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Effects of volcanism on water chemistry, Deception Island, Antarctica
Marine Geology Elsevier Publishing Company, Amsterdam - Printed in The Netherlands
Letter Section E f f e c t s o f v o l c a n i s m o n w a t e r c h e m i s t r y , D e c e p t i o n Island, A n t a r c t i c a
H. ELDERFIELD Department of Earth Sciences, University of Leeds, Leeds (Great Britain) (Received February 8, 1972) ABSTRACT Elderfield, H., 1972. Effects of volcanism on water chemistry. Deception Island, Antarctica. Mar. Geol., 13: M1-M6. Analyses are presented of waters from c~ater lakes on Deception Island and from coastal sea waters which were collected during a period of intense fumarolic activity and increasingseismicactivity prior to the 1969 eruption. Major-componentanalysisshows all samplesto be slightly modified sea waters. However, crater-lake waters are almost saturated with silica and all waters contain high levels of manganese (30 to 2,420/ag/1), suggestinga significant volcanic source for these elements. INTRODUCTION There is considerable geochemical interest in the possible changes occurring in sea water and other natural waters as a result of volcanic processes (e.g., White, 1955; Zelenov, 1964; Bostr6m and Peterson, 1966; Moore, 1966; Strakhov and Nesterova, 1968). However, direct studies of these phenomena are rarely possible because of the unpredictable timing of volcanic eruptions. This note reports the analyses of water samples collected during the few weeks of fumarolic activity culminating in the Deception Island eruption of February 1969. Deception Island is the most southern island in the South Shetland group and lies in Bransfield Strait north of the Antarctic Peninsula (Fig. 1A). The earliest reposed volcanic eruption was in 1842 (Wilkes, 1845). Since then intense fumarolic activity has persisted, and there is evidence from ice stratigraphy that two eruptions occurred between 1910 and 1920 (Oreheim, 1971). In December 1967 eruptions were again observed. Part of the activity was submarine and formed six closely associated craters (Fig. 1C) which reached above sea as a new island in Telefon Bay (Baker et al., 1969). The effects of the 1967 eruption were studied during December 1968 and January 1969 by an expedition sponsored by the Royal Society and British Antarctic Survey. During this time there was a build-up of fumarolic activity leading to the fissure eruption of February 1969. Water samples were collected during the period 4.12.68 to 27.1.69 and form the basis of this preliminary report.
M2
LETTER SECTION
~'w
~ " ~ ~. ~ - ~ " v
. ~
5~-
'~ ',
"
c~'C~'®
60"45'W
//;----
.~
~-
.~,8"
1
,
.
'
'
,
U
/Y /
'.
/
i
__
/
~030 C'
)-
,
Fig. 1. Map of Deception Island. A. Location rchtive to South Shethnd I s ~ d s and Antarctic Peninsula. B. Deception Island at the time of sample collections (D1-D8). C. Island formed in Telefon Bay by 1967 eruption.
