posted on 2018-05-16, 16:26authored byD. J. Smith, J. Naden, A.-J. Miles, H. Bennett, S. H. Bicknell
Mass wasting and landform modifying events have a profound impact on hydrothermal processes in terrestrial environments. Mass wasting events in submarine settings also modify hydrothermal systems and their associated mineralisation. We present evidence of a dynamic environment impacting on ore formation at the historically exploited Pb-Zn-(Ag) mineralisation of Triades, Milos island (Greece), formed in a submarine setting. Galena-sphalerite veins and barite-quartz gangue precipitated in the near subsurface or after exhalation of boiling hydrothermal fluids. Field evidence indicates that mineralisation was extensively reworked by debris flow events during formation. The mineral paragenetic sequence is consistent with a Pb-Zn-(Ag) massive sulphide system, and analogous to the early stages of a Kuroko-type deposit, but Triades lacks massive sulphide bodies. We suggest that mass wasting events literally truncated the developing mineral deposit as it formed on the seafloor, destroying massive sulphide bodies and limiting the development of the ore mineral assemblages. Mass wasting processes in volcanogenic massive sulphide systems are ore-destructive, with little opportunity for “telescoping”, unlike terrestrial equivalents. Shallow marine systems in terrains subject to mass wasting may have low preservation potential, or may be classified as epithermal-like vein systems rather than stockwork portions of massive sulphide deposits.
Funding
This work was supported by the Natural Environment Research Council (UK) grants
NE/M010848/1, NE/N019040/1, the NERC GW4+ Doctoral Training Partnership, and the
British Geological Survey’s University Funding Initiative (BUFI). A-JPM is supported by a
NERC DTP studentship (NE/L002434/1) and the BGS University funding initiative (BUFI
S345). JN publishes with the permission of the Executive Director, The British Geological
Survey (NERC).;This work was supported by the Natural Environment Research Council (UK) grants NE/M010848/1, NE/N019040/1, the NERCGW4 + Doctoral Training Partnership, and the British Geological Survey’s University Funding Initiative (BUFI). A-JPM is supported by a NERC DTP studentship (NE/L002434/1) and the BGS University funding initiative (BUFI S345). JN publishes with the permission of the Executive Director, The British Geological Survey (NERC).
History
Citation
Ore Geology Reviews, 2018, 97, pp. 143-151
Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/School of Geography, Geology and the Environment