摘要
The Xiong’er Group is occupied by volcanic lavas as well as minor sedimentary rocks and volcanic clastic rocks. The sedimentary rocks occur as interbeds in the Dagushi and Majiahe formations of the Xiong’er Group. Glauconites were discovered in the sandstone from the Majiahe Formation. Sedimentological and petrographic studies indicate that the glauconites have high content of K2O (> 8%), showing that these glauconites belong to the high-evolved glauconites. The characteristics of glauconites from the Majiahe Formation reflect that they formed in a high-energy shallow sedimentary environment, not in an environment with a slowly sedimentary rate. Shortly after the extension of the Xiong’er-Zhongtiao aulacogen, transgression was northward in the Palaeoproterozoic era. At the early stage of the Xiong’er Group, the southern part of Henan Province was in a marine environment, whereas the northern part is still in a continental environment. At the later stage, the southern area of Shanxi Province was in the marine environment, as indicated by the discoveries of glauconites in the Majiahe Formation.
