Abstract
The chemical and mineral composition of the bottom sediments, as well as the assemblages of carbonate planktonic and benthic fossils (nannoplankton, foraminifers), were analyzed in two cores obtained in the North Atlantic within the Peterburgskoe hydrothermal ore field and beyond its limits. Their sections include the Upper Pleistocene and Holocene sediments with the boundary between them located at the depth of 20 cm. It is established that planktonic fossils (foraminifers and nannoplankton) reflect the replacement of subtropical conditions in the Late Pleistocene by tropical environments in the Holocene. It is shown that hydrothermal fluids significantly affect biogenic carbonate sediments in the ore formation zone of the Peterburgskoe field (core 33L159) resulting in dissolution of microfossils and their replacement by hydrothermal material. Their transformation patterns and vertical distribution indicate the influx of diffuse acid solutions to sediments from below. In background sediments constituting the core 33L148 section located 5 km away from the ore field, microfossils exhibit good preservation through its entire length. The sediments from the basal part of the section demonstrate the slight influence of the aggressive acid medium reflected in the disappearance of pteropod remains and changes in the abundance and taxonomic composition of benthic foraminifers and nannofossils. These data may be used as a criterion for defining potential nearby active hydrothermal sources.
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References
M. S. Barash and N. S. Blyum, “Modern thanatocoenosises of planktonic foraminiferan in Northern and Equatorial Atlantic,” Okeanologiya (Moscow) 5(1), 108–115 (1975).
M. S. Barash, V. M. Kuptsov, and N. N. Os’kina, “The Atlantic Ocean: new data on chronology of Later Pleistocene and Holocene,” Byull. Kom. Izuch. Chetvertichn. Perioda, Akad. Nauk SSSR 27(3), 423–436 (1987).
I. I. Burmistrova, “Modern deep water communities of benthos foraminiferan in the Atlantic and Indian oceans,” in Neogene-Quaternary Paleooceanology (Nauka, Moscow, 1989), pp. 38–42.
I. F. Gablina, L. L. Demina, O. B. Dmitrenko, N. S. Os’kina, T. A. Khusid, E. A. Popova, and V. V. Shilov, “Composition and secondary alterations of microfossils in sediments of the Ashadze-1 hydrothermal field (tropical Mid-Atlantic Ridge),” Oceanology (Engl. Transl.) 51(3), 476–490 (2011).
I. F. Gablina, A. D. Lyutkevich, I. G. Dobretsova, V. E. Beltenev, E. V. Narkevskii, and A. N. Gustaitis, “Peculiarities of present-day sulfide mineralization at 19°15′–20°08′ N, Mid-Atlantic Ridge,” Dokl. Earth Sci. 442(2), 163–167 (2012).
V. F. Dubravin, Surface Water of the Atlantic Ocean (Gidrometeoizdat, St. Petersburg, 2001) [in Russian].
A. P. Lisitzyn, Oceanic Sedimentation (Nauka, Moscow, 1978) [in Russian].
N. P. Lukashina, Paleooceanology of the Northern Atlantic in Late Cainozoe and Emergence of Modern Thermohaline Oceanic Circulation Accodring to Results of Study of Foraminiferan (Nauchnyi Mir, Moscow, 2008) [in Russian].
S. Neshiba, Oceanology (Mir, Moscow, 1991) [in Russian].
V. N. Stepanov, Oceanosphere (Mysl’, Moscow, 1983) [in Russian].
V. V. Shilov, V. E. Bel’tenev, V. I. Ivanov, I. I. Rozhdestvenskaya, I. G. Dobretsova, E. V. Narkevskii, A. N. Gustaitis, G. A. Cherkashev, I. F. Gablina, and V. Yu. Kuznetsov, “New hydrothermal ore fields in the Mid-Atlantic Ridge: Zenith-Victoria (20°08′ N) and Petersburg (19°52′ N),” Dokl. Earth Sci. 442(1), 63–69 (2012).
W. H. Berger, “Planktonic foraminifera: selective solution and paleoclimatic interpretation,” Initial Rep. Deep Sea Drill. Proj. 15, 31–43 (1968).
M. L. Bremer and G. P. Louman, “Evidence for primary control of the distribution of central Atlantic Ocean benthonic foraminifera by degree of carbonate saturation,” Deep-Sea Res. 29, 987–998 (1982).
D. Bukry, “Biostratigraphy of Cenozoic sediments by calcareous nannofossils,” Micropaleontology 24(1), 44–60 (1978).
B. H. Corliss, “Recent benthonic Foraminifera distribution in the southeast Indian Ocean: Inferred bottom water routes and ecological implication,” Mar. Geol. 31, 115–138 (1979).
B. H. Corliss, “Microhabitats of benthic foraminifera within deep-sea sediments,” Nature 324, 435–438 (1983).
S. Gartner, “Calcareous nannofossil stratigraphy and revised zonation of the Pleistocene,” Marine Micropaleontol. 2, 1–25 (1977).
E. Martini and T. Worsley, “Standard Neogene calcareous nanoplankton zonation,” Nature 225(5229), 289–290 (1970).
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Original Russian Text © I.F. Gablina, O.B. Dmitrenko, N.S. Os’kina, T.A. Khusid, E.A. Popova, 2015, published in Okeanologiya, 2015, Vol. 55, No. 1, pp. 113–125.
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Gablina, I.F., Dmitrenko, O.B., Os’kina, N.S. et al. Impact of hydrothermal activity on carbonate fossils in bottom sediments of the tropical Atlantic. Oceanology 55, 100–111 (2015). https://doi.org/10.1134/S0001437015010051
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DOI: https://doi.org/10.1134/S0001437015010051