New Insights of the Crustal Structure Across Estonia Using Satellite Potential Fields Derived from WGM-2012 Gravity Data and EMAG2v3 Magnetic Data
2022; RELX Group (Netherlands); Linguagem: Inglês
10.2139/ssrn.4133490
ISSN1556-5068
AutoresJuan David Solano Acosta, Алвар Соэсоо, Rutt Hints,
Tópico(s)Geophysical and Geoelectrical Methods
ResumoGlobal WGM-12 gravity data and EMAG2v3 magnetic data were used to give new information of the Estonian crust. The Estonian Precambrian crystalline basement, composed of Paleo-Meso Proterozoic metamorphic and igneous rocks, is covered by a Paleozoic sedimentary rock deposit 100 – 800 m thick. To visualise crustal layers of the Estonian basement, we employed spectrum analysis of magnetic and gravity data. The gravimetric data was used to identify the depth of the Moho and Conrad discontinuities. The magnetic data has been evaluated to calculate the Curie point depth (CPD), which was then utilized to predict heat flow values over the study area. The subsurface of Estonia is divided into six petrological-structural zones: Tallinn, Alutaguse, Jõhvi, West-Estonian, Tapa and South-Estonian. Potential lineaments in each zone delineates a NW-SE trend. In order to assess the structural variations of the crust over Estonia, different profiles are presented showing contrasting values of potential field, CPD and heat flow, particularly in the Precambrian Rapakivi granitic plutons and the Paldiski-Pskov deformation zone. The depth of the Curie point reveals a mean value of 15 km, while the depth of the Moho suggests a mean value of 60 km, while the mean depth of the Conrad discontinuity is around 18 km.
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