GASPERI G.
Schema strutturale dell’area – Structural setting of the study area
Pages 45-54
Abstract
The Po Plain is of relatively recent origin. Untilless than 1 Ma ago) the area was entirely coveredby the Adriatic sea. The sea then gradually retreated eastwards from its Alpine and Apennine margins) leaving the North Adriatic area (fig. 15.3) alternatively submerged and emerged, and reached its present-day position during the first half of the Holocene. Surface sediments are mainly recent or very recent continental deposits; therefore deep structuresare only known through research carried out when drilling for oil (AgipMineraria) 1959; Pieri & Groppi, 1981; Mattavelli & alii, 1983; Dondi, 1985; Cassano & alii, 1986; Dendi & D’Andrea, 1987); shallower investigations aimed at studying water resources (Gr. St. FaldeAcquifere Profonde, 1979;Regione Emilia-Romagna, 1998). From the geological viewpoint) the Po Plain is a Tertiary sedimentary basin lying on the northern end-member of the Adriatic-Apulia block) between the fronts of opposing overthrusts) i.e., the south-verging thrusts of the «Southern Alps» and the north-vergingApennine structures) and subject to the double phenomenon of compression by the opposite chains (fig. 6.2). The orographic boundary of the chains) corresponding to the margin of the Po Plain) do not coincide with the structural boundary of the Alps and Northern Apennines) since they are extensively found in the subsurface of the plain) where they collide (Geomorphological Map, cfr. sectionB-B’J. The Alps are subdivided into two tectonic systems separatedby the InsubricLine. One) with Europeanvergence) is the typicalfold and thrust belt) north-verging towards…