the successful borehole (No. 4695). Further detailed geophysics will be conducted in the New Year in an effort to determine the cause of the anomalies.
6.4.3 Other Groundwater Activities
A short VLF Survey using a fixed Tx 27 transmitter was conducted in the Palapye area to locate the position of a concealed geological contact, for the Palapye Under ground Water Project.
Cooperation with the Department of Water Affairs and other development projects continued throughout the year. The tender documents for two projects, Rural Village Water Supplies and the Ramotswa Extension, were assessed and recommendations submitted to Water Affairs for conside ration. Close cooperation was also maintained with the BRGM personnel involved in the Kanye Underground Water Project.
6.5 Mineral Exploration
6.5.1 Mineral Exploration at Tsetsebjwe
As part of a programme of mineral exploration in
northeast Botswana a fault breccia near Tsetsebj~e was inve:.stigated for possible mineralisation.
32 observed gravity to Bouguer anomalies has not been
possible. Efforts to acquire the Departmen~ of Agricul-
tc:rc's Sperry Navigatcr for H coup=-e of weeks iL November
failed due to the commitments of the Land Utilisation
D.ivision. Furthermore, problems still exist with the
Department's Satellite equipment, though exhaustive tests
conducted in December indicate that the navigator is
operating accurately, albeit extremely slowly, (instead of
obtaining fixes within 24 hours, up to 4 days are needed
for accurate coordinates). It is however planned to
resume work on the programme, using the Satellite
Navigator, in the New Year.
------In:3 ti tutions
6.6.1 Magnetic QbservHtiQns Magnetic observations to determine tIle magnetic
secular variation were conducted in co-operation with
Messrs Williams and Moolman of the Magnetic Observatory,
Hermanu:3, RSA, during~he period 22nd August to 7th
September. Observations were taken at magnetic observation
beacons in Khutswe, Tshane, Ghanzi, Maun, Orapa and
Fraficistown. The survey will provide updated iDformation
on the Earth's magnetic field.
6.6.2 Heat Flow Measurements-----. DurIng July, Professor Henry Pollack contimJcd to
collect information on Heat Flow from selected boreholes
35 1/ I',I il I throughout Botswana. Professor Pollack returned to
Michigan, USA, at the end of July and a full report on the
results is expected in the New Year.
6.7 GeoQhysical Eguipment Two electromagnetic systems were tested during the year
prior to the purchase of additional EM equipment for the
division. A Slingram, horizontal loop system was tested over
the Letlhakeng site with personnel from tne Swedish Geolog.Lcal
company. The main drawback of the system is that it is limited
to one frequency. It is very simple to use, hO\vever, and has
proved successful in locating fractured aquifers in Zim~abwe.
Further tests were conducted in the Gaborone area in cooperation
with the Department of Water Affairs.
The Genie SESS electromagnetic system was tested in the
Letlhakeng area and over the established test sLte at Selebi-
Plhkwe. The advantage of the system is that it is more '~ versatile, in tha; the 4 frequencies used make quantitative
interpretation possible, particularly in the assessment of
conductivity over mineral prospects.
On the basis of these tests a Genie SE88 sys~em was ordered
in December and all the necessary docume,rtai;ion, including
~ender Board approv~l, cleared. "-. .. ~ The Haferlatrd .. ,borehole logger, purchased earlier in the --.~ year, \Vas tested by Dr. Dyck and Mr. Tlhabologang. The man'-lal
is unfortunately in German and there are severe reservations
on the overall performance of the equipment. Further tests
will be conducted in the New Year. The following items of
36 equipment were also acquired durIng the year:-
1. Geonics VLF electromagnetic system with Resistivity
attachment and ~obile Tx 27 transmitter. I 2. H.P. 85 desk top computer. I 3. 2 Lister generators. All the equipment has been commissioned and is operational.
