strati.ch - Lessico lithostratigrafico della Svizzera

Rappresentazione e statuto

Varianti storiche: Argille Scagliose (Bianconi 1840), argille scagliose (dal Piaz & Trevisan 1956), schistes froissés à olistolithes de terrains divers = argille scagliose (Trümpy 1976), Argille scagliose (Vannucchi & Bettelli 2010)

Tipo di origine

Definizione: Bianconi P. (1840) : Storia naturale dei terreni ardenti, dei vulcani fangosi, delle sorgenti infiammabili, dei pozzi idropirici e di altri fenomeni geologici oprati dal gas idrogeno e dell’origine di esso gas. Marsigli (Bologna), 164 p.

Revisione: Vannucchi Paola, Bettelli Giuseppe (2010) : Myths and recent progress regarding the Argille Scagliose, Northern Apennines, Italy. International Geology Review

Argille scagliose (scaly clay) is a geological term first used in 1840 to describe rocks in the Northern Apennines of Italy. The term was originally created to stress the mesoscopic scaliness of a type of rock that commonly outcrops in this area. The rock is also typified by a chaotic assemblage of blocky components that are embedded within the scaly matrix. Before the advent of plate tectonic concepts, the extreme complexity of these rocks posed an extreme challenge to interpret with then-standard concepts of deposition processes in sedimentary basins. Similar rocks were recognized in many other mountain belts, thus the term became widely used. At the same time, the emphasis of the term changed from a description of the matrix to a term with multiple, intensely debated, genetic associations. Only after the discovery of plate tectonics was it accepted that these rocks are formed at subduction boundaries, and that the multiple types of embedded blocks can have an origin from both slope-instabilities within an accretionary prism, and from tectonic reworking/deformation processes near the base of an active accretionary prism.