Dairi: An Example of Zn-Pb-Ag Sediment-hosted Deposit from Indonesia

Rivai, T. A., Yonezu, K., Tindell, T., Imai, A., Watanabe, K., Syafrizal, and Boyce, A. J. (2019) Dairi: An Example of Zn-Pb-Ag Sediment-hosted Deposit from Indonesia. In: 15th SGA Biennial Meeting on Life with Ore Deposits on Earth, Glasgow, Scotland, 27-30 Aug 2019, pp. 32-35. ISBN 9780852619629

Abstract

The Dairi Zn-Pb-Ag deposit is the first SEDEX deposit discovered in Indonesia thus understanding its genesis is key to future SEDEX exploration in Sumatra. Orebodies are hosted in Lower Carboniferous black shales-siltstones (stratiform orebodies) and dolostones (discordant orebodies) representing sag-phase sequence in the Dairi basin. The discordant orebodies are lower in stratigraphy and are conceptually understood as feeder zones to the overlying stratiform orebodies. The reduced and acid ore-forming fluid was moderately saline and warm (18-25 wt% NaCl eq., similar to 170 degrees C) before being diluted by seawater (3 wt% NaCl eq., similar to 3 degrees C). A geochemical halo around the stratiform orebodies is accompanied by ankerite and hyalophane. Reduced sulfur in the discordant orebodies is dominated by hydrothermal S isotope signature, whilst there is evidence of bacteriogenic sulfide in the stratiform orebodies.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Boyce, Professor Adrian
• Authors: Rivai, T. A., Yonezu, K., Tindell, T., Imai, A., Watanabe, K., Syafrizal, , and Boyce, A. J.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• ISBN: 9780852619629