Relationship of Fluviodeltaic Facies to Coal Deposition in the Lower Fort Union Formation (Palaeocene), South‐Western North Dakota

Record of glacial–eustatic sea-level fluctuations in complex middle to late Pennsylvanian facies in the Northern Appalachian Basin and relation to similar events in the Midcontinent basin

“…If present, their scale in outcrop would be noticeably smaller than the scale of the adjacent thick sandstone units that cut into them. Belt (1975) and Belt et al (1984, fig. 1) noted a similar scale discrepancy in Scottish Visean deposits, where cross-bedded sandstones at the top of delta-lobe switching cycles averaged an order of magnitude thinner than thicker IVF sandstones in paleovalleys that were cut into the delta deposits.…”

Coal-Bearing Depositional Systems

“…Natural levees are elevated above all other topographic features in the alluvial landscape ), but they are so intimately associated with fluvial sedimentation that sometimes they cannot be distinguished with certainty from the ripple cross-bedded zone at the top of the point bar. Indeed, Belt et al (1984) found levee bank deposits to be the most difficult to recognise in their study of Tertiary coal measures in the Williston Basin of North Dakota, U.S.A. The sediments which constitute natural levees are formed as spill-over deposits during flood peaks when the water volume conveyed through the river channels exceeds their holding capacity.…”

“…A mature delta complex consists therefore of a stack of partially overlapping lobes which carry a record of the repeated phases of delta construction and abandonment. One of many ancient examples is the coal-bearing Ludlow Member of the Fort Uriion Formation in the Williston Basin of North Dakota, U.S.A., which, according to Belt et al (1984) contains at the base a lower delta plain association, consisting of stacked subdelta lobes, which originated from fused crevasse splay deposits.…”

Tectonic development of an orogen-top rift recorded by its terrestrial sedimentation pattern: The Neogene Eşen Basin of southwestern Anatolia, Turkey

“…The lower facies subassociation represents a shallow lake and lake-margin mires that evolved by progressive inundation of fluvial floodplain areas (cf. Belt et al, 1984;McCabe, 1984). The middle facies subassociation represents deepening and basin-wide expansion of the lacustrine environment during a tectonically quiescent period, whereas the upper subassociation -with slump features and evaporites -indicates shrinking and partial desiccation of the lake, accompanied by fault activity (cf.…”