Nyiragongo volcanic eruptions of 1977 and 2002 emitted silica-undersaturated lavas named melilite-nephelinites with microlithic to sub-porphyritic textures, and consisted of olivine, clinopyroxene (augite), phlogopite...Nyiragongo volcanic eruptions of 1977 and 2002 emitted silica-undersaturated lavas named melilite-nephelinites with microlithic to sub-porphyritic textures, and consisted of olivine, clinopyroxene (augite), phlogopite, melilite, magnetite, and rare plagioclases. This melilite-nephelinite as an evolved rock, shows low SiO<sub>2</sub> (38.40 - 39.52 wt%) and MgO (3.10 - 4.01 wt%), and relatively high FeOt (13.76 - 14.10 wt%), Al<sub>2</sub>O<sub>3</sub> (15.01 - 16.48 wt%), CaO (11.00 - 12.29 wt%) and Na<sub>2</sub>O + K<sub>2</sub>O (10.34 - 11.85 wt%). Unlike LA-ICP-MS on silicate melt inclusions (SMIs) hosted in augite show a pristine melt of picrobasaltic (low Ti-picrite) rock poor in SiO<sub>2</sub> (31.14 - 32.26 wt%), FeOt (2.19 - 2.79 wt%), Al<sub>2</sub>O<sub>3</sub> (8.01 - 9.57 wt%), and Na<sub>2</sub>O + K<sub>2</sub>O (2.34 - 3.05 wt%), while enriched in MgO (20.27 - 28.63 wt%), and CaO (24.95 - 33.17 wt%). The sums (∑REEs) for lavas and SMIs are ranging 712 - 799 and 43 - 119 ppm respectively. REE contracted multi-element patterns showed a W-feature for most lavas except for SMIs. High Rb/Sr, and low Ba/Rb, Zr/Nb, and Sm/Hf ratios of lavas suggest a phlogopite-rich source of materials. .展开更多
Peperites are generated by magma intruding and mingling with wet unconsolidated or poorly consolidated sediments.Late Paleozoic peperites have been identified in the Darbut and Baijiantan ophiolitic belts at West Jung...Peperites are generated by magma intruding and mingling with wet unconsolidated or poorly consolidated sediments.Late Paleozoic peperites have been identified in the Darbut and Baijiantan ophiolitic belts at West Junggar,NW China.The peperites form successions up to 500 m thick interbedded with basaltic lava(sometimes pillow lava)and sedimentary rocks(i.e.limestones).The peperites are described and interpreted as resulting from basaltic lava bulldozed into wet,unconsolidated sediments at their basal contacts.The peperitebearing units are generally undeformed,occurring in continuous stratigraphic sections distributed regionally over a distance of 100 km on either side of the Darbut and Baijiantan ophiolitic belts,in contrast to the highly deformed slices of ophiolite.They demonstrate that the Darbut and Baijiantan ophiolitic belts should not be interpreted as significant plate boundaries and represent the underlying ocean crust uplifted along tectonic lineaments within a continuous shallow remnant ocean basin.Jordan et al.(2008)reported an occurrence of peperite in the Oman—United Arab Emirates(UAE)border region.In this border area the field relations of the pillow lavas surrounded by limestone with deformed bedding and peperite boundaries between the pillows and the limestone are consistent with the pillow lavas forming directly within carbonate sediments.The pillow lavas in Oman-UAE border area likely have formed as intrusions into water-saturated carbonate sediments deposited along the edges of seamounts.Based on the comparative study on the peperites associated pillow lavas within ophiolites between West Junggar and Oman,this paper proposes that the ophiolites with peperites associated pillow lavas surrounded by limestone were not formed in a typical ocean basin,but a shallow remnant ocean basin.展开更多