LETTER SECTION
M3
SAMPLINGAND ANALYSIS One-litre samples were collected in high-density polyethylene bottles from eight locations on the island (Fig. IB) by members of the survey party. Water temperatures were not recorded; at other times during the survey period temperatures of up to 97°C were noted for some inland waters. The samples were stored, without treatment, in the collection bottles and shipped to the British headquarters of the Antarctic Survey, and had remained unopened for about thirty months when the author was informed of their existence. Despite their long storage time, the unusual nature of the samples and the coincidence of their collection with active volcanic phenomena was thought sufficient to warrant their examination, and so the samples were collected and analysed shortly afterwards. The accuracy of the analytical data is subject to errors due to storage time and technique. This is likely to be most critical for the trace-element determinations where losses onto container surfaces can occur (Riley, 1965) resulting in underestimates of the concentrations of these elements at the time of sample collection. On arrival at the laboratory, pH and bicarbonate were first determined (by glass electrode). Waters were then filtered through 0.45 lam membrane filters, salinity determined (gravimetrically and conductimetricaUy), and analysed for sodium and potassium (by flame photometry), chloride (by potentiometric titration), and spectrophotometrically for sulphate (Bertolacini and Barney, 1957) and fluoride (Greenhalgh and Riley, 1961). Because of the limited sample volumes remaining after major-component analysis it was not possible to carry out a fully quantitative programme of trace-element analysis. Silicon was determined spectrophotometricaUy (Mullin and Riley, 1955), iron and manganese were analysed by direct atomic absorption spectrophotometry against spiked synthetic waters of equivalent sahnities, and A1, Cu, Pb, Co, Ni and Zn were measured semi-quantitatively by cathode-ray polarography. RESULTS AND DISCUSSION Major element compositions of the water samples are presented in Table I and the results of analyses for Fe, Mn and Si are listed in Table II. The coastal sea-water samples (D1-D4) and sample D5 from New Island crater 1 (which was open to the sea) have salinities and major element levels typical of normal sea water in near-shore regions, and are only slightly modified as a result of marine weathering and run-off from melting of glaciers on the island. Samples from enclosed craters (D6-D8) have salinities > 35% , but otherwise have major ion concentrations at normal levels. There is no evidence in any sample of fluoride enrichment, which is considered to be a sensitive indicator of volcanic activity (Wilknlss et al., 1971). Indeed F/C1 ratiosaverage 0.85.10 -s , lower than for normal sea water (6.7" 10-s). Concentrations of AI, Cu, Pb, Co, Ni and Zn showed no significant enrichment compared to averages far fresh- and sea-water, and are not reported here. Silicon and manganese, however, showed considerable variation from their levels in average sea water
10.8
31.164 34.626 34.484 36A80 35.627 37.628
35.000
7.50 7.70 8.00 7.45 7.55 7.65
24. 1.69
27. 1.69 27. 1.69
11.12.68
4.12.68
19. 1.69
D3
I)4 D5
D6
D7
D8
,1 salinities in % , major element concentrations in g/1. ,2 data from Culkin (1965).
Standard sea water , 2
1 1 o 5 ~50
33.288
7.25
13. 1.69
10.4
10.7
6.5 11.5
5.0
10.5
0.39
0.58
0.53
0A5 0A3
0.40
0.40
0.35
D2
9.3
29.996
7.25
Pendulum Cove from surface at low tide Port Foster from 10 m at low tide Pendulum Cove from s~face at low tide NW side of New Island New Island crate~ 1 from 6 m at high tide New Island crater 2 from 1.5 m Crater Lake from 1 m Land Cxater low tide
23.12.68
K÷
D1
Na ÷
Salinity
pH
Location
Date
Sample no.
Major components in waters of DeceptionIsland and in standard sea water *l
TABLE I
0.41
0.67
0.28
0.38
0.49 0A8
0.52
~44
0.46
1.29
0.75
1.15
1.35
1.30 1.25
1.10
1.25
1.10
0.008
0.003
0.002
0.002
0.0116 0.006
0.005
0.007
0.005
Ca 2+ Mg2+ Sr 2+
19.35
19.92
17.97
19.48
18.89 18.01
17.23
17.79
15.96
C1-
2.71
2.16
4.97
2A4
2.81 2.5
1.69
2.16
2.34
so4 2-
V<0.0001 <0.0001 0.0001 0.0004 ~0.0001 0.0003 0.0002 0.0001
0.0010
HCO~ 0.160 0.136 0.140 0.297 0.282 0.347 0.195 0.342
0.142
z
4~
LETTER SECTION
M5
TABLE II Fe, Mn and Si in waters of Deception Island and in average sea water*x Fe .2
Mn
Si
n.d. n.d. 180 n.d. n.d. n.d. 310 n.d.
