Hydrothermal Dolomite （HTD） is present in the Upper Sinian （Upper Proterozoic） Dengying Formation, east Sichuan Basin, China. The strata are comprised by primary dolomite. The HTD has various textures, including z...Hydrothermal Dolomite （HTD） is present in the Upper Sinian （Upper Proterozoic） Dengying Formation, east Sichuan Basin, China. The strata are comprised by primary dolomite. The HTD has various textures, including zebra dolomite, subhorizontal sheet-like cavities filled by saddle dolomite and breccias cemented by saddle dolomites as well occur as a fill of veins and fractures. Also co-occur MVT type lead-zinc ores in the study area. The δ13C and δ18O isotopes of HTD in the Upper Sinian Dengying Formation are lighter than those of the host rocks, while STSr/86Sr is higher. The apparent difference in carbon, oxygen and strontium isotopes, especially the large difference in S7Sr/S6Sr isotopes ratio indicate crystallization from hot basinal and/or hydrothermal fluids. Saddle dolomite was precipitated at temperatures of 270-320℃. The diagenetic parasequences of mineral assemblage deposited in the Dengying Formation are： （1） dolomite host rock →sphalerite-galena-barite-fluorite; （2） dolomite host rock →saddle dolomite →quartz; （3） dolomite host rock →saddle dolomite→bitumen; （4） dolomite host rock →saddle dolomite →barite. The mean chemical composition of the host dolomite matrix and HTD didn＇t change much during hydrothermal process. The fluids forming the HTDs in the Dengying Formation were mixtures of freshwater from the unconformity at the top of Sinian, fluids from diagenetic compaction and hydrocarbon generation ＆ expulsion from the Lower Cambrian Niutitang Formation mudstones or the Doushantuo Formation silty mudstones, and hydrothermal fluids from the basement. The hydrocarbon reservoirs associated with the HTD were mostly controlled by the basement faults and fractures and karsting processes at the unconformity separating Sinian and Cambrian strata. The hydrocarbon storage spaces of HTD included dissolved cavities and intercrystalline pores. Dissolution cavities are extensive at the top of Dengying Formation, up to about 46m below the unconformity between Sinian and Cambrian and were generated mainly during karstification. Hydrothermal alteration enhanced the reservoir property of the Dengying Formation dolomites with 3%-5% increase in porosity. No agreement has been reached why zebra dolomite occurs only in the Upper Sinian strata, which would indicate that HTD mineralization occurred during two different periods, each of them related to major extensional tectonic event. The early one related to the Xingkai taphrogenesis （Z2-C1） and the later one to the Emei taphrogenesis （D2-T2）. But, all the data from saddle dolomite suggest that the predominant crystallization occurred during the latter event.展开更多
目的观察皮质骨轨迹螺钉(cortical bone trajectory screw,CBT)与椎弓根螺钉(pedicle screw,PS)固定治疗腰椎管狭窄症早期临床疗效评价。方法选取2017年1月至2018年12月我院收治的100例腰椎管狭窄症患者为研究对象,随机分为CBT治疗组和P...目的观察皮质骨轨迹螺钉(cortical bone trajectory screw,CBT)与椎弓根螺钉(pedicle screw,PS)固定治疗腰椎管狭窄症早期临床疗效评价。方法选取2017年1月至2018年12月我院收治的100例腰椎管狭窄症患者为研究对象,随机分为CBT治疗组和PS治疗组,各50例,对比两组患者手术时间、出血量、住院时间、并发症、疼痛视觉模拟评分(VAS)和Oswestry功能障碍指数(ODI)。结果CBT治疗组患者手术出血量少于PS治疗组(P<0.05);两组患者手术时间及住院时间差异均无统计学意义(P均>0.05);两组患者术前和术后6个月VAS评分差异均无统计学意义(P均>0.05);术后1个月CBT治疗组VAS评分低于PS治疗组(P<0.05);两组患者术前VAS评分均高于同组术后1、6个月(P均<0.05)。两组患者术前、术后1、6个月ODI评分差异均无统计学意义(P均>0.05);CBT治疗组和PS治疗组患者术后1、6个月ODI评分均低于同组术前(P均<0.05);两组患者术后并发症发生率差异无统计学意义(P>0.05)。结论在腰椎管狭窄症的治疗中CBT与PS固定均有良好效果,CBT早期对疼痛的改善效果更好,且能够降低出血量,具有一定的推广应用价值。展开更多
