1887

Abstract

Summary

An integrated geophysical and geological study was conducted across the Nissedal Complex, Telemark, Norway, to better characterize its subsurface architecture. The investigation combined high-resolution airborne magnetic and radiometric surveys, ground gravity measurements, and petrophysical analyses of 717 samples. Airborne magnetic RTP and derivative maps reveal fault/shear zones, and a prominent oval anomaly associated with the high-density metagabbroic core. Radiometric ratio maps distinguish granitic gneiss units, aiding the delineation of the Tørdal and Treungen granites. Gravity data highlight a broad anomaly over the metagabbro and lows over felsic lithologies. Three 2D forward models, constrained by petrophysical parameters, show the metagabbro dipping southward to approximately 3 km below MSL beneath the Tørdal granite and reveal internal heterogeneity requiring felsic lenses. Three-dimensional inversions using VOXI Earth Modelling™ resolve discrete high-susceptibility rhyolitic bodies and a deep-seated high-density core extending to 6 km below MSL. The combined 2D and 3D approach refines the geometry of lithological units, structural trends, and magmatic bodies within the Nissedal Complex, providing a robust basis for updating bedrock maps and identifying areas where additional high-resolution gravity surveys would further constrain deep structures.

© EAGE Publications BV
Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.202520200
2025-09-07
2026-02-07

  • From This Site

    /content/papers/10.3997/2214-4609.202520200
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Baranov, V. and Naudy, H. [1957] Theory of reduction to pole of magnetic anomalies. Geophysics, 22, 223–244.
     [Google Scholar]
  2. Baranwal, V.C., Rodionov, A. and Ofstad, F. [2012] Helicopter-borne magnetic and radiometric geophysical survey in Kviteseid area, Telemark, Norway. NGU Report 2012.043.
     [Google Scholar]
  3. Gellein, J., Olesen, O. and Mathisen, A. [1993] The national gravity database at NGU. Norsk Geologisk Tidsskrift, 73, 123–130.
     [Google Scholar]
  4. Mogaard, J.O. [2006] Data Acquisition and Processing – Helicopter Geophysical Survey, Bamble, Ertelien and Sigdal, 2005. NGU Report 2006.021.
     [Google Scholar]
  5. Olesen, O., Gellein, J. and Mathisen, A. [2010] NGU Petrophysical Database: Methods and Applications. NGU Report 2010.045.
     [Google Scholar]
  6. Ofstad, F. and Tassis, G. [2021] Helicopter-borne magnetic and radiometric geophysical survey in Treungen and Vegårshei area, Agder, and Vestfold og Telemark counties. NGU Report 2021.007.
     [Google Scholar]
  7. Stampolidis, A., Ofstad, F. and Baranwal, V.C. [2014] Helicopter-borne magnetic and radiometric geophysical survey in the Kviteseid-Notodden-Ulefoss area, Telemark County. NGU Report 2013.049.
     [Google Scholar]
  8. Stampolidis, A. and Ofstad, F. [2015] Helicopter-borne magnetic and radiometric geophysical survey at Drangedal, Telemark County. NGU Report 2014.044.
     [Google Scholar]
  9. Svendby, A.K., Gunleiksrud, I., Torgersen, E., Bingen, B., Henderson, I.H.C., Nasuti, A., and BaranwalV.C., [2022] Foreløpig berggrunnskart Drangedal og Nissedal M 1: 75 000. Bedrock map Drangedal and Nissedal 1: 75 000. Norges geologiske undersøkelse.
     [Google Scholar]
/content/papers/10.3997/2214-4609.202520200
Loading
2D and 3D Geophysical and Geological Modelling of Nissedal Complex, Telemark, South Norway
Conference Proceedings 2025, 1 (2025); https://doi.org/10.3997/2214-4609.202520200
/content/papers/10.3997/2214-4609.202520200
/content/papers/10.3997/2214-4609.202520200
Loading

Data & Media loading...

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error