130 70 60 30 560 1,550 2,420 1,810
4,400 5,890 7,160 7,770 7,430 29,600 36,500 50,700
2
3,000
Deception Island waters
Sea waters Crater open to sea Crater lakes Average sea water*s
f D1 D2 D3 1)4 D5 f D6 D7 D8
10
.1 concentrations in/2g/k ,2 amount passing through 0.45/~n filter. .S averagesfrom Goldberg (1965). n.d. = not detected. (Table II). For the sea-water samples (D1-D4) Si concentrations are only slightly higher than for average sea water (3,000/ag/l), but increase from 4,400/ag/1 in the sample collected on 23.12.68 to 7,430/~g/lin that coUected on 27.1.69. These waters are also considerably enriched in manganese but, in contrast to Si, levels of Mn decrease temporally from 130 to 30 ~g/l. Since samples were collected at various stations within Port Foster the significance of these temporal variations is unknown; they may simply reflect local differences in coastal sea-water composition. Water samples from enclosed crater lakes are considerably enriched in both Si (up to 50,700/ag/l) and Mn (up to 2,420 ~tg/1). The sample from Land Crater (D8) is almost saturated with silica (concentration equivalent to 110 p.p.m. SiO2), and white precipitates are found within craters probably representing precursors of volcanic chert. The high Si and Mn levels in crater-lake waters as compared with coastal sea waters may be partly a reflection of metal accumulation in the former closed environment. However, other elements fail to show a similar increase, indicating a volcanic supply of manganese and silicon to Deception Island waters. A more detailed study is necessary before the mechanisms of metal enrichment can be resolved, and it is at present uncertain whether the analytical data represent a primary volcanic supply of metals to fresh- and sea-waters or high-temperature leaching of pyroclasts. It has been suggested (e.g., Hoss, 1957; Gibson and Towe, 1971) that certain silica deposits represent alteration products of volcanic debris. Leaching experiments (e.g., Krauskopf, 1956; Varentsov and Stepanets, 1970; Wilkniss et al., 1971) reveal a rapid decrease with time in the release of elements from volcanic materials, suggesting that inputs of Mn and Si by this mechanism will not affect nearby sea water during periods between eruptions. Further volcanic activity occurred at Deception Island in August 1970, partly destroying the new island
M6
LETTER SECTION
formed in 1967 (Baker and McReath, 1971), and it will be interesting to see if anomalous Si and Mn levels persist in Deception waters shortly to be sampled. ACKNOWLEDGEMENTS The author thanks members of the 1 9 6 8 - 1 9 6 9 expedition to Deception Island who collected the water samples, particularly P.E. Baker who kindly made the samples available for analysis; and also F. Buckley and other members of the Earth Sciences Department who assisted with analyses. REFERENCES Baker, P.E. and McReath, I., 1971. 1970 volcanic eruption at Deception Island. Nature, 231 : 5-9. Baker, P.E., Davies, T.G. and Roobol, M.J., 1969. Volcanic activity at Deception Island in 1967 and 1969. Nature, 224: 553-560. Bertolacini, R.J. and Barney, J.E., 1957. Colorimetric determination of sulfate with barium chlomnilate. Anal Chem., 29: 281-283. Bostr6m, K. and I~terson, M.N.A., 1966. Precipitates from hydrothermal exhalations on the Fast Pacific Rise. Econ. GeoL, 61: 1258-1265. Culkin, F., 1965. The major constituents of sea water. In: J.P. Riley and G. Skirrow (Editors), Chemical Oceanography. Academic Press, London, 1: 121 - 161. Gibson, T.G. and Towe, K.M., 1971. Eocene volcanism and the origin of Horizon A. Science, 172:152-154. Goldbcrg, E.D., 1965. Minor elements in sea water. In: J.P. Riley and G. Skirrow (Editors), Chemical Oceanography. Academic Press, London. 