Plume-ridge interaction in the Easter-Salas y Gomez seamount chain-Easter Microplate system: Pb isotope evidence

1998 ◽  
Vol 103 (B10) ◽  
pp. 24159-24177 ◽  
Author(s):  
Richard H. Kingsley ◽  
Jean-Guy Schilling
Keyword(s):  
Pb Isotope ◽  
Isotope Evidence ◽  
Easter Microplate ◽  
Seamount Chain

Easter microplate evolution: Pb isotope evidence

1989 ◽  
Vol 94 (B6) ◽  
pp. 7432 ◽  
Author(s):  
Barry B. Hanan ◽  
Jean-Guy Schilling
Keyword(s):  
Pb Isotope ◽  
Isotope Evidence ◽  
Easter Microplate

Pb-isotope evidence on the origin of the West Shropsh orefield, England

1996 ◽  
Vol 133 (5) ◽  
pp. 611-617 ◽  
Author(s):  
R. Haggerty ◽  
B. M. Rohl ◽  
P. D. Budd ◽  
N. H. Gale
Keyword(s):  
Sea Water ◽  
Multiple Sources ◽  
Pb Isotope ◽  
The West ◽  
Minor Variation ◽  
Isotope Data ◽  
Water Origin ◽  
Isotope Evidence ◽  
Significant Spread ◽  
Isotope Variation

AbstractPb-isotope data on ore galenas from the West Shropshire orefield show a significant spread of 20pb/204pb values, with minor variation in 207Pb/204Pb and 208Pb/204Pb ratios. These indicate that lead was derived from multiple sources, some of them uranium-enriched and incompletely mixed prior to ore deposition. Four possible mineralizing agents are considered: circulating sea-water, metamorphic waters, basinal brines and convecting formation waters. Pb-isotope data exclude a circulating sea-water origin for the mineralization, and best support a convecting formation water mineralizing agent. A model involving a single fluid tapping multiple lead sources is proposed to explain the observed Pb-isotope variation.

scholarly journals Trace-Element and Pb Isotope Evidence on Extracting Sulfides from Potassic Melts beneath Longmenshan and Molabushan Volcanoes, Wudalianchi, Northeast China

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 319 ◽  
Author(s):  
Sergei Rasskazov ◽  
Yi-Min Sun ◽  
Irina Chuvashova ◽  
Tatyana Yasnygina ◽  
Chen Yang ◽  
...  
Keyword(s):  
Trace Element ◽  
Volcanic Rocks ◽  
Volcanic Field ◽  
Lava Flows ◽  
Pb Isotope ◽  
Linear Pattern ◽  
Wide Range ◽  
Mantle Sources ◽  
Isotope Evidence ◽  
Isotope Study

In the Wudalianchi volcanic field, eruptions started with low-Mg potassic lava flows 2.5–2.0 Ma ago and later changed to both low- and moderate-Mg potassic compositions. Volcanic rocks from the Molabushan and Longmenshan volcanoes record an unusually wide range of Pb abundances (from 3.7 ppm to 21 ppm relative to predominant range of 10–15 ppm). To determine the cause of these, we performed a comparative trace-element and Pb isotope study of rocks from these volcanoes and older lava flows. On a uranogenic lead diagram, older low-Mg lavas from lithospheric mantle sources plot on a secondary isochron with a slope corresponding to an age of 1.88 Ga. This contrasts with moderate-Mg volcanic rocks from the Molabushan cone, interpreted to have been derived from a recent convective mantle source, which define a flat linear pattern. Low-Mg rocks from the Molabushan flow have lead isotopic compositions that indicate mixed Gelaqiu and Molabu sources. Relative to rocks from the Molabushan cone, moderate-Mg lavas and slags from the East Longmenshan volcano have modified compositions characterized by Pb, S, and Ni abundances, Ni/Co, Ni/MgO ratios as well as 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb, Ce/Pb, Th/Pb, and U/Pb ratios. We infer that the older Wudalianchi magmas were likely derived from a Paleoproterozoic lithospheric fragment, related to the evolved primordial mantle, and that later magmas were generated in the convecting mantle. These were influenced by segregation of small amounts of sulfides.

Provenance of the Old Red Sandstone: Pb isotope evidence from Arran, western Scotland

1984 ◽  
Vol 75 (2) ◽  
pp. 239-241 ◽  
Author(s):  
A. P. Dickin
Keyword(s):  
Significant Contribution ◽  
Strike Slip ◽  
Pb Isotope ◽  
Early Proterozoic ◽  
Red Sandstone ◽  
Boundary Fault ◽  
Crustal Block ◽  
Isotope Evidence ◽  
Strike Slip Movement ◽  
Proterozoic Age

ABSTRACTOld Red Sandstone sediments from Arran in western Scotland yield an array of Pb isotope compositions whose slope corresponds to an age of 1830 ± 400 Ma. These compositions are not consistent with a significant contribution of material from the Southern Highlands, Midland Valley, or Southern Uplands, but are similar to the Torridonian sandstones of NW Scotland. Bearing in mind the probable Laxfordian provenance of the Torridonian assemblage, this points to a source for the Old Red Sandstone in a crustal block of early Proterozoic age corresponding to the age of the Laxfordian episode. Since such a source is not presently in a position to yield the Old Red Sandstone, strike-slip movement along the Highland Boundary fault is a strong possibility.

Hf–Nd–Pb isotope evidence from Permian arc rocks for the long-term presence of the Indian–Pacific mantle boundary in the SW Pacific

2007 ◽  
Vol 254 (3-4) ◽  
pp. 377-392 ◽  
Author(s):  
O. Nebel ◽  
C. Münker ◽  
Y.J. Nebel-Jacobsen ◽  
T. Kleine ◽  
K. Mezger ◽  
...  
Keyword(s):  
Pb Isotope ◽  
Mantle Boundary ◽  
Sw Pacific ◽  
Isotope Evidence

scholarly journals The Dupal isotopic anomaly in the southern Paleo-Asian Ocean: Nd–Pb isotope evidence from ophiolites in Northwest China

Lithos ◽  
2014 ◽  
Vol 189 ◽  
pp. 185-200 ◽  
Author(s):  
Xijun Liu ◽  
Jifeng Xu ◽  
Paterno R. Castillo ◽  
Wenjiao Xiao ◽  
Yu Shi ◽  
...  
Keyword(s):  
Northwest China ◽  
Pb Isotope ◽  
Isotopic Anomaly ◽  
Isotope Evidence

Age of uranium mineralization at the Jabiluka and Ranger deposits, Northern Territory, Australia; new U-Pb isotope evidence

1987 ◽  
Vol 82 (4) ◽  
pp. 857-874 ◽  
Author(s):  
K. R. Ludwig ◽  
R. I. Grauch ◽  
C. J. Nutt ◽  
J. T. Nash ◽  
David Frishman ◽  
...  
Keyword(s):  
Northern Territory ◽  
Uranium Mineralization ◽  
Pb Isotope ◽  
Isotope Evidence

Sr-Nd-Pb isotope evidence against plume-asthenosphere mixing north of Iceland

1991 ◽  
Vol 107 (2) ◽  
pp. 243-255 ◽  
Author(s):  
Dieter F. Mertz ◽  
Colin W. Devey ◽  
Wolfgang Todt ◽  
Peter Stoffers ◽  
Albrecht W. Hofmann
Keyword(s):  
Pb Isotope ◽  
Isotope Evidence
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