scholarly journals Paleofluids and Recent fluids in the upper continental crust: Results from the German Continental Deep Drilling Program (KTB)

1997 ◽  
Vol 102 (B8) ◽  
pp. 18233-18254 ◽  
Author(s):  
P. Möller ◽  
S. M. Weise ◽  
E. Althaus ◽  
W. Bach ◽  
H. J. Behr ◽  
...  
Keyword(s):  
Continental Crust ◽  
Deep Drilling ◽  
Upper Continental Crust ◽  
Continental Deep Drilling

scholarly journals The silicon isotope composition of the upper continental crust

2013 ◽  
Vol 109 ◽  
pp. 384-399 ◽  
Author(s):  
Paul S. Savage ◽  
R. Bastian Georg ◽  
Helen M. Williams ◽  
Alex N. Halliday
Keyword(s):  
Continental Crust ◽  
Isotope Composition ◽  
Silicon Isotope ◽  
Upper Continental Crust

scholarly journals The zirconium isotope composition of the mantle and upper continental crust through time

2021 ◽  
Author(s):  
Shengyu Tian ◽  
Frédéric Moynier ◽  
Edward Inglis ◽  
Roberta L. Rudnick ◽  
Fang Huang ◽  
...  
Keyword(s):  
Continental Crust ◽  
Isotope Composition ◽  
Upper Continental Crust

scholarly journals Preliminary Description of the Origin of a Sedimentary – Exhalative Ore Deposit, in Molango, Hidalgo Mexico

2018 ◽  
Author(s):  
Eduardo Cerecedo-Sáenz ◽  
Ventura Rodríguez-Lugo ◽  
Juan Hernández-Ávila ◽  
Demetrio Mendoza-Anaya ◽  
Ma. Isabel Reyes-Valderrama ◽  
...  
Keyword(s):  
Continental Crust ◽  
Rare Earths ◽  
Mineral Deposit ◽  
Base Metals ◽  
Sulfur Deficiency ◽  
Ore Deposit ◽  
Upper Continental Crust ◽  
Distribution Of Elements ◽  
Hydrothermal Remobilization ◽  
Preliminary Description

This work shows the preliminary description of the origin of a sedimentary - exhalative outcrop of Jurassic Lower Pliensbachian. The location of this deposit was achieved by applying an examination based in the identification of sedimentary transgressions of heterochronies ages and the identification of a Rift – type mega –structure. According with the methodology, it was carried out a study of the discordant relationships between two types of sediments: continental and marine. According the characterization, it was noted the existence of light rare earths, in values that show positive anomalies in comparison with the distribution of elements in upper continental crust according to the Clarke [1], reflecting so a felsic affinity of the mineral deposit. Also, positive anomalies of platinum and Pd, were determined with marginal contents of Au and Ag; and finally the base metals Zn, Pb and Cu were detected in low contents, which could be due to the presence of altered shale. According to the sedimentary lithology found, which was of siliciclastic type; to the exhalative roots observed during the fieldwork; the presence of quartz minerals such as biotite and muscovite; the presence of minerals of hydrothermal remobilization like chalcopyrite with some base metals, altered shale, as well as sulfur deficiency; this mineral reservoir could be defined as a SEDEX – type.

Lithium isotopic composition and concentration of the upper continental crust

2004 ◽  
Vol 68 (20) ◽  
pp. 4167-4178 ◽  
Author(s):  
F.-Z. Teng ◽  
W.F. McDonough ◽  
R.L. Rudnick ◽  
C. Dalpé ◽  
P.B. Tomascak ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Continental Crust ◽  
Upper Continental Crust

Metal Sources in the Proterozoic Vazante-Paracatu Sediment-Hosted Zn District, Brazil: Constraints from Pb Isotope Compositions of Meta-Siliciclastic Units

2021 ◽  
Author(s):  
Neil A Fernandes ◽  
Gema R. Olivo ◽  
Daniel Layton-Matthews ◽  
Alexandre Voinot ◽  
Donald Chipley ◽  
...  
Keyword(s):  
Continental Crust ◽  
Isotopic Signature ◽  
Pb Isotope ◽  
Metal Sources ◽  
Upper Continental Crust ◽  
Basement Rocks ◽  
Siliciclastic Rocks ◽  
Brasiliano Orogeny ◽  
Isotope System ◽  
Parallel Arrays

ABSTRACT Different types of sediment-hosted whole-rock Pb isotope (206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb) compositions were determined from phyllites, carbonaceous phyllites (>1% TOC), and meta-litharenites belonging to the Serra do Garrote Formation, which is part of the Proterozoic Vazante Group, Brazil. Results were integrated with lithogeochemistry in order to identify the Pb isotopic signature of Zn enrichment (up to 0.24 wt.% Zn) associated with meta-siliciclastic-hosted sulfide mineralization that formed prior to the Brasiliano Orogeny (850 to 550 Ma) in order to (1) understand the nature of siliciclastic sediment sources, (2) identify possible metal sources in pre-orogenic meta-siliciclastic-hosted Zn mineralization, and (3) evaluate the genetic links between the Zn enrichment in the relatively reduced phyllite package, and different styles of syn-orogenic Zn ± Pb mineralization (hypogene Zn-silicate and Zn-Pb sulfide) in overlying dolomitic carbonates throughout the Vazante-Paracatu Zn District, Brazil. The whole-rock 206Pb/204Pb and 207Pb/204Pb isotope ratios of meta-siliciclastic rocks plot as positively sloping, sub-parallel arrays with radiogenic, upper continental crust compositions, which could represent a detrital contribution from at least two upper continental crust sources. However, the 206Pb/204Pb versus 207Pb/204Pb isotope system does not distinguish between Zn-enriched samples and un-mineralized samples. In the whole-rock 206Pb/204Pb–208Pb/204Pb plot, Zn-enriched samples form a flat trend of lower 208Pb/204Pb values (38.3 to 39.5) compared to the Zn-poor ones that follow common upper crustal trends. Zinc-enriched samples have low whole-rock Th/U values (<4) and higher whole-rock U concentrations compared to unmineralized samples. These support the hypothesis that U (± Pb) was added by pre-orogenic metalliferous fluids, which were in turn derived from underlying Paleoproterozoic and Archean basement rocks. Due to U addition, the original whole-rock thorogenic and uranogenic Pb isotope systems were decoupled in mineralized samples. Pre-orogenic metalliferous fluids have similar present-day first-order characteristics, including: (1) relatively high U/Pb and (2) low Th/U values, when compared to galena in the major carbonate-hosted Zn ± Pb deposits (Vazante, Morro Agudo, Ambrosia, Fagundes) in the Vazante Group. These results support the hypothesis that Zn-rich layers and veins in mineralized carbonaceous phyllites could be linked to the same origins as carbonate-hosted mineral deposits throughout the Vazante Basin, but further data are warranted. We suggest that the tectonic evolution of the Vazante Basin saw multiple phases of Zn-rich mineralization over protracted time periods from around 1200 to 550 Ma.

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