1993), and Gomez-Fernandez and Melendez (1994b), corresponds to Cycles IIC and IID proposed by Salomon (1982a; 1982b), and Cyclothem
II by Guiraud and Seguret (1985) (Fig.
Palynological and megafloral assemblages indicate that this formation is of Asturian-Cantabrian age, with the substage boundary occurring within Cyclothem
12, about 25 m above the Hub Coal Seam (Zodrow and Cleal 1985; Zodrow 1989a, b; Dolby 1988; Cleal et al.
Measured from the base of one limestone to the base of the next, each cyclothem
represents a few million years of geological time, in which depositional conditions changed from the warm clear-water marine conditions in which the limestones formed, to the more turbid deltaic and lagoonal environments in which the sandstones and shales were deposited.
1996): Paleontology of the Greenhorn Cyclothem
(Cretaceous, Late Cenomanian to Middle Turonian) at Black Mesa, Northeastern Arizona.
Consequently, marine and nonmarine beds alternate and interfinger to form a pattern of transgressive and regressive rock deposition, which is commonly referred to as the classic Pennsylvanian cyclothem
As such, this sequence is part of a cyclothem
(Gibling and Bird 1994) in a terrestrial environment of an extensive costal platform (Wightman et al.
Trace-element behavior and redox facies in core shales of Upper Pennsylvanian Kansas-type cyclothems
1 Percentage of clastic rocks in cyclothems
of Upper Carboniferous in USCB: CSS--Cracow Sandstone Series; MS--Mudstone Series; USSS--Upper Silesian Sandstone Series; PS--Paralic Series conglomerate sandstone CSS 3 81 MS 27 USSS 2 53 PS 47 Note: Table made from bar graph.
Diagenetic model for carbonate rocks in mid-continent Pennsylvanian eustatic cyclothems
Trace element behavior and redox facies in core shales of Upper Pennsylvanian Kansas-type cyclothems
Trace-element behaviour and redox facies in core shales of Upper Pennsylvanian Kansas-type cyclothems
165), the Gore Lignite Measures were mainly deposited "in a range of fluvial channel, overbank splay, floodplain and swamp environments, as indicated by the presence of in situ terrestrial plant remains, lateral persistence of the multiple coal seams, common root-penetrated seat earths, large scale upward-fining clastic sequences typical of fluvial cyclothems
, and the paucity of marine fauna.