Terrane is a geologic body of regional extent limited by faults , which is characterized by its own stratigraphic , magmatic , metamorphic and structural features that determine the tectonic history that distinguishes it from neighboring geological bodies. At least such a definition was given to the word terrane by the authors of the concept: PC Coney, DG Howell, DL Jones, JWH Monger, ER Shermer, NJ Silberling, J. Hillhouse, etc. However, even more radical views appeared later, which can be expressed in one phrase: “ the terrane can be the size of a button. ” With this approach, endless possibilities open up for detailing the separation of terranes, but the smaller the area, the less likely it will be possible to trace its history in detail. Thus, this situation can be compared with the well-known law of quantum mechanics - the principle of uncertainty .
The history of the term terrane
The word "terrane" in geological literature has long been used as an informal stratigraphic term in writing not only as terrane, but also terrain. The Oxford English Dictionary of 1989 and Webster's Third New International English Dictionary of 1966 prefer the spelling of terrane if the term is used in geology.
Before the advent of biostratigraphy , at the end of the 18th - beginning of the 19th centuries, terrane was considered a group of all formations with the same prevailing rock type, implying simultaneous accumulation in the sedimentary basin (non-Putunian sedimentation). Later, this definition changed following changes in attitudes towards neptunism. The word "terrane" is often used as a synonym for the word "formation (retinue)." In the geology of continents, the term "terrain" gradually began to refer to the stratigraphic system, but the First International Geological Congress recommended the preferred use of the term "system". From the end of the last century and almost until now, the term terrane has been used in geology in a vague stratigraphic sense. In the 1989 edition of the Oxford English Dictionary, such a definition of terrane is given - "this is the name for a related series, group or system of rock formations, a stratigraphic unit ." The Webster dictionary (1966) gives a similar definition: “terrane is a rock formation or a group of formations, or a territory, or an area over which a particular type of rock or group of rocks predominates”.
The Explanatory Dictionary of English Geological Terms (Gary et al., 1972) defines terrane as an obsolete term applied to a rock or group of rocks, and to the geographic area where they surface: “terrane is a complex, massif, series of formations, zone of rocks . An outdated term used to refer to rocks or groups of rocks, as well as their area of exit. The term is used in a general sense and does not necessarily mean a specific geological unit or a group of such units. ”
Thus, the word "terrane" was originally used both in a geographical and in a stratigraphic sense.
See also
Terrane Analysis