In order to enhance the understanding of the stage of magmatism and the relationship between Weishan alkaline complex and REE mineralization, the zircon U-Pb age and geochemistry of Weishan alkaline complex are conducted. The geochemical result shows that syenite series has the same geochemical characteristics, proving that they are from the same resource, and the syenite belong to metaluminous and alkaline series. They have high ∑REE, and distinct fractionation between HREE and LREE, exhibiting depleted in HREE, Nb, Ta, Zr, but enriched in LREE, Rb, Ba, Sr, and have slight Eu abnormality, which is consistent with the characteristics of mantle-derived magmatic rocks. The element-geochemical features reflect that the magma comes from enriched mantle. LA-ICP-MS zircon U-Pb ages of the ore-bearing quartz syenite and the aegirine-augite syenite are separately 122.4±2.0 Ma (MSWD=5.2) and 130.1±1.4 Ma (MSWD=9), and the presence of 2536±6.1 Ma (MSWD=1.6) inherited zircon is also an evidence that crustal materials have been involved in the magmatism process. It is concluded that Weishan syenites had come into being in an extensional setting after the transformation of the tectonic regime in the NCC in the Mesozoic area, when a large-scale enriched mantle melted to cause the generation of alkaline magma and a massive upwelling of the mantle materials from the asthenosphere to form finally the REE deposit after the formation of the alkaline rock complex.
In order to study whether the growth of trees existence mutations problems, measurement and calculation of the mutation based on the cusp model theory is applied to 10 common species single tree volume in Wang Ye Dian forest farm which is located in Chifeng City, Inner Mongolia, China. 10 northern common tree species were selected to carry out the experiment, the tree height (H), DBH (D), volume (V), diameter (D0) were measured which as the true value. To test the Internal and external accord accuracy of the “V-H-D” model by using the improved differential evolution algorithm and edge species and then compare the difference between model calculation value and instrument measuring. After a certain iteration, the results showed that the overall relative error (RS) of the model is in the range of [0.001, 0.05], the average relative error (E) is in the range of [-0.11, 0.02], and the overall prediction accuracy (P) is greater than 80%. The outcome had shown the good fitness of the model, namely the cusp catastrophe theory model applies to northern China 10 single species tree volume. With the growing of trees, when the height of the tree reaches a certain height, the volume will follow the theory model of cusp catastrophe theory. This is the cusp catastrophe theory model was first applied to the determination of single tree volume and got a better fitting result. Meanwhile, a low-dimensional model of mutation was established in the discontinuous measurement, which provides a theoretical and practical basis for the study of tree volume and various species of spatial competition.
