Levels of layered green rocks, characterized by the presence of a fibrous green tremolitic-actinolitic amphibole and/or scapolite, cropping out in the core of the San Martin anticline in the base of Vegadeo limestone (Lower Cambrian) are studied. The origin of the scapolite, under the point of view of the textural relations between the scapolite and the other minerals, is discussed, considering the fact that these series are near the intrusive granite of Boal. The presence of abundant scapolite in some levels is explained as the result of a high concentration of salts in the interstitial fluids of the original series, probably to some extent of evaporitic nature. Finally, it is concluded that the formation of such a mineral is related to the contact metamorphism caused by the thermic intrusion of the granite of Boal, and not to the phases of the Hercynian regional metamorphism of green-schist facies in this area.

Leidse Geologische Mededelingen

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Naturalis journals & series

Suárez, O., & Arias, E. (1981). Origen de la escapolita en metapelitas y rocas anfibolicas de series del Cambrico Inferior del Occidente de Asturias (NW de España). Leidse Geologische Mededelingen, 52(1), 101–107.