TY - JOUR
T1 - Liberation of Selenium from Alteration of the Bowland Shale Formation
T2 - Evidence from the Mam Tor Landslide
AU - Parnell, John
AU - Bullock, Liam
AU - Armstrong, Joseph
AU - Perez, Magali
N1 - This work was supported by the NERC under Grant NE/M010953/1. We are grateful to the UK Coal Authority for provision of analytical data for ochres. The manuscript was much improved by careful review and editing.
PY - 2018/11
Y1 - 2018/11
N2 - Abstract: The Bowland Shale Formation is anomalously rich in selenium (Se) at levels an order of magnitude greater than other black shales. The Mam Tor landslide, Derbyshire, England, offers an opportunity to measure whether the Se anomaly is conferred to the alteration products formed by oxidative water flow through the shale. Selenium in the shale is concentrated in diagenetic pyrite. Alteration of the shale causes decomposition of the pyrite to iron oxyhydroxide, which is carried in colloidal form (ochre) by springs draining the landslide. The iron oxyhydroxide contains anomalously high Se, and anomalously high Se was measured in water ponded where the ochre precipitated, although not in flowing groundwater. Other trace elements including cadmium and thallium also occur at concentrations higher than in other ochres. Given the widespread nature of the Se anomaly in the Bowland Shale Formation and equivalents across Britain and Ireland, any alteration products derived from workings through the shale should be disposed of with care.
AB - Abstract: The Bowland Shale Formation is anomalously rich in selenium (Se) at levels an order of magnitude greater than other black shales. The Mam Tor landslide, Derbyshire, England, offers an opportunity to measure whether the Se anomaly is conferred to the alteration products formed by oxidative water flow through the shale. Selenium in the shale is concentrated in diagenetic pyrite. Alteration of the shale causes decomposition of the pyrite to iron oxyhydroxide, which is carried in colloidal form (ochre) by springs draining the landslide. The iron oxyhydroxide contains anomalously high Se, and anomalously high Se was measured in water ponded where the ochre precipitated, although not in flowing groundwater. Other trace elements including cadmium and thallium also occur at concentrations higher than in other ochres. Given the widespread nature of the Se anomaly in the Bowland Shale Formation and equivalents across Britain and Ireland, any alteration products derived from workings through the shale should be disposed of with care.
U2 - 10.1144/qjegh2018-026
DO - 10.1144/qjegh2018-026
M3 - Article
SN - 1470-9236
VL - 51
SP - 503
EP - 508
JO - Quarterly Journal of Engineering Geology and Hydrogeology
JF - Quarterly Journal of Engineering Geology and Hydrogeology
IS - 4
ER -