Proceedings World Geothermal Congress 2010 Bali, , 25-29 April 2010

Isotope and Geochemical Investigations on Hot Springs in ,

Fredolin Javino1, Saim Suratman1, Zhonghe Pang2, Manzoor Ahmed Choudhry3, Joeffery Caranto4, Manuel Ogena4, Ibrahim Amnan1 1-Minerals and Geoscience Department Malaysia, 2- China Academy of Sciences, China, 3- Pakistan Institute of Nuclear Science and Technology, Pakistan, 4- National Oil Company, Philippines [email protected]

Keywords: Tawau, Sabah, Malaysia, isotope, investigations into the geothermal energy resources have geochemistry, geothermal been carried out mainly by the Minerals and Geoscience Department Malaysia (previously known as Geological ABSTRACT Survey Department Malaysia) since the late 80s. The preliminary findings are summarized below : Stable, radioactive isotopes and chemical concentrations have been used to investigate the origin, circulation time a) Geothermal indications in the Tawau- and subsurface history of geothermal waters of the region include many hot springs, mud Tawau region, particularly the Apas Kiri area. The pools and old steaming grounds. Geothermal Tawau region has the highest concentration of young secondary minerals such as chloride, pyrite and volcanics rocks of Late Tertiary (Pliocene) to Quaternary actinolite are widely distributed in the area. age, which therefore offers the best possibility of a heat b) The geology of the area with active geothermal source sufficient for a substantial geothermal resource. indications consists of Late Tertiary (Pliocene) to Thermal manifestations are found in seven areas, namely Quaternary dacitic to basaltic lava and tuff. The Tawau (T1), Upper Tawau (T2), Apas Kiri (A1, A2 , A4 volcanic activity is caused by the extension of the and A5), Balung (B1 and B2), Sungai Jepun (J1 and J2), Sulu Archipelago Arc-Trench System into the Mostyn and Tingkayu. An old steaming ground and hot , which was most active during mud pools are also found in the Apas Kiri area. the Pleistocene (Fig.1). Discharge of springs was up to 2.0 l/s with the surface temperature from 41.1 to 77.6oC. A maximum of eleven ) x E SCALE N 0 100 200 km E C x x sites were selected for collection of first set of water TO x IS x x x E L P x E x x samples and analysed for various isotopes (18-O, 2-H, 3- T x A L D T E S U L U S E A A H of water, 13-C and 14-C of dissolved inorganic carbon; IV T C P A x x O S N SIB (I 34-S and 18-O of dissolved sulphates) and water L E H B C U N R IE E D R T R T x x chemistry. Isotopic and geochemical data show that the E N U x x C H L 34 S U G E D IN origin of thermal waters is meteoric water. The δ S (in I A S R B C x A R x x - C x x x E R R SO4) value shows that the sulphate of all the sampled hot T - A x U T O R x C T E x R U A springs originated from a modern oceanic water (δ34-S of O x C I N 18 2 A Trace of subduction zone; dotted C S A B A H L where buried by sediments about +20%o VCDT). Tritium contents and δ O-δ H O x V diagram indicate that there is no mixing with shallow Strike - slip fault 18 x Active x X Inactive Pliocene-Quaternary volcano young groundwater. The Apas Kiri shows δ O x x xx x x x x x x significant shift of up to 2%o VSMOW ; one of the x x processes involved for the significant enrichment in isotopic and chloride contents in Apas Kiri hot springs is steam separation/evaporation. As for the water chemistry, Figure 1: Geologic setting of the Tawau-Semporna generally the Apas Kiri hot springs appear to have area (modified after Hamilton, 1979 and consistency in the levels of chloride, silica and cations, as Seismotectonic Map of Malaysia, 1986) well as spring temperatures that the water geothermometers reflect its good potential. The tritium c) The most active area of the geothermal content of all the hot springs is about zero showing showings is the Apas Kiri, Tawau area, where the o circulation time more than 60 years, which suggests, highest water temperature of 77.6 C had been these thermal waters were recharged before 1952 (nuclear recorded. Subsurface temperatures in the Apas Kiri weapon test). Reservoir temperatures estimated by δ18O area were estimated using Na/K geothermometers to o o (SO4-H2O) model are very encouraging; Apas Kiri shows be between 189 C and 236 C and this temperature 152-196oC, Sungai Jepun 124-156oC and Tawau 112oC. range shows that there is high potential for harnessing By using chemical geothermometers Na-K-Mg, the geothermal energy in this area (Figures 2 and 3). temperature obtained is ranging about 190-236oC, in which the Apas Kiri is the highest. 2. LOCATION The Apas Kiri is located 3 km to the north of Andrassy 1. INTRODUCTION Peak, which is located within the Tawau-Semporna The geothermal resources in the Tawau-Semporna region, Sabah, Malaysia (Figures 2 and 4). region, Sabah, Malaysia, is considered to be of high potential for geothermal energy resources. The initial

1 Javino et al.

118o 00'E 118o 30'E (Figures 4 and 5) and the recorded temperature ranges o o

yu a from 41.1 C to 77.6 C, with recorded flow rate of 0.3 – k g o in o 4 T 4 . 45' S 45' N N Tingkayu 1.0 l/s.

