Search results
Results from the WOW.Com Content Network
Foliation in geology refers to repetitive layering in metamorphic rocks. [1] Each layer can be as thin as a sheet of paper, or over a meter in thickness. [ 1 ] The word comes from the Latin folium , meaning "leaf", and refers to the sheet-like planar structure. [ 1 ]
Foliation is separated into two groups: primary and secondary. Primary deals with igneous and sedimentary rocks, while secondary deals with rocks that undergo metamorphism as a result of deformation. Cleavage is a type of secondary foliation associated with fine grained rocks.
Oblique foliation is a fabric that has achieved a steady state, but does not represent the total accumulated strain.. The structure is thought to result from the interplay of passive flattening and rotation of grains in a non-coaxial flow field on one hand and grain boundary migration destroying the developing shape fabric at the same time on the other hand.
Within shear zones with pronounced displacements a shear foliation may form at a shallow angle to the gross plane of the shear zone. This foliation ideally manifests as a sinusoidal set of foliations formed at a shallow angle to the main shear foliation, and which curve into the main shear foliation. Such rocks are known as L-S tectonites.
Structural geology is the study of the three-dimensional distribution of rock units with ... Generally the axial plane foliation or cleavage of a fold is created ...
A geologic period starting 23 million years ago and, depending on definition, either lasting until today or ending 2.6 million years ago with the beginning of the Quaternary. Nodule Small mass of a mineral with a contrasting composition to the enclosing sediment or rock. Not to be confused with concretion. non-clastic
2-dimensional section of Reeb foliation 3-dimensional model of Reeb foliation. In mathematics (differential geometry), a foliation is an equivalence relation on an n-manifold, the equivalence classes being connected, injectively immersed submanifolds, all of the same dimension p, modeled on the decomposition of the real coordinate space R n into the cosets x + R p of the standardly embedded ...
Ptygmatic folds are formed by highly plastic ductile deformation of the gneissic banding, and thus have little or no relationship to a defined foliation, unlike most regular folds. Ptygmatic folds can occur restricted to compositional zones of the migmatite, for instance in fine-grained shale protoliths versus in coarse granoblastic sandy ...