( s

MINISTRY OF COMMERCE, INDUSTRY AND WATER AFFAIRS

ANNUAL REPORT OF THE

GEOLOGICAL SURVEY DEPARTMENT

FOR THE YEAR ENDED 31 ST DECEMBER 1968

• I GENERAL

(a) Introduction

The Geological Survey Department in the Republic of is a "non-integrated" element of the Ministry of Commerce, Industry and Water Affairs. Its headquarters are at in southeastern Botswana, 4-7 miles south of the Botswana Government administrative headquarters at . The fundamental aim of the Geological Survey is the assessment of the mineral resources and underground water supply resources of Botswana with the intention of stimulating the realisation of their economic poten~al. A necessary preliminary to the attainment of these objectives is a study of the rocks and the geological structure over the whole of the country. Regional geological mapping and the publication of maps and reports describing the geology of Botswana is thus the main, prime function of the Geological Survey Department. Mineral survey work is carried out and this includes field geological and geophysical survey of mineral occurrences supplemented by laboratory work; prospecting for new mineral deposits; render­ ing assistance to prospecting organisations and operating mines; and wherever possible fur­ thering interest in Botswana's mineral potential. A third major task of the Geological Survey is the development of underground water supplies and general hydrogeological survey. In underground water development work the Geological Survey carries out the siting of water boreholes after geological and geophysical investigations and then controls drilling of the selected sites to the stage where productive boreholes can be passed to another Department within the Ministry, which is responsible for equipping boreholes and for the maintenance of Government pumping units. Hydrogeological research work is also carried out and the Geo­ logical Survey is gradually building up a considerable body of information about the nature and occurrence of underground water resources in Botswana. In underground water develop­ ment work, borehole drilling is carried out by the Drilling Branch section of the Geological Survey, which has its headquarters at Gaborone and is under the control of a Drill Superin­ tendent who is directly responsible to the Director of Geological Survey. Besides these main activities, the Geological Survey undertakes special investigations where geological advice is required, such as in certain engineering problems, and also renders assist­ ance to other Government Departments whenever required to do so. Special geological and geophysical investigations and research work are also undertaken where they are needed for a better understanding of the basic geology and geological structure of Botswana. The Director of Geological Survey is Mining Commissioner for Botswana and the Depart­ ment includes a Government Mining Engineer's division. Apart from specific functions the Geological Survey performs in relation to prospecting and mining this division is responsible for safe mining practices, the inspection of mines and machinery, and the implementation of explosives regulations. In the exercise of its dual functions as a Geological Survey and Mining Commissioner's office, the Department is responsible to Government for ensuring that mining company prospecting operations in Botswana are carried out energetically and efficiently with due regard to the provisions of the Mines and Minerals Act in force in the country. The main costs of running the Geological Survey and the full costs of the development of underground water supplies in Botswana by drilling during 1968 were again borne on normal budget estimates. Funds were also provided from a special Development Project scheme to allow an expansion of the.Geological Survey by the formation of the Government Mining Engineer's division. (b) SUDlInary of the Year's Work

Recruiting difficulties continued to be met with during 1968, and as a result of a number of resignations amongst both professional and technical staff the Geological Survey remained short-staffed throughout the year. The position in this regard was particularly serious during the second half of the year and even steps taken to provide an enh:nced entry point for Geolo­ gists did not assist recruitment. The staff shortage affected work in all spheres of Geological Survey activity. Regional reconnaissance geological mapping was continued and a total of about 1,750 square miles of previously unmapped country was geologically surveyed on a scale of 1: 125,000. Mapping was completed on three quarter degree sheet areas. Revision geological mapping was continued in southeastern Botswana. Owing to the staff position only a limited amount of work could be carried out on direct mineral survey projects. A regional survey of the mineral potential of an area in northern Botswana was initiated. Iron-ore and manganese-ore occurrences were investigated. Special investigations work in the sphere of mineral survey included case history geophysical studies on nickel deposits in northeastern Botswana using up to eight different ground geophysical techniques. In addition to the case history studies over known ore bodies, which are the subject ofdetailed investigations by mining companies at the present time, ground geophysical work was also carried out on behalf of one company to evaluate certain geophysical anomalies resulting from airborne electromagnetic and magnetic surveys. During the year 17 State Grants were issued conferring special prospecting licences over various areas of Botswana for a variety of minerals. At the end of 1968,21 grants of prospecting rights were in force. Brief summaries of the work carried out by mining and prospecting com­ panies in terms of these Grants of prospecting rights are given under the section on mineral survey in Part II, ECONOMIC GEOLOGY, of this report. Six applications for the grant of special prospecting licences were under consideration at the end of the year. In underground water development work, geological and geophysical surveys were again carried out in nearly all District Council areas. Considerable assistance was also rendered to World Bank consultants investigating water supply problems in connection with developing mines. This was carried out as a Government counterpart contribution. Ground-water research programmes were intensified in certain areas. . During 1968, a total of86 completed boreholes (both Government and for the private sector) were drilled on sites selected by officers of the Geological Survey. Of these boreholes, 70 were successful representing an overall success value of 81.5%' The Government Drilling Branch worked on 101 boreholes (including 16 cleaned and retested). The total footage drilled was 23,627 feet of which 16,844 feet were drilled in successful boreholes.

