Page 138 - Hydrogeology Principles and Practice

HYDC03 12/5/05 5:37 PM Page 121

Chemical hydrogeology 121

BO X
Continued
3.10

Table 1 Representative chemical analyses of saline and thermal groundwaters from four tin mines together with two fresh shallow
groundwater sites in the Carnmenellis Granite or its aureole. Locations are shown in Fig. 1. After Edmunds et al. (1985).
Site Mount Wellington Mine Pendarves Mine Wheal Jane Mine South Crofty Mine Shallow groundwater

1 2
Depth (m) 240 260 300 690 30 41
−1
Flow rate (L s ) 15 0.5 10 3.5 – –
Temperature (°C) 21.6 21.4 39.5 41.5 10.8 10.5
pH 5.6 6.9 6.4 6.5 4.92 –
−1
Na (mg L ) 125 29 1250 4300 14 12
K 12 3.1 72.0 180 2.8 4.0
Li 3.55 0.06 26.0 125 <0.01 <0.01
Ca 93 18 835 2470 7 13
Mg 11.9 5.0 22.0 73.0 2.7 2.4
Sr 1.43 0.06 12.8 40.0 <0.06 0.23
−1
HCO (mg L ) 9 67 21 68 4 9
3
NO 11.2 8.3 10 <0.2 2.1 26.0
3
SO 275 38 148 145 15 17
4
Cl 287 32 3300 11,500 25 21
F 0.29 2.90 3.30 2.70 <0.1 0.11
Br 0.9 <0.3 – 43.0 –
B 0.80 <0.01 3.3 11.0 –
SiO 19.2 34.2 28.4 34.2
2
−1
Fe (mg L ) 43.0 0.62 22.4 4.75 0.280 0.014
Mn 2.90 0.30 4.00 4.50 0.031 0.008
Cu 0.024 0.002 0.005 0.023 0.004 0.027
Ni 0.134 0.007 0.027 0.190 0.002 0.0015
Total mineralization 885 230 5747 19,002 73 105
−1
(mg L )
2
d H (‰ SMOW)* −35 −38 −31 −29
18
d O (‰ SMOW)* −5.4 −5.2 −5.7 −5.2
18
2
* d H and d O are measured in per mil relative to Standard Mean Ocean Water (SMOW; see Section 4.2).