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- W2049556736 abstract "We report high precision Pb isotopic data (2σ ≤ 100 ppm) together with Nd isotopes on depth profiles from two Fe–Mn crusts from the eastern Atlantic basin. The profiles provide a 13 Ma record of changes in eastern North Atlantic Deep Water (ENADW), and over the past 8 Ma for Mediterranean Outflow Water (MOW). Pb isotope ratios in the two records display gradual and systematic changes, tracking each other through time. The highly precise Pb isotopic data also resolve, for the first time, changes in all three Pb isotope ratios in a single Fe–Mn crust, and exhibit well-defined binary mixing lines in Pb isotope space. The Pb isotopic record of the Tropic Seamount crust shows that eastern Atlantic Pb has been dominated by binary mixing throughout the last 13 Ma. The Pb binary mixing lines further demonstrate that a change in Pb provenance to the eastern Atlantic occurred at 8 and 4 Ma. This is shown by the distinctive Pb isotopic compositions of the mixing components in the time intervals 4–0 Ma and 13–8 Ma. Consideration of Pb and Nd isotope systematics show that from 4 Ma to the present, the two endmember components correspond to NADW and Southern Component Water (SCW). The quasi-cyclic character of 206Pb/204Pb variations, as well as age progressive changes in the Pb mixing proportions of NADW and SCW endmembers, appear to reflect changes in deep water circulation. In particular, strengthening of the Pb and Nd isotopic signal associated with NADW since 3–4 Ma in both the eastern and western Atlantic basins implies that NADW advection from the western into the eastern Atlantic has been in operation over the past 4 Ma. During the period from 13 to 8 Ma, two entirely different sources of Pb and Nd existed in the eastern Atlantic. The radiogenic Pb and unradiogenic Nd component may have originated in the Norwegian–Greenland seas and the low 206Pb/204Pb—high εNd endmember component in the Southern ocean or Tethys. This suggestion is supported by evidence from paleoceanographic studies indicating the importance of Greenland–Scotland ridge activity in Miocene deep water production, and also the presence of a distinctive high δ13C water mass in the Southern Ocean, derived either locally or flowing in via Tethys. The 8 Ma record of the Lion Seamount crust (65GTV) demonstrates that Pb and Nd sources in MOW switched from predominantly internal, Mediterranean (European) sources prior to 4 Ma, to mainly external (Saharan) sources after 4 Ma. The gradual increase of Pb isotope ratios seen following the end of the Messinian reflects enhanced input of Saharan dust into the water column in the eastern Atlantic. The strengthening of the “Saharan” isotopic signal from about 4 Ma also matches the documented increase in aridity and dustiness in the Saharan and sub-Saharan regions and coincides with the re-establishment of water exchange between the Atlantic and Mediterranean after the Messinian. Although Pb and, to a lesser extent, Nd isotope ratios are distinct during the Messinian (6.5–5 Ma), there is no clear evidence for either a shutdown of MOW or a stronger North Atlantic signal during this period. The fact that a similar isotopic signal is observed, with an even higher amplitude in the ENADW record, shows that this signal is a feature of the whole eastern Atlantic. From 3 to 4 Ma ago, a source of radiogenic Pb and unradiogenic Nd appears to have dominated not only the eastern Atlantic but the world oceans, since it is seen ubiquitously in other Fe–Mn crusts at this time. This isotopic signal must be conveyed around the globe via the ocean circulation or the atmosphere. While the closure of the Panama gateway may have played an important role in these global changes in source(s) and/or fluxes of Pb and Nd to the oceans 3–4 Ma ago other events, in conjunction, such as the emergence of the Greenland–Scotland ridge, were probably also as influential." @default.
- W2049556736 created "2016-06-24" @default.
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- W2049556736 date "1999-05-01" @default.
- W2049556736 modified "2023-09-25" @default.
- W2049556736 title "Pb and Nd isotopes in NE Atlantic Fe–Mn crusts: Proxies for trace metal paleosources and paleocean circulation" @default.