(c) Organization and staJl"

Certain minor changes were made in the schemes of service for professional officers. The two posts of Senior Geologist were retitled Principal Geologist. The post of Geologist was retitled Geologist/Senior Geologist with the title changing to Senior Geologist on entering the

2 (f) Q.uarter Degree Sheet 2022», Lake Ngaud C.M. Thomas carried out a geological reconnaissance of this area during September prior to systematic mapping planned for 1969. Representative samples of the main lithological types found in the Formation, the Kgwebe Porphyry Formation, the Bodibeng sandstone (Karro System) and other sedimentary rocks of uncertain age and correlation were collected for study.

IV UNDERGROUND WATER DEVELOPMENT (a) Geological Survey Activities The Geological Survey continued to be responsible for the control of all underground water development work in Botswana, including both the siting of boreholes following, geological and geophysical work, and the subsequent drilling of selected water borehole sites. . In the course of this work geological and geophysical surveys were carried out in the Centra]" District; the North East District; ; ; Ngwaketse District; South East District; ; and and Lobatse township areas. During 1968, a total of 86 completed water boreholes (both Government and private) were drilled on sites selected after geological and geophysical surveys carried out by officers of the Department. Of these 86 boreholes, 70 were successful representing an overall success value of 81.50/0 which compares well with that achieved during 1967 (81 %) The total number of completed boreholes, however, is about 180/0 lower than the number completed on Geological Survey drilling sites in 1967. This was due not only to the severe shortage of professional and technical staff experienced by the Geological Survey itself during 1968, but also because of a shortage of supervisory drilling personnel, due both to absences on enforced leave periods on completion of contracts and to resignations. A contributory factor as regards the number of completed boreholes was that m many areas the average depth drilled was well above that for previous years. A tabulated list of boreholes drilled on sites selected by officers of the Geological Survey is given in Appendix IV. (b) Drilling Branch Activities During 196B, a total of23,627 feet was drilled by the Drilling Branch section of the Geological Survey in boreholes drilled for the development of underground water supplies. This footage is 8,236 feet less than the footage drilled in similar work during 1967, when a record footage was achieved. The reduced total is due not only to the shortage of staff referred to above, which 0 meant that at certain times of the year the Drilling Branch was only operating at about 50 /0 of its full strength, but also to the fact that two Drill Foremen were unable to carry out normal drilling duties for several weeks while assisting with detailed aquifer evaluation tests in the Orapa area. During the year 101 boreholes (including 16 boreholes cleaned and retested) were worked on. Of the totalof85 new boreholes worked on, 4 boreholes totalling 1,180 feet had to be abandoned for technical reasons and 5 boreholes totalling 1,706 feet remained uncompleted at the end of the year. Of the total footage of 21,921 feet drilled in completed boreholes for underground water development purposes, 16,844 feet were drilled in successful boreholes.