G. M ostyn Study Area 487 o o 117 58'E 117 59'E Scale : S. K a lu m

p a n g 0 1 km r P. B ait

i e

o v o 4 ta i 4

u R

r Semporna e n 30' n a n 30'

J1 and J2 u M a G. W ullersd orf N . i K G. Lucia p N S ta e u J er 751 SJR M 11 26 S. S G. Po ck 541 . o G. M aria B o UTR a P. B um B um 976 ART lu 4 4 u n

281 a g

w A 5

Tawau Hill Park a

T

23' 23' . ARS A 1-4 526 N N TRT S. SCALE G. Andrassy A p a 10 20 km T 1 s 0 4 o 4 o 15' 15' N N Taw au Tawau Hot Spring AR River water sample A 5 Apas 5 Mud Pool T 1 Apas 5 P. Sebatik J 1 and J2 Tawau Hill Park A 1-4 Apas Kiri Hot Springs Jepun River Hot Spring (Isotope rain gauge)

118o 00'E 118o 30'E

o o 4 4 24' Figure 2. Location of Apas Kiri Area and other Hot 24' N N

Springs in the Tawau region, Sabah, Malaysia. Apas 4

i

Active r Apas 2 i spouts A4B A4A APAS 4 Apas 1

( old steaming ground - several conical K

spouts and mud pools, temperature of s

o a hot water 77.6 (A4A ) and 74.8 C(A4B), p

and pH 7.44 an 7.46 respectively )

. A .

g S

o o Travertine Terrace 117 58'E 117 59'E T APAS 1 T ( 3 m cliff face coated VV A PA S 2 arg, chl,V with brown & green cal,act T A2D (60.5 /6.34)-not sampled algae) T A2C (54.2 /7.75) A2B(60.7 /7.69) A1B(/7.83)68.8 T T LEGEND : A2A (41.1 /7.66) A1A (/7.56)67.8 A2A Hot spring site V Figure 5. Linear structures of the Apas Kiri area Varg T Travertine V Dacite based on aerial photographs chl - Chlorite py - Pyritised 2 arg -Argillised SCALE These manifestations occur over a 3 km area in the Apas act - Actinolite V 0 100 m V V cal - Calcite py, arg Kiri. On the other hand, the total possible resource area within the A5 mud pools, interpreted based on previous geophysical investigations, is at least 700,000 m2.

Figure 3. Sketch of hot springs in the Apas Kiri area 3.2 Sungai Jepun (refer Fig. 2) Two hot springs found (J1 and J2) on the right bank of o 117 50’ Sungai Jepun, on the northeasterly foothills of Gunung G. Mostyn Pock (Pock Peak). The hot springs appear to discharge from contact between solid rock and ash deposit. Larger spring issues 3-4 m above river level, while second springs emerges 2 m above stream level, 30 m upstream. G. Lucia Slight smell of H2S and the rock nearby are hydrothermally altered and travertine is present. Green G. Maria J1 a nd J2algae grow in the hot spring discharge and in the main

’

’

5

5

2

2

stream.o The recorded flow rate of the main spring (J1) is

o

4 4 G. Pock

Ta wa u Hill Pa rk N N A5 1.5 – 2.0 l/s and the second spring (J2) is 0.5 – 1.0 l/s. Ap a s Kiri A1-4 4. PREVIOUS WORK ON GEOCHEMICAL T1 INVESTIGATIONS 4.1 Chemistry of Thermal Waters 0 Sc a le 20 km Analysis results (Table 1) showed that the thermal water 117o 50’ from the Apas Kiri have the characteristics of neutral pH sodium chloride water ; they have high concentrations of

Figure 4. A radarsat image of the Tawau region, 4.2 Chemical Geothermometry Sabah, Malaysia The subsurface temperature of the area has been estimated using different chemical parameters as shown 3. GEOTHERMAL SURFACE MANIFESTATIONS in Table 2. The silica geothermometer gave a low 3.1 Apas Kiri subsurface temperature probably due to the silica dilution The type of geothermal surface manifestations occurring of the waters in the Apas Kiri area. in the Apas Kiri area includes hot springs, seepages, ‘old The Na/K geothermometer on the other hand, gave a high steaming ground’ and mud pools. The geothermal subsurface temperature for the waters at Apas Kiri. activities are located in the vicinity of major lineaments

2 Javino et al.

Table 1. Chemistry of waters from springs in the Apas Kiri area. Note: 1. All cations & anions are expressed in ppm. 2. Total solids are expressed as mg/l, conductivity as µohm & turbidity as N.T.U. 3. na-not analysed Locality: Apas 1: Outflow Spring (contaminated with cold water seepage). Apas 5: Hot outlet at Mud Pool.

