Skip to main content Accessibility help
Hostname: page-component-55597f9d44-t4qhp Total loading time: 0.321 Render date: 2022-08-16T13:25:51.586Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "useNewApi": true } hasContentIssue true

Interplay between detrital and diagenetic processes since the last glacial maximum on the northwest Iberian continental shelf

Published online by Cambridge University Press:  20 January 2017

Kais Jacob Mohamed*
Dept. of Marine Geosciences and Land Management, University of Vigo, Faculty of Marine Sciences, Lagoas-Marcosende, 36310, Vigo, Spain Dept. Geology & Geophysics, Woods Hole Oceanographic Institution, MS #23 266 Woods Hole Rd. 02543, Woods Hole, MA, USA
Daniel Rey
Dept. of Marine Geosciences and Land Management, University of Vigo, Faculty of Marine Sciences, Lagoas-Marcosende, 36310, Vigo, Spain
Belen Rubio
Dept. of Marine Geosciences and Land Management, University of Vigo, Faculty of Marine Sciences, Lagoas-Marcosende, 36310, Vigo, Spain
Federico Vilas
Dept. of Marine Geosciences and Land Management, University of Vigo, Faculty of Marine Sciences, Lagoas-Marcosende, 36310, Vigo, Spain
Thomas Frederichs
Dept. of Marine Geophysics, University of Bremen, P.O. Box"330 440, D-28334 Bremen, Germany
*Corresponding author. Dept. of Marine Geosciences and Land Management, University of Vigo, Faculty of Marine Sciences, Lagoas-Marcosende, 36310, Vigo, Spain. Fax: + 34 986 81 25 56.E-mail (K.J. Mohamed).


Integrated analyses of magnetic, geochemical and textural data on six cores from the northwestern Iberian continental shelf allowed the reconstruction of the paleoenvironmental evolution of this area since the last glacial maximum (LGM). Four sedimentary units were identified, representing a succession from fluvial and subaerial settings to high and finally low-energy marine deposits subsequent to the post-LGM sea-level rise. The uppermost unit was deposited during the Holocene and its magnetic properties were controlled by the interplay between detrital input and early diagenetic reductive dissolution of magnetic minerals. Identification of a primary steady-state early diagenetic signal allowed the recognition of periods of increased detrital input, bounded by intervals of lower detrital input and intensified reductive diagenesis related to intensified upwelling in the area. These paleoenvironmental alternations are consistent with the climatic evolution of the late Holocene. During the Roman Warm Period and Medieval Warm Period, the combined effect of greater humidity and intense agricultural and mining activities led to a greater erosion and transport of detrital sediments to the shelf. In contrast, enhanced diagenetic reduction intervals, caused by upwelling intensification, were roughly coincident with the colder Dark Ages and the Little Ice Age.

