Lipids as indicators of paleoclimatic changes, II: terrestrial biomarkers

Madureira, Luiz A. S.; Piccinini, Alexandre

doi:10.1590/S1413-77391999000200001

Abstracts

Variations in the abundance of specific lipid biomarker compounds derived from terrestrial sources are shown to be closely related to past climatic changes. Despite biodegradation processes, which take place mostly at the water column and sediment water interface, these compounds are found well preserved in oceanic sediments. Here, their relative distribution is employed as a tool to assess changes in terrestrial fluxes to the seabed accompanying climatic variations during glacial and interglacial intervals. These changes in biomarker distribution were estimated in two sediment cores taken ttom the eastern North Atlantic, covering the past 210,000 years. Comparisons with other paleoclimate proxies showed good agreement and suggest that some specific groups of biomarkers are important indicators of changes in terrestrial inputs to the sea.

Biomarkers; Marine sediment; Chromatography; North Atlantic

A variação na abundância de alguns biomarcadores lipídicos derivados de aportes terrestres pode estar relacionada com mudanças climáticas no passado. Apesar dos processos de biodegradação que, na grande maioria, ocorrem na coluna aquática e na interface sedimento-água, esses compostos são encontrados bem preservados em sedimentos oceânicos. Nesse trabalho, a distribuição relativa desses compostos é empregada como uma ferramenta para avaliar mudanças no transporte de material terrestre para o mar em paralelo às variações climáticas durante os intervalos glaciais e interglaciais. As mudanças na distribuição dos biomarcadores foram estimadas em dois testemunhos coletados ao leste do Atlântico Norte e que correspondem aos últimos 210 mil anos. Os resultados mostraram uma boa correlação entre a distribuição dos biomarcadores e outros parâmetros paleoclimáticos previamente avaliados nos perfis, sugerindo que alguns grupos específicos de compostos orgânicos são importantes indicadores de aporte terrestre para ornar.

Biomarcadores; Sedimento marinho; Cromatografia; Atlântico Norte

RESEARCH ARTICLES

Lipids as indicators of paleoclimatic changes, II: terrestrial biomarkers

Luiz A. S. Madureira; Alexandre Piccinini

Departamento de Química da Universidade Federal de Santa Catarina (Campus Universitário Trindade, 88040 900 Florianópolis, SC, Brasil)

ABSTRACT

Variations in the abundance of specific lipid biomarker compounds derived from terrestrial sources are shown to be closely related to past climatic changes. Despite biodegradation processes, which take place mostly at the water column and sediment water interface, these compounds are found well preserved in oceanic sediments. Here, their relative distribution is employed as a tool to assess changes in terrestrial fluxes to the seabed accompanying climatic variations during glacial and interglacial intervals. These changes in biomarker distribution were estimated in two sediment cores taken ttom the eastern North Atlantic, covering the past 210,000 years. Comparisons with other paleoclimate proxies showed good agreement and suggest that some specific groups of biomarkers are important indicators of changes in terrestrial inputs to the sea.

Descriptors: Biomarkers, Marine sediment, Chromatography, North Atlantic.

RESUMO

A variação na abundância de alguns biomarcadores lipídicos derivados de aportes terrestres pode estar relacionada com mudanças climáticas no passado. Apesar dos processos de biodegradação que, na grande maioria, ocorrem na coluna aquática e na interface sedimento-água, esses compostos são encontrados bem preservados em sedimentos oceânicos. Nesse trabalho, a distribuição relativa desses compostos é empregada como uma ferramenta para avaliar mudanças no transporte de material terrestre para o mar em paralelo às variações climáticas durante os intervalos glaciais e interglaciais. As mudanças na distribuição dos biomarcadores foram estimadas em dois testemunhos coletados ao leste do Atlântico Norte e que correspondem aos últimos 210 mil anos. Os resultados mostraram uma boa correlação entre a distribuição dos biomarcadores e outros parâmetros paleoclimáticos previamente avaliados nos perfis, sugerindo que alguns grupos específicos de compostos orgânicos são importantes indicadores de aporte terrestre para ornar.

