... mas in a submarine and coastal environment that crop out on the coast to the north of Catania Acicastello, Acitrezza and as folloed at around 0.3 Ma by another episode of tholeiitic volcanism in the S sector of Etna. Beginning about 170 ka thousand years ago, mafic alkaline magmas ere emitted to form several eruptive centers Ancient Alkalic Centers Romano 1982 and possibly the first major Etnean edifice Ancient Etna of Gillot et al. 1994, including the Calanna and Trifoglietto I centers before the magmas became more evolved, leading to more explosive volcanism and the construction of a succession of volcanic edifices ith alternating pyroclastic and effusive products, hich has been comprehensively named Trifoglietto. INCLUDEPICTURE http.photo.netphotopcd4229mirage-volcano-7.3.jpg t MERGEFORMAT The major eruptive centers of this unit are Trifoglietto II, Vavalaci and Cuvigghiuni Gillot et al. 1994. Another series of major volcanic edifices gre, and partially ere destroyed, by caldera collapse, during the Mongibello stage hich is commonly subdivided into the Ancient and Recent Mongibello. The earlier includes the Ellittico and Leone volcanic centers and formation of the homonymous calderas, and eruption of the most evolved trachytic magmas during the history of Etna, hile the latter comprises the construction of the modern summit cone hich as interrupted at least once by caldera collapse Piano caldera, about 2 ka. The result of this eventful history is a highly complex edifice hose morphology is that of an asymmetric shield volcano topped by a stratocone and hose eastern flank hosts the Valle del Bove, a vast caldera depression formed during successive collapse events beginning during the late Trifoglietto stage and continuing through the Holocene. Much of the stratigraphic information regarding the groth of the various eruptive centers has in fact been gained from the alls of the Valle del Bove. aYi89HII !ubssXsajCUajU6OJQJtsJmHnHsHuaj6OJQJUJmHnHsH6CJOJQ
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