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卡拉沃索(Calabozos)火山中心Sr和Pb同位素数据(~(87)Sr/~(86)Sr=～0.7043,~(206)Pb/~(204)Pb=18.64—18.66,~(207)Pb/~(204)Pb=15.59—15.60,~(208)Pb/~(204)Pb=38.52—38.55)落在所报导的安第斯弧南部火山带(南纬33—42°)数值范围内。然而,δ~(18)O变化范围(5.0—6.3)通常包括了一些与该区总成分相似的火山岩相比偏低的一些值。卡拉沃索火口组合体(Caldera Complex)位于南纬35°30′,该区安第斯下面的陆壳厚度由>45公里向南变薄为～30公里。三个大体积的晚更新世火山灰流凝灰岩共同组成洛马塞卡凝灰岩(Loma SeCa Tuff),在卡拉沃索火口组合体中构成体积大于1000立方公里的喷发产物,它们是浅部地壳存在有一个重要的、长期活动的安山质到
The Sr and Pb isotope data of ~ (87) Sr / ~ (86) Sr ~ 0.7043, ~ (206) Pb / ~ (204) Pb = 18.64-18.66 and ~ (207) Pb in the Calabozos volcanic center /_(204)Pb=15.59-15.60,~(208)Pb/~(20))Pb=38.52-38.55) fall within the reported volcanic range of the Southern Andean Arc (33-42 ° S). However, the δ ~ (18) O variation (5.0-6.3) generally includes some values that are lower than volcanic rocks of similar composition to the total area. The Caldera Complex, located at 35 ° 30 ’South, has a crustal thickness of ~ 30 km south of> 45 km below the Andes. Three large volcanic tuffs of Late Pleistocene form the Loma SeCa tuff, forming an eruption of more than 1,000 cubic kilometers in the Karawooso fossil assemblage, which is present in the shallow crust Important, long-term activities of Ansan quality to