Igneous petrology was to some extent essentially a descriptive science until about 1960. The results were mainly obtained from field work, major element analyses, and microscopical studies. During the 1960's two simultaneous developments took place, plate tectonics became generally accepted, and the generation of magmas could now be related to the geodynamic features like convection cells and subduction zones. The other new feature was the development of new analytical apparatus which allowed high accuracy analyses of trace elements and isotopes. In addition it became possible to do experimental studies at pressures up to 100 kbar. <...>

Mathematical astrophysics and mathematical geophysics have their own journals and conferences, where practitioners discuss mathematical formulations that come to grips with the physical processes of the cosmos and planet Earth. Mathematical petrophysics is by no means new. It started in 1942 with the publication of an equation: the Archie equation.

Two words are used to describe the result of a stress: ‘deformation’ and ‘strain’. Deformation is a general term describing the change of shape, size and/or position of an object, while strain (or ‘internal’ deformation) is used when associated with some quantification of shape change. (Note that in French, deformation is used for both meanings.)
No stress, no deformation. Let us begin with deformation, which is the consequence of applying some stress. In the following section, however, symbols referring to a stress will naturally appear here and there. They name the principal directions of push (σ1) and pull (σ3). <...>

The roots of sedimentology and stratigraphy extend back to the 16th century; however, these disciplines are still growing and changing. Geologists continue to "fine tune" sedimentologic and stratigraphic concepts through a variety of research avenues and by using an array of increasingly sophisticated research tools. T he result is a continuous outpouring of fresh data and new ideas. In fact, it is becoming increasingly difficult to keep abreast of the flood of new information appearing in the geological literature. A glance through recent issues of a well-known sedimentology journal reveals important new papers on sedimentation and tectonics, depositional systems, carbonates, biosedimentology, diageneis, provenance, geochemistry, sediment transport and sedimentary structures, stratigraphic architecture, chronostratigraphy, numerical modeling, paleoclimatology, sequence stratigraphy, and basin analysis-to name but a few research areas. <...>