Pulsed uplift estimated from terrace elevations in the coast of Rome: evidence for a new phase of volcanic activity?

The most recent phase of activity from the Roman volcanoes, since 45 ka, ha s been interpreted to be the waning stage of the older explosive activity t hat peaked between 550 and 250 ka. Yet substantial regional uplift from app roximately 250 ka suggests that magma chambers beneath the area are growing rather than shrinking. We have estimated the uplift history of the region using radioisotopically and paleomagnetically constrained coastal terrace e levation data that allow us to correlate these terraces with marine oxygen isotopic stages 1-22. Elevations have been corrected for glacio-eustatic se a-level change. Our study shows that over the last million years, regional uplift of coastal terraces occurred in pulses that preceded volcanic activi ty at roughly 800 ka (in the Monti Sabatini) and 600 ka (in the Alban Hills ). The recent pulse of uplift since 250 ka occurred primarily during a peri od of relative volcanic dormancy that lasted from 250 to 45 ka. We hypothes ize that the most recent volcanic activity since 45 ka may reflect the comp letion of magma chamber recharge, suggesting the start of a new volcanic ep och. It is also possible that the local tectonic stress field changed recen tly from one dominated by transpression to one dominated by extension, allo wing magma to more easily reach the surface via normal faults. (C) 2001 Els evier Science B.V. All rights reserved.