2009 Vol. 42 No. 4
2009, 42(4): 1-10.
Abstract：
Jinshan and Maquan are two medium-sized gold deposits of a branch of the acute angle,which were formed by expansion of the western part of Lixian-Baiyun-Shanyang fault.We carried out the comparative analysis of the regional geological data and characteristics,and formation causes.Middle Devonian and Carboniferous,strata in the gold-bearing show that the gold sources of Maquan should come from the shallow strata;the analysis of the samples of quartz δ18O shows that the main physical component of the ore is ore-forming solution water,we get that the hydrothennal water was formed by a small amount of ore forming solution percolated through a large number of meteoric water.The characteristics of sulfur isotopic and REE patterns show deep-derived sulfur,but the rare earth elements also from the strata Through physical and chinical conditions of mineralization,them ineralization conditions shouldmeet low-temperatureweak salinity,weak acidity and weak reducing conditions Zhongchuan rock body is a heat source body of the formation of the deposit.Infection-type deposits should be fine (Carlin-type) gold deposits.The geological survey in the future should consider overall (in particular,the combination of the two deposits),so thatwe can realize the expansion of the existing deposits.
Jinshan and Maquan are two medium-sized gold deposits of a branch of the acute angle,which were formed by expansion of the western part of Lixian-Baiyun-Shanyang fault.We carried out the comparative analysis of the regional geological data and characteristics,and formation causes.Middle Devonian and Carboniferous,strata in the gold-bearing show that the gold sources of Maquan should come from the shallow strata;the analysis of the samples of quartz δ18O shows that the main physical component of the ore is ore-forming solution water,we get that the hydrothennal water was formed by a small amount of ore forming solution percolated through a large number of meteoric water.The characteristics of sulfur isotopic and REE patterns show deep-derived sulfur,but the rare earth elements also from the strata Through physical and chinical conditions of mineralization,them ineralization conditions shouldmeet low-temperatureweak salinity,weak acidity and weak reducing conditions Zhongchuan rock body is a heat source body of the formation of the deposit.Infection-type deposits should be fine (Carlin-type) gold deposits.The geological survey in the future should consider overall (in particular,the combination of the two deposits),so thatwe can realize the expansion of the existing deposits.
Abstract：
Based on the regional geological analysis,we know that there are 3 large-scale ductile shear zones from north to south in the studied area,which were caused by the collision and continual extrusion between South Plate and North Plate during the late Paleozoic Era.The ductile shear zones controlled the distribution of the gold deposits in the area.Three ductile deformation periods could be marked out from the late Variscanic period to the early Yanshanian period,and accompanied by gold activation,transfer and enrichment for different stages.The shear of deeper earth's crust andmagmatic activities provided the heat power andm inerallogenic elements and hold space for gold mineralization.The characteristics of gold vein (in Bayanwenduer shear cane) show that the fissures in shear canes are the favoredplace for enrichmentof Au element.Them etallogenic model of gold deposit related with ductile shear canes in Sunitezuoqi area,and ore-founding direction for gold are put forward.
Based on the regional geological analysis,we know that there are 3 large-scale ductile shear zones from north to south in the studied area,which were caused by the collision and continual extrusion between South Plate and North Plate during the late Paleozoic Era.The ductile shear zones controlled the distribution of the gold deposits in the area.Three ductile deformation periods could be marked out from the late Variscanic period to the early Yanshanian period,and accompanied by gold activation,transfer and enrichment for different stages.The shear of deeper earth's crust andmagmatic activities provided the heat power andm inerallogenic elements and hold space for gold mineralization.The characteristics of gold vein (in Bayanwenduer shear cane) show that the fissures in shear canes are the favoredplace for enrichmentof Au element.Them etallogenic model of gold deposit related with ductile shear canes in Sunitezuoqi area,and ore-founding direction for gold are put forward.
