EGU25-18755, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-18755
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Using Airborne Electromagnetic Data to Map Conductive Anomalies in the Karasjok Greenstone Belt Region
Shunguo Wang1,2, Trond Slagstad1, and Vikas Chand Baranwal1
Shunguo Wang et al.
  • 1The Geological Survey of Norway, Trondheim, Norway (shunguo.wang@ngu.no)
  • 2Norwegian University of Science and Technology, Trondheim, Norway (shunguo.wang@ntnu.no)

The Karasjok Greenstone Belt (KGB), located in northern Norway, is a key Archean-Proterozoic geological feature that shows the tectonic and magmatic processes of the Fennoscandian Shield. This elongated, northeast-southwest trending belt consists predominantly of metavolcanic and metasedimentary rocks, including mafic and ultramafic volcanics, banded iron formations, and sedimentary schists. The KGB records complex geological histories, including episodes of subduction, rifting, and metamorphism, primarily during the Paleoproterozoic era. Geochemical studies reveal that the belt's volcanic rocks are of both arc and rift-related origin, reflecting dynamic lithospheric processes during its formation.

The belt hosts significant mineral deposits, including gold, base metals, and rare earth elements, making it an important target for mineral exploration. The integration of geological and geophysical data continues to refine our understanding of the Karasjok Greenstone Belt’s evolution, its role in the assembly of the Fennoscandian Shield, and its broader implications for Precambrian tectonics. This study presents geophysical findings derived from four-frequency (0.9 kHz, 3 kHz, 12 kHz, and 25 kHz) airborne electromagnetic data (AEM05) acquired by the Geological Survey of Finland in 2009. One-dimensional (1D) inversion was carried out by using P223, a publicly available code. The inverted 1D resistivity models along a few selected flight lines in the KGB region reveal conductive anomalies sandwiched between the surface layer and the basement. These conductive anomalies correspond closely with those identified in apparent resistivity images derived from individual frequencies which corresponds to different depths. Moving forward, detailed lithological models will be integrated to refine and enhance the accuracy of the 1D resistivity inversions and all 1D inverse models will be visualized in three-dimensional (3D), providing deeper insights into the region's subsurface structure. We will also make attempts to invert the data in 3D.

How to cite: Wang, S., Slagstad, T., and Baranwal, V. C.: Using Airborne Electromagnetic Data to Map Conductive Anomalies in the Karasjok Greenstone Belt Region, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18755, https://doi.org/10.5194/egusphere-egu25-18755, 2025.