(Extracted and modified from P.S. Lim, Geo. Soc. Malaysia, Bulletin 29, July, 1991).

Samples Apas 1 Apas 5 Site Temp. oC 60 60 pH at 25oC 7.4 6.7 Dissolved SiO2 6.0 na Total SiO2 86 75 Ca 150.9 142.37 Mg 34.1 12.9 K 77.5 93.5 Na 760 925 Li 5.4 5 HCO3 705.16 544.12 SO4 312.5 476 Cl 1250 1410 F 0.65 0.63 B 21 60 As 150 250 Fe 0.3 0.2 Mn 0.3 0.8 Total Solids 3158 3446 Turbidity 2.55 * Conductivity 4910 5320 Na/K 16.7 16.9 Na/Ca 8.78 11.14 Na/Li 42.4 56.1 Cl/B 10.25 7.17 Cl/SO4 6.12 8.03 Cl/F 581.6 1205 Table 2 - Subsurface temperature calculated from chemical geothermometers (Extracted and modified from P.S. Lim, Geo. Soc. Malaysia, Bulletin 29, July, 1991).

Subsurface Temperature Silica Na/K Location Charge Spring Truesdell Fournier Truesdell Fournier (1971) Giggenbach Temperature Apas -10 75.6 (1975) 127.9 (1971)130.2 (1975)191.9 220.5 234.8 Kiri2Apas -14 72.2 129.9 132.6 193.1 221.4 235.2 Kiri2Apas -10 69.0 126.9 128.9 189.6 218.7 234.0 Kiri2Apas (A1) -4 60.0 120.8 121.7 188.7 217.9 233.0 Kiri5

4.3 Resistivity Study 5. THE PURPOSE OF THE CURRENT STUDY A resistivity investigation was carried out in the Apas Generally, the study targets to evaluate more precisely Kiri area as a result of the high subsurface temperature the potential of geothermal reservoirs for further found in the area. The results of the investigation are exploration and exploitation using isotope and shown in (Figures 6 and 7). An area within the A5 is geochemical techniques. found to be of good potential ; the geophysical contour within the A5 area is seen as ‘open-ended contour’ The specific objectives would include investigations on suggesting the resource area may extend to the north of the origin and dating of water, its chemical the Apas Kiri. characteristics and subsurface history, determination of reservoir temperatures, heat source and potential of the geothermal reservoirs, ranking and recommendation for detailed exploration.

3 Javino et al.

0200400 m Sc a le : 0 1 km

Apas 5 2

5

m Apas 5

S .

m A p 0 4 5 m a 1 s i S r . K i 0 A 0 i K r 1 s p i 4 m a a 3 i 0 p s 5 r A K i

. i K S r i s

3 a p A

. S Apas 4

ri 2 ApasS. A2pas Ki Apas 4 Apas 1 r i 2 S. A pas K i Apas 2

Apas 1

m

m

m

m

0

5

0

2

m 1

5

1

0

7

5

5 2

m m Road River 5 Contour Interval 2 0 5 Hot spring Mud pool Old steaming ground Road River Resource area

Hot spring Old steaming ground

Figure 6. Isoresistivity Map (AB = 1000 m), Apas Kiri Area, Tawau (modified from P.L.N., 1991). Figure 7: Probable resource area indicated by 6. GEOLOGY resistivity (modified from P.L.N., 1991) The Apas Kiri area is underlain mainly by dacitic lava, tuff and of Late Tertiary (Pliocene) to Quaternary age (Fig. 8). The dacitic agglomerate is found mainly in the west, northwest and northeast whereas dacitic lava and tuff are found in the central, south and eastern portions. The dacitic rocks are both mesocratic and melanocratic. The agglomerate is made up of angular 0 200 400 m clasts of dacitic lava and tuff in a fine-grained volcanic matrix.

The dacitic rocks are well jointed. An aerial photograph study (Fig. 5) showed that most of the linear structures Apas 5 are predominantly northwest, north and northeast direction. As seen on radarsat imagery (Fig. 4), most of S .