Abstract：
The integrated remote sensing prospecting mode can be built through the comprehensive analysis of remote sensing images information,mineralized alteration information,ore formation,ore-control tectonic information,and united intrusive rocks information,geophysical and geochemical unusual information in Tanjianshan goldmine,and guide Mineralization prediction with remote sensing in the northern margin of mineralization belt of Qaidam Basin.The prediction results show that there are good gold metallogenic conditions in integrated remote sensing information in Qinchuangou to Qianmeiling,Wandonggou and Dulonggou.The field verification and sampling tests prove that the Au metal grade purity is 0.30g/t in slate and quartz vein of Tanjianshan group of Ordovician to Silurian in Qinchuangou to Qianm eiling,1.22g/t in quartz veins of andesite and 0.37g/t in m ineralization zone of andesite and tuff of Tanjianshan group of Ordovician to Silurian in Dulonggou,0.48g/t in mineralization zone of andesite and tuff of Tanjianshan group of Ordovician to Silurian in Wandonggou fault zone Therefore,the application of the integrated remote sensing prospecting mode of Tanjianshan goldmine (typical deposit) for remote sensing exploration prediction achieved good results in the northern margin of Qaidam metallogenic belt(the same metallogenic belt).So,this method can be used as a remote sensing prospecting way to generalize and apply in m ineral prediction in the w estern areas,China.
The integrated remote sensing prospecting mode can be built through the comprehensive analysis of remote sensing images information,mineralized alteration information,ore formation,ore-control tectonic information,and united intrusive rocks information,geophysical and geochemical unusual information in Tanjianshan goldmine,and guide Mineralization prediction with remote sensing in the northern margin of mineralization belt of Qaidam Basin.The prediction results show that there are good gold metallogenic conditions in integrated remote sensing information in Qinchuangou to Qianmeiling,Wandonggou and Dulonggou.The field verification and sampling tests prove that the Au metal grade purity is 0.30g/t in slate and quartz vein of Tanjianshan group of Ordovician to Silurian in Qinchuangou to Qianm eiling,1.22g/t in quartz veins of andesite and 0.37g/t in m ineralization zone of andesite and tuff of Tanjianshan group of Ordovician to Silurian in Dulonggou,0.48g/t in mineralization zone of andesite and tuff of Tanjianshan group of Ordovician to Silurian in Wandonggou fault zone Therefore,the application of the integrated remote sensing prospecting mode of Tanjianshan goldmine (typical deposit) for remote sensing exploration prediction achieved good results in the northern margin of Qaidam metallogenic belt(the same metallogenic belt).So,this method can be used as a remote sensing prospecting way to generalize and apply in m ineral prediction in the w estern areas,China.
2009, 42(4): 30-36.
Abstract：
Mawu deposit is a medium-scale gold deposit,located in the east part of Minxian and the middle of metallogenic belt Min-Li.Ore formation,source of ore-forming materials and metallogenic geological background of Mawu are similar to the gold deposits of the Zhongchuan area.The test results of quartz reef of the main ore-forming stage of Mawu show that the hydrogen and oxygen isotopes are: δD is-78～-98‰,δ18OSMOW is 18.0～20.2‰,δ18Owater is 0.45～8.54‰,and the ore-forming fluids are the magmatic water,metamorphic water,metamorphic water and atmospheric precipitation in a mixture of water,of which the magmatic water and metamorphic water are the main water.In quartz reef of the main ore-forming stage,δ34S is+7.1-+7.9‰,the average is+7.65‰,and the δ34S shows smaller changer in the scope,showing the characteristics of formation of stratum sulfur.Isotopic data regional geological background and diagenetic mineralization characteristics have been combined with the region,showing that the mineralization of fluids relative well to magma function and inrush of Zhongchuan rock-body,the main ore-forming fluids from the magma and the formation,and have varying degrees of mixing with meteoric water.The main sources of ore-forming materials are from the strata and deep sources.
Mawu deposit is a medium-scale gold deposit,located in the east part of Minxian and the middle of metallogenic belt Min-Li.Ore formation,source of ore-forming materials and metallogenic geological background of Mawu are similar to the gold deposits of the Zhongchuan area.The test results of quartz reef of the main ore-forming stage of Mawu show that the hydrogen and oxygen isotopes are: δD is-78～-98‰,δ18OSMOW is 18.0～20.2‰,δ18Owater is 0.45～8.54‰,and the ore-forming fluids are the magmatic water,metamorphic water,metamorphic water and atmospheric precipitation in a mixture of water,of which the magmatic water and metamorphic water are the main water.In quartz reef of the main ore-forming stage,δ34S is+7.1-+7.9‰,the average is+7.65‰,and the δ34S shows smaller changer in the scope,showing the characteristics of formation of stratum sulfur.Isotopic data regional geological background and diagenetic mineralization characteristics have been combined with the region,showing that the mineralization of fluids relative well to magma function and inrush of Zhongchuan rock-body,the main ore-forming fluids from the magma and the formation,and have varying degrees of mixing with meteoric water.The main sources of ore-forming materials are from the strata and deep sources.
