LA-ICP-MS zircon U–Pb and muscovite K–Ar ages of basement rocks from the south arm of Sulawesi, Indonesia
LA-ICP-MS zircon U–Pb and muscovite K–Ar ages of basement rocks from the south arm of Sulawesi, Indonesia
复制标题
印度尼西亚苏拉威西岛南臂基岩的 LA-ICP-MS 锆石 U-Pb 和白云母 K-Ar 年龄
DOI：
10.1016/j.lithos.2017.08.023
复制
发表时间：
2017
期刊：
影响因子：
3.5
通讯作者：
Y. Hayasaka
中科院分区：
文献类型：
--
作者：
A. Jaya;O. Nishikawa;Y. Hayasaka
印度尼西亚苏拉威西南臂Bantimala、Barru和Biru基底杂岩中的锆石U-Pb和白云母K-Ar年龄为该区岩浆作用、变质作用和沉积的时间提供了新的信息，并对研究区的成因和演化具有重要意义。研究区域位于孙达兰东南边缘和鸟头-澳大利亚的交界处。Bantimala杂岩中碎屑物质的锆石U-Pb和比鲁杂岩中的角闪岩中的白云母K-Ar的年龄均落在早白垩世晚期(109~115 Ma)，这与以往的沉积岩和变质岩的年龄范围相似。来自Barru杂岩的片岩样品中最年轻的碎屑锆石年龄为三叠纪(243-247Ma)。这些年龄数据表明，这三个基底杂岩的原岩都参与了俯冲系统，并在早白垩世晚期变质，但班提玛拉杂岩和巴鲁杂岩在早白垩世晚期岩浆作用的影响下，其沉积环境存在一定的差异。侵入或以碎屑形式侵入三个基底杂岩的火成岩的锆石U-Pb年龄证实了晚白垩世和始新世的长英质火成岩活动。这些日期与南加里曼丹Meratus复合体报告的日期相似。苏拉威西南缘基底岩石的碎屑锆石年龄分布以中生代(白垩纪和三叠纪)和古生代为主，并有少量元古代年龄，支持西苏拉威西地块起源于环鸟头-澳大利亚地区，即内班达地块的假说。苏拉威西南缘侏罗纪锆石年龄组的缺失表明，苏拉威西南缘在裂谷早期从内班达地块中分离出来。西苏拉威西是由不同历史的内班达地块分开的若干块块组成的，这与西苏拉威西基岩中锆石组分布的多样性以及班蒂玛拉杂岩和巴鲁杂岩构造特征的总体方位差异有关。
The zircon U–Pb and muscovite K–Ar age from the Bantimala, Barru and Biru basement complexes in the South Arm of Sulawesi, Indonesia provide new information regarding the timing of magmatism, metamorphism and sedimentation in this region and have implications for the origin and evolution of the study area. The study area is at the juncture between the southeast margin of Sundaland and Bird's Head-Australia. The age of both the zircon U–Pb of detrital materials in the Bantimala Complex and the muscovite K–Ar of amphibolite in the Biru Complex fall in the Late Early Cretaceous (between 109 and 115 Ma), which is a similar age range to previous data for both the sedimentary and metamorphic rocks. The youngest detrital zircon in the schist samples from the Barru Complex fall into the Triassic in age (between 243 and 247 Ma). These age data indicate that the protolith of all three basement complexes were involved in the subduction system and metamorphosed in the late Early Cretaceous, but there are several differences in their deposition environment under and out of the influence of the late Early Cretaceous magmatism in the Bantimala and Barru Complexes, respectively. Felsic igneous activities are confirmed in the Late Cretaceous and the Eocene by the zircon U–Pb age of igneous rocks intruding or included as detrital fragments in three basement complexes. These dates are similar to those reported from the Meratus Complex of South Kalimantan. The detrital zircon age distributions of the basement rocks in the South Arm of Sulawesi display predominant Mesozoic (Cretaceous and Triassic) and Paleozoic populations with a small population of Proterozoic ages supporting the hypothesis that the West Sulawesi block originated from the region of the circum Bird's Head-Australian, namely the Inner Banda block. The absence of Jurassic zircon age population in the South Arm of Sulawesi suggests the division of the South Arm of Sulawesi from the Inner Banda block in early stage of rifting. Western Sulawesi is composed of several blocks separated from Inner Banda block with different histories, which is supported by the varieties of zircon population distribution in the basement rocks in the Western Sulawesi and also difference of general orientations of structural features between the Bantimala and Barru Complexes.