In order to understand the petrogenesis and tectonic setting of diorite and diabase units on Doumer Island, Antarctic Peninsula, this paper reports new laser ablation-inductively coupled plasma-mass spectrometry(LA-IC...In order to understand the petrogenesis and tectonic setting of diorite and diabase units on Doumer Island, Antarctic Peninsula, this paper reports new laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS) zircon U-Pb, geochemical, and Lu-Hf isotopic data for the magmatism. The diorite and diabase samples yielded zircon U-Pb ages of 55.4 ± 0.3 and 52.8 ± 0.4 Ma, respectively. These samples are enriched in the large ion lithophile elements and the light rare earth elements, and are depleted in the high field strength elements. The zircons in these samples yield eHf(t) values from 9.03 to 11.87 and model ages(TDM2) of 342–524 Ma. The major, trace, rare earth element(REE), and Hf isotopic data for the diorites indicate that these units were formed by the mixing of magmas generated by(a) the partial melting of mantle wedge material that experienced fluid-metasomatism in a subduction zone setting, and(b) the melting of juvenile crustal material induced by the upwelling of mantle-derived magmas in a subduction–collision setting. The diabase units contain higher total REE concentrations than the diorite, indicating they were derived from a different source region. These samples also have higher Mg~# values and contain lower concentrations of Cr and Ni than the diorites, and have weakly negative Nb and Ta anomalies with Nb/Ta values of <3. The zircons in these samples yield eHf(t) values from 9.08 to 11.11 and model ages(TDM2) of 389–503 Ma. The major, trace, REE, and Hf isotopic compositions of the diabase units indicate that that they were derived from the mixing of depleted mantle-derived magmas with magmas generated by the melting of juvenile crustal material which was induced by the upwelling of the mantle into the crust. Overall the Cenozoic diorite and diabase on Doumer Island is related to subduction environment.展开更多
日龄相同的杜梅二元杂交猪40头，初始体重为20．1±0．69 kg ，随机分为2组，每组4个重复，每个重复4～6头猪，分别在有运动场的水泥地面猪舍和发酵床猪舍中饲喂101 d，全程记录试验期间每天户外、水泥地面猪舍及发酵床猪舍内的气...日龄相同的杜梅二元杂交猪40头，初始体重为20．1±0．69 kg ，随机分为2组，每组4个重复，每个重复4～6头猪，分别在有运动场的水泥地面猪舍和发酵床猪舍中饲喂101 d，全程记录试验期间每天户外、水泥地面猪舍及发酵床猪舍内的气温。结果表明，50～70日龄阶段舍内气温，水泥地面舍29．4℃、发酵床猪舍27．5℃，发酵床组日增重、采食量、料肉比均好于水泥地面组；70～90日龄阶段，水泥地面舍与发酵床舍气温相同，发酵床组日增重、料肉比均高于水泥地面组，采食量低于水泥地面组；90～130日龄阶段，发酵床猪舍气温略高于水泥地面舍，采食量、料肉比和日增重无显著差异；130～150日龄阶段，舍外气温低于19℃，发酵床舍平均气温19．9℃，水泥地面舍18．6℃，发酵床组日增重、采食量比水泥地面组分别提高了6．4％和9．9％，料肉比均为3．32。说明发酵床养猪对猪的生产性能具有促进作用，小气候环境改变是促进猪生长的关键。展开更多
基金financially supported by China Geological Survey (Grant no. DD20160060)the National Natural Science Foundation of China (Grant nos. 4153209, 41872135)
文摘In order to understand the petrogenesis and tectonic setting of diorite and diabase units on Doumer Island, Antarctic Peninsula, this paper reports new laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS) zircon U-Pb, geochemical, and Lu-Hf isotopic data for the magmatism. The diorite and diabase samples yielded zircon U-Pb ages of 55.4 ± 0.3 and 52.8 ± 0.4 Ma, respectively. These samples are enriched in the large ion lithophile elements and the light rare earth elements, and are depleted in the high field strength elements. The zircons in these samples yield eHf(t) values from 9.03 to 11.87 and model ages(TDM2) of 342–524 Ma. The major, trace, rare earth element(REE), and Hf isotopic data for the diorites indicate that these units were formed by the mixing of magmas generated by(a) the partial melting of mantle wedge material that experienced fluid-metasomatism in a subduction zone setting, and(b) the melting of juvenile crustal material induced by the upwelling of mantle-derived magmas in a subduction–collision setting. The diabase units contain higher total REE concentrations than the diorite, indicating they were derived from a different source region. These samples also have higher Mg~# values and contain lower concentrations of Cr and Ni than the diorites, and have weakly negative Nb and Ta anomalies with Nb/Ta values of <3. The zircons in these samples yield eHf(t) values from 9.08 to 11.11 and model ages(TDM2) of 389–503 Ma. The major, trace, REE, and Hf isotopic compositions of the diabase units indicate that that they were derived from the mixing of depleted mantle-derived magmas with magmas generated by the melting of juvenile crustal material which was induced by the upwelling of the mantle into the crust. Overall the Cenozoic diorite and diabase on Doumer Island is related to subduction environment.
文摘日龄相同的杜梅二元杂交猪40头，初始体重为20．1±0．69 kg ，随机分为2组，每组4个重复，每个重复4～6头猪，分别在有运动场的水泥地面猪舍和发酵床猪舍中饲喂101 d，全程记录试验期间每天户外、水泥地面猪舍及发酵床猪舍内的气温。结果表明，50～70日龄阶段舍内气温，水泥地面舍29．4℃、发酵床猪舍27．5℃，发酵床组日增重、采食量、料肉比均好于水泥地面组；70～90日龄阶段，水泥地面舍与发酵床舍气温相同，发酵床组日增重、料肉比均高于水泥地面组，采食量低于水泥地面组；90～130日龄阶段，发酵床猪舍气温略高于水泥地面舍，采食量、料肉比和日增重无显著差异；130～150日龄阶段，舍外气温低于19℃，发酵床舍平均气温19．9℃，水泥地面舍18．6℃，发酵床组日增重、采食量比水泥地面组分别提高了6．4％和9．9％，料肉比均为3．32。说明发酵床养猪对猪的生产性能具有促进作用，小气候环境改变是促进猪生长的关键。
