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Manganese and nickel on the ocean floor
Geochimica et Cosmochimica Acta, 1959,Vol. 17, pp. 209 to 213. Pergamon PressLtd. Printedin Northern Irelanrl
Manganese and nickel on the ocean floor H. PETTERSSON Oceanografiska Institutet, GGteborg 4, Sweden (Received4 April 1959) OF all the elements found in deep-sea deposits few have a more puzzling distribution than the two ferrides, manganese and nickel. Both of them are present in higher concentrations than in igneous continental rocks. However, it is their horizontal and vertical distribution in ocean sediments, as revealed by the study of long sediment cores, which appear most enigmatic and seem to indicate that their origin may be different from that of the other elements. These traits appear most pronounced after a study of the long sediment cores raised from the Swedish Deep-Sea Expedition with the Albatross in 1947-1948. In ordinary igneous rocks from the continents the average content of manganese is estimated at O-1 per cent or 1000 p.p.m. In hydrolysates the average content is 620 p.p.m., whereas in red clay, according to CLARKE and STEICER, the average content is 7670 p.p.m. LANDERGREN’S (1954) more recent value is 9430 p.p.m. In general the red clay samples have a much higher manganese content in the Pacific than in the Atlantic Ocean. However, of much greater interest than the average values, derived from a large number of samples analysed, are the individual values found in different samples from the same core. By careful determination by means of the spectrograph on samples taken from a long core from the Romanche Deep in the equatorial Atlantic (lat. S OO”O7’ long. W 18”12’, depth 7315 m, length of core 14.1 m) LANDERCREN finds the average value from 140 samples, taken at intervals of 10 cm, to be 2400 p.p.m. of manganese. The individual values show very large variations, from a minimum i.e. in the ratio of 1 : 26. Over a of 700p.p.m. to a maximum of 18,000p.p.m., distance of 10 cm the content will fall from 18,000 to 900. The curve taken from LANDERGREN’S paper, here reproduced as Fig. 1, presents very sharp and distinct maxima, separated by equally pronounced minima. Equally strong and abrupt variations in the manganese content were found in a number of long cores from the equatorial Pacific Ocean, analysed in Goteborg by BERRIT and ROTSCHI (1956). It is obviously desirable to find an explanation for these extraordinary variations in the manganese content. The great master of deep-sea sedimentology, MURRAY (1876), declared the manganese in the deep-sea deposits and also the red clay itself to be derived from a subaqueous decomposition of volcanic debris. Other authors of that time assumed the manganese in the sediment to be derived from the sea-water. CLARKE in his review of the different hypotheses finds that by MURRAY to be the most probable. In recent times the main objection to the volcanic origin of suboceanic manganese has come from another master of deep-sea sedimentology, CORRENS (1937) of Gijttingen. From his study of the Atlantic cores raised from the Meteor
4
209
H. PETTERSSON expedition he concludes, that the excess manganese present in deep-sea sediments is largely derived through a biological extraction from the sea-water and a subsequent settling on to the ocean floor with calcareous shells. In an earlier paper the present writer has voiced some objections to this view, mainly from a quantitative standpoint PETTERSSON, 1945). Still earlier (PETTERSSON, 1931) in a short paper published in Swedish, the writer suggested, that at volcanic eruptions on the ocean floor, chemical reactions on a vast scale between the magma and the highly compressed sea-water may be expected to take place, leading to a release of mineral acids. The same explanation may account for extensive layers of red clay over areas where no influence from Arctic or Antarctic bottom currents can be evoked, but where there is instead an abundance of volcanic minerals and glass dispersed in the sediment. * Also CORRENS, in his report, expresses similar views, without expressly indicating mineral acids as operative: “Die submarine Verwitterung hat sich also in diesem Beispiel im besten Falle auf das Glas beschrankt, wenn es sich nicht iiberhaupt urn einen reinen Auslaugungsvorgang bei der Reaktion des heissen Magmas mit dem Meerwasser handelt.” From this view of the volcanic debris on the ocean floor as a possible source of suboceanic manganese GOLDBERG and ARRHENIUS (1957) in a joint paper take “In view of the obvious” (2) “necessity of separating the source of exception: the manganese from the deposits the emphasis on volcanic debris on the ocean bottom does not any longer seem to be necessary”. This somewhat apodictic statement is in contrast with views earlier expressed by one of the authors (ARRHENIUS) who in his important contribution to the Reports of the Swedish Deep-Sea Expedition (Vol. V., I, p. 112) states: “The higher concentration of manganese in its turn is believed to have its origin in decaying volcanic matter in this area”, and, in another place: “Especially in regions of volcanic activity amounts of manganese appear to be released by the submarine weathering of igneous rocks and to be separated from the iron through selective diffusion and precipitation.” Although LANDERGREN (1954) abstains from pronouncing a verdict upon the different theories for the origin of suboceanic manganese, he writes (ibid. p. 142). “One inclines to assume that the source of this ferride” (manganese) “is to a great extent different from that of the other ferrides”. BERRIT (1955), discussing the abnormally high values for manganese found in different Albatross cores, writes: “On peut se demander si ces valeurs exceptionelles de la teneur en manganese ne sont pas & rattacher & une activiti: volcanique et B l’erosion sous-marine, si la seule source du manganese est continental, ou s’il n’existe pas une autre source sous-marine, like au volcanisme.”