A p the geothermal manifestations occur around the Mount a 4

s i r K i i K r i s Maria Peak, namely the Apas Kiri (A1, A2, A4 and A5), a 3 p A . Balung, upper Tawau (T2) and Tawau (T1) hot springs. S These joints may reflect fracture zones due to updoming by magmatic pressure. These major fracture zones may Apas 4 ri 2 S . A pa s Ki play an important role in creating adequate fracture Apas 2 permeability for the outflow of geothermal fluids, Apas 1 especially in the upper Tawau and Balung areas where the hot springs are located close to these fracture zones. The lineament south of Maria Peak may represent a major north-south fracture zone which permits inflow of meteoric water into the geothermal system. It is inferred RoadRiver Hot spring Old steaming ground that the centre of reservoir is beneath the Peak, or more precisely at the southeast of Maria Peak as Dacitic agglomerate Dacitic lava and tuff indicated by the presence of H2S and geochemical characteristic of the hot spring waters.

The alteration in the rocks are mainly calcitised, Figure 8. Simplified geology of the Apas Kiri area chloritised and argillised. Pyritisation and silicification is more dominant in the northeast and the western part. 7. SAMPLING AND ANALYSIS Epidote and actinolite have been found in the rocks. The First set of sampling for isotope and geochemical agglomerate are commonly oxidised and argillised. includes collection of water for 18-O, 2-H, 3-H in water, 13-C and 14-C (in TDIC), 18-O & 34-S in sulphates. A collection of the Tawau precipitates for year 2003 were

4 Javino et al. also included for 18-O, 2-H, 3-H. Analyses for major the temperature obtained is ranging about 180-236 oC, in chemical ions and isotopes such as 18-O, 2-H, 3-H, 13-C which the Apas Kiri is the highest (refer Tables 2 and 6 and 14-C were carried out at the IAEA (Vienna) and the and Figures 13 and 15). PNOC Laboratories). The results are shown in Tables 3, 4, and 5. 8.1 Origin of Geothermal Waters Isotopic data can well differentiate between the three 8. RESULTS AND DISCUSSIONS possible types of origin of thermal waters i.e magmatic, The discharge temperature of the hot springs of Tawau oceanic and meteoric. Ranges of δ18-O of all the sampled region varies from 41.1 to 77.6oC in which the A4A is the hot springs of (i) Apas Kiri: -4.69 to -5.13%o VSMOW, highest. The thermal waters in Apas Kiri has high (ii) Sungai Jepun: -6.05 to -6.11%o VSMOW and (iii) concentrations of chloride, sodium and bicarbonate ions Tawau: -6.41%o VSMOW. As for the δ2-H (i) Apas Kiri: with pH of about neutral. In Apas Kiri, the EC ranges -37.0 to -41.2%o VSMOW, (ii) Sungai Jepun: -35.4%o to between 3,910 uS/cm and 4,750 uS/cm, in Sungai Jepun -36.1%o VSMOW and (iii) Tawau: -41.7%o VSMOW. 1,969-2,300 uS/cm and in Tawau 2,030 uS/cm. The These data do not show the presence of any significant chemistry shows that the thermal waters of the Apas Kiri amount of magmatic water which generally has δ18 : +6 area are sodium chloride water type (Table 3 and Fig. to +9%o and δ2-H: -40 to -80%o VSMOW (Pearson et al 12). ,1980; Giggenbach, 1992). The important feature of the fluids emerging from the hot springs in Apas Kiri is their The geochemical analysis results, as shown on Table 3, consistency in the levels of chloride, silica and cations, generally shows that the water sample chemistry appears which is high