Open AccessThe conductivity distribution in the North German sedimentary basin derived from widely spaced areal magnetotelluric measurements
Author(s) -
Losecke W.,
Knödel K.,
Müller W.
Publication year - 1979
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1979.tb01016.x
Subject(s) - magnetotellurics , geology , basement , structural basin , crust , sedimentary rock , sedimentary basin , seismology , geomorphology , petrology , geophysics , electrical resistivity and conductivity , paleontology , civil engineering , electrical engineering , engineering
Summary For the first time, a systematic magnetotelluric survey has been made of the North German sedimentary basin. It was intended to obtain details concerning the thickness, extent and structure of the sedimentary basin. A model of the basin was derived from data collected at about 50 sites. The model contains the distribution of the integrated conductivity of the strata above and below the Zechstein base, and depth values for the magnetotelluric (MT) basement ranging from 9 km (in the south) to 18 km (in the north). The integrated conductivity of the strata above the Zechstein base decreases from 4000 mho in the north to 5 mho in the south. In the pre‐Zechstein this trend is reversed, with 8000 mho in the south decreasing to 2000 mho in the north. In the southern part unexpectedly low resistivities (approximately 1 ohm.m) occur in the pre‐Zechstein. The model calculations suggest that the source of the North German conductivity anomaly lies in the upper crust. The anomaly is caused by the contact of poorly conducting material with very thick (approximately 10 km) well‐conducting sediments, which additionally show lateral conductivity variations outside the contact area.