Post on 26-Jul-2020
Mineral Systems and Mineral Prospectivity in Finnish Lapland
Ferenc Molnár Geological Survey of Finland
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Eero Hanski University of Oulu
MINSYSPRO 01.9.2014 – 31.08.2018
Subjects of Presentation
• Background of the project: aims and objectives
• The mineral system approach and mineral prospectivity mapping
• The MINSYSPRO consortium: research teams, international cooperation, research methods
• Mineral systems in Finnish Lapland - targets - current results
Native gold Pyrrhotite-pentlandite-chalcopyrite ore , Sakatti
Rompas
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Aims and Objectives of the Project
To support sustainable growth of mining industry in Finnish Lapland by development of a knowledge-based, environmentally friendly and cost effective exploration method which is capable of predicting mineral resources under cover.
To gather new knowledge of critical processes of ore formation in orogenic gold and magmatic sulphide/oxide mineral systems in Finnish Lapland by application of modern, cutting edge research methods. Development methods of computer-based conceptual and empirical mineral prospectivity mapping by using results of research on mineral systems.
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Vectors to ore
Conditions of primary and secondary enrichment
or dispersion of metals
Mineral Systems: Critical Processes and Parameters
Parameters
Structural control
Geodynamic setting
Relative and absolute timing of processes
Processes
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Selection of the relevant data based on the exploration model
or mineral system model
Spatial analysis
Validation, targeting
Mineral Prospectivity Mapping
Input pattern generation
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
The Current Status of the Orogenic Gold Mineral Prospectivity Map in the Central Lapland Greenstone Belt
Research on Magmatic and Hydrothermal Mineral Systems: Outstanding Questions
Sources of ore forming metals and transporting agents: - melts: mantle, crust, contamination - fluids: magmatic, metamorphic, basin fluids Multiple or single mineralization events: - different stages in one system or superimposition of independent systems? Footprints of magmatic and hydrothermal processes leading to accumulation of precious-, base- and critical metals: - which parameters are the best for vectoring towards ore? Effects of post-mineralization events on composition and grade of ore: - dispersion or concentration?
How we can transfer signatures of critical processes into 2D-3D geological models?
How the evaluation of mineral potential in Lapland is affected by incorporation of new knowledge and data into prospectivity mapping methods?
Major area of research in Finland
MISU Opening seminar, 21 April 2016, Helsinki MINSYSPRO Project
Orogenic Gold Mineral systems Ferenc Molnár Hugh O`Brien Peter Sorjonen-Ward Sayeb Muhammad Postdoctoral researchers: Alexander Middleton from 01.01.2015 to 05.02.2016 Matti Kurhila from 01.05.2016 to 30.01.2017
Antonin Richard Univ. Lorraine
Iain Pitcairn Univ. Stockholm
Harry Oduro Gareth Izon Univ. St. Andrews
Holly Stein Univ. Oslo Univ. Colorado
Jussi-Petteri Suuronen The European Synchro- tron Radiation Facility
Mineral Prospectivity Mapping Vesa Nykänen Satu Mertanen Tero Niiranen Eeva-Lisa Laine Ilkka Lahti Jouni Lerssi Postdoctoral researcher: T.B.N. from 01.08.2016 to 30.08.2018
Magmatic Mineral Systems Eero Hanski Shenghong Yang Markku Pirttijärvi Hannu Huhma Tuomo Karinen Tuomo Törmänen Yann Lahaye PhD students: Jukka Konnunaho Marko Moilanen Kirsi Luolavirta Fangfang Guo
Wolfgang Maier Univ. Cardiff
Richard Walker Igor Puchtel Univ. Maryland
Wenjun Qu Xiaoping Xia Chinese Acad. Sci.
Sergei Svetov Artem Mokrushin Paul Priprachkin Russian Acad. Sci.
Industry partners Agnico-Eagle Finland Oy. Dragon Mining Oy. Mawson Reosurces Oy. First Quantum Oy. Anglo-American Plc.
Research Consortium
MISU Opening seminar, 21 April 2016, Helsinki MINSYSPRO Project
Workflow of the Project and Tasks for the Research Teams
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Nu AttoM HR-ICP-MS with laser microprobe
Nu Plasma MC-ICP-MS with laser microprobe
JEOL JSM 7100F high resolution
FE-SEM
Mineralogy Geochronology, stable and radiogenic isotopes, trace elements Linkam MDSG 600 microT
Fluid inclusions
Cutting Edge Analytical Methods Applied to the Mineral System Research
• In situ analyses of individual minerals with high spatial resolution (micrometer scale) • Multiple stable and radiogenic isotope, trace element and fluid inclusion analyses from the same sample and even from the same mineral grain. • Research on the applicability of unconvetional stable and radiogenic isotope systems in better understandig ore- forming processes.
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Tragets of Research – Magmatic Mineral Systems
Layered mafic intrusions with Cr, Fe-Ti-V and Ni-Cu-PGE deposits
Komatiites with Ni-Cu-PGE deposits
Kolari-Kittilä- Sodankylä belt
Kuusamo belt Peräpohja belt Kuusamo belt
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Os-isotope Constraints on the Sources of Ore-producing Melts: 2.44 Ga Paleoproterozoic Layered Complexes
Os-isotope systematics in chromitite
The fertile magmas suffered crustal contamination, but were derived from mantle plume
and not from the subcontinental lithospheric mantle.
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Deposition Mechanism of PGE-rich Magmatic Sulfide Ore in Komatiite: Os-isotopic Evidence of Crustal Contamination
Lomalampi, komatiite hosted PGE-rich Ni-Cu deposit
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
38%
~20 % ~23 %
~6 % ~3 %
Average Ni content
(wt.%) in magnetite
Vectoring Towards High Grade Magmatic Ni-ore in Komatiites: Ni-content in Magnetite
Magmatic Ni-deposits in komatiites of Finland
Low grade Ni-ore and unmineralized
komatiites
High grade Ni-ore
Hydrothermal base-metal deposits
Magmatic Fe(-Ti-V) deposits
Magmatic Ni-Cu deposits in layered
complexes
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Tragets of Research – Orogenic Gold Mineral Systems
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Sources of Fluids in Gold Deposits, Central Lapland Greenstone Belt: In situ Sulphur Isotope Analyses by LA ICPMS
Iso-Kuotko
Suurikuusikko
Levijärvi-Luokinen
Suurikuusiikko – Kittilä Mine Pyrite δ34S ‰
1.8 2.1
3.1 2.3
3.0
Similarity of sulphur isotope data for different deposits and minerals
suggests to common regional (metamorphic) source of fluids.
Subtle core-rim variation in S-isotope compositions indicates repeated
fluid flow events.
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Xenotime
Monazite
Xenotime
Xenotime
aspy
nat. Bi
nat. Au
po
Geochronology: Identification of Repeated Hydrothermal Events Along the Same Regional Structure: U-Pb Dating of Hydrothermal
Xenotime and Monazite
Iso-Kuotko Au-deposit
In situ LA ICPMS analyses with high spatial resolution
Xenotime
Stage 1: 1854-1862 Ma Stage 2: 1757-1768 Ma
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
3D Geological Models: Recognition of Structural and Lithological Controls of Ore Deposition
Mafic volcanic rocks
Komatiite
Phyllite
Tholeiitic lava flows
Shear zones Saattopora Au(-Cu-Co) deposit
Location of one of the orebodies is controlled by a shear zone. The other orebody is located along a lithological contact bet- ween komatiite and phyllite.
po
cpy
cob
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
Simplified geological model
Typical texture of ore
3D model showing relationships between location of orebodies and structural/lithological features
3D distribution of auriferrous arsenopyrite
and pyrite in the host rock.
X-ray computed microtomography.
3D distribution of gold grains and mineral inclusions in arsenopyrite.
Synchrotron radiation based nanotomography.
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project
3D Micro- and Nanoscale Analysis of the Structural Control on Distribution of Ore Minerals
Suurikuusikko gold deposit
MinSysPro Project - Summary
• Systematic and multidiciplinary research based on the holistic mineral system approach. • Filling up gaps of knowledge of geological processes which led to the economically importand precious-, base- and critical metal mineral resources in Finnish Lapland. • Development of new mineral system models and mineral prospectivity mapping methods for better evaluation of targets for mineral exploration
Publications , up to Q1 2016 4 papers in peer-reviewed international scientific journals 11 presentations on international conferences 4 book chapters
MISU Seminar, 21 April 2016, Helsinki MINSYSPRO Project