Abstract
A comparison between the two very important sulfide belts Raahe-Ladoga Ore
Zone
(RLZ) in Finland and Southern Edge of Altay (SEA) in China, including geological
setting, metallogenic characters and geochemical exploration has been made.
The two sulfide belts share similarities but differ from each other in the
tectonic setting and metallogenic epoch. Polymetallic ores in RLZ and SEA are
the products of the submarine volcanism, but mainly Zn-Cu type is present in RLZ
and Pb-Zn, Cu-Pb-Zn and Cu-Zn types occur in SEA. A main Ni-Cu ore belt related
to the mafic-ultramafic intrusions is also present in the RLZ. RLZ is
metamorphosed to a higher grade than SEA.
The Viholanniemi Zn-Au deposit is a veinlet-disseminated type, possibly
beneath
the stratabound sulphide ores, and the Keketale Pb-Zn deposit is a stratabound
sulphide ore hosted by sedimentary rocks in the volcano-sedimentary formation.
They show many differences. It is suggested that stratabound sulphide ores
overlie stratigraphically the Viholanniemi stringer ores and Au-bearing
stringers underlie the Keketale stratabound ores. Geochemical explorations of
the two deposits exhibit different methods, subjects and procedures. Boulder
tracing and till geochemical exploration proved to be very effective in finding
the Viholanniemi deposit while stream sediment and soil geochemical surveys were
the major and effective tools in finding the Keketale deposit.
An extensional environment and the intensity of volcanism are the essential
conditions for the formation of polymetallic ores related to the volcanism. It
is feasible to classify the ores into the ores hosted by volcanics and
sedimentary rocks in a volcano-sedimentary formation. The stratigraphical
thickness of volcanic rocks and the amount of agglomerates are the two most
crucial factors needed to be considered in prospecting. The chemical variations
of the host rocks can indicate the sulphide ores hosted by sedimentary rocks in
some circumstances.
| Identifer | oai:union.ndltd.org:oulo.fi/oai:oulu.fi:isbn951-42-5787-1 |
| Date | 20 November 2000 |
| Creators | Zhang, X. (Xiping) |
| Publisher | University of Oulu |
| Source Sets | University of Oulu |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess, © University of Oulu, 2000 |
| Relation | info:eu-repo/semantics/altIdentifier/pissn/0355-3191, info:eu-repo/semantics/altIdentifier/eissn/1796-220X |
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