Descritores: Biomarcadores, Sedimento marinho, Cromatografia, Atlântico Norte.

Full text available only in PDF format.

Texto completo disponível apenas em PDF.

Acknowledgements

We thank Or. Shirley A. van Kreveld, Or. Janneke J. Ottens, Or. G. Ganssen, and Or. J. E. van Hinte for the bulk parameters and sediment samples provided. Luiz Madureira thanks CNPq for a postdoctoral scholarship and Alexandre Piccinini thanks PIBIC-UFSC for an undergraduate scholarship.

(Manuscript received 06 July 1998; revised 30 August 1999; accepted 08 November 1999)

Balsam, W. L. & McCoy Jr., F. W. 1987. Atlantic sediments: glacial/interglacial comparisons. Paleoceanography,5:531-542.
Bourbonniere, R A. & Meyers, P. A. 1996. Sedimentary geolipid records of historical changes in the watersheds and productivities of Lakes Ontario and Erie. Limnol.. Oceanogr., 41(2):352-359.
Brand, T. & Shimmield, G. 1992. The use of ²¹⁰Pb as an indicator of biological processes affecting the flux and sediment geochemistry of organic carbon in the North East Atlantic. In: Kershaw, P.J. & Woodhead, D.F. eds Radionuclides in the study of marine processes. New York, Elsevier. p.222-233.
Biogeochemistry of lipids in surface sediments of the Peru upwelling area at 15şS. Org. Geochem., 13(4-6):607-617.
Chester, R 1990. Marine geochemistry I. Oceans, chemical composition & chemical properties. London, Unwin Hyman Ltd. 698p.
Conte, M. H.; Volkman, J. K. & Eglinton, G. 1994. Lipid biomarkers of the Haptophyta. In: Leadbeater, B. & Green, J.C. eds The Haptophyte algae. Oxford, Claredon Press. p.351-377.
Cooper, J. E. & Bray, E. E. 1963. A postulated role of fatty acids in petroleum formation. Geochim. cosmochim. Acta, 27:1113-1127.
Cranwell, P. A.; Eglinton, G. & Robinson, N. 1987. Lipids of aquatic organisms as potential contributors to lacustrine sediments. 2. Org. Geochem., 11(6):513-527.
Farrimond, P.; Poynter, J. & Eglinton, G. 1990. A molecular stratigraphic study of Peru margin sediments, Hole 686B, Leg 112. In: Suess, E. & von Huene eds. Proceedings of the ocean drilling programo scientific results. 547-553.
Farrington, J. W.; Davis, A. C.; Sulanowski, J.; McCaffiey, M. A.; McCarthy, M.; Clitford, C. H.; Dickinson, P. & Volkman, J. K. 1988.
Gagosian, R B.; Peltier, E. T. & Zafiriou, O. C. 1981. Atmospheric transport of continentally-derived lipids to the tropical North Pacifico Nature, 291(5813):312-314.
Gagosian, R B.; Peltzer, E. T. & Merril, J. T. 1987. Long-range transport of terrestrially derived lipids in aerosols ftom the South Pacifico Nature, 325(6107):800-804.
Grimalt, J. O.; Albaigés, J.; Douabul, A. A. Z. & Al-Saad, H. T. 1985. n-AIkane distributions in surface sediments ftom the Arabian Gulf. Naturwissenschaft,72(1):35-37.
Grimalt, J. O.; Albaigés, J.; Alexander, G. & Hazai, I. 1986. Predominance of even carbon numbered aIkanes in coal seam samples of Nograd basin (Hungary). Naturwissenschaft., 73(12):729-731.
GRIP Members. Greeland lce-core Project (GRIP) Members. 1993. Climate instability during the last interglacial period recorded in the GRIP ice core. Nature, 364(6434):203-207.
