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A monzogranite dike cuts through the ludwigite orebody in the open pit of Wengquangou boron deposit, Liaodong Peninsula. Samples of the dike are collected for thin section and zircon LA-ICP-MS U-Pb geochronology analysis. The monzogranite dike is characterized by high SiO2 content (71.82%-75.68%) and high Na2O+K2O content (8.41%-10.57%), belonging to calc alkali-high K calc alkaline series granite. The zircon grains in the dikes are euhedral column in shape and dark in the CL image due to the high uranium content. The U-Pb upper intercept age is 1842±29 Ma, among which 9 testing points yield the weighted average age of 1842±30 Ma, indicating that the emplacement age of dike was Late Paleoproterozoic and the Wengquangou ludwigite deposit should be formed earlier. The age is consistent with the post-peak time of metamorphism in the Paleoproterozoic Jiao-Liao-Ji orogeny, reflecting the boron mineralization occurred during the process. [ABSTRACT FROM AUTHOR]

A new species of Ginkgo L., G. pediculata sp. nov., is described from the Lower Cretaceous of Liaoning Province, Northeast China, on the basis of a well-preserved ovule-bearing organ. The cuticles of the integument and peduncle are generally similar to those of the lamina and petiole of the associated Ginkgoites manchurica (Yabe et Ôishi) Cao, which is among the most widely distributed Ginkgo -like leaves in the Lower Cretaceous of Northeast China. The new species is close to the Jurassic Ginkgo yimaensis Zhou et Zhang and clearly distinguished from the Paleogene species Ginkgo cranei Zhou et al. and the extant Ginkgo biloba. Although the coeval Ginkgo apodes Zheng et Zhou and G. neimengensis Xu et al. from Northeast China bear more ovules, they both have no pedicel when matured as the living species. The associated Ginkgoites -type leaves morphologically also resemble those of the Jurassic species. Therefore, Ginkgo pediculata sp. nov. appears to be closely related to the Jurassic species and is the latest representative of the group with primitive type ovulate organs and vegetative leaves so far known of Ginkgo. Since there co-exist two different types of ginkgoes, one with primitive characters (Ginkgo pediculata) and the other such as Ginkgo apodes and G. neimengensis which resemble the extent species G. biloba , the Lower Cretaceous is a critical time in the morphological evolution of the genus Ginkgo , roughly corresponding to the major global floristic transformation marked by the rapid decline of gymnosperms and drastic rise of flowering plants. • A new species is described from the Lower Cretaceous of Northeast China. • The new species appears to be the latest representative of primitive Ginkgo. • The Early Cretaceous is a critical time in the evolution of the genus Ginkgo. [ABSTRACT FROM AUTHOR]

• The Wulong gold deposit was formed in the early Cretaceous. • The ore-forming fluids could be magmatic in origin. • The deposit was formed during lithospheric thinning of the eastern North China Craton. The Wulong deposit is the largest quartz vein-type gold deposit in the eastern Liaoning Province of China. The gold ore bodies are hosted by Mesozoic biotite-granites. The mineralization occurs as veins with lenticular shapes. Laser-ablation-ICP–MS zircon U–Pb dating was used to date the biotite-granite, granite porphyry, and fine-grained diorites at the Wulong deposit, yielding ages of 155.4 ± 0.9 Ma, 154.2 ± 1.2 Ma, and 123.1 ± 0.9 Ma, respectively. A sericite sample from the gold ore yields a 40Ar–39Ar plateau age of 122.8 ± 0.8 Ma (MSWD = 0.09). The calculated δ18O w values for the quartz range from 4.8% to 8.6% and the δD W values of fluid inclusion waters in quartz vary from −98% to −77%. The H–O isotope data indicates that ore-forming fluids could be of a magmatic origin. The δ34S values of metallic sulfides range from +1.1% to +2.4%, with an average of +1.8%, suggesting that the sulfur is derived from a magmatic source. The 3He/4He ratios of fluid inclusions in pyrite range from 0.36 to 0.65 Ra with an average of 0.50 Ra. The mantle helium involved in the ore-forming fluid ranges from 3.9% to 7.2%, indicating a crustal fluid source. The Wulong gold deposit was formed at ca. 120 Ma and it has a genetic association with contemporaneous fine-grained diorite. The Wulong deposit was formed during lithospheric thinning of the eastern North China Craton during the early Cretaceous. [ABSTRACT FROM AUTHOR]