Original Articles
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


Alonso, B., Ercilla, G., Casas, D., Estrada, F., Farr"n, M., Garc"a, M., Rey, D., Rubio, B., (2008). Late Pleistocene and Holocene sedimentary facies on the SW Galicia Bank (Atlantic NW Iberian Peninsula). Marine Geology 249, 4663.CrossRefGoogle Scholar
"lvarez, M.C., Flores, J.A., Sierro, F.J., Diz, P., Franc"s, G., Pelejero, C., Grimalt, J., (2005). Millennial surface water dynamics in the R"a de Vigo during the last 3000 years as revealed by coccoliths and molecular biomarkers. Palaeogeography, Palaeoclimatology, Palaeoecology 218, 113.CrossRefGoogle Scholar
Ares, A., Rey, D., Rubio, B., Mohamed, K., Bernabeu, A., Vilas, F., (2008). Reconstrucci"n paleoclim"tica de la plataforma continental gallega basada en datos geoqu"micos y magn"ticos. Geogaceta 44, 8790.Google Scholar
Bartels-J"nsd"ttir, H.B., Knudsen, K.L., Abrantes, F., Lebreiro, S., Eir"ksson, J., (2006). Climate variability during the last 2000 years in the Tagus Prodelta, western Iberian Margin: benthic foraminifera and stable isotopes. Marine Micropaleontology 59, 83103.CrossRefGoogle Scholar
Bern"rdez, P., Gonz"lez-"lvarez, R., Franc"s, G., Prego, R., B"rcena, M.A., Romero, O.E., (2008). Late Holocene history of the rainfall in the NW Iberian peninsula"Evidence from a marine record. Journal of Marine Systems 72, 366382.CrossRefGoogle Scholar
Berner, R.A., (1980). Early Diagenesis: A Theoretical Approach. Princeton University Press, Princeton, NJ., 241 pp.Google Scholar
Bloemendal, J., King, J.W., Hunt, A., Demenocal, P.B., Hayashida, A., (1993). Origin of the sedimentary magnetic record at Ocean Drilling Program Sites on the Owen Ridge, western Arabian Sea. Journal of Geophysical Research 98, 41994219.CrossRefGoogle Scholar
Bradley, R.S., Jones, P.D., (1993). "Little ice age" summer temperature variations: their nature and relevance to recent global warming trends. Holocene 3, 367376.CrossRefGoogle Scholar
Canfield, D.E., Berner, R.A., (1987). Dissolution and pyritization of magnetite in anoxic marine sediments. Geochimica et Cosmochimica Acta 51, 645659.CrossRefGoogle Scholar
Day, R., Fuller, M., Schmidt, V.A., (1977). Hysteresis properties of titanomagnetites: grain-size and compositional dependence. Physics of the Earth and Planetary Interiors 13, 260267.CrossRefGoogle Scholar
deCastro, M., Gomez-Gesteira, M., Alvarez, I., Prego, R., (2004). Negative estuarine circulation in the Ria of Pontevedra (NW Spain). Estuarine, Coastal and Shelf Science 60, 301312..CrossRefGoogle Scholar
Desprat, S., S"nchez Go"i, M.F., Loutre, M., (2003). Revealing climatic variability of the last three millennia in northwestern Iberia using pollen influx data. Earth and Planetary Science Letters 213, 6378.CrossRefGoogle Scholar
Dias, J.M.A., Boski, T., Rodrigues, A., Magalh"es, F., (2000). Coast line evolution in Portugal since the Last Glacial Maximum until present " a synthesis. Marine Geology 170, 177186.CrossRefGoogle Scholar
Dias, J.M.A., Gonzalez, R., Garcia, C., Diaz-del-Rio, V., (2002a). Sediment distribution patterns on the Galicia-Minho continental shelf. Progress in Oceanography 52, 215231.CrossRefGoogle Scholar
Dias, J.M.A., Jouanneau, J.M., Gonzalez, R., Arau?jo, M.F., Drago, T., Garcia, C., Oliveira, A., Rodrigues, A., Vitorino, J., Weber, O., (2002b). Present day sedimentary processes on the northern Iberian shelf. Progress in Oceanography 52, 249259..CrossRefGoogle Scholar
Diz, P., Frances, G., Pelejero, C., Grimalt, J.O., Vilas, F., (2002). The last 3000 years in the Ria de Vigo (NW Iberian Margin): climatic and hydrographic signals. The Holocene 12, 459468..CrossRefGoogle Scholar