14 In addition to this Government drilling, 6 successful boreholes totalling 2,206 feet were drilled on contract for De Beers Prospecting Botswana (Pty) Limited for aquifer evaluation tests carried out by Sir Alexander Gibb and Partners in collaboration with the Geological Survey in the Orapa area. Apart from normal drilling for Government purposes and in various District Council areas, a considerable amount of assistance w~ again given to De Beers Prospecting Botswana (Pty) Limited in the Orapa area both to assist company prospecting operations and the aquifer evaluation tests being carried out there. Ten successful boreholes totalling 4,496 feet were completed and one borehole 306 feet deep was in progress at the end of the year. In addition, a Geological Survey Department test borehole, 921 feet deep, was in progress at the end of the year. The majority of these boreholes were drilled on a repayment basis. In December a start was made with a drilling programme in the Selebi-Pikwe area to assist Bamangwato Concessions Limited in studies directed towards assessing available water reserves for water supplies which could be required in the mining and township construction stage should copper/nickel mines develop in this area. Pre-occupation with work in the Orapa area for De Beers Prospecting Botswana (Pty) Limited curtailed th"e amount of work possible on boreholes drilled on repayment for private applicants in the various District Council areas. Only five successful boreholes were completed in connection with the borehole repayment scheme which will result in revenue amounting to R6,663 accruing to Government. ' (c) General Hydrogeological Research Work

The staff position again curtailed the amount of work possible on this important research programme, but it did prove possible to make a number of advances in this field. A number of new automatic water level recorders were installed on suitable observation boreholes at such widely separated localities as Ghanzi, Nata, Francistown, , Orapa, Pikwe and Lobatse. A total of 16 automatic recorders are now in operation. In addition to these another 64 boreholes are monitored for changes in water level on a daily, weekly or monthly basis. Apart from at those centres listed above, these regular static water rest level measurements are made on observation boreholes in the Kalahari region, extending for over 100 miles west to the central Kalahari from Letlhakeng in the east, and from Serowe over 100 miles northwest "to the Letlhakane area near Orapa. A grant was obtained during the year from the International Atomic En~rgy Agency in Vienna to carry out a research project on the effectiveness and application of environmental tritium as a ground-water tracer in Botswana to he carried out in collaboration with the Nuclear Physics Research Laboratory at the University of the Witwatersrand. This project will last for one year commencing in January 1969. During the year detailed barometric levelling was carried out along a line of observation boreholes over a 120 mile long section from Serowe to Orapa and Lake Dow. A hydrogeological section was drawn up following the levelling. The Geological Survey carried out detailed aquifer evaluation tests by controlled pumping methods in the Orapa area in collaboration with Sir Alexander Gibb and Partners, consultants appointed by the World Bank for this study, and De Beers Prospecting Botswana (Pty) Limited. The study was designed to make.. an assessment of the available water resources for the water 15 requirements for the proposed diamond mine on the AK I prospect at Orapa and, in particular, ground-water supplies available in the Cave Sandstone Stage (Stormberg Series, Karroo System) underlying the Stormberg Series basaltic lava in this area. The initial tests were carried out on 4- eight-inch diameter boreholes drilled on a diamond pattern with boreholes on the longer axis 5,000 feet apart and 3,000 feet apart on the ..horter axis. Diamond drill cored observation boreholes were sited at distances of 150 and 1,000 feet from each borehole on the extension of each axis. A fUFther· six-inch dialll@ter observation borehole was drilled in the centre of the diamond. Detailed tests carried out included step drawdown and equilibrium tests in all boreholes. Following these tests, coefficients of transmissibility (T) and storage (S) were calculated and were found to vary from 250 to 1000 gallons per day per foot and from 0.0009 toO.0006 respectively. Distance - drawdown diagrams were constructed for a hypo­ thetical borehole in order to calculate long term effects of pumping without recharge and also to establish the probable economic costs and optimum spacing for a large well field. Further evaluation tests are planned on boreholes sited in relation to specific geological structures in the area. Systematic sampling of ground waters for chemical analysis is being continued and to date over 2,000 full analyses have been carried out. Borehole waters in the Kweneng Di~trict were sampled in collaboration with Dr. J.C. Vogel, of the Council for Scientific and Industrial Research in the Republic of South Mrica, for C-14- age determination work. The acquisition during the year of a borehole fluid salinity and temperature logger should prove to be of considerable assistance in locating entry points of water into boreholes. Extremely encouraging results were obtained at Orapa where entry points of water into a number of boreholes could be determined to within one. centimetre. A Huntec FS-3 single channel facsimile percussion seismic instrument was also purchased and found to be of considerable use in shallow groundwater surveys and for engineering geology problems. The self-potential (spontaneous polarisation) method is now being used as an adjunct to resistivity and magnetic surveys in areas ofshallow ground water and where underground water supplies can be expected from fissure systems. Encouraging results have been obtained. It is also planned to use a variety of electromagnetic techniques, including Mmagin the future selection of water borehole sites. . V SPECIAL INVESTIGATIONS