* Added to recent discoveries of numerous volcanic peaks, “guyots ” in the Pacific Ocean we have now the evidence from seismic investigations by GASKELL, HILL and SWALLOW (1958) proving the widespread occm-lence of submarine lava beds below the unconsolidated sediments in the Pacific and Indian Oceans, supporting the views of the dominant influence on the ocean floor from submarine volcanic activity. In the joint paper by ARREIENIUS and GOLDBERG (1957), p. 195, it is stated that the belief in the relatively high manganese contents of the foraminifera reported by CORRENS have been confirmed recently (ARRHENIUS, et csl., in preparation) by analyses of planktonic foraminifera caught by tow-net, So far no quantitative data on this find have reached the present author.
210
Manganeseand nickel on the Oceanfloor Instead of referring at length to the different views brought forward on this theme the present writer will refer only to the two figures showing the vertical distribution of manganese in two cores, one (Fig. 1) from the central Atlantic Ocean (LANDERGREN), the other in Fig. 2 from the west Pacific Ocean (Albatross core no. 100) analysed by BERRIT and ROTSCEI (1956). “According to the present author the very prominent maxima of manganese in these two cores are due to It would be most interesting to know volcanic outbreaks in the near locality. 0 cm
500
1000 1550
081
O-3
1.0 2.0
2 G 10 14 3 Mfl0,~103 Fig. 2.
%Mn Fig. 1.
how these remarkable curves are to be explained by the theories of biological extraction or of chemical precipitation from sea-water!” Nickel. In ordinary igneous rocks from the continents the average content of nickel according to SANDELL and GOLDICH (1943) is 80 p.p.m. or O*OOSper cent. According to spectrographic analyses by LANDERGREN on 140 samples taken from the core from the Romanche Deep, their average content is 138 p.p.m. or 0.0138 per cent for the whole core. Just as in the case of manganese there are striking variations along the core in nickel content, from a maximum of almost O-1 per cent or 990 p.p.m., to minima of 20 p.p.m. in the ratio of almost 50 : 1. On the other hand in a core from the equatorial Pacific Ocean analysed by ROTSCHI (1951) there were variations in the nickel content from a maximum of 624 p.p.m. to a minimum of 24 p.p.m., i.e. in the ratio of 26 : 1 (compare Figs. 3 and 4). In order to explain the relatively large content of nickel in deep-sea deposits PETTERSSONand ROTSCHI (1952) suggested that the excess nickel may be of cosmic origin. The maxima of nickel found in different levels of the cores might then be explained as due to an unusually heavy incidence from the cosmos. Against this interpretation SMALES and WISEMAN (1955) objected that the relatively low values for cobalt and copper found by them in the nickel from a deep-sea core make it unlikely that the suboceanic nickel is of cosmic origin. The acknowledged master of meteor studies, OPIK (1956), took exception to this 211
H.