Drago, T., Jouanneau, J.M., Dias, J.M.A., Prud'Homme, R., (1995). Os factores condicionantes da existencia e alimenta"ao do complexo silto-argiloso situado a Oeste do Douro. Mem"rias do Museu Laborat"rio Mineral"gico e Geol"gico da Facultade de Ciencias do Porto 41, 917921.Google Scholar
Drago, T., Oliveira, A., Magalha?es, F., Cascalho, J., Jouanneau, J.-, Vitorino, J., (1998). Some evidences of northward fine sediment transport in the northern Portuguese continental shelf. Oceanologica Acta 21, 223231.CrossRefGoogle Scholar
Dunlop, D.J., (2002a). Theory and application of the Day plot (Mrs/Ms versus Hcr/Hc) 1. Theoretical curves and tests using titanomagnetite data. Journal of Geophysical Research 107, 2056 .CrossRefGoogle Scholar
Dunlop, D.J., (2002b). Theory and application of the Day plot (Mrs/Ms versus Hcr/Hc) 2. Application to data for rocks, sediments, and soils. Journal of Geophysical Research B: Solid Earth 107, 5-1.Google Scholar
Dur"n, R., (2005). Estratigraf"a s"smica desde el "ltimo m"ximo glacial en la R"a de Pontevedra (NO Espa"a). Universidade de Vigo, Vigo., 300 pp.Google Scholar
Emirog?lu, S., Rey, D., Petersen, N., (2004). Magnetic properties of sediment in the R"a de Arousa (Spain): dissolution of iron oxides and formation of iron sulphides. Physics and Chemistry of the Earth, Parts A/B/C 29, 947959.CrossRefGoogle Scholar
Evans, M.E., Heller, F., (2003). Environmental Magnetism: Principles and Applications of Enviromagnetics. Academic Press (Elsevier), New York., 299 pp.Google Scholar
Ferna?ndez-Bastero, S., Velo, A., Garci?a, T., Gago-Duport, L., Santos, A., Garci?a-Gil, S., Vilas, F., (2000). Las glauconitas de la plataforma continental gallega: indicadores geoqui?micos del grado de evolucio?n. Journal of Iberian Geology 26, 233247.Google Scholar
Fraga, F., (1981). Upwelling off the Galician coast, Northwest Spain. Richards, F.A., Coastal Upwelling Series, 1 American Geophysical Union, Washington, DC., 176182.CrossRefGoogle Scholar
Garc"a-Garc"a, A., Garc"a-Gil, S., Vilas, F., (2005). Quaternary evolution of the R"a de Vigo, Spain. Marine Geology 220, 153179.Google Scholar
Gonz"lez-"lvarez, R., Franc"s, G., (2005). Paleoenvironmental conditions of the Galician continental shelf during the Holocene. Freitas, M.C., Drago, T., Coastal HOPE 2005 Proceedings 7475.Google Scholar
Gonz"lez-"lvarez, R., Bern"rdez, P., Pena, L.D., Franc"s, G., Prego, R., Diz, P., Vilas, F., (2005). Paleoclimatic evolution of the Galician continental shelf (NW of Spain) during the last 3000 years: from a storm regime to present conditions. Journal of Marine Systems 54, 245260.CrossRefGoogle Scholar
Hughen, K.A., Baillie, M.G.L., Bard, E., Bayliss, A., Beck, J.W., Bertrand, C.J.H., Blackwell, P.G., Buck, C.E., Burr, G.S., Cutler, K.B., Damon, P.E., Edwards, R.L., Fairbanks, R.G., Friedrich, M., Guilderson, T.P., Kromer, B., McCormac, F.G., Manning, S.W., Bronk Ramsey, C., Reimer, P.J., Reimer, R.W., Remmele, S., Southon, J.R., Stuiver, M., Talamo, S., Taylor, F.W., van der Plicht, J., Weyhenmeyer, C.E., (2004). Marine04 marine radiocarbon age calibration, 0"26 cal kyr BP. Radiocarbon 46, 10591086.CrossRefGoogle Scholar
Hughes, M.K., Diaz, H.F., (1994). Was there a "medieval warm period", and if so, where and when?. Climatic Change 26, 109142..CrossRefGoogle Scholar
Hurrell, J.W., Kushnir, Y., Visbeck, M., (2001). The North Atlantic Oscillation. Science 291, 603605.CrossRefGoogle ScholarPubMed
Justino, F., Peltier, W.R., (2005). The glacial North Atlantic Oscillation. Geophysical Research Letters 32, 14.CrossRefGoogle Scholar
Kao, S.-J., Horng, C.-S., Roberts, A.P., Liu, K.-K., (2004). Carbon"sulfur"iron relationships in sedimentary rocks from southwestern Taiwan: influence of geochemical environment on greigite and pyrrhotite formation. Chemical Geology 203, 153168.CrossRefGoogle Scholar
