Using Fourier transform infrared spectroscopy(FTIR),we measured water contents in quartz and feldspar for four kinds of felsic rocks,i.e.,undeformed granite,banded granitic gneiss,fine-grained felsic mylonite,and fine...Using Fourier transform infrared spectroscopy(FTIR),we measured water contents in quartz and feldspar for four kinds of felsic rocks,i.e.,undeformed granite,banded granitic gneiss,fine-grained felsic mylonite,and fine-grained quartz-mica schist,collected from Pengguan Complex and Kangding Complex in the Longmenshan tectonic zone,Sichuan,China.The absorbance spectra suggest that water in coarse-grained quartz and feldspar of undeformed granite and banded granitic gneiss occurs mainly as hydroxyl in crystal defects,and water in most of fine-grained quartz and feldspar of felsic mylonite is molecular water in inclusions and liquid-type water in grain boundaries,but in some cases it still occurs as hydroxyl in crystal defects.Water content of quartz in undeformed granite is 0.001 wt%-0.009 wt %,and that of feldspar 0.005 wt%-0.02 wt%.The banded granitic gneiss shows water contents of 0.002 wt%-0.011 wt% in quartz and 0.012 wt%-0.036 wt% in feldspar.Quartz ribbon and feldspar ribbon in fine-grained felsic mylonite show that their water contents are similar to those of coarse-grained quartz and feldspar in granite,0.002 wt%-0.011 wt%,and 0.004 wt%-0.02 wt%,respectively.Water contents of fine-grained quartz and feldspar are respectively 0.004 wt%-0.02 wt% and 0.012 wt%-0.06 wt%.Water content of quartz in fine-grained quartz-mica schist is 0.007 wt%-0.15 wt%.Water-bearing minerals display much higher water contents than those of nominally anhydrous minerals,and the percentage of water-bearing minerals in felsic rocks increases with the strain of rocks.These new data indicate that hydroxyl in crystal defects has basically not been released during the shear deformation,and on the contrary,the increase in molecular water in inclusions and liquid-type water in grain boundaries as well as water-bearing minerals after shear deformation leads to a significant increase of the water content in deformed rocks.Based on data of creep tests,it is inferred here that the fine-grained mylonites with more water have much lower strength t展开更多
Dust generated from bolt hole drilling in roof bolting operation could have high quartz content. As a dust control measure, vacuum drilling is employed on most of the roof bolters in US underground mines. However, fin...Dust generated from bolt hole drilling in roof bolting operation could have high quartz content. As a dust control measure, vacuum drilling is employed on most of the roof bolters in US underground mines. However, fine rock partic- ulates from drilling could escape from the dust collection system and become airborne under some circumstances causing the roof bolter operators expose to quartz-rich respirable dust. A previous research shows that drilling can be controlled through properly selected penetration and rotational rates to reduce the specific energy of drilling. Less specific energy means less energy is wasted on generating noise, heat and over-breakage of rock. It implies that proper control of drilling has a great potential to generate significantly less fine rock dust during drilling. The drilling experiments have been conducted to study the effect of controlling drilling on reducing respirable dust. The preliminary results show that the size distributions of respirable dust were different when controlling drilling in different bite depths. This paper presents the findings from laboratory experimental studies.展开更多