The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission...The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission.Lunar lava tubes are special underground caves formed by volcanic eruptions and are considered as ideal natural shelters and scientific laboratories for lunar base construction.This paper begins with an in-depth overview of the geological origins,exploration history,and distribution locations of lunar lava tubes.Subsequently,it delves into the presentation of four distinctive advantages and typical concepts for constructing bases within lava tubes,summarizing the ground-based attempts made thus far in lunar lava tube base construction.Field studies conducted on a lava tube in Hainan revealed rock compositions similar to those found during the Apollo missions and clear lava tube structures,making it a promising analog site.Lastly,the challenges and opportunities encountered in the field of geotechnical engineering regarding the establishment of lunar lava tube bases are discussed,encompassing cave exploration technologies,in-situ testing methods,geomechanical properties under lunar extreme environments,base design and structural stability assessment,excavation and reinforcement techniques,and simulated Earth-based lava tube base.展开更多
The carbonatite lavas found in the Kunyang Group were formed in submarine extrusive environment. Many igneous features (e.g. colors, textures, structures, minerals, inclusions) are clear. But most of their petrologic ...The carbonatite lavas found in the Kunyang Group were formed in submarine extrusive environment. Many igneous features (e.g. colors, textures, structures, minerals, inclusions) are clear. But most of their petrologic characteristics are different from typical carbonatites over the world. Most petrologic details of the rocks are given by comparison with other carbonatites and adjacent sedimentary dolomites. The discovery of the lavas proves that the carbonatite volcano also existed in Kunyang rift.展开更多
Field observation showed that there are many irregular leucocratic intrusive rocks in pillow lavas in the Danfeng Group in the Xiaowangjian area, north Qinling orogenic belt. Photomicrographs indicated that the protol...Field observation showed that there are many irregular leucocratic intrusive rocks in pillow lavas in the Danfeng Group in the Xiaowangjian area, north Qinling orogenic belt. Photomicrographs indicated that the protoliths of those altered leucocratic intr展开更多
Based on the geological mapping, it is suggested that the pillow lavas exposed in Jianshui area in southeastern Yunnan Province are emplaced into the western part of Shizong-Mile faults, the boundary between the Yangt...Based on the geological mapping, it is suggested that the pillow lavas exposed in Jianshui area in southeastern Yunnan Province are emplaced into the western part of Shizong-Mile faults, the boundary between the Yangtze and Cathaysian blocks, and mainly composed of tectonic massive of basalts and basaltic andsites. The geological and geochemical studies show that these lavas erupted in an island arc tectonic setting, which suggests that there existed the subduction of oceanic crust between the Yangtze and Cathaysian blocks. The paleontological fossils in the sedimentary interlayers between the volcanic rocks indicate that these pillow lavas erupted during Carboniferous-Permian. The geologic and geochemical evidence suggested that there existed an eastern branch of Paleo-Tethys between the Yangtze and Cathaysian blocks in southeastern Yunnan, South China.展开更多
