On 15 October 1995, a chasm suddenly formed in a residential area of the Camaiore Plain (Lucca), causing the destruction of some houses and serious damage to many others. In this paper both surface and underground geological features of the area are illustrated. They have been reconstructed on the basis of geological, geoelectrical, seismic and geognostic surveys. It was found that the bedrock in the sinkhole zone is made up of cavernous limestone, intensely fractured and intersected by various direct faults. This substratum is buried by extensive alluvial successions, which reach a thickness of about 140 m in the area. On the basis of surveys and drillings the substratum shows evidence of the presence of karst cavities, generally filled by breccia or by a limited accumulation of alluvial material. From the geological reconstruction, the disastrous event is attributed to a deep collapse in the calcareous substratum. The effects of this collapse were felt at the surface only after a considerable lapse of time, determined by the progress of the cavity upwards in the cover materials. It was therefore considered necessary to carry out analogous studies in the whole of the Camaiore plain, in order to identify any other geological conditions similar to those leading to the 1995 collapse.
Geologic features of the Camaiore plain linked to the 15 October 1995 sinkhole (Italy)
D'AMATO AVANZI, GIACOMO ALFREDO;PUCCINELLI, ALBERTO;
2002-01-01
Abstract
On 15 October 1995, a chasm suddenly formed in a residential area of the Camaiore Plain (Lucca), causing the destruction of some houses and serious damage to many others. In this paper both surface and underground geological features of the area are illustrated. They have been reconstructed on the basis of geological, geoelectrical, seismic and geognostic surveys. It was found that the bedrock in the sinkhole zone is made up of cavernous limestone, intensely fractured and intersected by various direct faults. This substratum is buried by extensive alluvial successions, which reach a thickness of about 140 m in the area. On the basis of surveys and drillings the substratum shows evidence of the presence of karst cavities, generally filled by breccia or by a limited accumulation of alluvial material. From the geological reconstruction, the disastrous event is attributed to a deep collapse in the calcareous substratum. The effects of this collapse were felt at the surface only after a considerable lapse of time, determined by the progress of the cavity upwards in the cover materials. It was therefore considered necessary to carry out analogous studies in the whole of the Camaiore plain, in order to identify any other geological conditions similar to those leading to the 1995 collapse.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
