Effect of Dolomitization on Physical Properties of Palaeozoic Carbonate Rocks - Case Study from South Estonia
| DOI | 10.3997/2214-4609-pdb.20.C010 |
|---|---|
| Year | 2006 |
| Book | Conference Proceedings, 2nd EAGE St Petersburg International Conference and Exhibition on Geosciences, Oct 2006, cp-20-00091 |
| Publisher | European Association of Geoscientists & Engineers |
| Publisher place | St. Peterburg |
| Pages | 1-5 |
| Type | abstract |
| Estonian author | |
| Language | English |
| Id | 8714 |
Abstract
Influence of dolomitization on Ordovician, Silurian and Devonian carbonate rocks was studied on 555 rock samples from 9 boreholes located at the south of Estonia. Density porosity and magnetic susceptibility of rock samples were analysed together with bulk chemical composition. Dolomitized rocks (dolostones and dolomitic marlstones) were compared to primary rocks (limestones and calcitic marlstones). Devonian rocks overlay either Silurian or Upper Ordovician rocks. Devonian fully dolomitized rocks could be compared only with Ordovician and Silurian primary rocks. Devonian rocks were also compared with Ordovician and Silurian dolomitized rocks in order to reveal influence of Devonian dolomitization on them. Porosity of Devonian and Silurian rocks was the highest and had secondary genesis. Many of the studied Palaeozoic dolomitized rocks have increased magnetic susceptibility and iron content. Early diagenetic dolomitized rocks from the lowermost part of the Ordovician and late diagenetic rocks from middleupper Ordovician have the most significant increase (23 times) in magnetic susceptibility and total iron content. Close values of magnetic susceptibility of Devonian, Upper Ordovician early diagenetic and Ordovician late diagenetic dolomitized rocks permits to support idea about influence of Devonian dolomitization on Ordovician rocks and Devonian time of late diagenetic dolomitization in Ordovician succession