The Noorabad-Harsin ophiolite is a part of the eastern Mediterranean-Zagros-Oman Tethyan ophiolites. This area is located in the south-southwest of the main Zagros thrust zone. This ophiolite consists of peridotites, ...The Noorabad-Harsin ophiolite is a part of the eastern Mediterranean-Zagros-Oman Tethyan ophiolites. This area is located in the south-southwest of the main Zagros thrust zone. This ophiolite consists of peridotites, serpentinites and pegmatite gabbros as mantle sequence whereas crustal sequence is composed of locally layered gabbros, isotropic gabbros, sheeted dike complex, basaltic to andesitic lavas and sedimentary rocks （radiolarites and Late Cretaceous pelagic limes- tones）. The diabase dikes are enriched in LREE relative to HREE （La（n）/Yb（n）=1.7-3.3）. Also, the andesites are enriched in LREE relative to HREE （La（n）/Yb（n）=3.1-5.37） and the pillow lavas are enriched in LILE （Th（n）/La（n）=2.1） while show a depletion in HFSE （Nb（n）/La（n）=0.07-0.2）. The basaltic-andesitic lavas exhibiting mainly calc-alkaline, with minor island-arc tholeiitic affinities, are characterized by enrichment in LILE and LREE and depletion in HFSE. These geochemical characteristics compared with other Tethyan ophiolites along the Bitlis-Zagros suture zone reveal a supra- subduction zone environment for the genesis of the Noorabad-Harsin ophiolites.展开更多
目的探讨树脂纳米陶瓷Lava Ultimate髓腔内固位冠修复老年脑卒中病人短冠磨牙的疗效。方法收集研究2018年3月至2021年10月北京市大兴区医院老年脑卒中短冠磨牙病人124例,根据修复方案分为两组,采用紫荆氧化锆全瓷冠修复治疗的61例病人...目的探讨树脂纳米陶瓷Lava Ultimate髓腔内固位冠修复老年脑卒中病人短冠磨牙的疗效。方法收集研究2018年3月至2021年10月北京市大兴区医院老年脑卒中短冠磨牙病人124例,根据修复方案分为两组,采用紫荆氧化锆全瓷冠修复治疗的61例病人为对照组,采用树脂纳米陶瓷Lava Ultimate髓腔内固位冠修复治疗的63例为观察组。采用改良美国公共卫生机构(United States public health service,USPHS)标准比较两组修复后6、12个月修复效果、微渗漏分级、并发症发生率、修复前、修复后12个月口腔健康影响程度量表中文版(OHIP-14)评分及修复后12个月李克特量表(Likert scale)评分。结果修复效果:修复后12个月观察组边缘密合度、颜色匹配度、修复体折裂、牙体完整性、继发龋合格率分别为93.65%(59/63)、93.65%(59/63)、96.83%(61/63)、96.83%(61/63)、95.24%(60/63),均高于对照组[80.33%(49/61)、81.97%(50/61)、83.61%(51/61)、81.97%(50/61)、83.61%(51/61)](P<0.05);微渗漏分级:两组修复后6、12个月微渗漏分级比较,差异无统计学意义(P>0.05);并发症:观察组并发症发生率3.17%(2/63)低于对照组14.75%(9/61)(P<0.05);口腔健康相关生活质量:修复后12个月观察组OHIP-14量表功能限制、生理疼痛、心理不适、生理障碍、心理障碍、社交障碍评分分别为(1.89±0.57)分、(2.03±0.62)分、(0.92±0.30)分、(0.53±0.18)分、(0.42±0.10)分、(0.63±0.25)分,均低于对照组[(2.55±0.74)分、(2.73±0.88)分、(1.29±0.27)分、(0.74±0.26)分、(0.31±0.13)分、(0.89±0.20)分](P<0.05);修复效果满意度:修复后12个月观察组修复效果自我评估、并发症满意度、生活质量满意度评分依次为(4.62±0.39)分、(4.25±0.44)分、(4.57±0.40)分,均高于对照组[(4.12±0.35)分、(3.86±0.35)分、(4.03±0.46)分](P<0.05)。结论树脂纳米陶瓷Lava Ultimate髓腔内固位冠修复应用于老年脑卒中病人短冠磨牙,修复效果良好,有助于降低并发症发生率,提高口腔健康相关生活质量,改善修复效果满意度。展开更多
目的探讨透视触发3DLAVA技术对肝实质病变及血管的显示情况。方法21例经手术病理或治疗后确诊的肝实质内病变的患者选入本次研究。应用1.5T扫描仪（GE Excite HD Twinspeed1.5T）。动脉期应用透视触发技术,以确保肝脏动脉早期的成功显...目的探讨透视触发3DLAVA技术对肝实质病变及血管的显示情况。方法21例经手术病理或治疗后确诊的肝实质内病变的患者选入本次研究。应用1.5T扫描仪（GE Excite HD Twinspeed1.5T）。动脉期应用透视触发技术,以确保肝脏动脉早期的成功显示。对所有时相的主动脉、门脉、肝实质及病灶绘制信号强度-时间曲线,同时对动脉相及门脉相采用最大密度投影（MIP）,观察肝动脉及门脉的显示情况。结果21例病人均获得高质量6~8个时相的全肝图像。信号强度-时间曲线显示所有病例的门脉及肝实质均在第三个时相达到峰值,而不同病灶的信号强度-时间曲线各有特点,对诊断能够提供更多的帮助。MIP结合原图能清楚显示肝固有动脉的3~4级分支,对门脉系统的显示率达到100%。结论透视触发3DLAVA技术能够清楚显示肝实质病变的动态增强特点,能够清楚显示肝动脉、门脉的分支及其与病灶的关系。展开更多