Hedges, J. J.; Clark, W. A.; Quay, P. D.; Richey, J. E.; Devol, A. H. & Santos, U. de M. 1986. Compositions and fluxes of particulate organic material in the Amazon River. Limnol. Oceanogr.,31(4):717-738.
Hooghiemstra, H. 1989. Variations of the NW Aftican trade wind regime during the last 140000 years: changes in pollen flux evidenced by marine sediment records. In: Leinen, M. & Sarnthein, M. eds Paleoclimatology and paleometeorology: modero and past patterns of global atmospheric transporto Boston, Kluwer Academic Publishers. p.733-770.
Huang, Y.; Collister, J. W.; Chester, R & Eglinton, G. 1993. Molecular and Ôl3C mapping of aeolian input of organic compounds into marine sediments in the Northeastern Atlantic. In: INTERNA TIONAL MEETING ON ORGANIC GEOCHEMISTRY, 16. Stavanger, Norway, 1993. Poster sessions. Norway, Fatch Hurtigtrykk. p.523-528.
Jasper, J. P. & Gagosian, R B. 1993. The relationships between sedimentary organic-carbon isotopic composition and organic biomarker compound concentration. Geochim. Cosmochim. Acta, 57(1):167-186.
Kevenvolden, K. A 1966. Molecular distributions of normal fatty acids and parafins in some lower cretaceous sediments. Nature, 209:573-577.
Legrand, M. R; Lorius, C.; Barkov, N. I. & Petrov. V. N. 1988. Vostok (Antarctica) ice core: atmospheric chemistry changes over the last climatic cycle (160,000 years). Atmos. Environ., 22(2):317-331.
Madureira, L. A S.; Conte, M. H. & Eglinton, G. 1995. Early diagenesis of lipid biomarker compounds in North Atlantic sediments. Paleoceanography, 10(3):627-642.
Madureira, L. A. S. 1994. Lipids in recent sediments ofthe eastern North Atlantic. Tese de doutorado. University of Bristol. 246p.
Madureira, L. A. S. 1997. Lipídios como indicadores de mudanças climáticas no passado 1: biomarcadores marinhos. Química Nova, 20(3):293-299.
Madureira, L. A. S.; van Kreveld, S. A.; Eglinton, G.; Conte, M. H.; Gassen, G.; van Hinte, J. E. & Ottens, J. J. 1997. Late Quaternary high-resolution biomarker and other sedimentary climate proxies in a northeast Atlantic core. Paleoceanography, 12(2):255-269.
Manighetti, B. & McCave, 1. N. 1995. Depositional fluxes, palaeoproductivity, and ice rafting in the NE Atlantic over the past 30 ka. Paleoceanography, 10(3):579-592.
Martinson, D. G.; Pisias, N. G.; Hays, J. D.; Imbrie, J.; Moore Jr., T. C. & Shackleton, N. J. 1987. Age dating and the orbital theory of the ice ages: development of a high-resolution O to 300,000-year chronostratigraphy. Qual. Res., 27(1):1-29.
McCaflTey, M. A.; Farrington, J. W. & Repeta, D. J. 1991. The organic geochemistry of Peru margin surface sediments n. Paleoenvironmental implications of hydrocarbon and alcohol profiles. Geochim. cosmochim. Actü, 55(2):483-498.
Meyers, P. A; Bourbonniere, R A & Takeuchi, N. 1980. Hydrocarbons and fatty acids in two cores of Lake Huron sediments. Geochim. cosmochim. Acta,44(8):1215-1221.
Ohkouchi, N.; Kawamura, K. & Taira, A. 1997. Fluctuations of terrestrial and marine biomarkers in the western tropical Pacific during the last 23,300 years. Paleoceanography, 12(4):623-630.
Poynter, J. & Eglinton, G. 1990. Molecular composition of three sediments from hole 717C: the Bengal Fan. Proceedings of the Ocean Drilling Program. Scientific Results, 116: 155-161.
