TY - JOUR
T1 - Variscan cycling of gold into a global coal reservoir
AU - Parnell, John
N1 - Funding Information:
This project is in support of the NERC SoS (Security of Supply of Critical Elements) programme, under Grant NE/M010953/1 . J. Johnston and J. Bowie provided skilled technical help. The manuscript benefitted from incisive reviews by N. Moles, Y. Wu, Carmine, and an anonymous reviewer, whose advice is much appreciated.
Funding Information:
This project is in support of the NERC SoS (Security of Supply of Critical Elements) programme, under Grant NE/M010953/1. J. Johnston and J. Bowie provided skilled technical help. The manuscript benefitted from incisive reviews by N. Moles, Y. Wu, Carmine, and an anonymous reviewer, whose advice is much appreciated.
PY - 2019/11
Y1 - 2019/11
N2 - The potential of coal and coal ash as a source of strategically and/or commercially valuable trace elements, including gold, is reflected in numerous analytical studies, reports to government, patents for new technology and the first commercial extraction facilities. It is shown here that there was a particular predisposition to the concentration of gold in the Upper Carboniferous (313–304 Ma) Carboniferous coals that dominate coal supplies in the northern hemisphere. Coal was deposited in foreland and other basins adjacent to the actively colliding Variscan-Alleghanian Orogen, while the orogenic belt was mineralized by gold ore from 410 to 310 Ma over 10,000 km from the Appalachians to China. High gold fertility in the orogenic belt, the additional concentration of gold along shear zones during transpression, and either rapid erosion (>1 km/Myr) of the orogenic belt into adjacent basins or hydrothermal mineralization of the basins, made the coals a trap for the consequent flux of gold. This cycling of gold is evidenced by enriched coal and gold palaeoplacers in coal-bearing sequences in numerous basins along the orogen. Provenance data, especially detrital zircon ages of 350–300 Ma, help to identify successions that were sourced from gold-rich terrains, and thus can focus the search for anomalously enriched coal.
AB - The potential of coal and coal ash as a source of strategically and/or commercially valuable trace elements, including gold, is reflected in numerous analytical studies, reports to government, patents for new technology and the first commercial extraction facilities. It is shown here that there was a particular predisposition to the concentration of gold in the Upper Carboniferous (313–304 Ma) Carboniferous coals that dominate coal supplies in the northern hemisphere. Coal was deposited in foreland and other basins adjacent to the actively colliding Variscan-Alleghanian Orogen, while the orogenic belt was mineralized by gold ore from 410 to 310 Ma over 10,000 km from the Appalachians to China. High gold fertility in the orogenic belt, the additional concentration of gold along shear zones during transpression, and either rapid erosion (>1 km/Myr) of the orogenic belt into adjacent basins or hydrothermal mineralization of the basins, made the coals a trap for the consequent flux of gold. This cycling of gold is evidenced by enriched coal and gold palaeoplacers in coal-bearing sequences in numerous basins along the orogen. Provenance data, especially detrital zircon ages of 350–300 Ma, help to identify successions that were sourced from gold-rich terrains, and thus can focus the search for anomalously enriched coal.
KW - Coal
KW - Gold
KW - Provenance
KW - Selenium
KW - Variscides
UR - http://www.scopus.com/inward/record.url?scp=85073029099&partnerID=8YFLogxK
U2 - 10.1016/j.oregeorev.2019.103158
DO - 10.1016/j.oregeorev.2019.103158
M3 - Article
AN - SCOPUS:85073029099
VL - 114
JO - Ore Geology Reviews
JF - Ore Geology Reviews
SN - 0169-1368
M1 - 103158
ER -