The Fengcheng Formation in the Mahu sag of the Junggar Basin was primarily composed of detritus, pyroclastic material, carbonates, and evaporites. In order to establish the diagenesis pathways of the Fengcheng Formation, some methods of polarized light microscope, SEM, CL, EPMA, LR, and fluid inclusion analysis were applied to discuss the diagenesis process. The results showed the following: (a) The formation of an alkaline lake was the result of the influence of a high concentration of sodium-rich sources, and it led to the preservation of alkaline minerals in the stratum. (b) After the sediments were buried, three mineral assemblages were formed in the Fengcheng Formation, which are carbonate mineral assemblages (i.e., calcite + ferreous dolomite), reedmergnerite and carbonate mineral assemblages (i.e., reedmergnerite + calcite + ferreous dolomite), and reedmergnerite and alkaline mineral assemblages (i.e., reedmergnerite + shortite + trona), respectively. (c) According to the homogenization temperature of reedmergnerite primary fluid inclusions, the alkaline diagenesis of Fengcheng Formation was divided into an early stage (≤100 °C) and a middle stage (>100 °C), respectively. The earlier stage is marked by the formation of ferrous saddle dolomite, quartz dissolution, and the agglutination of laumontite. These processes occurred under normal burial conditions. The latter is marked by the reedmergnerite’s appearance, which is correlated with the deep hydrothermal activity controlled by faults. (d) Based on sedimentary and diagenetic factors, including climate, provenance, diagenetic surroundings, and the action of subsurface fluid, the alkaline deposition-diagenesis model for shale series in four stages of the Fengcheng Formation was established.

Increasing exploration interest in oil and gas hosted by early Cambrian strata has focused research efforts on early Cambrian sandstones. The origin of phosphorus and the paleoenvironment of phosphorus-bearing sandstones from the Xinji Formation are discussed in this paper. X-ray diffraction, optical microscopy, grain size analysis, total organic carbon, and the concentrations of major, trace, and rare earth elements (REEs) are analyzed in this work. The sandstones are mostly sublitharenite with calcareous cement. The content of the sandstone samples is quartz (39.8%–73.9%), with illite (7.9%–27.6%) and calcite (4.5%–29%). The mineral particles of sandstone samples are mainly well sorted with a fine particle size, suggesting strong paleohydrodynamic force. The value of SiO₂ is 37.69%–78.19%, followed by Al₂O₃ (6.11%–13.67%). Compared with upper continental crust, the boron in the sandstone samples is relatively enriched, whereas Sc, Sr, and Ba are relatively depleted. The ΣREE content is 124.46–323.99 ppm. Phosphorus is of biogenic origin and enriched by upwelling current. The source of the Xinji Formation sandstone samples was mainly a mixture of sedimentary rock, granite, and alkali basalt, with the provenance of terrestrial clastic materials. The sandstone was deposited under oxic conditions and a warm and humid paleoclimate with saline to brackish features on a passive continental margin. Phosphorus occurring in sandstones is sensitive to paleoclimate and can be used as an indicator to judge paleoclimate, as it is more enriched in warm and humid weather.

The Fengcheng Formation in the Mahu Sag of the Junggar Basin was generally composed of detritus, pyroclastic material, carbonates, and evaporites. During the process of sedimentation, the climate was arid or semi-arid. Due to the effect of high concentration and sodium-rich source, an alkaline lake was formed, and alkaline minerals were also preserved in the stratum. After the sediments were buried, three mineral assemblages were formed in the Fengcheng Formation, which are carbonate mineral assemblages (i.e., calcite + ferreous dolomite), reedmergnerite and carbonate mineral assemblages (i.e., reedmergnerite + calcite + ferreous dolomite), and reedmergnerite and alkaline mineral assemblages (i.e., reedmergnerite + shortite + trona), respectively. According to the homogenization temperature of reedmergnerite primary fluid inclusions, alkaline diagenesis of Fengcheng Formation is divided into early stage（≤100℃） and middle stage（＞100℃）, respectively. The former is characterized by the generation of ferreous saddle dolomite, quartz dissolution, and agglutination of the laumontite, which occurred under normal burial conditions. The latter is marked by the reedmergnerite’s appearance, which is correlated to deep hydrothermal activity controlled by faults. Finally, based on sedimentary and diagenetic factors, including climate, provenance, diagenetic surroundings, and the action of subsurface fluid, the alkaline deposition-diagenesis model for shale series in four stages of the Fengcheng Formation was established.

《地球科学》(ISSN 1000-2383;CN42-1874/P) (原刊名《地球科学——中国地质大学学报》ISSN 1000-2383;CN42-1233/P)，创刊于1957年，是由教育部主管、中国地质大学主办的综合性地学学术理论期刊，月刊，2015年改名为《地球科学》,她以反映中国地质大学教学与科研最新的、高水平的基础地质、应用地质、资源与环境地质及地学工程技术研究成果为主要任务。

Samara fossils of Acer were unearthed from the Early Miocene Hannuoba Formation in central Inner Mongolia, China. Based on macro- and micro-characteristics, they were identified as Acer pretataricum sp. nov. of section Ginnala, and cf. Acer mono of section Platanoidea. We reconstructed the dispersal routes of these two sections according to their fossil records. During the Early Eocene, section Ginnala was confined to North America. In the Late Eocene, this section expanded westward to East Asia. It was distributed widely in East Asia. In the Late Tertiary, it potentially recolonized the European and American continents. Meanwhile, section Platanoidea was distributed disjunctively in East Asia and North America during the Eocene. Members of this section likely expanded westward from East Asia into Europe in the Oligocene. By the Miocene, it had achieved extensive distribution in the Northern Hemisphere. However, by the Pliocene, it was confined to East Asia and Western Europe. It may have spread eastward from East Asia to North America during the Holocene, finally forming its current existence in North America and the Eurasian continent. This investigation reveals distinct differences in the dispersal pathways of two sections, suggesting that the reconstruction of dispersal routes for Acer taxa should be conducted separately at the section level.