(a) Geophysical Studies

The main work in this sphere consisted of the initiation after April of a programme of detailed integrated case history geophysical studies of known or suspected ore deposits in various areas of Botswana. The geophysical methods employed included induced polarisation (time domain), Mm~g, vertical loop, electromagnetic, reconnaissance electromagnetic, gravimetric, magnetic, self potential and electrical resistivity. A breakdown of geophysical work carried ~ut during the course of these studies is as follows:-

16 (c) Bulldings

A block of five additional offices was completed during the year. These offices will be used to house officers of the newly created Government Mining Engineer's Division as well as newly recruited Geologists. Plans are in hand to provide additional office accommodation for Geologists, when this block will revert entirely to the Government Mining Engineer's Division. Staff houses were also under construction during the year for the Government Mining Engineer's Division and these should be completed during the first quarter of 1969.

VB CONFERENCES AND EXTRA- TERRITORIAL RELATIONS

R. Mason attended the annual congress of the Geological Society of held in Grahamstown in the Republic of South Africa in July. Mr. Mason presented two papers, "The Mobile Belt in Eastern Botswana" and "The Metamorphic History of the Tati Schist Belt". He was also joint author of another paper entitled "A reappraisal of Some Aspects of Precambrian Shield Geology".

vm REPORTS AND PUBLICATIONS

(a) PublicatioDs

The Departmental Annual Report for 1967 was issued in December. Publication of other material was delayed due to shortage of staff and hence the inability of more senior officers to pay attention to this work in view of their heavy commitments in other fields. Descriptions of all mapped areas are, however, available at Geological Survey headquarters at Lobatse, details of which can be supplied on request.

(b) Reports

The undermentioned, more important reports were prepared in addition to a number of short Departmental reports mainly concerning underground water supply investigations. By C. Boocock Annual Report of the Geological Survey Department for the year ended 31st December 1967. By C.M.H. Jennings Report on the ground-water storage capacity of the Lobatse area. Note on hydrological research in Botswana with special emphasis on research in the hydro­ geological field (to be published in the Journal of the South African Association for the Advancement of Science. ) By M.T.Jones The geology of the. Area (Quarter degree sheet 2425B).

19 APPENDIX I

Staff position at 31st December 1968

Geological Survey

Establishment Designation Director .. .. C. Boocock, O.B.E., M.SC., M.I.M.M., F.G.S., M.S.A.INST.M.M.

Deputy Director C.M.H. Jennings, M.SC. Principal Geologist . M.T. Jones, B.SC. (HONS.), F.G.S. Vacant (1) 'I Government Mining Engineer Vacant (1) 8 Geologists/Senior Geologists .. R.N. Crockett, B.SC. (HONS.), F.G.S.

J.D. Bennett, B.SC. (HONS.), PH.D., F.G.S.

C.M. Thomas, B.SC. (HONS.) Vacant (5) 1 Assistant Government Mining Engineer Vacant (1) 2 Chemists.. G.L. Adams, B.SC. L.G. Hutton, B.SC. (HONS.), G.R.I.C., Dip. p.oc. 2 Cartographers . K.Jennings C.A. Candy Administrative Assistant . W.H. Palmer Personal Secretary .. Miss D.V. Turner 5 Scientific Assistants . R.J. Hastings J.A.]. de Wet F. Bicheno Vacant (2) 2 Senior (Diamond) Drillers W. Burgoffer Vacant (1) Laboratory Technician .. R.J. Malejane Geological Draughting Assistant (C.I) E. Moabi Higher Clerical Officer (C.2) H. Keaikitse Laboratory Assistant (C.I) E.K. Mpatane 1 Works Staff Grade II (C. 1) L. Kgomela 3 Clerical Officers (C.3) 3 2 Copy typists.. (D.5.4) 2

