Orogens are the locus of intense deformation and metamorphism, mainly caused by convergent tectonics and burial. Yet, deeply buried rocks – metamorphosed at high pressure (HP) – are customarily met at the surface, even in “recent” systems such as the Alps. The long-standing question is naturally “how are these rocks brought back to the surface?” …[Read More]
This contribution is a very detailed field report of the Sino-French expedition in eastern Tibet that took place in 1980-1982. Armijo and coauthors accurately analyse the different tectonic styles present in the north and south of the Yarlung-Zangbo Suture Zone, frequently defined as the “chord” joining the eastern and western syntaxes of the Himalayan orogen …[Read More]
Following the impact of the global plate kinematics revolution, researchers in the 70s and 80s made significant efforts to compare records of deformed rocks in outcrops to large-scale deformation and kinematics. By publishing “S-C Mylonites” 1984, Gordon A. Lister and Arthur W. Snoke gave a step forward for the TS community. The paper contributed to …[Read More]
The establishment of plate tectonics in the 1960s triggered a reappraisal of the development of mountain belts and facilitated the physics-based understanding of mountain building processes. Many models for mountain building were, however, mostly conceptual, and there was no appropriate theory that described the first-order mechanics of mountain belts. In 1983, this gap was – …[Read More]
In “Propagating extrusion tectonics in Asia: New insights from simple experiments with plasticine”, Tapponnier and co-authors (1982) describe one of the most famous analogue experiments in the history of Earth Sciences. The experiment was performed in the laboratories of Rennes (France), at the beginning of the ‘80s. The article aims to shed light onto the …[Read More]
The now-classic paper of Boyer & Elliott (1982) presented a novel and general geometric framework to study thrust systems. The framework describes thrust surfaces by lines of contact between thrusts, or branch lines, and lines of thrust termination, or tip lines, and examines how they join into imbricate fans or duplexes. The framework allows accurate …[Read More]
Ramsay’s 1980 important contribution is a practical and theoretical handbook about shear zones, where the reader can find a detailed classification of shear zones, their description, and mathematical explanation. A definition of the concept of shear zones opens the article, followed by the shear zones classification into three types, namely brittle (e.g., Fig. 1a), brittle-ductile …[Read More]
In 1980 Brace and Kohlstedt published a short paper that constrains the strength of continental lithosphere by extrapolating laboratory measurements of rock strength to geological conditions. Their approach follows earlier work by Goetze and Evans (1979) and relies on two key considerations. First, the brittle strength is given by the frictional strength of rocks following …[Read More]
Continental extension strongly affects the topography of continents by shaping elongated rift valleys, referred to as rift basins in the geological record. A strong implication of the formation of these basins is a two-step subsidence history: an initial rapid subsidence during extension, and a second, slower subsidence once active extension has ceased. Although this observation …[Read More]
The paper “Fault Rocks and Fault Mechanisms” by R. H. Sibson (1977), was one of the first studies that established major connections between the rocks that form in faults, and their conditions and mechanics during formation at crustal scale. Concretely, Sibson (1977) established: 1.) links among the textures and lithologies that develop along fault zones …[Read More]