compared to the other sampled hot springs to have consistency in the levels of chloride, silica and in the area ; the maximum EC is 4,750uS/cm for Apas cations, as well as spring temperatures that the water Kiri hot springs, while Sungai Jepun is 1,969-2,300 geothermometers reflects good potential of Apas Kiri uS/cm and Tawau is 2,030 uS/cm. The chloride content (Fig. 13). of Apas Kiri ranges from 1,078-1,336 ppm, whereas Sungai Jepun ranges from 146-147 ppm and Tawau is The isotopes analysis result for river and rainfall samples 353 ppm. Normally the ocean waters show δ18-O and δ2- shows that the levels of tritium (Tables 4) ranges from H of about 0%o VSMOW, the salinity from 33,500 to 0.8-1.5TU for the river and 1.4-7.6TU for the Tawau 37,600 ppm and chloride about 19,300 ppm (Clark et al., precipitate which are considered very low i.e. ranges 1998). from -1.57%o to -10.23%o VSMOW. As for the rivers, the δ18-O levels range from -6.67%o to -7.26%o Modern oceanic sulphates has δ34-S values of about VSMOW. The mean δ18-O value for the Tawau +20%o VSMOW (Krouse, 1980). From the δ34-S values, precipitate -6.13%o VSMOW ; this mean-value could be obtained for this sampled hot springs in Tawau, are used for projection to the linear LMWL to determine for reflective of modern oceanic origin. The presence of very the end-members of meteoric water and could be low or about zero tritium content in the hot springs water projected to the Apas Kiri isotopic content for the other also suggests that the water has no mixing with the young end-members. groundwater. From the isotopic and geochemical data obtained, it 8.2 Tritium and Radiocarbon Dating shows that the origin of thermal waters are meteoric waters. The δ34S (in SO4) value shows that the sulphate The duration of circulation in deep reservoir has been of all the sampled hot springs originated from a modern estimated by the radioactive isotopes 3-H, and 14-C. The oceanic water (δ34-S of about +20%o VCDT). Tritium sampled hot springs in Tawau has about zero 3-H content contents and δ18-O-δ2-H diagram indicate that there is which suggest that the circulation time is more than 60 no mixing of shallow young groundwater. The Apas Kiri years. The tritium has half-life of 12.43years. shows δ18-O significant shift of up to 2%o VSMOW ; 14-C has half life of 5,730 years. It is useful for dating one of the processes involved for the significant geothermal fluids as they have normally much longer enrichment in isotopic and chloride contents in Apas Kiri circulation time. The dilution of 14-C is accounted for in hot springs is steam separation/evaporation (Fig. 14). the decay equation by the dilution factor or fraction, q, The triangular plot of main anions for hot springs of the and the age of groundwater is determined by the Tawau area (Fig. 9) shows that the A5 is the nearest to radioactive decay equation. the heat source rock or in general, the Apas Kiri area, as q = d13C(DIC) - d13C (Soil Sed) / d13C (Soil CO ) - d13C indicated by the enhanced amount of chloride. Plots of 2 (Soil Sed), boron vs. chloride (Fig. 11) further validate the Apas Kiri hot springs are located near to the heat source rock. The where d13C (Soil Sed) = 0 chloride, when plotted against temperature (Fig. 10), could indicate that the hot springs in Apas Kiri varies in and temperature, probably due to its location. The A4A and