21 Artisan (C.2) 1 Tracer (C.2) 1 2 Laboratory Assistarits (C.3) 2 2 Tracers (C.3). 2 1 Storeman (C.4.3) 2 Field Assistants (C.3) 1 33 Motor Drivers (C.3) 21 Industrial Class not enumerated

Underground Water Development (Drilling Branch)

Drill Superintendent E.M.F. Owen Assistant Drill Superintendent C.P. Hattingh Senior Driller .. M.J. Swart Scientific Assistant .. D.J.V. Pretorius 9 Drill Foremen . W.J. du Plessis P.H.F. Moll A.S.A. Pelser J.L. Bouwer F.C. Eloff F.H. Schutz Vacant (3) Higher Technical Officer (Works Staff Grade 1) .. C. Sterk Clerk/Storekeeper (C.l) . L. Botlhole Clerical Officer (C.3) 1 14- Motor Drivers (C.3) 10 Industrial Class not enumerated

22 APPENDIX n

Statistics of drilling operations carried out by the Drilling Branch of the Geological Survey and by Contract Drilling

bO"O I c:: c:: ~ rJ 4J .... =' I '"'0=' "0 0 4J '0 ~ j'"' 100 ..c:: j'"' ..c:: -=t;, j 4J j'"' "0 '"'4J .S ~ ~ "0 j'"' ~ ~ ----"0 rJ 4J c:: til c:: ~ ;Z c:: "0 0 ..c:: 5 0 4J -a 2 ~ =' rJ '0 4J 4J u c:: ..c:: 100 U "0 "0 o '"' '0 4J "c:: 5 e0 4J -E.g ..c:: 4J u =' c:: g, u ~ ..loC 4J ~ .8 u co: 4J bO ~-;n _ '"' 4J "0 a ,&l 4J c:: 0 .B 4J "0 ij1 '"' '"' ~ =' co: "0 =' .S ~ ~ c:: j "0 "0 ~ c:: "0 0 toI 4J 4J ~ .S .S .... .S .S "0 ~ ~ u.c E c:: rJ "0 -tolca. ~ 0 Q. "0 "0 "0 "0 "0 g, '0 -0 '0 4J 4J 0 .c E b/) ~ ~ ~ .c 5 c u 0 ~ QJ u -a.8.£ u u CIS ~ ·c ·c ~ ·c ~ u .. "0 "0 "0 > e.,., .D c "0 "0 4J o U toI '"' ; .& :s ] toI toI toI U 4J "0 .8 .. tI«) tI«) bO '- V c '" .... bO be 100 C '0 X. t '0 15 '0 0 -; s c S IS S 13 S S IS u d o t &; 0 0 ci 0 8 8- ; z z.,., ~ z :z. z z ~ :] l] II (&.. (&..,g ~ tV ~ Central District 16 15 8 4.568 2,4!19 1,708 180 181 9,550 Kgatleng District 5 5 3 1,103 588 515 1,700 Kweneng District 2 2 2 407 407 2,250 Ngwaketse District 5 4 4 1,286 1,175 111 6~960 South East District 1 1 1 306 306 1,200 North East District 7 7 6 1,169 1,015 154 5,900 Government (including Veterinary, Agriculture, Townships repayment boreholes drilled other than for Tribal applicants) 55* 49 42 3 3 16,994 13,060* 1,520 1,000 1,414 94,860

91 82 66 4 5 25,833 19,050* 3,897 1,180 1,706 122,420

*Includes 6 boreholes totalling 2,206 feet drilled on contract for De Beers Prospecting Botswana (Pty) Limited in ground- water investigations carried out by Sir Alexander Gibb and Partners, and the Geological Survey at Orapa. APPENDIX m

Table of Boreholes Drilled in 1968

Static Depth Water Water Official Locality Depth rield in Struck in Rest Geology No. . in G.P.H. feet Level feet in feet