Kleiven, H.F., Kissel, C., Laj, C., Ninnemann, U.S., Richter, T.O., Cortijo, E., (2008). Reduced North Atlantic deep water coeval with the glacial Lake Agassiz freshwater outburst. Science 319, 6064..CrossRefGoogle ScholarPubMed
Kruiver, P.P., Dekkers, M.J., Heslop, D., (2001). Quantification of magnetic coercivity components by the analysis of acquisition curves of isothermal remanent magnetisation. Earth and Planetary Science Letters 189, 269276.CrossRefGoogle Scholar
Lamb, H.H., (1985). Climate History and the Future. Princeton University Press, Princeton, NJ., 835 pp.Google Scholar
Larrasoan?a, J.C., Roberts, A.P., Stoner, J.S., Richter, C., Wehausen, R., (2003). A new proxy for bottom-water ventilation in the eastern Mediterranean based on diagenetically controlled magnetic properties of sapropel-bearing sediments. Palaeogeography, Palaeoclimatology, Palaeoecology 190, 221242.CrossRefGoogle Scholar
Lebreiro, S.M., France?s, G., Abrantes, F.F.G., Diz, P., Bartels-Jo?nsdo?ttir, H.B., Stroynowski, Z.N., Gil, I.M., Pena, L.D., Rodrigues, T., Jones, P.D., Nombela, M.A., Alejo, I., Briffa, K.R., Harris, I., Grimalt, J.O., (2006). Climate change and coastal hydrographic response along the Atlantic Iberian margin (Tagus Prodelta and Muros Ri?a) during the last two millennia. Holocene 16, 10031015.CrossRefGoogle Scholar
Lesueur, P., Tastet, J.P., Weber, O., (2002). Origin and morphosedimentary evolution of fine-grained modern continental shelf deposits: the Gironde mud fields (Bay of Biscay, France). Sedimentology 49, 12991320.CrossRefGoogle Scholar
Liu, J., Zhu, R., Roberts, A.P., Li, S., Chang, J., (2004). High-resolution analysis of early diagenetic effects on magnetic minerals in post-middle-Holocene continental shelf sediments from the Korea Strait. Journal of Geophysical Research B: Solid Earth 109, B03103 .CrossRefGoogle Scholar
Mart"nez-Cortizas, A., Valcarcel-D"az, M., P"rez-Alberti, A., Castillo-Rodr"guez, F., Blanco-Chao, R., (1999). O cambio clim"tico e os paleoclimas cuaternarios. Mart"nez-Cortizas, A., P"rez-Alberti, A., Atlas clim"tico de Galicia Conseller"a de Medioambiente. Xunta de Galicia, Santiago de Compostela., 167185.Google Scholar
Martins, V., Jouanneau, J., Weber, O., Rocha, F., (2006). Tracing the late Holocene evolution of the NW Iberian upwelling system. Marine Micropaleontology 59, 3555.CrossRefGoogle Scholar
Martins, V., Dubert, J., Jouanneau, J., Weber, O., da Silva, E.F., Patinha, C., Alveirinho Dias, J.M., Rocha, F., (2007). A multiproxy approach of the Holocene evolution of shelf"slope circulation on the NW Iberian Continental Shelf. Marine Geology 239, 118.CrossRefGoogle Scholar
Mohamed, J., (2006). Influencia clim"tica, diagen"tica y antropog"nica sobre la se"al magn"tica y geoqu"mica de los sedimentos marinos cuaternarios del noroeste de la Pen"nsula Ib"rica. Ph.D. Thesis, Faculty of Marine Sciences, University of Vigo, Vigo, , Spain. 298 pp.Google Scholar
Mun?oz Sobrino, C., Ramil-Rego, P., Go?mez-Orellana, L., Varela, R.A.D., (2005). Palynological data on major Holocene climatic events in NW Iberia. Boreas 34, 381400.CrossRefGoogle Scholar
Nagata, T., Carleton, B.J., (1987). Magnetic remanence coercivity of rocks. Journal of Geomagnetism and Geoelectricity 39, 447461.CrossRefGoogle Scholar
Oliveira, A., Rocha, F., Rodrigues, A., Jouanneau, J., Dias, A., Weber, O., Gomes, C., (2002). Clay minerals from the sedimentary cover from the northwest Iberian shelf. Progress in Oceanography 52, 233247..CrossRefGoogle Scholar
Passier, H.F., De Lange, G.J., Dekkers, M.J., (2001). Magnetic properties and geochemistry of the active oxidation front and the youngest sapropel in the eastern Mediterranean sea. Geophysical Journal International 145, 604614.CrossRefGoogle Scholar
