THE VELENJE LIGNITE - Its Petrology and Genesis
Miloš Markič & Reinhard F. Sachsenhofer
2010, 30 x 21 cm
Price: 30,00 EUR
The monograph entitled »TheVelenje Lignite – Its Petrology and Genesis« presents results of more than 15-years lasting study of this Pliocene lignite embedded in the intermountain Velenje basin, which is located at the junction of the easternmost part of the Southern Calcareous Alps and the Karavanke / Karawanken Mts. in N Slovenia. The lignite seam of a “mega-lens” geometry, 8 km long, up to 2.2 km wide, on average 60 m but in the central southern part more than 100 m thick, represents one of thicker lignite seams worldwide. The seam is exploited 300–450 m underground by a modern mining technology, known as the “Velenje mining method”. The lignite, which provides ca. one third of electric energy produced and used in Slovenia, is medium to low grade by its ash yield and sulphur content. It can be designated as the calcium (moderately) rich lignite, which is a consequence of its evolution from a primary biomass in a relatively alkaline, low-lying, eutrophic to minerotrophic (paleo)geoenvironment considerably influenced by the pre-Tertiary carbonates of the basin's hinterland and the basement. This is a general explanation why the Velenje lignite contains mostly 1.5–3 % (db) (extremely up to 5 % (db)) sulphur and why it is more or less well gelified, as well as characterized by trends in contents and ratios of different organo-chemical (biomarker) compounds. Original vegetation environments, giving to the seam a general division into five coal facies units, were identified as wet forest swamps, bush moors and fens, less and less minerotrophic upwards the seam.
The monograph starts with presentation of early geological studies and mining history. It continues with short presentation of the geological setting of the area, of the lignite itself and of the most outstanding geological studies in the last 40 years. The largest part deals with macro- and micro-petrography of the lignite, interpretation of original peat-forming environments and explanation of effects of biochemical coalification process. A special part presents a lithotype classification, which was originally developed for the Velenje lignite. One chapter talks about the coal rank determination and one chapter about the inorganic geochemical characterization. The final part of the monograph is discussion on genesis in which also published results of other than strictly petrological investigations – as especially of palynology, and of organic and isotopic geochemistry – have been taken into account.