2111 Molepolole, K wen eng District 181 Blank Alluvial deposits (30'), Waterbecg System sandstone and shale (64') and diabase. 2114 Masengwaneng, North East District 150 900 99, 106, 144 74 Basement Complex granite, decomposed to 70'. 2117 Dukwe, Central District 572 1,500 361,518 123 Kalahari Beds (30') mudstone, shale & sandstone (Ecca Series, Karroo System) with dolerite (l00-110') and (220-330). 2118 Orapa, Central District 426 1,440 80, 380 39 Basalt (380') and Cave Sandstone (Stormberg Series, Karroo System). 2119 Morapo, Central District 140 Blank Basement Complex granite, decomposed to 55'. Kalahari Beds (40'), Pretoria Series shale, siltstone ~ 2120 Taka, Ngwaketse District 347 3,600 245, 285 to 330 214 ~ and minor basic instrusive (310') and Dolomite Series chert (Transvaal System). 2123 Matunte, Ngwaketse District 377 .1,500 132, 315 142 Kalahari Beds (100'), diabase (310'), sandstone and shale (Watetberg System and intrusive). 2124 Francistown township 100 300 80 30 Recent (20') and Basement Complex schist, de- composed to 70'. 2125 Francistown township 110 2,000 65 to 70 30 Basement Complex schist, decomposed to 75'. 2126 Molepolo1e, Kweneng District 46 400 33 to 41 28 Semi-consolidated Waterberg System gravel. 2127 Molepolo1e, K wen eng District 326 1,500 85,314, 322 72 Gravel (40') dolerite (310') and Waterberg System sandstone. • 2128 Molepolole, K wen eng District 118 Blank Gravel (30') and decomposed dolerite. 2129 Morapo, Central District 100 700 45 22 Dolerite, decomposed to 50'. 2130 Orapa, Central District 420 2,000 342 47 Basalt (342') and Cave Sandstone (Stormberg Series, Karroo System). 2131 Francistown township 148 200 90,98 30 Baseinent Complex schist with brecciated zone at 100 feet. 2132 Francistown township 150 2,000 90 to 110 22 Basement Complex gneiss and schist with brecciated zone at 110'. Kalahari Beds (460'), siltstone & shale (470'), dolerite (520') sandstone (590') & dolerite (Ecca Series, Kar- roo System). 2133 Phuduhudu, Kgalagadi District 600 1,150 490, 580 430 Basalt (210') & Cave Sandstone (Stormberg Series, 200 Karroo System). Static Depth Water Water Official Locality Depth rield in Struck in Rest Geology No. in G.P.H. .feet Level Jeet in feet

2f35 Lobatse town$hip 200 2,000 146 11:A Cherty gravel (60'), chert (150') & dolomite (Dolo- mIte Series, Transvaal System). 2136 Lobatse township 135 3,000 119 90 Cherty & cherty gravel (120') & dolomite (Dolomite Series, Transvaal System). 2137 Franci~town township 215 1,200 92 51 Basement Complex schist, decomposed to 70'. 2138 Francistown township 127 2,000 60, 103, 125 Basement Complex schist, decomposed to 80'. 2139 Molepolole, K weneng District 289 250 108 74- Dolerite (200') decomposed to 120' & Waterberg t System quartzitic sandstone. 2140 Molepolole, K weneng District llB 2,000 64,82, 109, 118 40 Waterberg System shale, siltstone & quartzitic sand- stone. 2141 Francistown township 130 2,000 66, 70, ll2 40 Basement Complex schist, decomposed to 70'. 2142 Francistown township 130 2,000 70 to 114 30 Basement Complex schist & amphibolite, decomposed to 110'. 2143 Francistown township 200 4,000 67, 102, 150 48 Basement Complex schist & minor dolerite, decom- "-=l (J1 posed to 70'. 2144- Orapa, Central District 450 1,800 389 49 Basalt (389') and Cave Sandstone (Stormberg Series, Karroo System.) 2145 Serow.e, Central District 662 Blank 85 52 Cave Sandstone (Stormberg Series, Karroo System) (10 g.p.h.) to 270' and Waterberg System quartzitic sandstone & shale. 2146 Dukwe, Central District 456 2,000 386 123 Kalahari Beds (40'), mudstone & shale (100'), dolerite (170'), carbonaceous shale and coal (380') and sand- stone (Ecca Series, Karroo System). 2147 Francistown township 300 4,000 64,84, 110 50 Basement Complex amphibolite, broken & partly de- composee to 140'. 2148 Molepolole, K weneng District 320 Blank Waterberg System shale, siltstone & quartzitic sand- stone. 2149 Francistown township 130 2,000 u60 36 Basement Complex schist, de(:omposed to 60'. 2150 Francistown township 110 2,000 61,71 32 Basement Complex schist, dec:omposed to 60'. 1 2.151 Ootsi. South Ea$t Distri<:t 306 1.200 80 & on 60. 350 15 Cherty gravel (70 ) & Waterberg System shales. 2152 Orapa, Central District 423 3,600 60,350,390 39 "Basalt (330') and Cave Sandstone (Stormberg Series, Karroo System). 2153 Orapa Central District 921 IN PROGRESS Basalt & Cave Sandstone (Stormberg Series, Karroo System). 2154 Orapa, Central District 585 1,000 64,390,520 45 Basalt (288') & Cave Sandstone (Stormberg Series, 570 Karroo System). Static Depth Water Water Official Locality Depth rield in Struck in Rest Geology No. in G.P.H. feet Level feet in feet

