Assessing the impact of black shale processes on REE and the U–Pb isotope system in the southern Appalachian Basin

Lev, Steven; Filer, Jonathan K.

doi:10.1016/j.chemgeo.2003.12.012

Cited by 36 publications

(11 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A C C E P T E D M A N U S C R I P T REE concentrations, particularly Ce (e.g., Frimmel, 2009), have been cited as sensitive indicators of palaeoredox conditions (Liu et al, 1988;German and Elderfield, 1990; however see doubts raised by Lev and Filer, 2004).…”

Section: Rare Earth Elements (Ree)mentioning

confidence: 99%

Influence of palaeoweathering on trace metal concentrations and environmental proxies in black shales

Marynowski

Pisarzowska

Derkowski

et al. 2017

Palaeogeography, Palaeoclimatology, Palaeoecology

View full text Add to dashboard Cite

show abstract

Section: Rare Earth Elements (Ree)mentioning

confidence: 99%

Influence of palaeoweathering on trace metal concentrations and environmental proxies in black shales

Marynowski

Pisarzowska

Derkowski

et al. 2017

Palaeogeography, Palaeoclimatology, Palaeoecology

View full text Add to dashboard Cite

show abstract

“…Minor enrichment of MREE observed in samples from the chlorite and biotite zones, relative to PAAS (Fig. 5a), may reflect mobility of these elements during low-grade metamorphism and/or earlier diagenesis (e.g., Lev and Filer 2004).…”

Section: Deposition and Diagenesismentioning

confidence: 99%

Regional geochemical variations in a metamorphosed black shale: a reconnaissance study of the Silurian Smalls Falls Formation, Maine, USA

Slack

Baalen

Reusch

2020

atgeol

View full text Add to dashboard Cite

A reconnaissance geochemical study of 21 samples of sulphidic black phyllite and schist from the Silurian Smalls Falls Formation in Maine was undertaken in order to evaluate compositional changes during regional metamorphism. These samples represent variably metamorphosed black shale. Analyzed samples come from the chlorite zone in northern Maine and the biotite, garnet, and staurolite-andalusite zones in west-central Maine. Strata of the Smalls Falls Formation are distinctive in containing abundant pyrite and/or pyrrhotite (total S = 1.2–9.7 wt%), but only minor organic matter or graphite (TOC = 0.43–1.85 wt%); TOC/S ratios are uniformly low (average = 0.37 ± 0.22). Median enrichment factors were calculated for each element by normalizing the concentration to Ti in each sample to the Ti-normalized median composition of global black shale. In the chlorite zone, moderate to large decreases in enrichment factors (-23.1 to -49.8%) are evident for V, Cr, Cu, Ni, Zn, Pb, Sb, and U, attributed here to various factors during sedimentation plus variable element mobility during diagenesis. With increasing metamorphic grade (biotite through staurolite-andalusite zones), systematic small to extreme decreases (-14.5 to -99.0%) were found for Ba, Sb, Au, and U, together with less-systematic moderate to large decreases (-35.4 to -61.1%) for V and As. Molybdenum shows an extreme decrease (-94.7%) from the garnet to staurolite-andalusite zones. Excluding Ba, these results are interpreted to mainly reflect mobility of trace elements during pyrite recrystallization, and during the metamorphic transformations of organic matter to graphite and of pyrite to pyrrhotite. Moderate to large increases for Rb (+28.1 to +61.5%) and Th (+39.1 to +47.3%) from the biotite to staurolite-andalusite zones likely record the introduction of alkalis and mass loss, respectively, during metamorphism. Three samples from one site in the garnet zone differ in having anomalously high Fe/Al and low La/Yb ratios, attributed here to epigenetic formation of pyrite and related leaching of light rare earth elements during syn-metamorphic, channelized fluid flow.Geologic and geochemical data indicate that strata of the Smalls Falls Formation were deposited during an interval of anoxia on the northwestern flank of the Central Maine Basin, for which detrital sources included an evolved continental arc. Onset of anoxia coincided with deposition of the Mayflower Hill Formation of the Vassalboro Group, on the basin’s southeastern flank, related to emergence of the Brunswick subduction complex. We suggest that this emergence played a role in promoting both lateral and vertical circulation changes, nutrient loading, and deoxygenation through subsequent basin closure that culminated with Acadian deformation and metamorphism. Based on the relatively high contents of total sulphur present in our Smalls Falls samples, sediments in the Black Sea represent the only known plausible candidate among those in modern suboxic to euxinic basins.

show abstract

“…The maximum uranium concentration in those shales reaches 320 lg/g. Uranium in Devonian shale in the Appalachian Basin of the eastern USA, in the Parkhouse marine shale from the Late Carboniferous in the UK and in the Timahdit black shale in Morocco are all abundant, with concentrations of 2-36 lg/g, >8 lg/g and 41 lg/g, respectively (Lev and Filer, 2004;Lev et al, 2008;Fisher, 2001;Galindo et al, 2007). In China, the best-known uranium-rich strata are Lower Silurian and Lower Cambrian black shales that occur in the Yangtze Platform with a uranium concentration >10 lg/g.…”

Section: Introductionmentioning

confidence: 98%

Uranium enrichment in lacustrine oil source rocks of the Chang 7 member of the Yanchang Formation, Erdos Basin, China

Hua¹,

Zhang

et al. 2010

Journal of Asian Earth Sciences

View full text Add to dashboard Cite

Assessing the impact of black shale processes on REE and the U–Pb isotope system in the southern Appalachian Basin

Cited by 36 publications

References 18 publications

Influence of palaeoweathering on trace metal concentrations and environmental proxies in black shales

Influence of palaeoweathering on trace metal concentrations and environmental proxies in black shales

Regional geochemical variations in a metamorphosed black shale: a reconnaissance study of the Silurian Smalls Falls Formation, Maine, USA

Uranium enrichment in lacustrine oil source rocks of the Chang 7 member of the Yanchang Formation, Erdos Basin, China

Contact Info

Product

Resources

About