Rieley, G.; Collier, R J.; Jones, D. M. &. Eglinton, G. 1991. The biogeochemistry of Ellesmere Lake, UK - I: source correlation of leaf wax inputs to the sedimentary lipid recordo Org. Geochem., 17(6):901-912.
Santos, V.; Billet, D. S. M.; Rice, A. L. & Wolff, G. A 1994. Organic matter in deep sea sediments from the Porcupine abyssal plain in the north-east Atlantic Ocean 1. Lipids. Deep Sea Res., 41(5-6):787-819.
Scalan, R S. & Smith, J. E. 1970. An improved measure of the odd-even predominance in the normal alkanes of sediment extracts and petroleum. Geochim. cosmochim. Acta, 34:611-620.
Schneider, R R.; Müller, P. J. & Ruhland, G. 1995. Late Quaternary surface circulations in the east equatorial South Atlantic: Evidence from alkenone sea surface temperatures. Paleoceanography, 10(2): 197-219.
Simoneit, B. R T. 1977. Organic matter in eolian dust over the Atlantic Oceano Mar. Chem., 5(4-6):443-464.
Simoneit, B. R T.; Chester, R. & Eglinton, G. 1977. Biogenic lipids in particulates from lower atmosphere over the eastern Atlantic. Nature, 267(5613):682-685.
Simoneit, B. R T. 1978. The organic chemistry of marine sediments. In: Riley, J.P. & Chester, R eds Chemical oceanography. London, Academic Press. v.7 p. 233-311.
Volkman, J. K.; Smith, D. J.; Eglinton, G.; Forsberg, T. E. V. & Comer, E. D. S. 1981. Sterol and fatty acid composition of four marine Haptophycean algae. J. mar. biol. Ass. U.K., 61 (2):509-527.
Schultz, D. M. & Quinn, J. G. 1972. Fatty acids in surface particulate matter ftom the North Atlantic. J. Fish. Res. Bd Can.,29:1482-1486.
Uchupi, E. 1971. Bathymetric atlas of the Atlantic, Caribbean, and Gulf of Mexico. Woods Hole Oceanographic Institution, WHOI 71-72, unpublished manuscript.
van Kreveld, S. A; Knappertsbusch, M.; Ottens, J. J.; Ganssen, G. & van Hinte, J. E. 1996. Biogenic carbonate and ice-rafted debris (Heinrich layers) accumulation in deep sea sediments ftom a Northeast Atlantic piston core. Mar. Geol., 131(1-2):21-46.
van Kreveld, S. A 1996. Late quaternary sediment records of mid-latitude Northeast Atlantic calcium carbonate production and dissolution. Tese de doutorado. Amsterdan, Free University. 212 p.
Venkatesan, M. I. & Kaplan, I. R 1987. The lipid geochemistry of Antarctic marine sediments: Bransfield Strait. Mar. Chem., 21(4):347-375.
Villanueva, J.; Grimalt, J. O.; Cortijo, E.; Vidal, L. & Labeyrie, L. 1997. A biomarker approach to the organic matter deposited in the North Atlantic during the last climatic cycle. Geochim. cosmochim. Acta, 61(21):4633-4646.
Wakeham, S. G. & Beier, J. A. 1991. Fatty acid and sterol biomarkers as indicators of particulate matter source and alteration processes in the Black Sea. Deep-Sea Res., 38 (Suppl.2): S943-S968.
Zhao, M.; Rosell-Melé, A & Eglinton, G. 1993. Comparison of two Uk37 sea surface temperature records for the last climatic cycle at ODP site 658 ftom the subtropical Northeast Atlantic. Palaeogeogr. Palaeoclimatol. Palaeoecol., 103:57-65.
Zhao, M.; Beveridge, N. A S.; Shackleton, N. J.; Sarnthein, M. & Eglinton, G. 1995. Molecular stratigraphy of cores ofI northwest Aftica: sea surface temperature history over the last 80 ka. Paleoceanography, 10(3):661-675.

