Gold in Irish Coal: Palaeo-Concentration from Metalliferous Groundwaters

Gold in Irish Coal: Palaeo-Concentration from Metalliferous Groundwaters

Gold grains, up to 40 μm in size and containing variable percentages of admixed platinum, have been identified in coals from the Leinster Coalfield, Castlecomer, SE Ireland, for the first time. Gold mineralisation occurs in sideritic nodules in coals and in association with pyrite and anomalous sele...

Full description

Saved in:
Bibliographic Details
Published in:Minerals (Basel) 2020-07, Vol.10 (7), p.635
Main Authors: Bullock, Liam A., Parnell, John, Armstrong, Joseph G.T., Perez, Magali, Spinks, Sam
Format: Article
Language:eng
Subjects:
Bedrock
Coal
Coal mining
Cores
Creeks & streams
Gold
groundwater
Heat flow
Heat transmission
Heavy metals
Interfaces
Low temperature
Mass spectrometry
Metal concentrations
Metals
Mineralization
Minerals
Nodules
Orogeny
Oxidoreductions
Platinum
Pyrite
Scanning electron microscopy
Scientific imaging
Sediments
Selenium
Siderite
Soil erosion
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Gold grains, up to 40 μm in size and containing variable percentages of admixed platinum, have been identified in coals from the Leinster Coalfield, Castlecomer, SE Ireland, for the first time. Gold mineralisation occurs in sideritic nodules in coals and in association with pyrite and anomalous selenium content. Mineralisation here may have reflected very high heat flow in foreland basins north of the emerging Variscan orogenic front, responsible for gold occurrence in the South Wales Coalfield. At Castlecomer, gold (–platinum) is attributed to precipitation with replacive pyrite and selenium from groundwaters at redox interfaces, such as siderite nodules. Pyrite in the cores of the nodules indicates fluid ingress. The underlying Caledonian basement bedrock is mineralised by gold, and thus likely provided a source for gold. The combination of the gold occurrences in coal in Castlecomer and in South Wales, proximal to the Variscan orogenic front, suggests that these coals along the front could comprise an exploration target for low-temperature concentrations of precious metals.
ISSN:2075-163X
2075-163X