A demonstration of an affinity between pyrite and organic matter in a hydrothermal setting
1 Department of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK
2 Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB24 3UE, UK
3 Department of Geological Sciences, Stockholm University, 106 91 Stockholm, Sweden
Geochemical Transactions 2011, 12:3 doi:10.1186/1467-4866-12-3Published: 7 February 2011
One of the key-principles of the iron-sulphur world theory is to bring organic molecules close enough to interact with each other, using the surface of pyrite as a substrate in a hydrothermal setting. The present paper explores the relationship of pyrite and organic matter in a hydrothermal setting from the geological record; in hydrothermal calcite veins from Carboniferous limestones in central Ireland. Here, the organic matter is accumulated as coatings around, and through, pyrite grains. Most of the pyrite grains are euhedral-subhedral crystals, ranging in size from ca 0.1-0.5 mm in diameter, and they are scattered throughout the matrix of the vein calcite. The organic matter was deposited from a hydrothermal fluid at a temperature of at least 200°C, and gives a Raman signature of disordered carbon. This study points to an example from a hydrothermal setting in the geological record, demonstrating that pyrite can have a high potential for the concentration and accumulation of organic materials.