PETCCERSSOX
view stating (p. 116): “A reconsideration of Smales’ and Wiseman’s results show that they are not so negative at ali, the apparent contradiction being partly due to the arithmetic of presentation . . .” Assuming an admixture of I*25 per cent, of cosmic substance to the sediment, with 2 per cent nickel content, i)PIK finds that the relative abundance of nickel and copper agree very well with the hypothesis of cosmic (meteoritic) origin: “Smales and Wiseman compared only the abundance ratios of the red clay with v cm
1500 c-002
0.01 003
0.1
0.00a02 094 ---NiO%
%Ni
LL_I-_-L~.._.__
Fig. 3.
Fig. 4.
those of the two parent substances, without calculating how they would resuIt in a mixture. Their analyses actually support the hypothesis of cosmic origin, with the possibility that cobalt is more abundant in the zodiacal dust than in the ~PIK sums up his reasoning with: “Pettersson’s hypothesis of the meteorites.” cosmic origin of the deep-sea nickel has gained considerable support.” Recently GOLDBERG (1954) has propounded a theory for the “scavenging” of various trace elements into the sediments like nickel by the hydrated oxides of manganese and iron. In support of this view GOLDBERG quotes results from analyses made here in GGteborg on some Pacific sediments, from which he infers that t*he ratio &fNi is remarkably constant, varying only between 38 and 53, with the exception of two cores in which it is considerably higher. These two exceptions GOLDBERG explains from an admixture of volcanic glass, palagonite and phillipsite to the two cores, giving them higher values for the ratio manganese to nickel. This appears as a typical misuse of average values from core analyses. Scrutinizing instead the analyses of individual samples, from which the table quoted by GOLDBERC was computed, one finds very considerable variations of the lXn/Ni ratio in these cores, variations which refute GOLDBERG’S hypothesis of a constant &/Ni ratio. From the assumption that the hydroxides of manganese and nickel act as 212
Mangmeseand nickelon the oceanfloor scavengers for nickel, one must expect a close correlation between the content of nickel and of the two other ferrides in our cores. This is certainly not the case, as a scrutiny of t.he results published by LANDERGREN and by BERRIT and ROTSCHX proves. The writer, therefore, finds no reason to abandon his earlier published view, that the origin of the two elements here discussed in the deep-sea sediment’s is different from that of the other ferrides, especially as regards the anomalously high values for manganese and nickel contents, the former being largely due to suboceanic volcanic action, the latter due to contributions from the cosmos. REFERENCES BERRIT G. R. (1955) Etude des Teneurs en Manganese eta. Xerlcl. ~ceu~ag~.Inst. 23, BERRIT G. R. and ROTSCHI H. (1956) &-ports S~~ed~~~ Deep-Sea ~x~e~~~~o~ Vol. VI, Fnsc. 2. CORRENS C. (1937) Die Sedimente d.dq, Atl. Oceans. W&s. Ergebn. d&k,. atlant. Exped. ‘Meteor’. 3, 3. CORRENS C. (1941) Beiixggez. Geochem. d. Eisens und Manganq. Nacho. A&d. W&s. Giittilzgen. GASKELL T., HILL M. and SWALLOW J. (1958) Seismic investigations. Phil. Trans. 251, 23-63. GOLDBERG E. (1954) Marine geochemistry etc. J. Geol. 62, 254. GOLBDERG E. and ARRHXXIUS G. (1957) Chemistry of pacific pelagic sediments. Geochim. et Cosmockim. Acta 13, 153. LAKDERGREN 8. (1954) Reports Swedislb Deep-Sea Expedition Vol. VII, Fast. 2. Gateborg. MCRRAY J. (1876) Proc. Roy. Sot. Edin. 9,255. ~~PIK E. J. (1956) Interplanetary dust etc. A&. J. 4, 116. PETTERSSON H. (1931) Djuphavets radiumhalt. Ymer. 51 36. PETTERSSON H. (1945) Iron and manganese on the ocean floor. 2Medd. ~ce~nog~. I%&. 7, PETTERSSON H. and ROTSCHI K. (1952) Geo~h~m. et Co~moch~m. Aeta 2, 81. Repports of the Sul~~h~ Deep-Sea ~xped~t~o~ Vol. II, IV and V. G&eborg. ROTSCHI H. (1951) Etude des teneurs en fer etc. Centre de Recherches et d’_&udes 2-22. SANDELL E. and GOLDICN 8. (1943) J. GeoE. 51, 161-189. SN~ALES A. and WISEMAN J. (1955) IVature, Lond. 175, 464.