Publication Dates

Publication in this collection
22 Apr 2013
Date of issue
1999

History

Accepted
08 Nov 1999
Reviewed
30 Aug 1999
Received
06 July 1998

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

[1] Balsam, W. L. & McCoy Jr., F. W. 1987. Atlantic sediments: glacial/interglacial comparisons. Paleoceanography,5:531-542.

[2] Bourbonniere, R A. & Meyers, P. A. 1996. Sedimentary geolipid records of historical changes in the watersheds and productivities of Lakes Ontario and Erie. Limnol.. Oceanogr., 41(2):352-359.

[3] Brand, T. & Shimmield, G. 1992. The use of ²¹⁰Pb as an indicator of biological processes affecting the flux and sediment geochemistry of organic carbon in the North East Atlantic. In: Kershaw, P.J. & Woodhead, D.F. eds Radionuclides in the study of marine processes. New York, Elsevier. p.222-233.

[4] Biogeochemistry of lipids in surface sediments of the Peru upwelling area at 15şS. Org. Geochem., 13(4-6):607-617.

[5] Chester, R 1990. Marine geochemistry I. Oceans, chemical composition & chemical properties. London, Unwin Hyman Ltd. 698p.

[6] Conte, M. H.; Volkman, J. K. & Eglinton, G. 1994. Lipid biomarkers of the Haptophyta. In: Leadbeater, B. & Green, J.C. eds The Haptophyte algae. Oxford, Claredon Press. p.351-377.

[7] Cooper, J. E. & Bray, E. E. 1963. A postulated role of fatty acids in petroleum formation. Geochim. cosmochim. Acta, 27:1113-1127.

[8] Cranwell, P. A.; Eglinton, G. & Robinson, N. 1987. Lipids of aquatic organisms as potential contributors to lacustrine sediments. 2. Org. Geochem., 11(6):513-527.

[9] Farrimond, P.; Poynter, J. & Eglinton, G. 1990. A molecular stratigraphic study of Peru margin sediments, Hole 686B, Leg 112. In: Suess, E. & von Huene eds. Proceedings of the ocean drilling programo scientific results. 547-553.

[10] Farrington, J. W.; Davis, A. C.; Sulanowski, J.; McCaffiey, M. A.; McCarthy, M.; Clitford, C. H.; Dickinson, P. & Volkman, J. K. 1988.

[11] Gagosian, R B.; Peltier, E. T. & Zafiriou, O. C. 1981. Atmospheric transport of continentally-derived lipids to the tropical North Pacifico Nature, 291(5813):312-314.

[12] Gagosian, R B.; Peltzer, E. T. & Merril, J. T. 1987. Long-range transport of terrestrially derived lipids in aerosols ftom the South Pacifico Nature, 325(6107):800-804.

[13] Grimalt, J. O.; Albaigés, J.; Douabul, A. A. Z. & Al-Saad, H. T. 1985. n-AIkane distributions in surface sediments ftom the Arabian Gulf. Naturwissenschaft,72(1):35-37.

[14] Grimalt, J. O.; Albaigés, J.; Alexander, G. & Hazai, I. 1986. Predominance of even carbon numbered aIkanes in coal seam samples of Nograd basin (Hungary). Naturwissenschaft., 73(12):729-731.

[15] GRIP Members. Greeland lce-core Project (GRIP) Members. 1993. Climate instability during the last interglacial period recorded in the GRIP ice core. Nature, 364(6434):203-207.

[16] Hedges, J. J.; Clark, W. A.; Quay, P. D.; Richey, J. E.; Devol, A. H. & Santos, U. de M. 1986. Compositions and fluxes of particulate organic material in the Amazon River. Limnol. Oceanogr.,31(4):717-738.

