The volcano-sedimentary succession of the Cerro Piche Graben, Río Negro province, Patagonia (Argentina), was studied U–Pb and Lu–Hf in zircon. As well, a stratigraphic, sedimentological, palynology and a review of the paleoflora content was made. The combined stratigraphic and geochronological study on the volcano-sedimentary succession indicates that the Cerro Piche Graben was developed during the Early Jurassic and allow us to propose the Cerro Piche Formation. This formation is composed of a lower volcanic succession (named the Loma Blanca Member) that is restricted to the tectonic depression and that was probably emplaced during the Sinemurian (ca. 191 Ma), and an upper sedimentary succession (named the El Tono Member) that was unconformably deposited over the lower sequence during the Pliensbachian (ca. 183 Ma). The sedimentological study of the upper sequence allows to recognition of nine sedimentary cycles related to the evolution of an alluvial fan. The palynofacies interpretations reflect intermittent exposure to weathering and/or intense reworking of organic components as a result of a dynamic sedimentary system with a high terrestrial input, sediment reworking, and/or intermittent subaerial exposure. The paleoflora preserved in this sedimentary succession is composed exclusively of conifers and assigned to Cupessinoxylon sp., and probably corresponds to an arboreal paleocommunity. The U–Pb data on Early Jurassic detrital zircon grains from the El Tono Member indicate a maximum depositional age (MDA) of 185 Ma for this sequence, and the Lu–Hf data support a reworked continental crust for the zircon source. . Additionally, the U–Pb and Lu–Hf data obtained during this work together with data from the North Patagonian Massif supports the recognition of four magmatic cycles, called C0, C1 (including C1_i source), C2 and C3. The C1 (172–180 Ma) and the C3 (155–162 Ma) cycles indicate mixing of juvenile mantle-derived and reworked crustal components in the parental magma of zircons and the C0 (182–192 Ma) cycle, which includes the distal volcanism identified in the Cerro Piche Graben, the C1_i (172–180 Ma) and C2 (166–169 Ma) cycles seemingly represent three episodes of crustal reworking.

在锆石中研究了U-Pb和Lu-Hf对阿根廷巴塔哥尼亚里奥内格罗省塞罗皮库格拉本的火山沉积沉积演替。同时，进行了地层学，沉积学，孢粉学和古植物含量的综述。火山沉积相演替的地层学和地质年代学研究表明，塞罗皮库格拉本是在侏罗纪早期形成的，这使我们能够提出塞罗皮库组。该地层由下部火山岩演替层（称为洛马布兰卡成员）（仅限于构造凹陷）（可能在西尼古里亚时期（约191 Ma）期间发生）和上部沉积演替层（称为El Tono成员）组成。在Pliensbachian（约183 Ma）期间，它不整合地沉积在较低层序上。上部层序的沉积学研究可以识别与冲积扇演化有关的九个沉积循环。孢粉的解释反映了由于具有高地面投入的动态沉积系统，沉积物重整和/或间歇性地下暴露而导致的间歇性暴露于风化和/或有机成分的强烈返工。该沉积层序中保存的古植物完全由针叶树组成，并被分配给 和/或间歇性暴露于地下。该沉积层序中保存的古植物完全由针叶树组成，并被分配给 和/或间歇性暴露于地下。该沉积层序中保存的古植物完全由针叶树组成，并被分配给Cupessinoxylon sp。，并且可能对应于树栖古群落。来自El Tono成员的侏罗纪碎屑锆石早期颗粒的U–Pb数据表明，该层序的最大沉积年龄（MDA）为185 Ma，Lu–Hf数据支持了锆石源的重做大陆壳。。另外，与北方巴塔哥尼亚地块数据这项工作期间获得一起在U-Pb和路-铪数据支持识别四个岩浆周期，称为C0，C1（包括C1_我源），C2和C3。C1（172–180 Ma）和C3（155–162 Ma）周期表明，锆石母岩浆中的地幔衍生和返工的地壳成分混合在一起，而C0（182–192 Ma）周期则包括远端在Cerro Piche Graben中发现的火山活动，C1 _i （172–180 Ma）和C2（166–169 Ma）周期似乎代表了地壳返修的三个阶段。