Minerals are the main components of sediments, whose terrigenous parts are carried into the ocean by rivers or winds and deposit directly or indirectly. The amount of the terrigenous minerals in marine sediments indir...Minerals are the main components of sediments, whose terrigenous parts are carried into the ocean by rivers or winds and deposit directly or indirectly. The amount of the terrigenous minerals in marine sediments indirectly indicates the source area of supply and the strength of the transport agent. Minerals in sediment are strongly affected by tectonic movement and geomorphic evolution in long time scale. Therefore, large tectonic movement must lead to change of mineral components and fluxes. The South China Sea(SCS)basin experienced two tectonic expansions in Cenozoic; the second expansion occurred between 32～15.5Ma, formed the central basin. The Palawan block moved far away from the northern continent. The Tibet Plateau experienced three accelerated uplifts at 25～17Ma.B.P, 10～8Ma.B.P and ～4Ma.B.P～present In order to determine the effective tectonic movement proxy indexes and find more evidence for the two large tectonic events in marginal sea sedimentary mineral composition and their fluxes were studied. Quartz, feldspar, clay minerals and terrigenous minerals were extracted from the sediments of site 1 148 of ODP LEG 184 by chemical dissolution method, the contents and their mass accumulation rate(MAR)were calculated. According to the chronology data in the initial report of ODP LEG 184, vertical distribution of the terrigenous minerals and their content and fluxes against age were established. Therefore, the response of content and flux of terrigenous minerals to the expansion of South China Sea floor(SCS)and the uplift of the Tibet Plateau were discussed. The results showed that the highest terrigenous mineral components between 33～27.5Ma was correlated with the start of SCS floor expansion and the ridge jump while it was affected by the uplift of Tibet Plateau after 24.5Ma. The accelerated uplift phases were very prominently revealed in the sediments, especially the rapid uplift since 4Ma ago. The provenance of terrigenous mineral components changed from southeast to northwest at about 24.5Ma as展开更多
在大牛地气田太原组太2段砂岩储层岩心及薄片观察鉴定、物性测试分析基础上,重点研究了鄂尔多斯盆地大牛地气田太原组太2段砂岩储层特征。研究表明:研究区太原组太2段以中-粗粒石英砂岩为主,其次为岩屑石英砂岩,储集空间以剩余原生粒间...在大牛地气田太原组太2段砂岩储层岩心及薄片观察鉴定、物性测试分析基础上,重点研究了鄂尔多斯盆地大牛地气田太原组太2段砂岩储层特征。研究表明:研究区太原组太2段以中-粗粒石英砂岩为主,其次为岩屑石英砂岩,储集空间以剩余原生粒间孔隙和次生孔隙组合为主,平均孔隙度7.6%,平均渗透率为0.52 m D,总体上为低孔特低渗透性储层。储层岩石颗粒的粒度、岩石学类型和孔隙类型是影响储层物性的主要地质因素:岩石物性与粒度、石英含量成正比,粒间孔对储层物性贡献最大。展开更多
基金supported by National Natural Science Foundation of China(Grant No.40972146)State Key Laboratory of Earthquake Dynamics(Grant Nos. LED2009A01,LED2008A03)
文摘Using Fourier transform infrared spectroscopy(FTIR),we measured water contents in quartz and feldspar for four kinds of felsic rocks,i.e.,undeformed granite,banded granitic gneiss,fine-grained felsic mylonite,and fine-grained quartz-mica schist,collected from Pengguan Complex and Kangding Complex in the Longmenshan tectonic zone,Sichuan,China.The absorbance spectra suggest that water in coarse-grained quartz and feldspar of undeformed granite and banded granitic gneiss occurs mainly as hydroxyl in crystal defects,and water in most of fine-grained quartz and feldspar of felsic mylonite is molecular water in inclusions and liquid-type water in grain boundaries,but in some cases it still occurs as hydroxyl in crystal defects.Water content of quartz in undeformed granite is 0.001 wt%-0.009 wt %,and that of feldspar 0.005 wt%-0.02 wt%.The banded granitic gneiss shows water contents of 0.002 wt%-0.011 wt% in quartz and 0.012 wt%-0.036 wt% in feldspar.Quartz ribbon and feldspar ribbon in fine-grained felsic mylonite show that their water contents are similar to those of coarse-grained quartz and feldspar in granite,0.002 wt%-0.011 wt%,and 0.004 wt%-0.02 wt%,respectively.Water contents of fine-grained quartz and feldspar are respectively 0.004 wt%-0.02 wt% and 0.012 wt%-0.06 wt%.Water content of quartz in fine-grained quartz-mica schist is 0.007 wt%-0.15 wt%.Water-bearing minerals display much higher water contents than those of nominally anhydrous minerals,and the percentage of water-bearing minerals in felsic rocks increases with the strain of rocks.These new data indicate that hydroxyl in crystal defects has basically not been released during the shear deformation,and on the contrary,the increase in molecular water in inclusions and liquid-type water in grain boundaries as well as water-bearing minerals after shear deformation leads to a significant increase of the water content in deformed rocks.Based on data of creep tests,it is inferred here that the fine-grained mylonites with more water have much lower strength t
