Depositional environments of coals and associated siliciclastic sediments in the Lower and Middle Jurassic of Denmark: the Oresund - 5, -7, -13, -15 and -18 wells

Abstract

Five cored wells located in the Fennoscandian Border Zone in the Oresund area, Denmark, encountered Lower or Middle Jurassic coal-bearing strata; the coal seams are Lignite to Sub-bituminous A/High Vol. Bituminous C in rank. A number of shallowing-upward units are recognized in the five wells. Each unit is capped by a coal seam. The investigated coals represent almost entirely fresh water peat-forming environments. Three main types of environments are defined. In general, the three types of environments form ecosystems characterized by groundwater influence, nutrient supply, and vegetation. Successions representing hydrological evolution towards drier conditions due to vertical peat accretion are recognized in some of the seams. -from Author