2155 Francistown township 104 2,000 60,72,92 42 Basement C~mplex schist, decomposed to 70'. 2156 Tati Siding, North East District 154 Blank Basement Complex granite, decomposed to 50'. . 2157 Dukwe, Central District 456 2,000 252,363 125 Ecca Series shale, siltstone and sandstone (Karroo System). 2158 Molepolole, Kweneng District 307 Blank Waterberg System shale, siltstone and sandstone with diabase (41' to 183'). 2159 Gambule, North East District 170 2,000 98, 125, 160 62 Basement Complex gneiss and amphibolite, decom- posed to 60'. 2160 Sekakangwe, North East District 150 2,000 101, 108, 115 80 Basement Complex gneiss and amphibolite, decom- 135 posed to 110'. 2161 Phuduhudu, Kgalagadi District 500 Borehole abandoned for techmcal reasons Kalahari Beds. 2162 Serowe, Central District 300 1,800 159 102 Basalt (159') & Cave Sandstone (Stormberg Series, Karroo System). 2163 Khaka, Central District 494 2,400 250,390,428 190 Kalahari Beds (174'), basalt (424') and {Jave Sand- r-.,j 0') stone (Karroo System Stormberg Series.) 2164- Kanye, Ngwaketse District 211 Blank Dolerite, decomposed to 100'. 2165 Dukwe, Central District 468 900 265, 324 101 Siltstone (90'), dolerite (190'), shale with minor coal and sandstone (Ecca Series, Karroo System). 2166 Malete, Central District 300 250 180 165 Basement Complex granite, decomposed to 180' and diabase. 2167 Shashi Drift, North East District 180 600 84,94, 114 75 Basement Complex schist and amphibolite (170') and granite. 2168 Makaleng, NorthEast District 215 100 114 90 Basement Complex granite, decomposee to 70'. 2169 Molepolole, Kweneng District 300 Blank Shale (70'), quartzite (110'), diabase (240') and quartzite (Waterberg System) 2170 , Kgatleng District 262 Blank Gaborone type granite. 2171 Serowe, Central District 700 2,200 520 to 550 301 No samples. 2172 Malete, Central District 250 Blank Basement Complex granite, decomposed to 90' . 2173 Phareng (Kanye) Ngwaketse District 200 4,000 170, 189 10 Sandstone (Waterberg System). 2174 Orapa, Central District 424 3,460 360,420 54 Basalt (360') and Cave Sandstone (Stormberg Series, Karroo System). 2175 Orapa, Central District 412 2,000 382,390,408 50 Basalt (375') and Cave Sandstone (Stormberg Series, Karroo System). 2176 Mambo, North East District 150 300 73, 135 65 Basement Complex granite, decomposed to 70'. 2177 , Kgatleng District 253 Blank Felsite (Kanye Volcanic Group). Static Depth Water Water Official Locality Depth rield in Struck in Rest Geology No. in G.P.H. feet Level feet in feet

