The Campi Flegrei and its offshore prolongation (Pozzuoli Bay) are a volcanic area dominated by a collapse caldera associated with the Neapolitan Yellow Tuff (NYT) eruption, occurred at ~15 ka BP, and by an intra-caldera resurgent dome. We present new insights into: a) the geometry and kinematics of faults formed inside the caldera, b) the architecture of the resurgent dome, and c) the relationship between the structural elements of the resurgent dome and ground deformations. This work is based on the integration of high- and ultra-high resolution seismic data, swath bathymetry data and ground deformation maps. The main results highlight that the NYT caldera, offshore, is characterized by an ellipsoidal shape, elongated towards the ESE direction, with axes of ~8 km and ~7 km. It is bounded by a ~6 km long and 1–2 km wide ring fault zone (RFZ) mainly consisting of an inward-dipping normal fault system and antithetic, outwarddipping, faults. The sedimentary fill of the caldera is up to 60 m thick, and can be divided into six units, characterized by different seismic facies, composition and depositional process.The inner-caldera resurgent dome, ~ 5 km in diameter, is limited by inner boundary of RFZ and consists in a broad antiformal structure with brittle deformation localized in an apical graben. The base of the resurgence corresponds to the thalweg of the Epitaffio valley in the western sector of the Pozzuoli Bay and the Bagnoli valley in the eastern one. The maximum cumulative uplift of the resurgent dome is ~180 m while its average uplift rate is ~ 9–12 mm/year, between 15.0–6.6 ka BP. A subsidence of ~10 m is suggested by the drowning of the infralittoral prograding wedge below the present-day storm wave base for the last 2 ka.The deformation velocity pattern of the Campi Flegrei displays a radial symmetry centered on the Pozzuoli harbor. It is possible to distinguish three almost-concentric sectors namely S1, S2, S3 with decreasing velocity from S1 (13-32 mm/year) to S3 (0.3-7.7 mm/year). The highest value (26-32 mm/year) is recorded at the Pozzuoli harbor. Sector S1 is bounded by a NE– SW-trending fault to the west and NW–SE faults to the east. The data suggests that this sector coincides with the resurgent dome of NYT caldera. The base of the latter corresponds to the faults bordering sector S1, and it can be correlated with the base of the resurgence recognized offshore. Sector S2 represents a narrow strip located between the base of the resurgence and the onland prolongation of the inner boundary of the RFZ.The results of our research provide new insights into the stratigraphic architecture and the shallow structure of the NYT collapse-caldera in the Pozzuoli Bay. Furthermore, they represent a base to reconstruct the entire onshore-offshore geometry of the inner-caldera resurgence and infer new constraints on the dynamics of the fluid flow system and magma source at depth.
Corradino M., P.F. (2016). Architecture of the NYT caldera and inner resurgent dome (Pozzuoli Bay, Campi Flegrei): new insights from seismic reflection and DInSAR data. RENDICONTI ONLINE DELLA SOCIETÀ GEOLOGICA ITALIANA, 40.
|Data di pubblicazione:||2016|
|Titolo:||Architecture of the NYT caldera and inner resurgent dome (Pozzuoli Bay, Campi Flegrei): new insights from seismic reflection and DInSAR data|
Corradino, Marta (Corresponding)
PEPE, Fabrizio (Corresponding)
|Citazione:||Corradino M., P.F. (2016). Architecture of the NYT caldera and inner resurgent dome (Pozzuoli Bay, Campi Flegrei): new insights from seismic reflection and DInSAR data. RENDICONTI ONLINE DELLA SOCIETÀ GEOLOGICA ITALIANA, 40.|
|Nome del convegno:||Geosciences on a changing planet: learning from the past, exploring the future - 88° Congresso della Società Geologica Italiana|
|Anno del convegno:||7-9 Settembre 2016|
|Luogo del convegno:||Napoli|
|Settore Scientifico Disciplinare:||Settore GEO/02 - Geologia Stratigrafica E Sedimentologica|
Settore GEO/03 - Geologia Strutturale
|Appare nelle tipologie:||1.05 Abstract in atti di convegno pubblicato in rivista|