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Estonian Geological Sections (05.06.09)
 Estonian geological sections Hundreds of high-quality cores have been drilled on the Estonian territory since 1958 in the course of geological mapping and prospecting for mineral resources and groundwater supplies, However, the material obtained has been analysed to a greatly variable degree, depending on the particular geological task. Detailed restudy of selected drill cores was started at the Geological Survey of Estonia in 1995. Until now nine issues of the journal Estonian Geological Sections have been published, each dealing with one core (Fig. 1). The bedrock succession studied ranges from the Proterozoic (Palaeoproterozoic–Neoproterozoic) to the Palaeozoic (Cambrian–Devonian). The stratigraphic subdivision of the sections (Table 1) has been improved on the basis of data on the distribution of chitinozoans, conodonts and ostracods in the Ordovician and Silurian, and acanthodians in the Devonian. Rock composition has been specified using different chemical and mineralogical analyses (Table 2). Stable isotope data of Ordovician and Silurian rocks were first included in the 2003 issue. The issue on the Soovälja (K–1) core includes data from the deepest drill hole (815.2 m) in Estonia, made in the Kärdla meteorite crater in the course of geological deep mapping of Hiiumaa Island in 1990. From 2003 on the appendixes of issues are available on the CD-ROM. These include photo-logs of the core, photos of selected intervals and thin sections with descriptions, laboratory data, and drawings illustrating the rock types in combination with fossil distribution and stratigraphic scale. More than 70 people have contributed to the publication of the journal, among them over 50 authors from eight geological institutions of the USA, Denmark, Sweden, Finland, Lithuania and Estonia (Table 3). A large dataset has been compiled as a result of long-term collaboration between the authors, and thus the journal can be considered as a kind of Estonian geological heritage from the older generation to the younger.
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