文摘Nyiragongo volcanic eruptions of 1977 and 2002 emitted silica-undersaturated lavas named melilite-nephelinites with microlithic to sub-porphyritic textures, and consisted of olivine, clinopyroxene (augite), phlogopite, melilite, magnetite, and rare plagioclases. This melilite-nephelinite as an evolved rock, shows low SiO<sub>2</sub> (38.40 - 39.52 wt%) and MgO (3.10 - 4.01 wt%), and relatively high FeOt (13.76 - 14.10 wt%), Al<sub>2</sub>O<sub>3</sub> (15.01 - 16.48 wt%), CaO (11.00 - 12.29 wt%) and Na<sub>2</sub>O + K<sub>2</sub>O (10.34 - 11.85 wt%). Unlike LA-ICP-MS on silicate melt inclusions (SMIs) hosted in augite show a pristine melt of picrobasaltic (low Ti-picrite) rock poor in SiO<sub>2</sub> (31.14 - 32.26 wt%), FeOt (2.19 - 2.79 wt%), Al<sub>2</sub>O<sub>3</sub> (8.01 - 9.57 wt%), and Na<sub>2</sub>O + K<sub>2</sub>O (2.34 - 3.05 wt%), while enriched in MgO (20.27 - 28.63 wt%), and CaO (24.95 - 33.17 wt%). The sums (∑REEs) for lavas and SMIs are ranging 712 - 799 and 43 - 119 ppm respectively. REE contracted multi-element patterns showed a W-feature for most lavas except for SMIs. High Rb/Sr, and low Ba/Rb, Zr/Nb, and Sm/Hf ratios of lavas suggest a phlogopite-rich source of materials. .
基金granted by the Natural Science Foundation of China(NSFC Grant No.41572199)
文摘Peperites are generated by magma intruding and mingling with wet unconsolidated or poorly consolidated sediments.Late Paleozoic peperites have been identified in the Darbut and Baijiantan ophiolitic belts at West Junggar,NW China.The peperites form successions up to 500 m thick interbedded with basaltic lava(sometimes pillow lava)and sedimentary rocks(i.e.limestones).The peperites are described and interpreted as resulting from basaltic lava bulldozed into wet,unconsolidated sediments at their basal contacts.The peperitebearing units are generally undeformed,occurring in continuous stratigraphic sections distributed regionally over a distance of 100 km on either side of the Darbut and Baijiantan ophiolitic belts,in contrast to the highly deformed slices of ophiolite.They demonstrate that the Darbut and Baijiantan ophiolitic belts should not be interpreted as significant plate boundaries and represent the underlying ocean crust uplifted along tectonic lineaments within a continuous shallow remnant ocean basin.Jordan et al.(2008)reported an occurrence of peperite in the Oman—United Arab Emirates(UAE)border region.In this border area the field relations of the pillow lavas surrounded by limestone with deformed bedding and peperite boundaries between the pillows and the limestone are consistent with the pillow lavas forming directly within carbonate sediments.The pillow lavas in Oman-UAE border area likely have formed as intrusions into water-saturated carbonate sediments deposited along the edges of seamounts.Based on the comparative study on the peperites associated pillow lavas within ophiolites between West Junggar and Oman,this paper proposes that the ophiolites with peperites associated pillow lavas surrounded by limestone were not formed in a typical ocean basin,but a shallow remnant ocean basin.