A4B hot springs are located away from the river surface t = -8267 ln (a /q.a0), water, thus the surface temperatures are higher compared 14 to the other hot springs. The isotope and geochemical where a = d C(DIC) of the 14-C sample and a0 = 100 characterisitcs of the Apas Kiri show that it is an outflow pMC. region. Reservoir temperatures estimation by using δ18- O (SO4-H2O) model are very encouraging ; Apas Kiri By using the above formulae, age of hot springs water shows 152-196 oC, Sungai Jepun 124-156 oC and Tawau obtained are as follows : 112 oC. By using chemical geothermometers Na-K-Mg,

5 Javino et al.

A1A = 15,200 years, A1B = 16,400 years, A2B = 15,300 • to Dr. Yunus Daud of University of Indonesia, years and T1 = 38,700 years. Jakarta. • to the Technical University of Graz and the 9. CONCLUSIONS Joanneum Research Institute of Graz, The thermal waters of hot springs in Tawau are especially Prof. Ralf Benischke, Dr. Albreicht originated from local meteoric water. The δ34S (in SO4) Leis, Dr. Peter Reichl and Dr. Beyene value shows that the sulphate of all the sampled hot Yehdegho for their time spent, ideas and springs originated from a modern oceanic water (δ34-S of supervisions on data interpretation and work about +20%o VCDT), and do not have any mixing of strategies. • shallow young groundwater. One of the major processes to the Director of Sabah Parks Datuk Lamri involve is steam separation/evaporation, which indicated Ali, and his officers Fatimah Simin and Simon by the significantly enriched isotope and chloride Limbawang for their supports in this project, contents in Apas Kiri hot springs. The hot springs of especially on Tawau precipitate collection. Apas Kiri is significantly enriched or has δ18-O shift of up to 2%o. Tritium data of all the hot springs are about REFERENCES zero which indicate that the duration of deep circulation of thermal fluids is more than 60 years i.e. the recharge Clark, I.D. and Fritz, P. (1998). Environmental Isotopes occurred before 1952 (nuclear weapon test). The 14-C in Hydrogeology. Lewis Publishers Boca Raton, activities corrected by 13-C data suggest that the age of New York. the sampled hot springs in Tawau ranges from 15,200 to Giggenbach, W.F., (1992). Isotopic shift in waters for 38,700 years. geothermal and volcanic systems along convergent plate boundaries & their origin, Earth and Planetary As a result of the reassessment of the data, it is concluded Science Letters, 113: p495-510. that the Apas Kiri (which is an outflow region) and Mount Maria areas have the best geothermal potential, Hamilton, W., 1979. Tectonics of the Indonesian Region. which mean the center of reservoir or upflows are U.S. Geological Survey Professional Paper, 1078. beneath the southeastern part of Mount Maria, but may extends to the North of Apas Kiri (Balung Area). The Krouse, H.R., 1980.Sulphur isotopes in our environment. In : Handbook of Environmental Isotope estimation of reservoir temperatures by δ18-O (SO4-H2O) model are very encouraging ; the Apas Kiri shows 152- Geochemistry, Vol.1.P.Fritz and J.-Ch. Fontes (eds.). 196oC, Sungai Jepun 124-156oC and Tawau 112oC. By Elsevier Scientific Publishing Company using the chemical geothermometers Na-K-Mg (inclusive Amsterdam-Oxford-New York. p222-257. of previous estimations), the temperature obtained is Lim, P.S., 1991. Geothermal prospecting in the o ranging about 180-236 C, in which the Apas Kiri is the Semporna Peninsula with emphasis on the Tawau highest. area. Geological Society of Malaysia, Bulletin 29, July, 1991, pp135-155. ACKNOWLEDGEMENTS Lim, P.S., 1991. Prospects and Potential Areas of The authors wish to acknowledge: Geothermal Resources in Sabah. Proceedings of the 22nd Geological Conference, 1991, p186-194. • to the Director General of JMGM Dato’ Yunus Abd. Razak for his support in this project. Pearson, F.J. and Rightmire, C.T., (1980), Sulphur and • to the Director of JMG Sabah, Alexander Yan, oxygen isotopes in aqueous sulphur compounds. In: and Engineering Geology Head Mr. Adam Handbook of Environmental Isotope Isotope Liau, for their support in this project. Geochemistry,Vol.1.P.Fritz and J.-Ch. Fontes (eds.). • to the IAEA in Vienna, Austria. Elsevier Scientific Publishing Company, • to Prof. Klaus Froehlich for his ideas on Amsterdam-Oxford-New York. p227-257. investigation strategies and for the isotope data State Electricity Corporation (P.L.N.), 1991. Resistivity interpretation. Survey at Andrassy Area, Tawau Sabah. • to Prof. Dr. Luis Araguas-Araguas of Isotope Hydrology Section, IAEA, Vienna.

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Table 3. Chemical composition and field data of the hot springs in Tawau region, Sabah, Malaysia

Sample Sampling Altitude pH at Nos. Location Longitude Latitude ToC EC Na K Mg Ca Cl SO4 HCO3 SiO2 Li B ID Date (m) 25oC

1 A2A Apas Kiri 27/Apr/04 117o58'30" 4o21'33" 160 41.1 3910 7.66 716.0 68.50 14.60 194.0 1078.0 281.0 567.0 71.1 3.66 46.10

2 A2C Apas Kiri 27/Apr/04 117o58'30" 4o21'33" 160 54.2 4750 7.75 847.0 75.50 16.10 208.0 1231.0 317.0 627.0 69.9 4.17 51.30

3 A5 Apas Kiri 27/Apr/04 117o59'1" 4o22'39" 270 60.0 2600 8.02 858.0 86.80 13.10 165.0 1336.0 297.0 239.0 83.1 4.73 55.60

4 A2B Apas Kiri 27/Apr/04 117o58'30" 4o21'33" 160 60.7 4340 7.69 792.0 76.20 16.10 208.0 1213.0 315.0 619.0 74.3 4.07 51.10

5 A1A Apas Kiri 27/Apr/04 117o58'30" 4o21'33" 163.5 67.8 4300 7.56 815.0 77.90 16.70 212.0 1198.0 312.0 668.0 80.2 4.12 45.50

6 A1B Apas Kiri 27/Apr/04 117o58'30" 4o21'33" 163.5 68.8 4350 7.83 810.0 78.40 16.50 211.0 1218.0 313.0 649.0 81.9 4.15 51.40

7 A4B Apas Kiri 27/Apr/04 117o58'30" 4o21'33" 180 74.8 4380 7.44 838.0 81.1 16.70 214.0 1237.0 323.0 668.0 81.8 4.18 52.00

8 A4A Apas Kiri 27/Apr/04 117o58'30" 4o21'33" 180 77.6 4200 7.46 837.0 82.9 16.80 215.0 1246.0 323.0 606.0 77.8 4.28 52.50