2178 Pilane, Kgatleng District 207 750 172, 193, 148 Felsite (Kanye Volcanic Group). 21'79 Orapa, Central District 464 2,:540 360,380,440 51 Basalt (340') and Cave Sandstone (Stormberg Series, Karroo System). 2180 Selokolela, Ngwaketse District (Phitsane) 176 1,800 140 & on 91 Sand (40') and chert breccia (Dolomite Series, Transvaal System). , 2181 Seolwane, Central District 200 Blank Basement Complex granite, decomposed to 120'. 2182 Orapa, Central District -t02 5,000 90 to 295 48 Basalt (295') and Cave Sandstone (Stormberg Series, Karroo System). 2183 Orapa, Central District 385 3,000 45, 285 33 Basalt (280') and Cave Sandstone (Stormberg Series, Karroo System). 2184 Orapa, Central District 335 3,000 225 34 Basalt (280') and Cave Sandstone (Stormberg Series, • Karroo System). 2185 Orapa, Central Distr~ct 455 3,000 270 50 Basalt (375') and Cave Sandstone (Stormberg Series, t.,J Karroo System). -.....) ?lR6 Seolwane, Central District 200 Blank Basement Complex granite, decomposed to 90'. 2187 Matamora () Kgatleng District 200 450 104, 130 83 Alluvium (40') and Basement Complex granite, de- composed to 140'. 2188 Seolwane, Central District 180 Borehole abandoned for technical reasons Rasement Complex granite. 2189 Seolwane, Central District 245 500 180 141 Basement Complex granite, decomposed to 180'. 2190 Orapa, Central District 304 3,000 90. 200 39 Basalt (200') and Cave Sandstone (Stormberg Series, 2192 Orapa, Central District 430 2,500 60, 379, 420 48 Karroo System). Basalt (380') and Cave Sandstone (Stormberg Series, Karroo System). 2193 Orapa. Central District 450 2,570 50,345,370 48 Basalt (340') and Cave Sandstone (Stormberg Series, 425,445 Karroo System). 2194 Nata, Central District 83 Blank 41 38 Recent fluviatile sands. (Saline supply) 2195 Maunatlala, Central District 120 1,200 45 36 Basement Complex granite, decomposed to 70'. 2196 Maitlo a Phuduhudu, Kgalagadi District 230 Borehole abandoned for technual reasons Kalahari Beds. 2197 Diphala, Ngwaketse District 275 60 98 48 Maroon and dark grey quartzitic sandstone (Water- berg System) and diabase. 2198 Orapa, Central District 325 3,000 90 30 Basalt (220') and Cave Sandstone (Stormberg Series, Karroo System). 2199 Orapa, Central District 432 3,600 38,50,282, 2626 Basalt (280') and Cave Sandstone (Stormberg Series, 304,314,324 Karroo System). Static Depth Water Water Official Locality Depth Yield in Struck in Rest Geology No. in G.P.H. feet Level feet in feet

2200 Bushman Mine, Central District 256 Blank Basement Complex gneiss, schist, metaquartzite and amphibolite. I 2201 Ratholo, Central District 240 900 205 168 Basement Complex gneiss and minor amphibolite. 2202 Motale (Selebi) Central District 154 2,400 55, 72, 78, 110 36 Basement Complex gneiss and amphibolite, decom­ posed .to 80'. 2203 Bushman Mine, Central District 187 In progress Basement Complex gneiss and amphibolite. 2204 Lebowane-la-Mamapokoro (Molotoana), Kgatleng D~strict 181 500 120 90 Diabase, decomposed to 120'. 2205 Maido a Phuduhudu, Kgalagadi District 270 Borehole abandoned for technical Kalahari Beds. reasons 2206 Orapa, Central District 306 In Progress Basalt and Cave Sandstone (Stormberg Series, Karroo System). 2207 Dintswane, Ngwaketse District III In Progress Kalahari Beds (80'), shale, siltstone and sandstone (Waterberg System). t-:) CO 2211 Maitlo a Phuduhudu, Kgalagadi Dist 258 In Progress Kalahari :aeds and Cave Sandstone (Stormberg Series, Karroo System).

Private boreholes drilled 08 sites selected by the Geologi~al Survey

Z.1568 Molopo Ranch, Molopo State Lands 412 1,200 260 260 Kalahari Beds Z.1572 Paje, Central District 471 800 420 280 Basalt (150') and Cave Sandstone (Stormberg Series, Karroo System). Z.1573 Serowe, Central District 202 1,300 50 33 Cave Sandstone (Stormberg Series~Karroo System). Z.1600 8JM, Molopo State Lands 522 660 379,470, Kalahari Beds to 480 Z.1618 28JM, Molopo State Lamds In Progress