40Ar/39Ar and U-Pb SHRIMP dating of Aptian tuff cones in the Aisén Basin, Central Patagonian Cordillera
40Ar/39Ar and U-Pb SHRIMP dating of Aptian tuff cones in the Aisén Basin, Central Patagonian Cordillera
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巴塔哥尼亚山脉中部艾森盆地阿普第凝灰岩锥的 40Ar/39Ar 和 U-Pb SHRIMP 定年
DOI：
10.1016/j.jsames.2009.11.003
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发表时间：
2010
影响因子：
1.8
通讯作者：
C. Fanning
中科院分区：
文献类型：
--
作者：
M. Suárez;A. Demant;R. D. L. Cruz;C. Fanning
巴尼奥新沃火山杂岩的Surtseyan凝灰岩锥体在巴塔哥尼亚科迪莱拉中部的南方盆地北部的Aisén盆地的衰退期在浅海喷发。该火山杂岩侵位于豪特里期至阿普提亚阿普莱格组早期，这是该盆地最年轻的沉积单元，当时沉积物仍是湿的。三个新的Ar/Ar年龄(角闪石)和一个U-Pb SHRIMP年龄(锆石)获得了122-121 Ma的一致的早期Aptian年龄。这些数据与阿普勒组和凝灰岩锥之间的接触关系相吻合。这些年代也与从研究区域以南100公里处的阿普勒组采集的早期阿普提亚菊石的年代一致，这是在这个单位发现的最年轻的化石。Divisadero群的阿普提安至阿尔比安陆下火山岩，拟整形地覆盖在阿普莱格组之上。巴诺-新沃火山杂岩的侵位早于艾森盆地消失。
Surtseyan tuff cones of the Baño Nuevo Volcanic Complex erupted in shallow marine water during the waning stage of the Aisén Basin, the northern part of the Austral Basin of the Central Patagonian Cordillera. This volcanic complex was emplaced within the Hauterivian to early Aptian Apeleg Formation, the youngest sedimentary unit of this basin, whilst the sediments were still wet. Three new Ar/Ar dates (amphibole) and one U–Pb SHRIMP date (zircon) from this complex yielded concordant early Aptian ages of 122–121Ma. These data agree with the contact relationships between the Apeleg Formation and the tuff cones. These dates also agree with those of early Aptian ammonites collected from the Apeleg Formation 100km south of the study area, which represent the youngest fossils identified in this unit. Aptian to Albian subaerial volcanic rocks of the Divisadero Group, paraconformably overlie the Apeleg Formation. The emplacement of the Baño Nuevo Volcanic Complex pre-dates the disappearance of the Aisén Basin.