9 J1 Jepun River 28/Apr/04 118o22'50" 4o28'4" 60 64.9 1969 8.22 255.0 3.77 0.18 322.0 146.0 1182.0 ND 47.7 <0.05 1.39

10 J2 Jepun River 28/Apr/04 118o22'50" 4o28'4" 60 63.9 2300 8.48 265.0 3.87 0.07 321.0 147.0 1204.0 ND 49.1 <0.05 1.73

11 T1 Tawau Town 28/Apr/04 117o55'47" 4o17'47" 35 48.8 2030 7.69 297.0 22.60 9.15 125.0 353.0 338.0 288.0 65.2 1.07 14.20

Note : ND - Not Detected

7 Javino et al.

Table 4. Isotopic composition and field data of the rivers and rainfall in Tawau region, Sabah, Malaysia δ18O δ2H 3H ± 2σ Altitude Nos. Sample ID Location Sampling Date (m) [‰ VSMOW] [‰ VSMOW] [TU] [TU]

River water : 1 AR Apas Kiri River 160.0 7/19/2003 -6.67 -39.7 1.5 0.4 2 ART Apas 5 River Tributary 270.0 7/19/2003 -6.67 -40.3 1.3 0.4 3 SJR Jepun River 60.0 7/19/2003 -6.79 -42.7 1.1 0.3 4 TRT Tawau River Trib. near T1 35.0 7/20/2003 -7.26 -44.8 1.3 0.3 5 UTR Upper Tawau River 265.0 7/19/2003 -7.19 -42.5 0.8 0.3 Rainfall, elevation 281 m amsl.: 6 TP2 Tawau Hill Park 3/19/2003 -1.99 -4.9 7.6 0.6 7 TP3 Tawau Hill Park 3/31/2003 -10.23 -72.0 na na 8 TP4a Tawau Hill Park 4/13/2003 -2.98 -10.3 na na 9 TP4b Tawau Hill Park 4/30/2003 -1.57 -0.2 na na 10 TP5a Tawau Hill Park 5/18/2003 -14.10 -99.6 na na 11 TP5b Tawau Hill Park 6/10/2003 -4.99 -24.3 na na 12 TP6 Tawau Hill Park 7/7/2003 -5.79 -32.8 na na 13 TP7 Tawau Hill Park 7/18/2003 -10.01 -64.3 na na 14 TP8 Tawau Hill Park 8/4/2003 -6.37 -34.6 1.4 0.4 15 TP9 Tawau Hill Park 9/30/2003 -5.84 -31.3 na na 16 TP10 Tawau Hill Park 10/18/2003 -3.11 -11.5 na na

Note : na - not analysed

8 Javino et al.

Table 5. Isotopic composition and field data of the hot springs in Tawau region, Sabah, Malaysia

18 2 34 18 3 13 14 δ O δ H δ Ssulphate δ Osulphate H ± 2σ δ CDIC CDIC ± 2σ

Sample Sampling [‰ Nos. Location ID Date [‰VSMOW] [‰VSMOW] [‰ VCDT] VSMOW] [TU] [TU] [‰ VPDB] [pMC] [pMC]

1 A2A Apas Kiri 7/17/2003 -4.91 -37.0 20.1 6.4 < 0.6 na na na na

2 A2C Apas Kiri 7/17/2003 -4.83 -39.3 19.0 4.2 < 0.6 na -3.5 58.7 8.6

3 A5 Apas Kiri 7/19/2003 -4.69 -38.7 17.5 5.6 < 0.6 na na na na

4 A2B Apas Kiri 7/16/2003 -4.97 -39.0 20.2 5.4 < 0.6 na -5.1 4.0 0.6

5 A1A Apas Kiri 7/17/2003 -5.06 -39.8 19.7 6.3 < 0.6 na -5.7 4.5 1.2

6 A1B Apas Kiri 7/16/2003 -5.13 -39.9 19.8 6.7 < 0.6 na -5.4 3.7 0.7

7 A4A Apas Kiri 9/26/2002 -5.08 -41.2 na na < 0.6 na na na na

8 J1 Jepun River 7/15/2003 -6.05 -35.4 16.5 8.1 0.4 0.4 -7.2 na na

9 J2 Jepun River 7/19/2003 -6.11 -36.1 16.2 5.4 0.4 0.3 -23.6 na na

10 T1 Tawau Town 7/20/2003 -6.41 -41.7 20.9 8.9 < 0.6 na -10.8 < 0.8 na

Note : na - not analysed

9 Javino et al.

Cl Legend Hotsprings

M A T U R E W A A5 T E R S A1-2 A4

T1 G R O U N D W A T E R S STEAM-HEATED WATERS SO4 HCO3

Fig. 9. Triangular plot of main anions for hot springs of Tawau area

80 A4A A4B

70 A1B J1 A1A

) J2

C A2B o

( 60 A5 T

A2C

50 T1

A2A 40 0 400 800 1200 1600 Cl (mg/l)

