Abstract

Zircon from granitoids of the multiphase Turga massif (Eastern Transbaikalia) shows various morphological features and compositions of trace elements. This granitoid massif of the Kukulbey complex is spatially associated with rocks of the Shakhtama monzonitoid complex, whose ages are about 133 and 158 Ma, respectively. Zircon from different granitoid phases of the Kukulbey complex demonstrates a decrease in Hf content and an increase in Th, U, Y, and REE concentrations. The trace element accumulation in zircon and rocks of the main phase of the Turga massif (Li-Li-siderophyllite granites) was accompanied by a significant rise of their crystallization temperature, relatively to the earlier phase. The indicative features of zircon in these granites—the intensive development of specific twinning (up to 30% of all grains) and the presence of contrasting growth zones—confirm the idea of increasing crystallization temperatures and alkalinity of the melt. These features of zircon, together with geochemical composition of rocks, indicate that amazonite granites of the Turga massif belong to the alkaline type of Li–F-bearing granites with a mixed geochemical specialization: on the one hand, Li, Ta, and Nb, which are typical for the ore-bearing (peraluminous rare-metal) Orlovka massif; and on the other hand, Zr, REE, Th, and U, which are more typical for alkaline granites.

中文翻译：

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Turga多相地块中的锆石与亚马孙花岗岩（东跨贝卡利亚）及其成岩意义

摘要

多相图尔加断层（东部透贝卡利亚）花岗岩中的锆石显示出各种形态特征和微量元素组成。库库尔贝（Kukulbey）复杂体的这种花岗岩质地块与Shakhtama monzonitoid复杂体的岩石在空间上相关，它们的年龄分别约为133 Ma和158 Ma。Kukulbey复合物的不同花岗岩相中的锆石显示Hf含量降低，Th，U，Y和REE浓度升高。相对于早期阶段，Turga断层的主要相（Li-Li-铁橄榄石花岗岩）的锆石和岩石中的微量元素积累伴随着其结晶温度的显着升高。这些花岗岩中锆石的指示性特征-特殊孪晶的密集发展（占所有晶粒的30％）以及生长区域的对比鲜明-证实了提高结晶温度和熔体碱度的想法。锆石的这些特征，再加上岩石的地球化学组成，表明图尔加断层的亚马孙花岗岩属于碱性的含Li-F的花岗岩，具有混合的地球化学特征：一方面是Li，Ta和Nb，这些是含矿石（含铝的稀有金属）奥尔洛夫卡岩块的典型特征；另一方面，Zr，REE，Th和U，这对于碱性花岗岩来说更为典型。表明Turga断层的亚马逊石花岗岩属于含Li-F的碱性类型的花岗岩，具有混合的地球化学特性：一方面，Li，Ta和Nb是含矿石的典型特征（含大量稀土元素，金属）奥尔洛夫卡地块；另一方面，Zr，REE，Th和U，这对于碱性花岗岩来说更为典型。表明Turga断层的亚马逊石花岗岩属于碱性的Li–F花岗岩，具有混合的地球化学特性：一方面，Li，Ta和Nb是含矿石的典型特征（含大量稀土元素，金属）奥尔洛夫卡地块；另一方面，Zr，REE，Th和U，这对于碱性花岗岩来说更为典型。