基金supported by the National Natural Science Foundation of China(Nos.52125903 and 52339001).
文摘The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission.Lunar lava tubes are special underground caves formed by volcanic eruptions and are considered as ideal natural shelters and scientific laboratories for lunar base construction.This paper begins with an in-depth overview of the geological origins,exploration history,and distribution locations of lunar lava tubes.Subsequently,it delves into the presentation of four distinctive advantages and typical concepts for constructing bases within lava tubes,summarizing the ground-based attempts made thus far in lunar lava tube base construction.Field studies conducted on a lava tube in Hainan revealed rock compositions similar to those found during the Apollo missions and clear lava tube structures,making it a promising analog site.Lastly,the challenges and opportunities encountered in the field of geotechnical engineering regarding the establishment of lunar lava tube bases are discussed,encompassing cave exploration technologies,in-situ testing methods,geomechanical properties under lunar extreme environments,base design and structural stability assessment,excavation and reinforcement techniques,and simulated Earth-based lava tube base.
文摘The carbonatite lavas found in the Kunyang Group were formed in submarine extrusive environment. Many igneous features (e.g. colors, textures, structures, minerals, inclusions) are clear. But most of their petrologic characteristics are different from typical carbonatites over the world. Most petrologic details of the rocks are given by comparison with other carbonatites and adjacent sedimentary dolomites. The discovery of the lavas proves that the carbonatite volcano also existed in Kunyang rift.
基金the National Natural Science Foundation of China (Grant No. 40472119)the Programme of Excellent Young Scientists of the Ministry of Land and Resourcesof China+1 种基金the Ministry of Science and Technology of China (Grant Nos. 2002CB412608 and 2006BABOlAll)the China Geological Survey (Grant Nos. 1212010633601 and 1212010611807)
文摘Field observation showed that there are many irregular leucocratic intrusive rocks in pillow lavas in the Danfeng Group in the Xiaowangjian area, north Qinling orogenic belt. Photomicrographs indicated that the protoliths of those altered leucocratic intr
文摘Based on the geological mapping, it is suggested that the pillow lavas exposed in Jianshui area in southeastern Yunnan Province are emplaced into the western part of Shizong-Mile faults, the boundary between the Yangtze and Cathaysian blocks, and mainly composed of tectonic massive of basalts and basaltic andsites. The geological and geochemical studies show that these lavas erupted in an island arc tectonic setting, which suggests that there existed the subduction of oceanic crust between the Yangtze and Cathaysian blocks. The paleontological fossils in the sedimentary interlayers between the volcanic rocks indicate that these pillow lavas erupted during Carboniferous-Permian. The geologic and geochemical evidence suggested that there existed an eastern branch of Paleo-Tethys between the Yangtze and Cathaysian blocks in southeastern Yunnan, South China.
文摘The Noorabad-Harsin ophiolite is a part of the eastern Mediterranean-Zagros-Oman Tethyan ophiolites. This area is located in the south-southwest of the main Zagros thrust zone. This ophiolite consists of peridotites, serpentinites and pegmatite gabbros as mantle sequence whereas crustal sequence is composed of locally layered gabbros, isotropic gabbros, sheeted dike complex, basaltic to andesitic lavas and sedimentary rocks （radiolarites and Late Cretaceous pelagic limes- tones）. The diabase dikes are enriched in LREE relative to HREE （La（n）/Yb（n）=1.7-3.3）. Also, the andesites are enriched in LREE relative to HREE （La（n）/Yb（n）=3.1-5.37） and the pillow lavas are enriched in LILE （Th（n）/La（n）=2.1） while show a depletion in HFSE （Nb（n）/La（n）=0.07-0.2）. The basaltic-andesitic lavas exhibiting mainly calc-alkaline, with minor island-arc tholeiitic affinities, are characterized by enrichment in LILE and LREE and depletion in HFSE. These geochemical characteristics compared with other Tethyan ophiolites along the Bitlis-Zagros suture zone reveal a supra- subduction zone environment for the genesis of the Noorabad-Harsin ophiolites.
