160
5 SEDIMENTARY STRUCTURES
Fig. 5.30. Vertical load structures in interbedded sands and siltstones. Torridonian (Pre-Cambrian) Isle of
Fladday, Scotland. Bed A is undeformed, bed B shows well-developed load casts on its lower surface, and
bed C has split into discrete pseudonodules.
5.3.4.2 Slumps and Slides
Slump structures, like the structures previously described, involve the penecontemporaneous plastic deformation of sand and mud. Slump folds, however, commonly show
clear evidence of extensive lateral movement in a consistent direction (Fig. 5.31). Slump
folds are commonly associated with penecontemporaneous faulting and with major lowangle zones of decollement termed "slide planes." Large masses of sediments are latFig. 5.31. Geologist perplexed by sight of slump bedding in Lisan Marls (Quaternary). Sodom, Israel.
5 SEDIMENTARY STRUCTURES
Fig. 5.30. Vertical load structures in interbedded sands and siltstones. Torridonian (Pre-Cambrian) Isle of
Fladday, Scotland. Bed A is undeformed, bed B shows well-developed load casts on its lower surface, and
bed C has split into discrete pseudonodules.
5.3.4.2 Slumps and Slides
Slump structures, like the structures previously described, involve the penecontemporaneous plastic deformation of sand and mud. Slump folds, however, commonly show
clear evidence of extensive lateral movement in a consistent direction (Fig. 5.31). Slump
folds are commonly associated with penecontemporaneous faulting and with major lowangle zones of decollement termed "slide planes." Large masses of sediments are latFig. 5.31. Geologist perplexed by sight of slump bedding in Lisan Marls (Quaternary). Sodom, Israel.