A hectare of fresh striations on the Arkitsa Fault, central Greece
Striated faults: visual appreciation of their constraint on possible paleostress tensors
Transtensional faulting patterns ranging from pull-apart basins to transform continental margins: an experimental investigation
Structural and kinematic evolution of a Miocene to Recent sinistral restraining bend: the Montejunto massif, Portugal
Implications of meso-structures for deformational history of the Moose Mountain structure, Canadian Rocky Mountain foothills

It is increasingly apparent that faults are typically not discrete planes but zones of deformed rock with a complex internal structure and three-dimensional geometry. In the last decade this has led to renewed interest in the consequences of this complexity for modelling the impact of fault zones on fluid flow and mechanical behaviour of the Earth’s crust. A number of processes operate during the development of fault zones, both internally and in the surrounding host rock, which may encourage or inhibit continuing fault zone growth. The complexity of the evolution of a faulted system requires changes in the rheological properties of both the fault zone and the surrounding host rock volume, both of which impact on how the fault zone evolves with increasing displacement.

Often times a student is introduced to geophysics as a rather specialized branch of geology, employed only for prospecting or in graduate research. Geophysics courses are usually taken later in a college schedule after adequate preparation in physics and mathematics. Because it is a broad, interdisciplinary area of physical science, one can obtain a background in geophysics by taking selected studies in several different but related fields.

Many of the problems which arise during a study in structural geology are essentially exercises in three-dimensional geometry. Data acquired from field-observations—strike and dip of planes (beddingplanes, planes of schistosity or cleavage, faults, etc.), the pitch and plunge of lineations (outcrops, slickensides, micro-folds, flow-lines, elongation of mineral components or of inclusions, etc.) and all other related vector data are incorporated in a geological map and in accompanying illustrative sections. Both in the construction of such sections and of related block-diagrams, and in the further study of the structural features of an area, it is frequently necessary to make various calculations. Sometimes, indeed, as in many of the problems of mining geology and in the interpretation of borehole cores, the necessity for calculation arises at an even earlier stage since such fundamentals as the dip and strike of a bedded series are only indirectly derived from the observed data.  <...>

Many of the problems which arise during a study in structural geology are essentially exercises in three-dimensional geometry. Data acquired from field-observations—strike and dip of planes (beddingplanes, planes of schistosity or cleavage, faults, etc.), the pitch and plunge of lineations (outcrops, slickensides, micro-folds, flow-lines, elongation of mineral components or of inclusions, etc.) and all other related vector data are incorporated in a geological map and in accompanying illustrative sections. Both in the construction of such sections and ofrelated block-diagrams, and in the further study of the structural features of an area, it is frequently necessary to make various calculations. Sometimes, indeed, as in many of the problems of mining geology and in the interpretation of borehole cores, the necessity for calculation arises at an even earlier stage, since such fundamentals as the dip and strike of a bedded series are only indirectly derived from the observed data.<...>

Folds and thrust faults formed by layer-parallel shortening coaxial with extensional structures such as normal dip-slip faults and ductile necking structures with orthorhombic fabric symmetry are usual, but little-recognised structures formed within normal dip-slip shear zones bounding rifts. They are generated because of the shear distribution in a zone of progressive deformation and may be later extended and disrupted depending on which part of the strain ellipsoid they may be located.

The essential difference in the formation between conjugate brittle shear fractures and ductile shear zones is that the intersection angle of conjugate faults in the contractional quadrants in the former is acute (usually w60
) and obtuse (usually 110
) in the latter. The Mohr-Coulomb failure criterion is an experimentally validated empirical relationship, which structural geologists use to interpret the stress directions based on the orientation of the brittle shear fractures. However, a simple application of this criterion assuming that the principal stresses are vertical or horizontal throughout the crust fails to explain crustal scale low-angle normal faults, high-angle reverse faults and certain types of conjugate strike-slip faults that have intersection angles in the compressional quadrants greater than 90
.