[17] Hooghiemstra, H. 1989. Variations of the NW Aftican trade wind regime during the last 140000 years: changes in pollen flux evidenced by marine sediment records. In: Leinen, M. & Sarnthein, M. eds Paleoclimatology and paleometeorology: modero and past patterns of global atmospheric transporto Boston, Kluwer Academic Publishers. p.733-770.

[18] Huang, Y.; Collister, J. W.; Chester, R & Eglinton, G. 1993. Molecular and Ôl3C mapping of aeolian input of organic compounds into marine sediments in the Northeastern Atlantic. In: INTERNA TIONAL MEETING ON ORGANIC GEOCHEMISTRY, 16. Stavanger, Norway, 1993. Poster sessions. Norway, Fatch Hurtigtrykk. p.523-528.

[19] Jasper, J. P. & Gagosian, R B. 1993. The relationships between sedimentary organic-carbon isotopic composition and organic biomarker compound concentration. Geochim. Cosmochim. Acta, 57(1):167-186.

[20] Kevenvolden, K. A 1966. Molecular distributions of normal fatty acids and parafins in some lower cretaceous sediments. Nature, 209:573-577.

[21] Legrand, M. R; Lorius, C.; Barkov, N. I. & Petrov. V. N. 1988. Vostok (Antarctica) ice core: atmospheric chemistry changes over the last climatic cycle (160,000 years). Atmos. Environ., 22(2):317-331.

[22] Madureira, L. A S.; Conte, M. H. & Eglinton, G. 1995. Early diagenesis of lipid biomarker compounds in North Atlantic sediments. Paleoceanography, 10(3):627-642.

[23] Madureira, L. A. S. 1994. Lipids in recent sediments ofthe eastern North Atlantic. Tese de doutorado. University of Bristol. 246p.

[24] Madureira, L. A. S. 1997. Lipídios como indicadores de mudanças climáticas no passado 1: biomarcadores marinhos. Química Nova, 20(3):293-299.

[25] Madureira, L. A. S.; van Kreveld, S. A.; Eglinton, G.; Conte, M. H.; Gassen, G.; van Hinte, J. E. & Ottens, J. J. 1997. Late Quaternary high-resolution biomarker and other sedimentary climate proxies in a northeast Atlantic core. Paleoceanography, 12(2):255-269.

[26] Manighetti, B. & McCave, 1. N. 1995. Depositional fluxes, palaeoproductivity, and ice rafting in the NE Atlantic over the past 30 ka. Paleoceanography, 10(3):579-592.

[27] Martinson, D. G.; Pisias, N. G.; Hays, J. D.; Imbrie, J.; Moore Jr., T. C. & Shackleton, N. J. 1987. Age dating and the orbital theory of the ice ages: development of a high-resolution O to 300,000-year chronostratigraphy. Qual. Res., 27(1):1-29.

[28] McCaflTey, M. A.; Farrington, J. W. & Repeta, D. J. 1991. The organic geochemistry of Peru margin surface sediments n. Paleoenvironmental implications of hydrocarbon and alcohol profiles. Geochim. cosmochim. Actü, 55(2):483-498.

[29] Meyers, P. A; Bourbonniere, R A & Takeuchi, N. 1980. Hydrocarbons and fatty acids in two cores of Lake Huron sediments. Geochim. cosmochim. Acta,44(8):1215-1221.

[30] Ohkouchi, N.; Kawamura, K. & Taira, A. 1997. Fluctuations of terrestrial and marine biomarkers in the western tropical Pacific during the last 23,300 years. Paleoceanography, 12(4):623-630.

[31] Poynter, J. & Eglinton, G. 1990. Molecular composition of three sediments from hole 717C: the Bengal Fan. Proceedings of the Ocean Drilling Program. Scientific Results, 116: 155-161.

[32] Rieley, G.; Collier, R J.; Jones, D. M. &. Eglinton, G. 1991. The biogeochemistry of Ellesmere Lake, UK - I: source correlation of leaf wax inputs to the sedimentary lipid recordo Org. Geochem., 17(6):901-912.