基金funded by National Basic Research Program of China (Grant No. 2012CB214805)
文摘Hydrothermal Dolomite （HTD） is present in the Upper Sinian （Upper Proterozoic） Dengying Formation, east Sichuan Basin, China. The strata are comprised by primary dolomite. The HTD has various textures, including zebra dolomite, subhorizontal sheet-like cavities filled by saddle dolomite and breccias cemented by saddle dolomites as well occur as a fill of veins and fractures. Also co-occur MVT type lead-zinc ores in the study area. The δ13C and δ18O isotopes of HTD in the Upper Sinian Dengying Formation are lighter than those of the host rocks, while STSr/86Sr is higher. The apparent difference in carbon, oxygen and strontium isotopes, especially the large difference in S7Sr/S6Sr isotopes ratio indicate crystallization from hot basinal and/or hydrothermal fluids. Saddle dolomite was precipitated at temperatures of 270-320℃. The diagenetic parasequences of mineral assemblage deposited in the Dengying Formation are： （1） dolomite host rock →sphalerite-galena-barite-fluorite; （2） dolomite host rock →saddle dolomite →quartz; （3） dolomite host rock →saddle dolomite→bitumen; （4） dolomite host rock →saddle dolomite →barite. The mean chemical composition of the host dolomite matrix and HTD didn＇t change much during hydrothermal process. The fluids forming the HTDs in the Dengying Formation were mixtures of freshwater from the unconformity at the top of Sinian, fluids from diagenetic compaction and hydrocarbon generation ＆ expulsion from the Lower Cambrian Niutitang Formation mudstones or the Doushantuo Formation silty mudstones, and hydrothermal fluids from the basement. The hydrocarbon reservoirs associated with the HTD were mostly controlled by the basement faults and fractures and karsting processes at the unconformity separating Sinian and Cambrian strata. The hydrocarbon storage spaces of HTD included dissolved cavities and intercrystalline pores. Dissolution cavities are extensive at the top of Dengying Formation, up to about 46m below the unconformity between Sinian and Cambrian and were generated mainly during karstification. Hydrothermal alteration enhanced the reservoir property of the Dengying Formation dolomites with 3%-5% increase in porosity. No agreement has been reached why zebra dolomite occurs only in the Upper Sinian strata, which would indicate that HTD mineralization occurred during two different periods, each of them related to major extensional tectonic event. The early one related to the Xingkai taphrogenesis （Z2-C1） and the later one to the Emei taphrogenesis （D2-T2）. But, all the data from saddle dolomite suggest that the predominant crystallization occurred during the latter event.
文摘目的观察皮质骨轨迹螺钉(cortical bone trajectory screw,CBT)与椎弓根螺钉(pedicle screw,PS)固定治疗腰椎管狭窄症早期临床疗效评价。方法选取2017年1月至2018年12月我院收治的100例腰椎管狭窄症患者为研究对象,随机分为CBT治疗组和PS治疗组,各50例,对比两组患者手术时间、出血量、住院时间、并发症、疼痛视觉模拟评分(VAS)和Oswestry功能障碍指数(ODI)。结果CBT治疗组患者手术出血量少于PS治疗组(P<0.05);两组患者手术时间及住院时间差异均无统计学意义(P均>0.05);两组患者术前和术后6个月VAS评分差异均无统计学意义(P均>0.05);术后1个月CBT治疗组VAS评分低于PS治疗组(P<0.05);两组患者术前VAS评分均高于同组术后1、6个月(P均<0.05)。两组患者术前、术后1、6个月ODI评分差异均无统计学意义(P均>0.05);CBT治疗组和PS治疗组患者术后1、6个月ODI评分均低于同组术前(P均<0.05);两组患者术后并发症发生率差异无统计学意义(P>0.05)。结论在腰椎管狭窄症的治疗中CBT与PS固定均有良好效果,CBT早期对疼痛的改善效果更好,且能够降低出血量,具有一定的推广应用价值。
