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Heilangou gold deposit is located in the east of Jiaobei area, and the proven gold reserves currently account for more than 70 % of that of Penglai area. The intrusive rocks related to mineralization in this area are rich in silicon, and alkali while lacking magnesium, with TFeO (1.22 %-12.36 %,with an average of 3.38 %),and the Rb mass fraction is less than 270×10-6. The REE chondrite-normalized distribution curve has an obvious right-leaning distribution model and weak positive Eu anomaly, and the w (Rb)/w (Nb) value is 7.8-36.0,which is A-type granite, with the characteristic of low-Mg adakites. The crystal ages of intrusive rocks measured by the LA-ICP-MS zircon U-Pb method are respectively (172.8±0.3)Ma, (172.8±0.4)Ma, and (174.0±0.4)Ma, which are all related to magmatic activity in the early Middle Jurassic. Heilangou gold area is mainly controlled by the lower crust and lithospheric mantle, and the source of ore-forming material is related to the partial melting of the crust and upwelling of lithospheric mantle and asthenosphere mantle, which belongs to the mixed material source of crust and mantle. [ABSTRACT FROM AUTHOR]

Protection of cultivated land around cities has been an important topic in the territorial spatial planning, which is of great significance in guaranteeing ecological and food security and contributing to the sustainable development of cities. In this study, we quantified the synergistic relationship between natural quality characteristics and surrounding site conditions of cultivated land, by integrating the three-line demarcation requirements of permanent basic cultivated land red line, ecological red line, and urban development boundary. On the basis of Land Evaluation and Site Assessment (LESA) theory, this study establishes a cultivated land suitability evaluation system based on the comprehensive evaluation system of natural quality and site conditions, establishes cultivated land use and protection zones around the main urban area of Anshan City, and puts forward the control measures of cultivated land protection zones. The results showed that the cultivated land in the main urban area of Anshan could be divided into four types: permanent basic cultivated land area accounting for 80.7%, permanent basic cultivated land reserve area accounting for 10.15%, urban development boundary flexible use area accounting for 3.98%, and ecological restoration area accounting for 5.17%. The evaluation results reflected the differences in the cultivated land quality and site environment stability and integrated the policy requirements of the three-line demarcation. The layout of cultivated land around the main urban area was effectively explored, and the permanent basic farmland protection zone was delineated, which met the requirements of flexible development of urban boundaries and control of ecological red line for effective land use. [ABSTRACT FROM AUTHOR]