**2. Geological history of the pontine plain and Alban Hills volcano**

The topics of interest are the Pontine Plain and Alban Hills, which had a much younger genesis. Pliocene–Quaternary, than the sedimentary terrains outcrop-ping around the Pontine Plain (**Figure 4**). At the upper Pliocene–Pleistocene, the shoreline


#### **Figure 4.**

*Chronologic interval covering the formation of the pontine plain (Pliocene–Pleistocene). Modified from (https:// www.isprambiente.gov.it/scala\_tempi\_geologici?current\_era=Miocene).*

#### **Figure 5.**

*A geological model of the pontine plain around the Pliocene (3 ma ago). B geological model around the middle Pleistocene (200,000 years ago). C geological model around the end of the Pleistocene (50,000 years ago). D geological model around the Holocene (10,000 years ago). Modified from https://www.parcocirceo.it/pdf/ Piano%20del%20Parco%203%20pag%2029-57.pdf.*
