Relatively to argilas of the Oven of the Brick they are constituted by siltes argillaceous carbonated, with conquferos fragmentos, and of acinzentada coloration. The calcareous rocks of Entrecampos occur approximately from 7 mts of depth in the Street of the Commerce. They are composed for siltosas and marly fine sands, with arenticos limy levels. To the hidrogeolgico level, it is observed presence of water between the 2,5 and the 6 mts of depth. These levels correspond to the local fretico level. All the zone of the Decrease of Lisbon, as well as its immediacy, corresponds to the assigned person ' ' Esteiro of the Baixa' ' , area currently levelled, and that if it finds the South for the Estuary of the Tejo open. Laterally one meets delimited by hills of the Castle and San Francisco (Chiado).
3.2. Description-Archaeological context the archaeological intervention was carried through in the Street of Is Julio and in the Street of the Commerce, in the Decrease of Lisbon, vulgo Low Pombalina, for having there been built, order of the Marquis of Pigeon house, after terramoto that it devastated the city in 1 of November of 1755, notable workmanship of oitocentista architecture, classified as Listed property, through Decree 95/78, of 12 of September. This zone of the city, one of the most afectadas for the catastrophe, has come to disclose interesting data concerning the generality of the previous times to the Terramoto of 1755, fruit of the archaeological interventions of emergency that has come there to be carried through and that, allied to the historical inquiry, they make possible a bigger knowledge on the old urban mesh (some of the small farms are Chinese Mandarim (between the August Street and the Street of the Shoemakers), having been identified two arteries there: the Street of the Mats and the Street/Alley of the Cabriteiros; BCP (two areas with pavement had been registadas, being able, presumably, to be attributed to the Street of the Carapuceiros and Rua of the Chancudo); BNC (the Street of the Confectionery was detected there, parallel to the New Street).