Abstract The Sunsas syn-to post-orogenic high-K calc-alkaline magmatism is crucial to understand the tectonic and thermodynamic history of the Sunsas Orogeny in the southwestern part of the Amazonian Craton. This orogeny is correlated with the Grenville orogenic cycle (c. 1.3 to 0.95 Ga) of Laurentia. Three granitic intrusions from Sunsas belt were classified as fractionated I-type and hybrid A-type granites. The first, the Nomoca granodiorite presents calc-alkaline affinity with peraluminous-magnesian composition (Mg0 = 1.61 wt%), and typical characteristics of intermediate magmas (SiO2 = 67.3 w%). The La Asunta and Nocemano syenogranites have calc-alkaline affinity with peraluminous-ferrous composition (FeO = 2.26–3.31 wt%) and characteristics of silica-rich magmas (SiO2 = 70.4–74.9 w%). Geochemical fractionation patterns suggest that the granites were derived from the reworking of two crustal protolith sources in the same tectonic environment. The Nomoca, La Asunta and Nocemano intrusions yield crystallization ages between 1.17 and 1.08 Ga. Inherited zircon cores with 3.63 and 2.91 Ga Archean ages from Nomoca and Nocemano intrusions may be correlated to the Superior Province evolution, which is located in the south-central part of the Canadian Shield. These U–Pb ages strengthen the geotectonic model for the Rodinia supercontinent with Laurentia-Baltica-Amazonia configuration. Paleoproterozoic (2.12–1.69 Ga) and Mesoproterozoic (1.4–1.3 Ga) U–Pb inherited zircon ages from these intrusions support intensive reworking of the Paragua basement. A concordant age of 555 Ma for zircon rims suggests reworking of the Sunsas Province during the Neoproterozoic Brasiliano Orogeny.

中文翻译：

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Sunsas 带格伦维尔时代岩体的 U-Pb 年代学和地球化学 - 玻利维亚，西南亚马孙克拉通：构造和岩浆影响

摘要 Sunsas 同步到造山后高钾钙碱性岩浆作用对于了解亚马逊克拉通西南部 Sunsas 造山运动的构造和热力学历史至关重要。这种造山运动与劳伦西亚的格伦维尔造山循环（约 1.3 至 0.95 Ga）有关。三个来自 Sunsas 带的花岗岩侵入体被归类为分馏 I 型和混合 A 型花岗岩。第一，Nomoca 花岗闪长岩与过铝镁质组成（Mg0 = 1.61 wt%）具有钙碱性亲和性，具有典型的中间岩浆特征（SiO2 = 67.3 w%）。La Asunta 和 Nocemano 正长花岗岩与过铝-亚铁成分（FeO = 2.26–3.31 wt%）具有钙碱性亲和力，并具有富含二氧化硅的岩浆（SiO2 = 70.4–74.9 w%）的特征。地球化学分馏模式表明，这些花岗岩来自同一构造环境中两个地壳原岩源的再加工。Nomoca、La Asunta 和 Nocemano 侵入体的结晶年龄介于 1.17 和 1.08 Ga 之间。来自 Nomoca 和 Nocemano 侵入体的具有 3.63 和 2.91 Ga 太古代年龄的继承锆石核可​​能与位于中南部的 Superior Province 演化有关加拿大盾牌。这些 U-Pb 年龄加强了具有劳伦特-波罗的海-亚马逊构造的罗迪尼亚超大陆的大地构造模型。来自这些侵入体的古元古代 (2.12-1.69 Ga) 和中元古代 (1.4-1.3 Ga) U-Pb 继承的锆石年龄支持对巴拉瓜基底进行密集改造。