The PASTA Project: investigation of Po and Apennine Sediment Transport and Accumulation

The northwestern Adriatic Sea from the Po River mouth to the Gargano Peninsula (Figure 1) is an ideal location to study sedimentary processes that fi ll foreland basins and form epicontinental shelves. These semi-enclosed shelves form in depressions on continental crust; they differ in morphology and origin from pericontinental shelves, which are found along the edges of ocean basins and are largely the result of sea-level rise. A number of epicontinental shelves are extant today (e.g., Yellow Sea, Baltic Sea), and they were more common during the geologic past when sea level was relatively stable. For example, during the Cretaceous Period (~100 million years ago), an epicontinental shelf ran north-south through the middle of the North American continent, received sediments from the Rocky Mountains, and created the oil-producing strata in that region. Mountain building on the Italian Peninsula created the Apennines and Alps, whose weight has depressed the adjacent crust (foreland basin) in the Adriatic Sea. The relief of these ranges continues to stimulate land-surface erosion that produces sediment, fi lls the northern Adriatic, and forms the epicontinental shelf. The sediment is transported by the Po River and a host of smaller Apennine rivers to the south (Figure 1). The Po is one of the dominant drainage basins in Europe, extending eastward across northern Italy--bounded by and receiving sediment from the south fl ank of the Alps and the north fl ank of the Apennines. The river enters the northern Adriatic just south of Venice, and has formed a prominent delta at its mouth. A characteristic of the Adriatic epicontinental shelf is minimal expenditure of energy by tides and ocean swells.