The eruption characteristics of the Tarim flood basalt

Integration of field investigation, regional stratigraphic comparison, remote sensing and image interpretation allow us to divide the Tarim Permian flood basalt province into three eruptive cycles listed by decreasing age; Kupukuziman flood basalt (KP), Felsic pyroclastic rocks (FP), Kaipaizileike flood basalt (KZ). KP features flood basalt and tuff; in the outcrop in Keping and Yingmaili areas, it can be differentiated into two units containing three thick layers of basaltic lava flows. These three layers decrease to one layer of basaltic lava flow in the Halahatang area; however, felsic pyroclastic rocks and lava layer thicknesses increase in the Halahatang area. FP in the outcrop in Keping area consists of ash fall tuff, ignimbrite, resedimented pyroclastic rocks, and the tuff layer interbedded with the normal elastic rocks section from top to bottom. This section is comparable to the tuff layer in the Yingmaili and Halahatang area, thus reveals one layer of lava flow covering an extensive area clue to a unit of the eruption of the FP. KZ mainly features flood basalt in its Kaipaizileike section, identifications of 4 eruptive units, 8 layers of flood basalt, and I layer of andesitic basalt were made. Traces of elastic rocks were found between eruption units, but no FP interlayers were found. This characteristic is different from Yingmaili and Halahatang volcanic se.quences, but similar to the flood basalt in Tazhong area. The differentiation between these three volcanic cycles reveals that Tarim flood basalt underwent a "flood basalt-felsic pyroclastic rocks-flood basalt " transformation, and is similar to Afro-Arabian large igneous province; thus, a comparative study between these two regions is merited

Soil Diversity as Affected by Land Use in China: Consequences for Soil Protection

Rapid land-use change in recent decades in China and its impact on terrestrial biodiversity have been widely studied, particularly at local and regional scales. However, the effect of land-use change on the diversity of soils that support the terrestrial biological system has rarely been studied. Here, we report the first effort to assess the impact of land-use change on soil diversity for the entire nation of China. Soil diversity and land-use effects were analyzed spatially in grids and provinces. The land-use effects on different soils were uneven. Anthropogenic soils occupied approximately 12% of the total soil area, which had already replaced the original natural soils. About 7.5% of the natural soil classes in China were in danger of substantial loss, due to the disturbance of agriculture and construction. More than 80% of the endangered soils were unprotected due to the overlook of soil diversity. The protection of soil diversity should be integrated into future conservation activities