213
Manganese and nickel on the ocean floor H. PETTERSSON Oceanografiska Institutet, GGteborg 4, Sweden (Received4 April 1959) OF all the elements found in deep-sea deposits few have a more puzzling distribution than the two ferrides, manganese and nickel. Both of them are present in higher concentrations than in igneous continental rocks. However, it is their horizontal and vertical distribution in ocean sediments, as revealed by the study of long sediment cores, which appear most enigmatic and seem to indicate that their origin may be different from that of the other elements. These traits appear most pronounced after a study of the long sediment cores raised from the Swedish Deep-Sea Expedition with the Albatross in 1947-1948. In ordinary igneous rocks from the continents the average content of manganese is estimated at O-1 per cent or 1000 p.p.m. In hydrolysates the average content is 620 p.p.m., whereas in red clay, according to CLARKE and STEICER, the average content is 7670 p.p.m. LANDERGREN’S (1954) more recent value is 9430 p.p.m. In general the red clay samples have a much higher manganese content in the Pacific than in the Atlantic Ocean. However, of much greater interest than the average values, derived from a large number of samples analysed, are the individual values found in different samples from the same core. By careful determination by means of the spectrograph on samples taken from a long core from the Romanche Deep in the equatorial Atlantic (lat. S OO”O7’ long. W 18”12’, depth 7315 m, length of core 14.1 m) LANDERCREN finds the average value from 140 samples, taken at intervals of 10 cm, to be 2400 p.p.m. of manganese. The individual values show very large variations, from a minimum i.e. in the ratio of 1 : 26. Over a of 700p.p.m. to a maximum of 18,000p.p.m., distance of 10 cm the content will fall from 18,000 to 900. The curve taken from LANDERGREN’S paper, here reproduced as Fig. 1, presents very sharp and distinct maxima, separated by equally pronounced minima. Equally strong and abrupt variations in the manganese content were found in a number of long cores from the equatorial Pacific Ocean, analysed in Goteborg by BERRIT and ROTSCHI (1956). It is obviously desirable to find an explanation for these extraordinary variations in the manganese content. The great master of deep-sea sedimentology, MURRAY (1876), declared the manganese in the deep-sea deposits and also the red clay itself to be derived from a subaqueous decomposition of volcanic debris. Other authors of that time assumed the manganese in the sediment to be derived from the sea-water. CLARKE in his review of the different hypotheses finds that by MURRAY to be the most probable. In recent times the main objection to the volcanic origin of suboceanic manganese has come from another master of deep-sea sedimentology, CORRENS (1937) of Gijttingen. From his study of the Atlantic cores raised from the Meteor
4
209
H. PETTERSSON expedition he concludes, that the excess manganese present in deep-sea sediments is largely derived through a biological extraction from the sea-water and a subsequent settling on to the ocean floor with calcareous shells. In an earlier paper the present writer has voiced some objections to this view, mainly from a quantitative standpoint PETTERSSON, 1945). Still earlier (PETTERSSON, 1931) in a short paper published in Swedish, the writer suggested, that at volcanic eruptions on the ocean floor, chemical reactions on a vast scale between the magma and the highly compressed sea-water may be expected to take place, leading to a release of mineral acids. The same explanation may account for extensive layers of red clay over areas where no influence from Arctic or Antarctic bottom currents can be evoked, but where there is instead an abundance of volcanic minerals and glass dispersed in the sediment. * Also CORRENS, in his report, expresses similar views, without expressly indicating mineral acids as operative: “Die submarine Verwitterung hat sich also in diesem Beispiel im besten Falle auf das Glas beschrankt, wenn es sich nicht iiberhaupt urn einen reinen Auslaugungsvorgang bei der Reaktion des heissen Magmas mit dem Meerwasser handelt.” From this view of the volcanic debris on the ocean floor as a possible source of suboceanic manganese GOLDBERG and ARRHENIUS (1957) in a joint paper take “In view of the obvious” (2) “necessity of separating the source of exception: the manganese from the deposits the emphasis on volcanic debris on the ocean bottom does not any longer seem to be necessary”. This somewhat apodictic statement is in contrast with views earlier expressed by one of the authors (ARRHENIUS) who in his important contribution to the Reports of the Swedish Deep-Sea Expedition (Vol. V., I, p. 112) states: “The higher concentration of manganese in its turn is believed to have its origin in decaying volcanic matter in this area”, and, in another place: “Especially in regions of volcanic activity amounts of manganese appear to be released by the submarine weathering of igneous rocks and to be separated from the iron through selective diffusion and precipitation.” Although LANDERGREN (1954) abstains from pronouncing a verdict upon the different theories for the origin of suboceanic manganese, he writes (ibid. p. 142). “One inclines to assume that the source of this ferride” (manganese) “is to a great extent different from that of the other ferrides”. BERRIT (1955), discussing the abnormally high values for manganese found in different Albatross cores, writes: “On peut se demander si ces valeurs exceptionelles de la teneur en manganese ne sont pas & rattacher & une activiti: volcanique et B l’erosion sous-marine, si la seule source du manganese est continental, ou s’il n’existe pas une autre source sous-marine, like au volcanisme.”
