What is a synsedimentary fold?

A synsedimentary fold is a geological fold that forms at the same time as sedimentary deposition occurs. In structural geology, folds are generally stacks of originally planar surfaces that are bent or curved during permanent deformation. While many folds are formed later by shortening of existing layers, synsedimentary folds develop concurrently with the accumulation of sediments in settings such as sedimentary basins.

What we know

• A fold in structural geology is a stack of originally planar surfaces, such as sedimentary strata, that are bent or curved during permanent deformation. [2]
• Synsedimentary folds are specifically defined as those folds formed during sedimentary deposition. [2]
• Folds can form under varied conditions of stress, pore pressure, and temperature gradient, including in soft sediments. [2]
• The geological evolution of sedimentary basins involves complex tectonic processes like folding and the formation of basins during periods such as the Mesozoic and Cenozoic. [3, 4] · medium confidence

Where to go next

• how it workedHow do geological folds form?
• the bigger pictureWhat is a fold train?
• what caused itHow do sedimentary basins evolve?
• compared withWhat are primary flow structures in igneous rocks?
• a case in pointWhat is a fault propagation fold?
• an unexpected connectionHow do igneous intrusions cause rock folding?Although folds are typically thought of as results of tectonic shortening in sedimentary layers, they can also be produced by the effects of high-level igneous intrusions such as laccoliths.

Sources

• [1]fold (Wikidata Q81659) · CC0 1.0
• [2]Fold (geology) · CC BY-SA 4.0
• [3]Geology of the Western Carpathians · CC BY-SA 4.0
• [4]Cheshire Basin · CC BY-SA 4.0
• [5]Aquitaine Basin · CC BY-SA 4.0