Abstract：
Hougou-Dapingshan area,where three manganese(Mn)-phosphor(P) metallogenic belts were discovered recently in Lower Cambrain Tananpo Formation,located in the middle-eastern segment of the South Qinling Mn-P Metallogenic Zone.There were four Mn orebodies and one P orebody in the Ⅱ metallogenic belts.It is often that Mn-P orebodies were separated with a texture of upper Mn seam and lower P seam.The geochemical characteristics of the surface and deep rocks samples of major trace elements from the Ⅱ metallogenic belts were analyzed.The results show that the material source of Mn-Porebodies is similar,but both sediment ary environment including the sediment ary redox conditions,sediment ary area and water body condition is different.These are possible major reasons for Pand Mn separate layering mineralization.
Hougou-Dapingshan area,where three manganese(Mn)-phosphor(P) metallogenic belts were discovered recently in Lower Cambrain Tananpo Formation,located in the middle-eastern segment of the South Qinling Mn-P Metallogenic Zone.There were four Mn orebodies and one P orebody in the Ⅱ metallogenic belts.It is often that Mn-P orebodies were separated with a texture of upper Mn seam and lower P seam.The geochemical characteristics of the surface and deep rocks samples of major trace elements from the Ⅱ metallogenic belts were analyzed.The results show that the material source of Mn-Porebodies is similar,but both sediment ary environment including the sediment ary redox conditions,sediment ary area and water body condition is different.These are possible major reasons for Pand Mn separate layering mineralization.
2009, 42(4): 46-52.
Abstract：
We set forth different understandings of whether the position of manganese-bearing ore belt belongs to Jixian,Sinian period or Cambrian period in the east and in the surroundings of Presinian Bikou ancient land,the article analysis and research follows that manganese-bearing rock series are the deposits in Sinian-Cambrian period overlying on the Presinian Motianling antichinorium folded belt belonging to the contemporaneous deposit(i.e.,Upper Sinian Series).Owing to the different geological structural setting and different sedimentary environment,high-quality manganese ore concentrates in the southern belt; while the manganese ore with high phosphorus is located in the northern belt,where infiltration manganese deposit by weathering process formed in the favorable positions for structure and rock series.We also give suggestions about the criteria for ore prospecting and search direction for manganese.
We set forth different understandings of whether the position of manganese-bearing ore belt belongs to Jixian,Sinian period or Cambrian period in the east and in the surroundings of Presinian Bikou ancient land,the article analysis and research follows that manganese-bearing rock series are the deposits in Sinian-Cambrian period overlying on the Presinian Motianling antichinorium folded belt belonging to the contemporaneous deposit(i.e.,Upper Sinian Series).Owing to the different geological structural setting and different sedimentary environment,high-quality manganese ore concentrates in the southern belt; while the manganese ore with high phosphorus is located in the northern belt,where infiltration manganese deposit by weathering process formed in the favorable positions for structure and rock series.We also give suggestions about the criteria for ore prospecting and search direction for manganese.
2009, 42(4): 53-59.
Abstract：
The Wachapo bauxite deposit exists in time of Paleozoic erathem carbonas rock unconformity surface,accepts deposition disconnection controlling soft and floury strictly.The large-scale bauxite deposit is composed of 3 ore belts,more than 30 ore bodies,and is one of the main rich aluminium(sticky) ore belts in Henan province.The laterate-rization and mineral deposit forms are relative closely to the damp tropical climate;the depression unequal in size on the surface and dissolving fighting against the allocation are the locating space of the bauxite deposits.That the bay lago on depo sits each other is the advant age of the bauxite deposit formation.The research shows that the mineral deposit belongs to marine facies cause of formation short distance carry-machinery deposition give first place to bauxite type.