文摘目的探讨树脂纳米陶瓷Lava Ultimate髓腔内固位冠修复老年脑卒中病人短冠磨牙的疗效。方法收集研究2018年3月至2021年10月北京市大兴区医院老年脑卒中短冠磨牙病人124例,根据修复方案分为两组,采用紫荆氧化锆全瓷冠修复治疗的61例病人为对照组,采用树脂纳米陶瓷Lava Ultimate髓腔内固位冠修复治疗的63例为观察组。采用改良美国公共卫生机构(United States public health service,USPHS)标准比较两组修复后6、12个月修复效果、微渗漏分级、并发症发生率、修复前、修复后12个月口腔健康影响程度量表中文版(OHIP-14)评分及修复后12个月李克特量表(Likert scale)评分。结果修复效果:修复后12个月观察组边缘密合度、颜色匹配度、修复体折裂、牙体完整性、继发龋合格率分别为93.65%(59/63)、93.65%(59/63)、96.83%(61/63)、96.83%(61/63)、95.24%(60/63),均高于对照组[80.33%(49/61)、81.97%(50/61)、83.61%(51/61)、81.97%(50/61)、83.61%(51/61)](P<0.05);微渗漏分级:两组修复后6、12个月微渗漏分级比较,差异无统计学意义(P>0.05);并发症:观察组并发症发生率3.17%(2/63)低于对照组14.75%(9/61)(P<0.05);口腔健康相关生活质量:修复后12个月观察组OHIP-14量表功能限制、生理疼痛、心理不适、生理障碍、心理障碍、社交障碍评分分别为(1.89±0.57)分、(2.03±0.62)分、(0.92±0.30)分、(0.53±0.18)分、(0.42±0.10)分、(0.63±0.25)分,均低于对照组[(2.55±0.74)分、(2.73±0.88)分、(1.29±0.27)分、(0.74±0.26)分、(0.31±0.13)分、(0.89±0.20)分](P<0.05);修复效果满意度:修复后12个月观察组修复效果自我评估、并发症满意度、生活质量满意度评分依次为(4.62±0.39)分、(4.25±0.44)分、(4.57±0.40)分,均高于对照组[(4.12±0.35)分、(3.86±0.35)分、(4.03±0.46)分](P<0.05)。结论树脂纳米陶瓷Lava Ultimate髓腔内固位冠修复应用于老年脑卒中病人短冠磨牙,修复效果良好,有助于降低并发症发生率,提高口腔健康相关生活质量,改善修复效果满意度。
文摘目的探讨透视触发3DLAVA技术对肝实质病变及血管的显示情况。方法21例经手术病理或治疗后确诊的肝实质内病变的患者选入本次研究。应用1.5T扫描仪（GE Excite HD Twinspeed1.5T）。动脉期应用透视触发技术,以确保肝脏动脉早期的成功显示。对所有时相的主动脉、门脉、肝实质及病灶绘制信号强度-时间曲线,同时对动脉相及门脉相采用最大密度投影（MIP）,观察肝动脉及门脉的显示情况。结果21例病人均获得高质量6~8个时相的全肝图像。信号强度-时间曲线显示所有病例的门脉及肝实质均在第三个时相达到峰值,而不同病灶的信号强度-时间曲线各有特点,对诊断能够提供更多的帮助。MIP结合原图能清楚显示肝固有动脉的3~4级分支,对门脉系统的显示率达到100%。结论透视触发3DLAVA技术能够清楚显示肝实质病变的动态增强特点,能够清楚显示肝动脉、门脉的分支及其与病灶的关系。
