bordatörések

Bordatörések, literally “border fractures,” is a term used in geology to describe fractures that form along or adjacent to the boundaries between different rock units. The word is composed of elements meaning border or edge and fracture, and is used to emphasize the linkage between fracture development and lithological contacts.

Bordatörések arise through a variety of processes. Differential stress at contacts between rock types, differential cooling or unloading, and the later reactivation of existing boundaries can all contribute to fracture formation at unit boundaries. They can occur in igneous, metamorphic, and sedimentary sequences and may be oriented parallel to, cross-cutting, or otherwise related to nearby faults and shear zones.

In the field, bordatörések are identified by careful structural mapping, noting fracture planes that align with lithological contacts, cross-cutting relationships with other structures, and consistency with regional tectonic history. Geophysical methods and borehole data can help define their extent in the subsurface. Their presence can influence rock permeability and mechanical behavior, affecting hydrogeology, mineral exploration, and engineering projects. In sedimentary basins, bordatörések may control fluid pathways and reservoir boundaries; in metamorphic terranes, they can localize deformation and metamorphic gradients.

Overall, bordatörések are a specific type of fracture tied to the boundaries between rock units, illustrating how lithology and tectonics interact to shape the fracture architecture of the crust. They are considered alongside other structures such as faults, joints, and shear zones in structural geology.