1 st International Geo-Cultural Symposium Kaldera 2014 FIELD GUIDE

Transcription

1 1 st International Geo-Cultural Symposium Kaldera 2014 Prof. Tim Druitt FIELD GUIDE Prof. Dimitris Papanikolaou

2 Figure 1. Swath Bathymetric Map of Santorini volcanic field (Nomikou et al. 2012) Figure 2. Schematic cartoon depicting the geological cross section through the Hellenic Volcanic Arc, from the molassic back-arc Cretan Basin to the Cycladic island of Ios in the back-arc area (Kilias et al. 2013)

3 Figure 3. Depths of magma storage beneath Santorini (Cadoux et al. In press)

4 Figure 4. Simplified geological map, and ignimbrite fans of the Minoan eruption (Druitt 2014)

5 Figure 5. Combined bathymetric and topographic map of Santorini Caldera (Nomikou et al. 2014)

6 First explosive cycle Second explosive cycle Figure 6. Age data for the Santorini caldera (Druitt et al. 1999, modified) Cycle Major pyroclastic eruptions Approx age (ka) Minoan 3.6 Cape Riva Cape Tripiti Upper Scoriae 2 Upper Scoriae 1 Vourvoulos Middle Pumice Cape Thera Lower Pumce Lower Pumice Cape Therma 3 Cape Therma 2 Cape Therma Dominantly silicic Dominantly intermediate Minor tephra sequences Figure 7. The main pyroclastic units (Druitt et al. 1999;)

7 Figure 8. Evolution of the volcanic field over the last 70,000 years (Druitt et al. 1999) Figure 9. Structural context of the Skaros lava shield (Druitt et al. 1999)

8 Figure 10. Chronostratigraphy of the period 70 to 22 ka (Fabbro et al. 2013) Figure 11. Architecture and Ar-Ar ages of the Therasia Dome Complex (Fabbro et al. 2013)

9 Figure 12. Geological map of the cliff at Fira (Druitt et al. 1999) Figure 13. View of the cliff just south of Fira (Druitt et al. 1999)

10 Figure 14. Fault zone cross cuts the Middle Pumice Plinian deposits on the port of Fira.

11 Figure 15. Characteristic lava dyke at the southern part of Thirassia island Figure 16. Thirassia dome complex

12 Figure 17. View of Cape Skaros (Druitt et al. 1999) Figure 18. View of Cape Therma (Druitt et al. 1999)

13 Figure 19 Lava dykes trending NE-SW at the northern part of the Santorini caldera walls (Nomikou et al. 2012). Figure 20 Kolumbo fault line at the northern part of Santorini caldera (Peristeria volcano).

14 Figure 21. Geomorphological map of the caldera wall (Druitt & Francaviglia 1992) Figure 22. Reconstruction of Bronze-Age Santorini (Druitt & Francaviglia 1992)

15 Figure 23. Products of the Minoan eruption in the quarry north of Akrotiri Figure 24. Four phases of the Minoan eruption (Druitt 2014)

16 Figure 25. Reconstruction of events during the Minoan eruption (Druitt 2014)

17 Figure 26. Geological map of the Kameni islands (Druitt et al. 1999) Figure 27. Development of the Kameni islands (Nomikou et al. 2014)

18 Figure28 Onshore/offshore lava flow outlines for historic lava flows in the vicinity of the Kameni islands (Nomikou et al., 2014).

19 Figure 29. Deformation and seismicity during the unrest period from Jan 2011 to March 2012 (Newman et al. 2012) Source location Figure 30. Model of total vertical deformation (Depth 4,4 Km, Volume 14,9 x10 6 Km 3 (Parks et al., 2012)