Details

Autor(en) / Beteiligte

• Yao, Hui-Qiang
• Zhou, Huai-Yang
• Peng, Xiao-Tong
• Bao, Shen-Xu
• Wu, Zi-Jun
• Li, Jiang-Tao
• Sun, Zhi-Lei
• Chen, Zhi-Qiang
• Li, Ji-Wei
• Chen, Guang-Qian

Titel

Metal sources of black smoker chimneys, Endeavour Segment, Juan de Fuca Ridge: Pb isotope constraints

Ist Teil von

• Applied geochemistry, 2009-10, Vol.24 (10), p.1971-1977

Ort / Verlag

Kidlington: Elsevier Ltd

Erscheinungsjahr

2009

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Hydrothermal chimney sulfides, vent cap chimney samples, Fe-oxide and basalts from sediment-starving Juan de Fuca Ridge, in the Endeavour segment, exhibit a range of Pb isotope ratios ( 206Pb/ 204Pb = 18.658–18.769; 207Pb/ 204Pb = 15.457–15.566; 208Pb/ 204Pb = 37.810–38.276). The data array is not parallel to the northern hemisphere mantle reservoirs indicating a possible sediment component within the sulfides. By assuming that the potential end-member sediment component has a 207Pb/ 204Pb (15.70) similar to Middle Valley sediment, it is suggested the potential end-member sediment component may have 206Pb/ 204Pb = 18.90; 208Pb/ 204Pb = 38.82. Basalt-derived Pb for the Endeavour segment hydrothermal system involves about 50/50 leaching of E-MORB and T2-MORB. Detailed observations show the Mothra field derives more Pb from T2-MORB than the Main Endeavour field does. According to the binary mixing model, the results show little Pb (<1.5%) or no Pb derivation from sedimentary sources. However, the high NH 4 + , CH 4 and Br/Cl ratios in hydrothermal fluids are consistent with a sediment component within the segment. Reconciling the Pb isotope data with the chemistry data of hydrothermal fluids, it is suggested that the sediment component may be located in a lower temperature recharge zone where Pb could not be mobilized from the sediment.