144
5 SEDIMENTARY STRUCTURES
Fig. 5.10. Photograph looking down on a bedding surface that exhibits parting lineation. Old Red Sandstone
(Devonian), Mitcheldean, England.
decimeters. "Varves," typical of lacustrine deposits, are measurable in millimeters. The
term "upward-fining sequence" is normally applied to intervals of several beds whose
grain size fines up over several meters.
5.3.3.4 Cross-Bedding
Cross-bedding is one of the most common and most important of all sedimentary structures. It is ubiquitous in traction current deposits in diverse environments. Crossbedding, as its name implies, consists of inclined dipping bedding, bounded by subhorizontal surfaces. Each of these units is termed a set. Vertically contiguous sets are
Fig. 5.11. Sketch of current or parting lineation. This appears as a graining on bedding planes of moderately
cemented fissile sandstones. It indicates the sense, but not the direction, of the depositing current.
5 SEDIMENTARY STRUCTURES
Fig. 5.10. Photograph looking down on a bedding surface that exhibits parting lineation. Old Red Sandstone
(Devonian), Mitcheldean, England.
decimeters. "Varves," typical of lacustrine deposits, are measurable in millimeters. The
term "upward-fining sequence" is normally applied to intervals of several beds whose
grain size fines up over several meters.
5.3.3.4 Cross-Bedding
Cross-bedding is one of the most common and most important of all sedimentary structures. It is ubiquitous in traction current deposits in diverse environments. Crossbedding, as its name implies, consists of inclined dipping bedding, bounded by subhorizontal surfaces. Each of these units is termed a set. Vertically contiguous sets are
Fig. 5.11. Sketch of current or parting lineation. This appears as a graining on bedding planes of moderately
cemented fissile sandstones. It indicates the sense, but not the direction, of the depositing current.