文摘Dust generated from bolt hole drilling in roof bolting operation could have high quartz content. As a dust control measure, vacuum drilling is employed on most of the roof bolters in US underground mines. However, fine rock partic- ulates from drilling could escape from the dust collection system and become airborne under some circumstances causing the roof bolter operators expose to quartz-rich respirable dust. A previous research shows that drilling can be controlled through properly selected penetration and rotational rates to reduce the specific energy of drilling. Less specific energy means less energy is wasted on generating noise, heat and over-breakage of rock. It implies that proper control of drilling has a great potential to generate significantly less fine rock dust during drilling. The drilling experiments have been conducted to study the effect of controlling drilling on reducing respirable dust. The preliminary results show that the size distributions of respirable dust were different when controlling drilling in different bite depths. This paper presents the findings from laboratory experimental studies.
文摘Minerals are the main components of sediments, whose terrigenous parts are carried into the ocean by rivers or winds and deposit directly or indirectly. The amount of the terrigenous minerals in marine sediments indirectly indicates the source area of supply and the strength of the transport agent. Minerals in sediment are strongly affected by tectonic movement and geomorphic evolution in long time scale. Therefore, large tectonic movement must lead to change of mineral components and fluxes. The South China Sea(SCS)basin experienced two tectonic expansions in Cenozoic; the second expansion occurred between 32～15.5Ma, formed the central basin. The Palawan block moved far away from the northern continent. The Tibet Plateau experienced three accelerated uplifts at 25～17Ma.B.P, 10～8Ma.B.P and ～4Ma.B.P～present In order to determine the effective tectonic movement proxy indexes and find more evidence for the two large tectonic events in marginal sea sedimentary mineral composition and their fluxes were studied. Quartz, feldspar, clay minerals and terrigenous minerals were extracted from the sediments of site 1 148 of ODP LEG 184 by chemical dissolution method, the contents and their mass accumulation rate(MAR)were calculated. According to the chronology data in the initial report of ODP LEG 184, vertical distribution of the terrigenous minerals and their content and fluxes against age were established. Therefore, the response of content and flux of terrigenous minerals to the expansion of South China Sea floor(SCS)and the uplift of the Tibet Plateau were discussed. The results showed that the highest terrigenous mineral components between 33～27.5Ma was correlated with the start of SCS floor expansion and the ridge jump while it was affected by the uplift of Tibet Plateau after 24.5Ma. The accelerated uplift phases were very prominently revealed in the sediments, especially the rapid uplift since 4Ma ago. The provenance of terrigenous mineral components changed from southeast to northwest at about 24.5Ma as
文摘在大牛地气田太原组太2段砂岩储层岩心及薄片观察鉴定、物性测试分析基础上,重点研究了鄂尔多斯盆地大牛地气田太原组太2段砂岩储层特征。研究表明:研究区太原组太2段以中-粗粒石英砂岩为主,其次为岩屑石英砂岩,储集空间以剩余原生粒间孔隙和次生孔隙组合为主,平均孔隙度7.6%,平均渗透率为0.52 m D,总体上为低孔特低渗透性储层。储层岩石颗粒的粒度、岩石学类型和孔隙类型是影响储层物性的主要地质因素:岩石物性与粒度、石英含量成正比,粒间孔对储层物性贡献最大。
