Heritage Stone, Brecha da Arrábida, Portugal

Abstract

The “Brecha da Arrábida” consists of an informal unit of the Upper Jurassic (Middle to Upper Oxfordian) located at the base of the “Marls, clays, limestone with black pebbles and conglomerates of Arrábida” Formation, defined at the most recent version of the Portuguese Geological Map at the 1/50.000 scale (38-B-Setúbal, IGM, 1994).The use of “Brecha da Arrábida” is closely associated with the history of the city of Setúbal. The proximity of the city to the extraction sites allowed the “Brecha da Arrábida” to become the essential raw material for the construction of various infrastructures that marked the history of the city. Given its aesthetic peculiarity and interest as a scientific object, the “Brecha da Arrábida” is profusely referenced in the bibliography, the oldest dating back to the seventeenth century, in the early “beginnings” of Geology. The facies and petrographic description, as well as its cartographic representation, aroused the interest of some scientists who marked the beginning of Portuguese Geology in the first half of the nineteenth century. From a strictly school point of view, the set of quarries in “Brecha da Arrábida” provides several possibilities of itineraries for study visits for basic education, secondary and university.