Abstract

The article overviews concepts of the formation of sedimentary sequences of the Belt-Purcell Supergroup, a classical Upper Precambrian section of the Rocky Mountains (North America). Analysis of data on the bulk chemical composition of mudstones of the Belt-Purcell Supergroup (González-Álvarez, 2005; González-Álvarez and Kerrich, 2010) suggests that the overwhelming part of the fine-grained aluminosiliciclastic filling in the Belt Basin was delivered from complexes with non-Archean geochemical characteristics. During almost the entire period of sedimentary filling in the Belt Basin, the fine-grained aluminosiliciclastic material was delivered by large river arteries similar to modern rivers of category 1, i.e., major rivers draining large (>100 000 km²) continental areas (Bayon et al., 2015), and category 2 (rivers draining the “mixed/sedimentary” rocks). This fact confirms the concept of the formation of sedimentary sequences of the Belt-Purcell Supergroup inferred from both traditional geological methods and analysis of data on the U–Pb isotopic ages of detrital zircons and monazites from sandstones of various lithostratigraphic units.

中文翻译：

---

带盆地（落基山脉）：沉积杂岩的组成及其沉积充填的一些特征

摘要

本文概述了贝尔特-珀塞尔超群沉积层序形成的概念，该超群是落基山脉（北美）的经典上前寒武纪部分。对 Belt-Purcell 超群泥岩的整体化学成分数据的分析（González-Álvarez，2005；González-Álvarez 和 Kerrich，2010）表明，Belt 盆地的细粒硅铝质碎屑充填物的绝大部分来自具有非太古代地球化学特征的复合体。几乎在带盆地沉积充填的整个时期，细粒硅铝质碎屑物质由类似于现代 1 类河流的大河动脉输送，即排水量大的主要河流（>100 000 km ²) 大陆地区（Bayon 等人，2015 年）和第 2 类（排放“混合/沉积”岩石的河流）。这一事实证实了从传统地质方法和对来自不同岩性地层单元砂岩的碎屑锆石和独居石的 U-Pb 同位素年龄数据分析所推断的带-珀塞尔超群沉积层序形成的概念。