Volcano‐Tectonic Evolution of the Christiana‐Santorini‐Kolumbo Rift Zone. Issue 11 (22nd November 2022)

• Record Type: Journal Article
• Authors: Preine, J.; Hübscher, C.; Karstens, J.; Nomikou, P.
• Is Part Of: Tectonics. Volume 41:Issue 11(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-22
• Subjects: volcano‐tectonics -- Santorini -- rifting -- back‐arc -- Hellenic Arc -- Aegean Sea; Geology, Structural -- Periodicals; 551.8
• DOI: 10.1029/2022TC007524
• Languages: English
• ISSNs: 0278-7407

Abstract

Abstract: Located on the Hellenic Arc, the Christiana‐Santorini‐Kolumbo (CSK) rift zone represents one of the most active and hazardous volcano‐tectonic systems in the Mediterranean. Although this rift zone has been intensively studied, its tectonic evolution and the interplay of volcanism and tectonism are still poorly understood. In this study, we use high‐resolution reflection seismic imagery to reconstruct the opening of the rift basins. For the first time, we relate the activity of individual faults with the activity of specific volcanic centers in space and time. Our analysis shows a pre‐volcanic NNE‐SSW‐oriented paleo basin underneath the CSK volcanoes, representing a transfer zone between Pliocene ESE‐WNW‐oriented basins, which was overprinted by a NE‐SW‐oriented tectonic regime hosting Late Pliocene volcanism that initiated at the Christiana Volcano. All subsequent volcanoes evolved parallel to this trend. Two major Pleistocene tectonic pulses preceded fundamental changes in the volcanism of the CSK rift including the occurrence of widespread small‐scale volcanic centers followed by focusing of activity at Santorini with increasing explosivity. The observed correlation between changes in the tectonic system and the magmatism of the CSK volcanoes suggests a deep‐seated tectonic control of the volcanic plumbing system. In turn, our analysis reveals the absence of large‐scale faults in basin segments affected by volcanism indicating a secondary feedback mechanism on the tectonic system. A comparison with the evolution of the neighboring Kos‐Nisyros‐Yali volcanic field zone and Rhodos highlights concurrent regional volcano‐tectonic changes, suggesting a potential arc‐wide scale of the observed volcano‐tectonic interplay. Plain Language Summary: How do regional tectonic movements and large volcanoes interact? Seismological studies indicate complex volcano‐tectonic feedback links, but, so far, information on the long‐term interactions between tectonics and volcanism is rarely available. The Christiana‐Santorini‐Kolumbo (CSK) rift zone lies in the Aegean Sea and is notorious for its devastating volcanic eruptions, earthquakes, and tsunamis. This region offers the opportunity to study volcano‐tectonic interactions over several million years. In this study, we use high‐resolution seismic imagery to reconstruct the evolution of the rift basins and the CSK volcanoes. We find that all volcanoes lie in a Pliocene transfer zone connecting extensional basins. Volcanism initiated as this older tectonic regime was intersected by a NE‐SW‐directed fault system. Subsequently, all volcanoes evolved parallel to this trend. Several distinct tectonic reorganizations occurred in the Pleistocene, which had a pronounced influence on the CSK volcanoes. In turn, our analysis indicates that the emergence of volcanism also impacted the tectonic evolution of the rift system hindering the evolution of large‐scale normal faults in the volcanic basins. The observed tectonic reorganizations seem to reflect major changes in the stress regime of the Hellenic Arc, potentially also affecting adjacent volcanic centers whose volcano‐tectonic evolution is only poorly constrained so far. Key Points: We reconstruct the volcano‐tectonic evolution of the Christiana‐Santorini‐Kolumbo rift zone using multichannel seismic data The overprint of a Pleistocene NE‐SW striking fault system on a Pliocene E‐W oriented system initiated the emergence of volcanism Regional tectonics had a primary control on the volcanic plumbing system, while magmatism had a secondary influence on the tectonic system