The Luusika potential field anomaly, eastern Estonia: modelling results
This study considers the anomalous gravity and magnetic fields in the Alutaguse petrological–structural domain, eastern Estonia. A 10 km wide local maximum (+6.26 mGal) Bouguer anomaly field was discovered at 58.96°N, 26.61°E from the ground gravity data by the Estonian Land Board in 2010–2011. The...
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| Format: | Article |
| Language: | English |
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Estonian Academy Publishers
2018-11-01
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| Series: | Estonian Journal of Earth Sciences |
| Subjects: | |
| Online Access: | http://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2018/issue_4/earth-2018-4-228-237.pdf |
| _version_ | 1818325473620393984 |
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| author | Marija Dmitrijeva Jüri Plado Tõnis Oja |
| author_facet | Marija Dmitrijeva Jüri Plado Tõnis Oja |
| author_sort | Marija Dmitrijeva |
| collection | DOAJ |
| description | This study considers the anomalous gravity and magnetic fields in the Alutaguse petrological–structural domain, eastern Estonia. A 10 km wide local maximum (+6.26 mGal) Bouguer anomaly field was discovered at 58.96°N, 26.61°E from the ground gravity data by the Estonian Land Board in 2010–2011. The ground magnetic field intensity measurements indicated a positive magnetic anomaly of 600 nT, in addition to the local gravity maximum. Based on depth estimations, the centre of the anomaly source is placed at 2500–3000 m within the ~1.8 to 1.9 Ga Svecofennian basement. To provide information on the physical properties of the causative source of the anomalies, the geophysical modelling of potential fields was carried out by testing a number of lithologies as sources. The lithologies considered were the known post-orogenic and anorogenic magmatic intrusions in the Estonian basement, as well as typical metamorphic rocks of the Alutaguse domain. The obtained models indicate that the Luusika feature has a range of densities from 2760 to 2920 kg/m3 and magnetic susceptibilities from 20 000 × 10–6 to 56 000 × 10–6 SI. These models suggest that the Luusika causative source is an intermediate to the mafic rock unit, similar to post-orogenic or anorogenic massifs of the Svecofennian basement of Estonia. |
| first_indexed | 2024-12-13T11:45:03Z |
| format | Article |
| id | doaj.art-f566f35893b947ebb3bf6e2abeaaf15e |
| institution | Directory Open Access Journal |
| issn | 1736-4728 1736-7557 |
| language | English |
| last_indexed | 2024-12-13T11:45:03Z |
| publishDate | 2018-11-01 |
| publisher | Estonian Academy Publishers |
| record_format | Article |
| series | Estonian Journal of Earth Sciences |
| spelling | doaj.art-f566f35893b947ebb3bf6e2abeaaf15e2022-12-21T23:47:33ZengEstonian Academy PublishersEstonian Journal of Earth Sciences1736-47281736-75572018-11-0167422823710.3176/earth.2018.1810.3176/earth.2018.18The Luusika potential field anomaly, eastern Estonia: modelling resultsMarija Dmitrijeva0Jüri Plado1Tõnis Oja2School of Chemical Engineering, The University of Adelaide, SA 5005, Australia; dmitrijeva.maria@gmail.comInstitute of Ecology and Earth Sciences, University of Tartu, Ravila 14A, 50411 Tartu, Estonia; juri.plado@ut.eeDepartment of Geodesy, Estonian Land Board, Mustamäe tee 51, 10621 Tallinn, Estonia; tonis.oja@maamet.eeThis study considers the anomalous gravity and magnetic fields in the Alutaguse petrological–structural domain, eastern Estonia. A 10 km wide local maximum (+6.26 mGal) Bouguer anomaly field was discovered at 58.96°N, 26.61°E from the ground gravity data by the Estonian Land Board in 2010–2011. The ground magnetic field intensity measurements indicated a positive magnetic anomaly of 600 nT, in addition to the local gravity maximum. Based on depth estimations, the centre of the anomaly source is placed at 2500–3000 m within the ~1.8 to 1.9 Ga Svecofennian basement. To provide information on the physical properties of the causative source of the anomalies, the geophysical modelling of potential fields was carried out by testing a number of lithologies as sources. The lithologies considered were the known post-orogenic and anorogenic magmatic intrusions in the Estonian basement, as well as typical metamorphic rocks of the Alutaguse domain. The obtained models indicate that the Luusika feature has a range of densities from 2760 to 2920 kg/m3 and magnetic susceptibilities from 20 000 × 10–6 to 56 000 × 10–6 SI. These models suggest that the Luusika causative source is an intermediate to the mafic rock unit, similar to post-orogenic or anorogenic massifs of the Svecofennian basement of Estonia.http://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2018/issue_4/earth-2018-4-228-237.pdfpotential fieldsmagnetic susceptibilitydensityEstoniageophysical modellingAlutaguse domain. |
| spellingShingle | Marija Dmitrijeva Jüri Plado Tõnis Oja The Luusika potential field anomaly, eastern Estonia: modelling results Estonian Journal of Earth Sciences potential fields magnetic susceptibility density Estonia geophysical modelling Alutaguse domain. |
| title | The Luusika potential field anomaly, eastern Estonia: modelling results |
| title_full | The Luusika potential field anomaly, eastern Estonia: modelling results |
| title_fullStr | The Luusika potential field anomaly, eastern Estonia: modelling results |
| title_full_unstemmed | The Luusika potential field anomaly, eastern Estonia: modelling results |
| title_short | The Luusika potential field anomaly, eastern Estonia: modelling results |
| title_sort | luusika potential field anomaly eastern estonia modelling results |
| topic | potential fields magnetic susceptibility density Estonia geophysical modelling Alutaguse domain. |
| url | http://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2018/issue_4/earth-2018-4-228-237.pdf |
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