Abstract
The Dobrudzha Coalfield (Carboniferous, northeast Bulgaria) is formed near the northern margin of the Variscan mobile zone after a post-Tournaisian erosive phase. Shallow marine and subaerial sediments were deposited over a large flat area. The Dobrudzha Coalfield appeared as a fault-delimited depression during the late Late Visean and Namurian A, in which subaerial coal-bearing sediments were deposited. To the north-east, shallow marine (epiplatform) sediments were still being deposited. In the depression, large swamp-lacustrine milieu is filled to some extent by clastic sediments eroded from rising side of the faults, which were consedimentary-active. From these positive areas, coal pebbles as well as plant-fragments were transported and deposited. In the northern part of the depression, near the end of the Namurian A, swamp and maybe lacustrine conditions existed near the shore-line, as indicated by quartz sandstones with some quartz pebbles, interpreted as a bar.
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