Postma, H., (1967). Sediment transport and sedimentation in the estuarine environment. Lauff, G.H., Estuaries American Association for the Advancement of Science, Washington DC., 651658.Google Scholar
Rey, J., (1993). Relaci"n morfosedimentaria entre la plataforma continental de Galicia y las R"as Baixas y su evoluci"n durante el Cuaternario. Instituto Espa"ol de Oceanograf"a, Madrid, Espa"a., 233 pp.Google Scholar
Rey, D., Mohamed, K.J., Bernabeu, A., Rubio, B., Vilas, F., (2005). Early diagenesis of magnetic minerals in marine transitional environments: geochemical signatures of hydrodynamic forcing. Marine Geology 215, 215236.CrossRefGoogle Scholar
Rey, D., Rubio, B., Mohamed, K., Vilas, F., Alonso, B., Ercilla, G., Rivas, T., (2008). Detrital and early diagenetic processes in Late Pleistocene and Holocene sediments from the SW Galicia Bank inferred from high-resolution enviromagnetic and geochemical records. Marine Geology 249, 6492.CrossRefGoogle Scholar
Roberts, A.P., (1995). Magnetic properties of sedimentary greigite (Fe3S4). Earth and Planetary Science Letters 134, 227236..CrossRefGoogle Scholar
Roberts, A.P., Pillans, B.J., (1993). Rock magnetism of Lower Middle Pleistocene marine sediments, Wanganui Basin, New Zealand. Geophysical Research Letters 20, 839842.CrossRefGoogle Scholar
Roberts, A.P., Weaver, R., (2005). Multiple mechanisms of remagnetization involving sedimentary greigite (Fe3S4). Earth and Planetary Science Letters 231, 263277.CrossRefGoogle Scholar
Sagnotti, L., Roberts, A.P., Weaver, R., Verosub, K.L., Florindo, F., Pike, C.R., Clayton, T., Wilson, G.S., (2005). Apparent magnetic polarity reversals due to remagnetization resulting from late diagenetic growth of greigite from siderite. Geophysical Journal International 160, 89100.CrossRefGoogle Scholar
Snowball, I., Moros, M., (2003). Saw-tooth pattern of North Atlantic current speed during Dansgaard-Oeschger cycles revealed by the magnetic grain size of Reykjanes Ridge sediments at 59"N. Paleoceanography 18, 4-1.CrossRefGoogle Scholar
Stuiver, M., Reimer, P.J., (1993). Extended 14C data base and revised CALIB 3.0 14C age calibration program. Radiocarbon 35, 215230.CrossRefGoogle Scholar
Thompson, R., Oldfield, F., (1986). Environmental Magnetism. Allen and Unwin, London, UK., 227 pp.CrossRefGoogle Scholar
Vilas, F., Bernabeu, A., Rubio, B., Rey, D., (2010). Estuarios, r"as y llanuras intermareales. Arche, A., Sedimentolog"a: del proceso f"sico a la cuenca sedimentaria Publicaciones del CSIC, Madrid., 621675.Google Scholar
Vilas, F., Bernabeu, A.M., Me?ndez, G., (2005). Sediment distribution pattern in the Rias Baixas (NW Spain): main facies and hydrodynamic dependence. Journal of Marine Systems 54, 261276.CrossRefGoogle Scholar
Winklhofer, M., Zimanyi, G.T., (2006). Extracting the intrinsic switching field distribution in perpendicular media: a comparative analysis. Journal of Applied Physics 99, 8, 08E710-1-3.CrossRefGoogle Scholar
Supplementary material: File

Mohamed et al. Supplementary Material

Supplementary Material

Download Mohamed et al. Supplementary Material(File)
File 38 KB
Cited by

Save article to Kindle

To save this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the or variations. ‘’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Interplay between detrital and diagenetic processes since the last glacial maximum on the northwest Iberian continental shelf
Available formats

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Interplay between detrital and diagenetic processes since the last glacial maximum on the northwest Iberian continental shelf
Available formats

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Interplay between detrital and diagenetic processes since the last glacial maximum on the northwest Iberian continental shelf
Available formats

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *