Three-Dimensional Geologic Modeling of the Kiruna Mining District, Sweden: Insights into the Crustal Architecture and Structural Controls on Iron Oxide-Apatite Mineralization Show others and affiliations
2024 (English) In: Economic geology and the bulletin of the Society of Economic Geologists, ISSN 0361-0128, E-ISSN 1554-0774, Vol. 119, no 5, p. 1089-1113Article in journal (Refereed) Published
Abstract [en]
To support economic decisions and exploration targeting, as well as to understand processes controlling the mineralization, three-dimensional structural and lithological boundary models of the Kiruna mining district have been built using surface (outcrop observations and measurements) and subsurface (drill hole data and mine wall mapping) data. Rule-based hybrid implicit-explicit modeling techniques were used to create district-scale models of areas with high disproportion in data resolution characterized by dense, clustered, and distant data spacing. Densely sampled areas were integrated with established conceptual studies using geologic conditions and the addition of synthetic data, leading to variably constrained surfaces that facilitate the visualization, interpretation, and further integration of the geologic models. This modeling approach proved to be efficient in integrating local, frequently sampled areas with district-scale, sparsely sampled regions. Dominantly S-plunging lineation on N-S–trending fracture planes, characteristic fracture mineral fill, and weak rock mass at the ore contact indicated by poor core orientation quality and rock quality description suggest that ore-parallel fractures in the Kiirunavaara area were more commonly reactivated. Slight variation in the angular relationship of fracture sets situated in different fault-bounded blocks suggests that strain accommodation across the orebodies was uneven. The location of brittle faults identified in drill core, deposit-scale structural analysis, and aeromagnetic geophysical maps indicate a close relationship between fault locations and the iron oxide-apatite mineralization, suggesting that uneven stress accommodation and proximity of conjugate fault sets played an important role in juxtaposing blocks from different crustal depths and control the location of the iron oxide-apatite orebodies.
Place, publisher, year, edition, pages Society of Economic Geologists , 2024. Vol. 119, no 5, p. 1089-1113
National Category
Geology
Research subject Ore Geology
Identifiers URN: urn:nbn:se:ltu:diva-109757 DOI: 10.5382/econgeo.5080 ISI: 001308885800002 Scopus ID: 2-s2.0-85201868842 OAI: oai:DiVA.org:ltu-109757 DiVA, id: diva2:1895620
Note Validerad;2024;Nivå 2;2024-09-06 (joosat);
Full text: CC-BY-NC license;
Funder: Luossavaara Kiirunavaara AB (LKAB)
2024-09-062024-09-062024-11-20 Bibliographically approved