Rockmagnetic studies of Upper Jurassic limestones from Southern Germany

Acquisition of isothermal remanent magnetization (IRM) and the behaviour of IRM during high and low temperature treatment indicate that magnetite, goethite and minor quantities of hematite determine the magnetic properties of the Upper Jurassic limestones in Southern Germany. The direction of natural remanent magnetization (NRM) of magnetite is of detrital, synsedimentary origin, whereas the goethite, although its NRM is extremely stable against AF cleaning, has been magnetized only partly during the Jurassic. Part of the goethite NRM is interpreted to be of Tertiary (pre-Upper Miocene) age being formed during a period of Karstification in the Lower Tertiary. The apparent polarity sequence described earlier (Heller, 1977) is not of Jurassic age.           ARK: https://n2t.net/ark:/88439/y050321 Permalink: https://geophysicsjournal.com/article/165 &nbsp