* Added to recent discoveries of numerous volcanic peaks, “guyots ” in the Pacific Ocean we have now the evidence from seismic investigations by GASKELL, HILL and SWALLOW (1958) proving the widespread occm-lence of submarine lava beds below the unconsolidated sediments in the Pacific and Indian Oceans, supporting the views of the dominant influence on the ocean floor from submarine volcanic activity. In the joint paper by ARREIENIUS and GOLDBERG (1957), p. 195, it is stated that the belief in the relatively high manganese contents of the foraminifera reported by CORRENS have been confirmed recently (ARRHENIUS, et csl., in preparation) by analyses of planktonic foraminifera caught by tow-net, So far no quantitative data on this find have reached the present author.
210
Manganeseand nickel on the Oceanfloor Instead of referring at length to the different views brought forward on this theme the present writer will refer only to the two figures showing the vertical distribution of manganese in two cores, one (Fig. 1) from the central Atlantic Ocean (LANDERGREN), the other in Fig. 2 from the west Pacific Ocean (Albatross core no. 100) analysed by BERRIT and ROTSCEI (1956). “According to the present author the very prominent maxima of manganese in these two cores are due to It would be most interesting to know volcanic outbreaks in the near locality. 0 cm
500
1000 1550
081
O-3
1.0 2.0
2 G 10 14 3 Mfl0,~103 Fig. 2.
%Mn Fig. 1.
how these remarkable curves are to be explained by the theories of biological extraction or of chemical precipitation from sea-water!” Nickel. In ordinary igneous rocks from the continents the average content of nickel according to SANDELL and GOLDICH (1943) is 80 p.p.m. or O*OOSper cent. According to spectrographic analyses by LANDERGREN on 140 samples taken from the core from the Romanche Deep, their average content is 138 p.p.m. or 0.0138 per cent for the whole core. Just as in the case of manganese there are striking variations along the core in nickel content, from a maximum of almost O-1 per cent or 990 p.p.m., to minima of 20 p.p.m. in the ratio of almost 50 : 1. On the other hand in a core from the equatorial Pacific Ocean analysed by ROTSCHI (1951) there were variations in the nickel content from a maximum of 624 p.p.m. to a minimum of 24 p.p.m., i.e. in the ratio of 26 : 1 (compare Figs. 3 and 4). In order to explain the relatively large content of nickel in deep-sea deposits PETTERSSONand ROTSCHI (1952) suggested that the excess nickel may be of cosmic origin. The maxima of nickel found in different levels of the cores might then be explained as due to an unusually heavy incidence from the cosmos. Against this interpretation SMALES and WISEMAN (1955) objected that the relatively low values for cobalt and copper found by them in the nickel from a deep-sea core make it unlikely that the suboceanic nickel is of cosmic origin. The acknowledged master of meteor studies, OPIK (1956), took exception to this 211
H.
PETCCERSSOX
view stating (p. 116): “A reconsideration of Smales’ and Wiseman’s results show that they are not so negative at ali, the apparent contradiction being partly due to the arithmetic of presentation . . .” Assuming an admixture of I*25 per cent, of cosmic substance to the sediment, with 2 per cent nickel content, i)PIK finds that the relative abundance of nickel and copper agree very well with the hypothesis of cosmic (meteoritic) origin: “Smales and Wiseman compared only the abundance ratios of the red clay with v cm
1500 c-002
0.01 003
0.1
0.00a02 094 ---NiO%
%Ni
LL_I-_-L~.._.__
Fig. 3.