- W2049556736 cites W1524308656 @default.
- W2049556736 cites W1967771543 @default.
- W2049556736 cites W1967781300 @default.
- W2049556736 cites W1969489851 @default.
- W2049556736 cites W1976156138 @default.
- W2049556736 cites W1976700002 @default.
- W2049556736 cites W1979850032 @default.
- W2049556736 cites W1980639973 @default.
- W2049556736 cites W1981886448 @default.
- W2049556736 cites W1983859977 @default.
- W2049556736 cites W1985190430 @default.
- W2049556736 cites W1985522240 @default.
- W2049556736 cites W1987276983 @default.
- W2049556736 cites W1987375343 @default.
- W2049556736 cites W1992372095 @default.
- W2049556736 cites W1994370491 @default.
- W2049556736 cites W1995172428 @default.
- W2049556736 cites W1996055672 @default.
- W2049556736 cites W1999275164 @default.
- W2049556736 cites W2003297399 @default.
- W2049556736 cites W2008330648 @default.
- W2049556736 cites W2008839641 @default.
- W2049556736 cites W2013693414 @default.
- W2049556736 cites W2017758463 @default.
- W2049556736 cites W2017876526 @default.
- W2049556736 cites W2018598067 @default.
- W2049556736 cites W2022175403 @default.
- W2049556736 cites W2023493266 @default.
- W2049556736 cites W2025960501 @default.
- W2049556736 cites W2027851654 @default.
- W2049556736 cites W2030221992 @default.
- W2049556736 cites W2031369440 @default.
- W2049556736 cites W2032466071 @default.
- W2049556736 cites W2032645826 @default.
- W2049556736 cites W2033017292 @default.
- W2049556736 cites W2037858880 @default.
- W2049556736 cites W2039100744 @default.
- W2049556736 cites W2043350301 @default.
- W2049556736 cites W2044586867 @default.
- W2049556736 cites W2045133665 @default.
- W2049556736 cites W2045810886 @default.
- W2049556736 cites W2050319095 @default.
- W2049556736 cites W2052300736 @default.
- W2049556736 cites W2052607692 @default.
- W2049556736 cites W2052844436 @default.
- W2049556736 cites W2055112629 @default.
- W2049556736 cites W2056427537 @default.
- W2049556736 cites W2057105411 @default.
- W2049556736 cites W2059804112 @default.
- W2049556736 cites W2062306740 @default.
- W2049556736 cites W2062552134 @default.
- W2049556736 cites W2062660587 @default.
- W2049556736 cites W2063551569 @default.
- W2049556736 cites W2067587044 @default.
- W2049556736 cites W2068348304 @default.
- W2049556736 cites W2076535157 @default.
- W2049556736 cites W2077724426 @default.
- W2049556736 cites W2077885569 @default.
- W2049556736 cites W2083792058 @default.
- W2049556736 cites W2087195094 @default.
- W2049556736 cites W2087307320 @default.
- W2049556736 cites W2088877368 @default.
- W2049556736 cites W2090535593 @default.
- W2049556736 cites W2093158629 @default.
- W2049556736 cites W2093628159 @default.
- W2049556736 cites W2093892810 @default.
- W2049556736 cites W2094066183 @default.
- W2049556736 cites W2096729913 @default.
- W2049556736 cites W2100309389 @default.
- W2049556736 cites W2101999386 @default.
- W2049556736 cites W2112628010 @default.
- W2049556736 cites W2139337289 @default.
- W2049556736 cites W2142180479 @default.
- W2049556736 cites W2144613562 @default.
- W2049556736 cites W2156328732 @default.
- W2049556736 cites W2167266316 @default.
- W2049556736 cites W2321821390 @default.
- W2049556736 cites W3042789115 @default.
- W2049556736 doi "https://doi.org/10.1016/s0016-7037(99)00068-x" @default.
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