1: 163-196. Greenhalgh, R. and Riley, J.P., 1961. The determination of fluoride in natural waters with particular reference to sea water.AnaL Chim. Acta, 25;179-188. Hoss, H., 1957. Untersuchungen fiber die Petrographie kulmischer Kieseischiefer.Beitr. Mineral Petrogr., 6:59-88. Krauskopf, K.B., 1956. Separation of manganese from iron in the formation of manganese deposits in volcanic association. Pro¢ Int. GeoL Congr., 20th, Mexico, Symp. Manganese, 1 : 119-131. Moore, J.G., 1966. Rate of palagonitizatlon of submarine basalt adjacent to Hawaii. U.S. GeoL Surv. Prof. Pa/~, 550-D:D163-D171. Mullin, J.B. and Riley, J.P., i955. The colorimetric determination of sificate with special reference to sea and natural waters. Anal Chim. Acta, 12:162-176. Orheim, O., 1971. Antarctic "Geology and Geophysici Universitets Forlaget, Oslo, 372 pp. Riley, J.P., 1968. Analytical chemistry of sea water. In: J.P. Riley and G. Skirrow (Editors), Chemical Oceanography. Academic Press, London, 2:295-424. Strakhov, N.M. and Nesterova, I.L., 1968. Effects of volcanism on the geochemistry of marine deposits in the Sea of Okhotsk. Geochem. Int., 5:644-666. Varentsov, I.M. and Stepanets, M.I., 1970. Experimental modelling of the leaching of manganese by sea water from mafic volcanic materiaL DokL Akad Nauk S.S.S,R., 190: 192-195. White, D.E., 1955. Thermal spr'mgsand epithermal ore deposits. Econ. GeoL, 50th Anniv. VoL, pp. 99-154. Wilkes, C., 1845. Narrative o f the United States Exploring Expedition during the Years 1838, 1839, 1840, 1841, 1842. Whittaker, London, 372 pp. Wiikniss,P.E., Warner, T.B. and Cart, R.A., 1971. Some aspocts of the goochemistry of F, Fe and Mn in coastal waters and in fresh-water springs on the southeast coast of Hawaii. Mar. GeoL, 11 :M39-M46.
Letter Section E f f e c t s o f v o l c a n i s m o n w a t e r c h e m i s t r y , D e c e p t i o n Island, A n t a r c t i c a
H. ELDERFIELD Department of Earth Sciences, University of Leeds, Leeds (Great Britain) (Received February 8, 1972) ABSTRACT Elderfield, H., 1972. Effects of volcanism on water chemistry. Deception Island, Antarctica. Mar. Geol., 13: M1-M6. Analyses are presented of waters from c~ater lakes on Deception Island and from coastal sea waters which were collected during a period of intense fumarolic activity and increasingseismicactivity prior to the 1969 eruption. Major-componentanalysisshows all samplesto be slightly modified sea waters. However, crater-lake waters are almost saturated with silica and all waters contain high levels of manganese (30 to 2,420/ag/1), suggestinga significant volcanic source for these elements. INTRODUCTION There is considerable geochemical interest in the possible changes occurring in sea water and other natural waters as a result of volcanic processes (e.g., White, 1955; Zelenov, 1964; Bostr6m and Peterson, 1966; Moore, 1966; Strakhov and Nesterova, 1968). However, direct studies of these phenomena are rarely possible because of the unpredictable timing of volcanic eruptions. This note reports the analyses of water samples collected during the few weeks of fumarolic activity culminating in the Deception Island eruption of February 1969. Deception Island is the most southern island in the South Shetland group and lies in Bransfield Strait north of the Antarctic Peninsula (Fig. 1A). The earliest reposed volcanic eruption was in 1842 (Wilkes, 1845). Since then intense fumarolic activity has persisted, and there is evidence from ice stratigraphy that two eruptions occurred between 1910 and 1920 (Oreheim, 1971). In December 1967 eruptions were again observed. Part of the activity was submarine and formed six closely associated craters (Fig. 1C) which reached above sea as a new island in Telefon Bay (Baker et al., 1969). The effects of the 1967 eruption were studied during December 1968 and January 1969 by an expedition sponsored by the Royal Society and British Antarctic Survey. During this time there was a build-up of fumarolic activity leading to the fissure eruption of February 1969. Water samples were collected during the period 4.12.68 to 27.1.69 and form the basis of this preliminary report.
M2
LETTER SECTION
~'w
~ " ~ ~. ~ - ~ " v
. ~
5~-
'~ ',
"
c~'C~'®
60"45'W
//;----
.~
~-
.~,8"
1
,
.
'
'
,
U
/Y /
'.
/
i
__
/
~030 C'
)-
,
Fig. 1. Map of Deception Island. A. Location rchtive to South Shethnd I s ~ d s and Antarctic Peninsula. B. Deception Island at the time of sample collections (D1-D8). C. Island formed in Telefon Bay by 1967 eruption.
LETTER SECTION
M3
SAMPLINGAND ANALYSIS One-litre samples were collected in high-density polyethylene bottles from eight locations on the island (Fig. IB) by members of the survey party. Water temperatures were not recorded; at other times during the survey period temperatures of up to 97°C were noted for some inland waters. The samples were stored, without treatment, in the collection bottles and shipped to the British headquarters of the Antarctic Survey, and had remained unopened for about thirty months when the author was informed of their existence. Despite their long storage time, the unusual nature of the samples and the coincidence of their collection with active volcanic phenomena was thought sufficient to warrant their examination, and so the samples were collected and analysed shortly afterwards. The accuracy of the analytical data is subject to errors due to storage time and technique. This is likely to be most critical for the trace-element determinations where losses onto container surfaces can occur (Riley, 1965) resulting in underestimates of the concentrations of these elements at the time of sample collection. On arrival at the laboratory, pH and bicarbonate were first determined (by glass electrode). Waters were then filtered through 0.45 lam membrane filters, salinity determined (gravimetrically and conductimetricaUy), and analysed for sodium and potassium (by flame photometry), chloride (by potentiometric titration), and spectrophotometrically for sulphate (Bertolacini and Barney, 1957) and fluoride (Greenhalgh and Riley, 1961). Because of the limited sample volumes remaining after major-component analysis it was not possible to carry out a fully quantitative programme of trace-element analysis. Silicon was determined spectrophotometricaUy (Mullin and Riley, 1955), iron and manganese were analysed by direct atomic absorption spectrophotometry against spiked synthetic waters of equivalent sahnities, and A1, Cu, Pb, Co, Ni and Zn were measured semi-quantitatively by cathode-ray polarography. RESULTS AND DISCUSSION Major element compositions of the water samples are presented in Table I and the results of analyses for Fe, Mn and Si are listed in Table II. The coastal sea-water samples (D1-D4) and sample D5 from New Island crater 1 (which was open to the sea) have salinities and major element levels typical of normal sea water in near-shore regions, and are only slightly modified as a result of marine weathering and run-off from melting of glaciers on the island. Samples from enclosed craters (D6-D8) have salinities > 35% , but otherwise have major ion concentrations at normal levels. There is no evidence in any sample of fluoride enrichment, which is considered to be a sensitive indicator of volcanic activity (Wilknlss et al., 1971). Indeed F/C1 ratiosaverage 0.85.10 -s , lower than for normal sea water (6.7" 10-s). Concentrations of AI, Cu, Pb, Co, Ni and Zn showed no significant enrichment compared to averages far fresh- and sea-water, and are not reported here. Silicon and manganese, however, showed considerable variation from their levels in average sea water
10.8
31.164 34.626 34.484 36A80 35.627 37.628
35.000
7.50 7.70 8.00 7.45 7.55 7.65
24. 1.69
27. 1.69 27. 1.69
11.12.68
4.12.68
19. 1.69
D3
I)4 D5
D6
D7
D8
,1 salinities in % , major element concentrations in g/1. ,2 data from Culkin (1965).
Standard sea water , 2
1 1 o 5 ~50
33.288
7.25
13. 1.69
10.4
10.7
6.5 11.5
5.0
10.5
0.39
0.58
0.53
0A5 0A3
0.40
0.40
0.35
D2
9.3
29.996
7.25
Pendulum Cove from surface at low tide Port Foster from 10 m at low tide Pendulum Cove from s~face at low tide NW side of New Island New Island crate~ 1 from 6 m at high tide New Island crater 2 from 1.5 m Crater Lake from 1 m Land Cxater low tide
23.12.68
K÷
D1
Na ÷
Salinity
pH
Location
Date
Sample no.
Major components in waters of DeceptionIsland and in standard sea water *l
TABLE I
0.41
0.67
0.28
0.38
0.49 0A8
0.52
~44
0.46
1.29
0.75
1.15
1.35
1.30 1.25
1.10
1.25
1.10
0.008
0.003
0.002
0.002
0.0116 0.006
0.005
0.007
0.005
Ca 2+ Mg2+ Sr 2+
19.35
19.92
17.97
19.48
18.89 18.01
17.23
17.79
15.96
C1-
2.71
2.16
4.97
2A4
2.81 2.5
1.69
2.16
2.34
so4 2-
V<0.0001 <0.0001 0.0001 0.0004 ~0.0001 0.0003 0.0002 0.0001
0.0010
HCO~ 0.160 0.136 0.140 0.297 0.282 0.347 0.195 0.342
0.142
z
4~
LETTER SECTION
M5
TABLE II Fe, Mn and Si in waters of Deception Island and in average sea water*x Fe .2
Mn
Si
n.d. n.d. 180 n.d. n.d. n.d. 310 n.d.
130 70 60 30 560 1,550 2,420 1,810
4,400 5,890 7,160 7,770 7,430 29,600 36,500 50,700
2
3,000
Deception Island waters
Sea waters Crater open to sea Crater lakes Average sea water*s
f D1 D2 D3 1)4 D5 f D6 D7 D8
10
.1 concentrations in/2g/k ,2 amount passing through 0.45/~n filter. .S averagesfrom Goldberg (1965). n.d. = not detected. (Table II). For the sea-water samples (D1-D4) Si concentrations are only slightly higher than for average sea water (3,000/ag/l), but increase from 4,400/ag/1 in the sample collected on 23.12.68 to 7,430/~g/lin that coUected on 27.1.69. These waters are also considerably enriched in manganese but, in contrast to Si, levels of Mn decrease temporally from 130 to 30 ~g/l. Since samples were collected at various stations within Port Foster the significance of these temporal variations is unknown; they may simply reflect local differences in coastal sea-water composition. Water samples from enclosed crater lakes are considerably enriched in both Si (up to 50,700/ag/l) and Mn (up to 2,420 ~tg/1). The sample from Land Crater (D8) is almost saturated with silica (concentration equivalent to 110 p.p.m. SiO2), and white precipitates are found within craters probably representing precursors of volcanic chert. The high Si and Mn levels in crater-lake waters as compared with coastal sea waters may be partly a reflection of metal accumulation in the former closed environment. However, other elements fail to show a similar increase, indicating a volcanic supply of manganese and silicon to Deception Island waters. A more detailed study is necessary before the mechanisms of metal enrichment can be resolved, and it is at present uncertain whether the analytical data represent a primary volcanic supply of metals to fresh- and sea-waters or high-temperature leaching of pyroclasts. It has been suggested (e.g., Hoss, 1957; Gibson and Towe, 1971) that certain silica deposits represent alteration products of volcanic debris. Leaching experiments (e.g., Krauskopf, 1956; Varentsov and Stepanets, 1970; Wilkniss et al., 1971) reveal a rapid decrease with time in the release of elements from volcanic materials, suggesting that inputs of Mn and Si by this mechanism will not affect nearby sea water during periods between eruptions. Further volcanic activity occurred at Deception Island in August 1970, partly destroying the new island