Fig. 4.
those of the two parent substances, without calculating how they would resuIt in a mixture. Their analyses actually support the hypothesis of cosmic origin, with the possibility that cobalt is more abundant in the zodiacal dust than in the ~PIK sums up his reasoning with: “Pettersson’s hypothesis of the meteorites.” cosmic origin of the deep-sea nickel has gained considerable support.” Recently GOLDBERG (1954) has propounded a theory for the “scavenging” of various trace elements into the sediments like nickel by the hydrated oxides of manganese and iron. In support of this view GOLDBERG quotes results from analyses made here in GGteborg on some Pacific sediments, from which he infers that t*he ratio &fNi is remarkably constant, varying only between 38 and 53, with the exception of two cores in which it is considerably higher. These two exceptions GOLDBERG explains from an admixture of volcanic glass, palagonite and phillipsite to the two cores, giving them higher values for the ratio manganese to nickel. This appears as a typical misuse of average values from core analyses. Scrutinizing instead the analyses of individual samples, from which the table quoted by GOLDBERC was computed, one finds very considerable variations of the lXn/Ni ratio in these cores, variations which refute GOLDBERG’S hypothesis of a constant &/Ni ratio. From the assumption that the hydroxides of manganese and nickel act as 212
Mangmeseand nickelon the oceanfloor scavengers for nickel, one must expect a close correlation between the content of nickel and of the two other ferrides in our cores. This is certainly not the case, as a scrutiny of t.he results published by LANDERGREN and by BERRIT and ROTSCHX proves. The writer, therefore, finds no reason to abandon his earlier published view, that the origin of the two elements here discussed in the deep-sea sediment’s is different from that of the other ferrides, especially as regards the anomalously high values for manganese and nickel contents, the former being largely due to suboceanic volcanic action, the latter due to contributions from the cosmos. REFERENCES BERRIT G. R. (1955) Etude des Teneurs en Manganese eta. Xerlcl. ~ceu~ag~.Inst. 23, BERRIT G. R. and ROTSCHI H. (1956) &-ports S~~ed~~~ Deep-Sea ~x~e~~~~o~ Vol. VI, Fnsc. 2. CORRENS C. (1937) Die Sedimente d.dq, Atl. Oceans. W&s. Ergebn. d&k,. atlant. Exped. ‘Meteor’. 3, 3. CORRENS C. (1941) Beiixggez. Geochem. d. Eisens und Manganq. Nacho. A&d. W&s. Giittilzgen. GASKELL T., HILL M. and SWALLOW J. (1958) Seismic investigations. Phil. Trans. 251, 23-63. GOLDBERG E. (1954) Marine geochemistry etc. J. Geol. 62, 254. GOLBDERG E. and ARRHXXIUS G. (1957) Chemistry of pacific pelagic sediments. Geochim. et Cosmockim. Acta 13, 153. LAKDERGREN 8. (1954) Reports Swedislb Deep-Sea Expedition Vol. VII, Fast. 2. Gateborg. MCRRAY J. (1876) Proc. Roy. Sot. Edin. 9,255. ~~PIK E. J. (1956) Interplanetary dust etc. A&. J. 4, 116. PETTERSSON H. (1931) Djuphavets radiumhalt. Ymer. 51 36. PETTERSSON H. (1945) Iron and manganese on the ocean floor. 2Medd. ~ce~nog~. I%&. 7, PETTERSSON H. and ROTSCHI K. (1952) Geo~h~m. et Co~moch~m. Aeta 2, 81. Repports of the Sul~~h~ Deep-Sea ~xped~t~o~ Vol. II, IV and V. G&eborg. ROTSCHI H. (1951) Etude des teneurs en fer etc. Centre de Recherches et d’_&udes 2-22. SANDELL E. and GOLDICN 8. (1943) J. GeoE. 51, 161-189. SN~ALES A. and WISEMAN J. (1955) IVature, Lond. 175, 464.
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