[33] Santos, V.; Billet, D. S. M.; Rice, A. L. & Wolff, G. A 1994. Organic matter in deep sea sediments from the Porcupine abyssal plain in the north-east Atlantic Ocean 1. Lipids. Deep Sea Res., 41(5-6):787-819.

[34] Scalan, R S. & Smith, J. E. 1970. An improved measure of the odd-even predominance in the normal alkanes of sediment extracts and petroleum. Geochim. cosmochim. Acta, 34:611-620.

[35] Schneider, R R.; Müller, P. J. & Ruhland, G. 1995. Late Quaternary surface circulations in the east equatorial South Atlantic: Evidence from alkenone sea surface temperatures. Paleoceanography, 10(2): 197-219.

[36] Simoneit, B. R T. 1977. Organic matter in eolian dust over the Atlantic Oceano Mar. Chem., 5(4-6):443-464.

[37] Simoneit, B. R T.; Chester, R. & Eglinton, G. 1977. Biogenic lipids in particulates from lower atmosphere over the eastern Atlantic. Nature, 267(5613):682-685.

[38] Simoneit, B. R T. 1978. The organic chemistry of marine sediments. In: Riley, J.P. & Chester, R eds Chemical oceanography. London, Academic Press. v.7 p. 233-311.

[39] Volkman, J. K.; Smith, D. J.; Eglinton, G.; Forsberg, T. E. V. & Comer, E. D. S. 1981. Sterol and fatty acid composition of four marine Haptophycean algae. J. mar. biol. Ass. U.K., 61 (2):509-527.

[40] Schultz, D. M. & Quinn, J. G. 1972. Fatty acids in surface particulate matter ftom the North Atlantic. J. Fish. Res. Bd Can.,29:1482-1486.

[41] Uchupi, E. 1971. Bathymetric atlas of the Atlantic, Caribbean, and Gulf of Mexico. Woods Hole Oceanographic Institution, WHOI 71-72, unpublished manuscript.

[42] van Kreveld, S. A; Knappertsbusch, M.; Ottens, J. J.; Ganssen, G. & van Hinte, J. E. 1996. Biogenic carbonate and ice-rafted debris (Heinrich layers) accumulation in deep sea sediments ftom a Northeast Atlantic piston core. Mar. Geol., 131(1-2):21-46.

[43] van Kreveld, S. A 1996. Late quaternary sediment records of mid-latitude Northeast Atlantic calcium carbonate production and dissolution. Tese de doutorado. Amsterdan, Free University. 212 p.

[44] Venkatesan, M. I. & Kaplan, I. R 1987. The lipid geochemistry of Antarctic marine sediments: Bransfield Strait. Mar. Chem., 21(4):347-375.

[45] Villanueva, J.; Grimalt, J. O.; Cortijo, E.; Vidal, L. & Labeyrie, L. 1997. A biomarker approach to the organic matter deposited in the North Atlantic during the last climatic cycle. Geochim. cosmochim. Acta, 61(21):4633-4646.

[46] Wakeham, S. G. & Beier, J. A. 1991. Fatty acid and sterol biomarkers as indicators of particulate matter source and alteration processes in the Black Sea. Deep-Sea Res., 38 (Suppl.2): S943-S968.

[47] Zhao, M.; Rosell-Melé, A & Eglinton, G. 1993. Comparison of two Uk37 sea surface temperature records for the last climatic cycle at ODP site 658 ftom the subtropical Northeast Atlantic. Palaeogeogr. Palaeoclimatol. Palaeoecol., 103:57-65.

[48] Zhao, M.; Beveridge, N. A S.; Shackleton, N. J.; Sarnthein, M. & Eglinton, G. 1995. Molecular stratigraphy of cores ofI northwest Aftica: sea surface temperature history over the last 80 ka. Paleoceanography, 10(3):661-675.