Fig. 10. Plot of Chloride vs. Temperature for hot springs of Tawau area 60 A5 A1B, A2C, A2B, A4A, A4B

A2A A1A 40 ) l / g m ( B

20

T1

J1 J2 0 0 400 800 1200 1600 Cl (mg/l)

Fig. 11. Plot of Chloride vs. Boron for hot springs of Tawau area

10 Javino et al.

A4 8 0 0 C 8 a A4B lc A1A i u ) m A1B l ( (C C A2A e 6 J1a d 0 ) i 0 + A2B r 6 M o J2 l a A2C h g C n + e A5 ) s 4 i J2 4 u O 0 0 m S 4 ( J1 ( M te T1 a g f l ) u S 2 0 0 2 T1 A2B A4 A5 A1B A2C A4B A1AA2A

Mg2 SO 0 0 4 2 J1 J2 2 S ) 8 0 0 o 4 3 0 0 8 d 0 2 i 0 O u 4 C m H ( ( ) N te g a a S 4 ) n 6 u M 0 + o 0 l ( 0 P 6 0 f 6 0 b 4 a m o 0 r t u t 6 a e i a c ( s s i S e s i B O n u + 4 g m ) a 3 ) 6 ( 0 4 M 0 0 K 8 O 6 0 4 ) 0 C 0 ( 8 e t a T1 n o b A2B r 8 a A1B 2 0 0 0 0 2 C 8 A2CA4BA4 A2A A5 T1 A4B A1B J1 A4 A2C A1AA2A J2 A2B Ca 80 60 40A1A 20Na+K HCO33 +CO 20 40 60 80 Cl Calcium (Ca)A5 Chloride (Cl) C A T I O N S%meq/l A N I O N S

Fig. 12. Piper diagram of hot springs water samples of Tawau area Na/1000

Legend Hotsprings

160 180 200 220 240 J 260 280 300 A 320 340 T1

ROCK DISSOLUTION

100 0 20 40 60 80 K/100 Mg

Fig. 13. Evaluation of Na-K-Mg temperatures of thermal waters for sampled hot springs of Tawau area (Giggenbach, 1988)

0.0 Tawau rainfall-THP Station rainfall -20.0 Jepun River(J1 and 2) hot springs T1 hot spring -40.0 Apas Kiri (A1,A2 and A4) hot springs Apas Kiri A5 mud pools -60.0 Apas River trib. water (near A5) Apas River water (near A1,2 and 4) -80.0

H ( VSMOW) ( H 2 18 Tawau River trib.(near T1) 2 δ H = 7.9655 δ O + 13.434 δ R2 = 0.9957 Upper Tawau River (near THP) -100.0 Linear (Tawau rainfall-THP Station)

-120.0 -15.00 -10.00 -5.00 0.00 5.00 δ18O ( VSMOW)

Fig. 14. d18-O vs. d2-H diagram for hot springs, rivers and rainfall of Tawau area

11 Javino et al.

14 12 10 (‰) 4 8 6

O of SO O of 4 18 δ 2 -7 -6 -5 -4 18 δ O of H2O (‰)

18 18 18 Fig. 15. δ O(SO4) vs. δ O(H2O) diagram showing reservoir temperatures and relevant isotherms based on the δ O(SO4- H2O) geothermometer.

Table 6. Reservoir temperatures estimate by O-18 (SO4-H2O) model for hot springs of Tawau area. Spring Date of Code sampling O-18 (water) O-18 (Sulphate) Alpha18O ToC

A1A 7/17/2003 -5.06 6.3 1.0114581 158.0004689

A1B 7/16/2003 -5.13 6.7 1.0118798 152.3146179

A2A 7/17/2003 -4.91 6.4 1.0113306 159.7659507

A2B 7/16/2003 -4.97 5.4 1.0104294 172.8970722

A2C 7/17/2003 -4.83 4.2 1.0090337 195.8514595

A4A 9/26/2002 -5.08

A5 7/19/2003 -4.69 5.6 1.0103334 174.3684578

J1 7/15/2003 -6.05 8.1 1.0142318 124.3021019

J2 7/19/2003 -6.11 5.4 1.0115839 156.281101

T1 7/20/2003 -6.41 8.9 1.0154059 112.2614528

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