Viséan Fossil Plants from the Jiujialu Formation in Central Guizhou Province: Implications for Age of Bauxite and Palaeoenvironment

Abstract

Fossil plants from the carbonaceous shale of upper part of the Lower Carboniferous Jiujialu Formation in Lindai bauxite deposit fill a gap regarding the distribution of Early Carboniferous flora in Central Guizhou Province. Here the Lindai plant assemblage is systematically described, and its composition and geological age are discussed. Research demonstrates that 9 species in 6 genera of the fossil plants are discovered in this study, and they belong to lycopsids, sphenopsids and ferns, respectively. Based on the analysis of the floral composition, the geological age of the Lindai plant assemblage belongs to the Early Carboniferous Viséan. The discovery of Lindai plant assemblage not only provides a new fossil evidence to restrict the age of bauxite deposits in Lower Carboniferous Jiujialu Formation of Central Guizhou Province, but also has great significance to further research the palaeoecological setting and floral evolution during the Early Carboniferous.

Peat Accumulation and Early Carboniferous Environments of the Kizel Coal Basin, the Urals, Russia

“…Based on the current study, this type of locality corresponds to a zone of swampy-forest vegetation enriched by different species, both grassy and arborescent. Such plant communities of swampy forest are typical of many localities of the Euramerican paleofloristic realm (Chaloner and Meyen, 1977;Wagner et al, 1983;DiMichele et al, 2002DiMichele et al, , 2007Greb et al, 2006;Willard et al, 2007;Oplustil et al, 2009;Naugolnykh and Jin, 2014;etc) and the Cathaysian realm (Luo et al, 2020). These communities, very similar to each other physiognomically, were characteristic of both the Early Carboniferous (Mississippian) and the Middle to Late Carboniferous (Pennsylvanian) floras of Euramerica.…”

Effect of Karst Geomorphology on the Sedimentary Mineralization and Geochemical Distribution of Bauxite: An Example from the Xiaoyuan Area in Qingzhen, Guizhou Province

“…At the end of the Ordovician, the Duyun Movement caused an uplift of the central Guizhou region from underwater to land, forming the Central Guizhou Uplift [17,19]. In the middle stage of the early Devonian, the seawater transgression from south to north created a sea basin in the southern Guizhou area, although the area from Hezhang County to Anshun City, Kaili City, and Sandu County remained a terrestrial environment [4]. The sea level dropped in the middle and late Devonian, but the sea water did not completely withdraw from the southern Guizhou area.…”

“…The section can be divided into the top bauxite stratum (Xy1), lower bauxite stratum (Xy3-8), and bottom iron clay stratum (Xy9-11). The top bauxite layer is thought to have been formed by re-silicification caused by humic acid during late diagenesis [4]. The interbedding of the clastic and compact structures and the inclusion of a clay rock mass in the central bauxite layer show the alternations of the hydrodynamic transport strength and rapid accumulation [14].…”

“…The Jiujialu Formation bauxite was deposited in a closed lagoon basin until a largescale regression occurred in the middle stage of the Viséan, transforming the lagoon into saline, alkali land with high salinity due to evaporation. Subsequently, the salinity levels decreased due to precipitation and surface runoff, and the area evolved into a swamp covered by early Carboniferous flora [4,31]. As the plants grew, humic acid was generated and deposited in the upper part of the Jiujialu Formation due to atmospheric precipitation and surface runoff, resulting in a weakly acidic environment.…”

“…The bauxite deposits in the central Guizhou region were largely formed during the warm and humid Viséan stage of the Carboniferous [1][2][3][4][5]. Most are karst bauxite deposits based on bedrock lithology [6].…”