Thrust and nappe tectonics in orogenic settings – A historical review

Abstract

Thrust systems are important components of orogenic belts as they reflect the dynamics of thrust belt evolution and record information about crustal shortening processes in accretionary prisms. The current knowledge on this subject is the result of three centuries of research. Here, we review the evolution of thrust systems and related mountain-building processes from early field-based observations and experimental work to the arrival at our current body of knowledge.

We realize that even though the amount of available data increased dramatically in the last part of the 20th century, notably through hydrocarbon exploration drilling and seismic data acquisition, some of ideas and conclusions found in early studies are both relevant and impressive. The close connection between experiments and field observations exercised by the pioneers was an important key to progress. Field mapping in the late 1800s lead researchers to the conclusion that overthrusting involving up to 100-km-scale thrust displacements must have occurred during the formation of the Caledonides and the Alps. These pioneers knew that evidence and information were to be found from the study of rocks in outcrop. They accepted the field-based evidence for thrust tectonics, even though they had no tectonic model at hand that could explain such large-scale thrusting. This and similar historical examples underscore the everlasting importance of objective field observations, and of being willing to develop, change, and if so needed, reject existing models.