Syneresis crack

Syneresis cracks are formed by the contraction of clay in response to changes in the salinity of a liquid surrounding a deposit.

[4] The markings would have been formed subaqueously on the bedding surface and could resemble desiccation mudcracks, but are not continuous and vary in shape.

Syneresis cracks in some shales and lime mudstones may initially be preserved as small cavities, which then usually fill with silt and sand from either the overlying or underlying beds and laminae.

[6] Desiccation mudcracks are usually continuous, polygonal, and have U- or V-shaped cross sections that would have been filled in with sediment from above.

Syneresis cracks, however, are usually discontinuous, spindle or sinuous in shape, and have U- or V-shaped cross sections that have been filled in with sediment from above or below.