M6
LETTER SECTION
formed in 1967 (Baker and McReath, 1971), and it will be interesting to see if anomalous Si and Mn levels persist in Deception waters shortly to be sampled. ACKNOWLEDGEMENTS The author thanks members of the 1 9 6 8 - 1 9 6 9 expedition to Deception Island who collected the water samples, particularly P.E. Baker who kindly made the samples available for analysis; and also F. Buckley and other members of the Earth Sciences Department who assisted with analyses. REFERENCES Baker, P.E. and McReath, I., 1971. 1970 volcanic eruption at Deception Island. Nature, 231 : 5-9. Baker, P.E., Davies, T.G. and Roobol, M.J., 1969. Volcanic activity at Deception Island in 1967 and 1969. Nature, 224: 553-560. Bertolacini, R.J. and Barney, J.E., 1957. Colorimetric determination of sulfate with barium chlomnilate. Anal Chem., 29: 281-283. Bostr6m, K. and I~terson, M.N.A., 1966. Precipitates from hydrothermal exhalations on the Fast Pacific Rise. Econ. GeoL, 61: 1258-1265. Culkin, F., 1965. The major constituents of sea water. In: J.P. Riley and G. Skirrow (Editors), Chemical Oceanography. Academic Press, London, 1: 121 - 161. Gibson, T.G. and Towe, K.M., 1971. Eocene volcanism and the origin of Horizon A. Science, 172:152-154. Goldbcrg, E.D., 1965. Minor elements in sea water. In: J.P. Riley and G. Skirrow (Editors), Chemical Oceanography. Academic Press, London. 1: 163-196. Greenhalgh, R. and Riley, J.P., 1961. The determination of fluoride in natural waters with particular reference to sea water.AnaL Chim. Acta, 25;179-188. Hoss, H., 1957. Untersuchungen fiber die Petrographie kulmischer Kieseischiefer.Beitr. Mineral Petrogr., 6:59-88. Krauskopf, K.B., 1956. Separation of manganese from iron in the formation of manganese deposits in volcanic association. Pro¢ Int. GeoL Congr., 20th, Mexico, Symp. Manganese, 1 : 119-131. Moore, J.G., 1966. Rate of palagonitizatlon of submarine basalt adjacent to Hawaii. U.S. GeoL Surv. Prof. Pa/~, 550-D:D163-D171. Mullin, J.B. and Riley, J.P., i955. The colorimetric determination of sificate with special reference to sea and natural waters. Anal Chim. Acta, 12:162-176. Orheim, O., 1971. Antarctic "Geology and Geophysici Universitets Forlaget, Oslo, 372 pp. Riley, J.P., 1968. Analytical chemistry of sea water. In: J.P. Riley and G. Skirrow (Editors), Chemical Oceanography. Academic Press, London, 2:295-424. Strakhov, N.M. and Nesterova, I.L., 1968. Effects of volcanism on the geochemistry of marine deposits in the Sea of Okhotsk. Geochem. Int., 5:644-666. Varentsov, I.M. and Stepanets, M.I., 1970. Experimental modelling of the leaching of manganese by sea water from mafic volcanic materiaL DokL Akad Nauk S.S.S,R., 190: 192-195. White, D.E., 1955. Thermal spr'mgsand epithermal ore deposits. Econ. GeoL, 50th Anniv. VoL, pp. 99-154. Wilkes, C., 1845. Narrative o f the United States Exploring Expedition during the Years 1838, 1839, 1840, 1841, 1842. Whittaker, London, 372 pp. Wiikniss,P.E., Warner, T.B. and Cart, R.A., 1971. Some aspocts of the goochemistry of F, Fe and Mn in coastal waters and in fresh-water springs on the southeast coast of Hawaii. Mar. GeoL, 11 :M39-M46.