6.8 Electronics Laboratory and Geophysics Workshop
The routine maintenance and repair of the DepartifJent's electronic instrumentation continued throughout the year. Major repairs and modifications included the following:-
1. Diatype Machine (Drawing Office) 2. Dionex Machine (Chemistry Laboratory) 3. Atomic Absorption Spectrophotometer (Chemistry Laboratory) 4. Satellite Navigator (Geophysics Division) 5. A.V.L. Navigator (Dept. of Agriculture) 6. MP2 Magnetometer (Geophysics Division) 7. Spectrophotometer (Chemistry Laboratory) 8. Motor for Vacuum Pump (Drawing Office) 9. Service of two Fluke meters (Geophysics Division) I 10. Repair of Huntec Transmitter (Geophysics Division) f 11. Ion Chromatograph (Chemistry Laboratory) 12. Polishing Machine (Mineral Dressing Lob.) 13. Repair of the Vacuum Pump (Mineral Dressing Lob.) 14. Atomic Absorption Spectrometer (Chemistry Labor'utory)
In co-operation with the Department of Ar,r.i.cuJtur'C' flnd
British Aerospace, an Automatic Vehicle .Locnt.i.orl (AV]') ::Y:1Lt~11I
37 Annual [(eport of the Geological Survey Department for 1983. The petroleum prospects of Botswana (a brochure).
2. Bulletins 24 and 25 are printed and will be published as soon as the accompanying [naps are printed. Bulletin 27 is "ith the Government Printer and Bulletins 23, 26, 29 and 30 are in preparation. The Annotated Bibliography of the Geology of Botswana, from 1977 onwards, is being compiled.
3. 403 copies of Departmental publications were sold during 1984 and 615 copies were distributed free or on an exchange basis.
4. Papers on Botswana by staff members, published externally, were as follows:- The character of fractured rock aquifers in eastern Botswana, by D.K. Buckley and P. Zeil.. Challenges in African HydroJ.ogy and Water Resources, pp. 25 - 36 (Proc. Harare Symp., July, 1984). Hydrogeological data collection, storage, retrieval and water law in Botswana, by M. Sekwale (op. cit. pp. 221 - 228).
Early Jurassic pillow lavas and palynomorphs in the Karoo of eastern Botswana, by D.T. Aldiss, J.M. Benson* and C.C. Rundle*. Nature, Vol. 310, No. 5975, pp. 302 - 304. (* not GSB staff).
61 5. The following internal reports were filed:- Aldiss, D.T. Notes on copper mineralisation in metabasite in the Kwebe Hills. DTA/7/84.
Comments on the geology of the Okwa Valley near the Gantsi-Lobatse Road (2221B), Gantsi District. DTA/8/84.
A report on the use of a ground magnetometer survey to aid geological mapping in the Phitshane Molopo area (2525C, 2525D, 2525A3, 2524B4), DTA/9/84.
Pillow lavas and palynomorphs in the Karoo of eastern Botswana (2228A) - supplementary data and comment. DTA/lO/84.
Notes on the geology of Tsele Hill, near Mochudi (2426A). DTA/ll/84.
Buckley, D,K. Mochudi Groundwater Exploration Project - Final report. DKB/4/83.
Report on pump testing in some boreholes in Mochudi,DKB/5/83.
Geological and hydrological infor mation from water borehole drilling Waterberg rocks at MolepoloJe and
Mochudi, 1982 - 1983. DKB/6/8Lf.
62 An inventory of Lobatse Township boreholes.DKB/7/84.
Groundwater recharge and water level fluctuations at boreholes 38 and 4258, Mochudi, 1983 - 84.DKB/8/84.
Groundwater exploration at Letlhakeng, Phase I. DKB/9/84.
Groundwater level record, borehole 2136, January, 1982 - February, 1984. DKB/IO/84.
ClerK, G.C., The coal resources of Botswana.
Lock, N.P. & GCC/2/84, NPL/ll/84, RAS/4/84. Smith, R.A.
Gould, D. Lithological logs of boreholes drilled in the Molopo Farms Project study area from 1/8/82 - 31/5/84. DGX/22/84.
Gould, D. and A geological interpretation of Rathbone, P.A. Landsat imagery of the Molopo Farms Project area. DG/21/84, PAR/4/84.
Gwosdz, W. Report on calcrete deposits at Segwagwa Pan and at Segeng, Southern District. WG/48/84.
Investigation of the gypsite from Bojanamane, Central District. WG/49/84.
63 Reserve calcul£l.tion for Lebung and Bojanamane gypsum deposits.
Gwosdz, W. Bnd Da'~a on brickeart~s, wea-th,ered
Kara, H. mu d s t -ones an d Sl.tC1"1 es. il('/'''l/''!/';":J {~.-I, HK/12/84.
Gwosdz, W. Interi~ report on calcrete deoosits at Ngopilo Hi]l and Segeng,
Sou'thern District. WG/52/8L,.
Report on Jnvestigations of tbe tailings dump at Kgwakgwe Hill, Kanye, WG/53/84.
Hutchi.ns, D. G. A short note on the geophysical
survey at Selebi-Phikwe. DGH/33/8i,.
Lock, N.l'. Addendum to 'Moisture tes~work on a coal sample from Morupule Colliery' (NH/9/83, HK/e/83) NPL/10/81.j.
MukliopacJhyay, S, K. A rapid method for the determ.ination of manganese in manganese ores.
r·;eumann-Hedli.n, C, Palapye GrollYldwater Exploration
Project. Vol. ~, CNR/g/e4.
Palapye Ground\vater lczplorat:L on Project. Vol. 11, CNR/10/e4.
RamoYlyane, P. Assessment of weathered Precambrisn
mu2.c;tcr,e/ s1181e, east of Hamotswe
64 station, as raw material for brick
mal,ing pnrposes. ?R/l/n4.
Rathbone, P.A. The application of electrical
soundings to determine depth to
bedrock in the Molopo Farms Project
Study f-lrea. PAE/S/84. M. von Hoyer Lobatse se'Jlcrage scheme, treatment
plant area Lobat.se Estate,s, ground-
we,ter monitoring, 1'183. (MvH/:3/81J).
Zc;.j.l, P. PEJI'l bore\101e survej :Ln the
Ngami area. PZ/2/84.
A short note on geo~lysical survey
at Selebi-Phikwe P2/3/84.
Electromagnetic survey at
Selebi-Phikwe copper/nicke"l mine.
6. The j,nternal reporl;,; are 1wing indexed by degree
squares and a st::b,ject index is p'l armed.
_.'---'-'Eecords and '--' Information 1) ?eference i.ndexes to the company prospecting
reports by licence nu~ber and degree square
are jeirg compiled.
2) The l'eports were frequently consul -ced by staff
of pro"'pecting and rnin.ing companies and 01., ,Or' organ:Lsations, .; n particuJer froDI GoldL'ic·.. ld::,
Morex, Falconbridg~ and RIo Tjni0.
65 ,3) Advice and assistance were also given to, among others, representatives of the Southern Rural Development Association, the Agricultural Division of the Botswana Development Corporation and several visiting students.
8.5 Drilling Section
The Hydreq Gryphon drilling rig was employed on a coal exploration project in the Dinokwe area.
Phase one of the programme was completed in May, 1984. Six holes were cored to a total of 1159 metres. Also in May the Boyles Rig started and completed a series of 10 shallow cored holes around the Nata area. The project was in conjun- ction with the Roads Department to ascertain the potential of calcrete aggregate deposits.
The Hydreq Gryphon rig then moved to the Serowe area where 2 monitoring holes were drilled for the hydrogeology division. This completed, it was then used to clean and flush out 6 other existing boreholes.
A request was made by the German Division working in Kalakamati for the use of a small mobile machine (the Minute
~lan rig). It was explained that this machine had limitations. If hard formations were encountered before the required depth was reached it would not be capable of penetration. Indeed this was the case and further drilling was abandoned.
Satisfactory progress has been made with regard to the training of local personnel and they deserve praise for their
66 diligent and conscientious approach to their work.
On the job experience was provided for the trainees attached to the Driller Training Scheme by the drilling instructor, Mr. R. Gagne.
67