The Wachapo bauxite deposit exists in time of Paleozoic erathem carbonas rock unconformity surface,accepts deposition disconnection controlling soft and floury strictly.The large-scale bauxite deposit is composed of 3 ore belts,more than 30 ore bodies,and is one of the main rich aluminium(sticky) ore belts in Henan province.The laterate-rization and mineral deposit forms are relative closely to the damp tropical climate;the depression unequal in size on the surface and dissolving fighting against the allocation are the locating space of the bauxite deposits.That the bay lago on depo sits each other is the advant age of the bauxite deposit formation.The research shows that the mineral deposit belongs to marine facies cause of formation short distance carry-machinery deposition give first place to bauxite type.
2009, 42(4): 60-75.
Abstract：
The stratigraphic division of Beishan mountains and east Tianshan mountains,in the Conjunction Area of Xinjiang Uygur Autonomous Region,Gansu Province and Inner Mongolia Autonomous Region,is different,because they belong to different administrative regions.But the stratigraphic correlation indicates that the stratum of east Tianshan mountains and Beishan mountains is continuous,and this can provide an important basis for tectonic division.Theses tectonic units,such as Archean-Paleoproterozoic Beishan complex (Ar2Pt1Bc),mesoproterowic Changcheng system Xingxingxia group (ChX) and Gudongjing group (ChG),Jixian syst}n Kawabulake group (JxK) and Pingtoushan formation constitute the center of Xingxingxia-an sham micro-pant,and Dunhuang micro-lant ism ainly made up of Archean-PaleoproterowicDunhuang complex (Ar2Pt1Bc) and a little mesoproterozoic Changcheng system Qianluzi group (ChQ).The accessory basiswhat the Hongliuhe-Niuquanzi-Xichangjing ophiolite beltwas confirmed Eopaleowic suture wne is that there is Precambrian stratum of containing phosphorus-vanadium-uranium-manganese in the south side of this belt,which indicate the extension and shallow-subdeep water sedimentary environment before cracking of the south plate and the north plate This evidenceproves that Hongliuhe-Niuquanzi-Xichangjing ophiolite belt lies in the location where the south plate and the north plate was splined and aggregated.
The stratigraphic division of Beishan mountains and east Tianshan mountains,in the Conjunction Area of Xinjiang Uygur Autonomous Region,Gansu Province and Inner Mongolia Autonomous Region,is different,because they belong to different administrative regions.But the stratigraphic correlation indicates that the stratum of east Tianshan mountains and Beishan mountains is continuous,and this can provide an important basis for tectonic division.Theses tectonic units,such as Archean-Paleoproterozoic Beishan complex (Ar2Pt1Bc),mesoproterowic Changcheng system Xingxingxia group (ChX) and Gudongjing group (ChG),Jixian syst}n Kawabulake group (JxK) and Pingtoushan formation constitute the center of Xingxingxia-an sham micro-pant,and Dunhuang micro-lant ism ainly made up of Archean-PaleoproterowicDunhuang complex (Ar2Pt1Bc) and a little mesoproterozoic Changcheng system Qianluzi group (ChQ).The accessory basiswhat the Hongliuhe-Niuquanzi-Xichangjing ophiolite beltwas confirmed Eopaleowic suture wne is that there is Precambrian stratum of containing phosphorus-vanadium-uranium-manganese in the south side of this belt,which indicate the extension and shallow-subdeep water sedimentary environment before cracking of the south plate and the north plate This evidenceproves that Hongliuhe-Niuquanzi-Xichangjing ophiolite belt lies in the location where the south plate and the north plate was splined and aggregated.
2009, 42(4): 76-83.
Abstract：
Regional data indicate that Xiangshan-Qinglongshan area was a shallow open mesa in the early Ordovician Period,and they accepted the platform facies carbonate deposition.To early Ordovician later period,because the Helan aulacogen crack fell again,the ancient geography appearance and the environment of deposition in this area had the remarkable change,the western Xiangshan region turned into continental slope-times of deep-sea,deep-sea basin,and the water depth of the eastern (Qinglongshan region) had more significantly increased than previous period,but it still inherited nature of the early plat form.By comparating and analyzing the charact eristics of Ordovician sediment ary strata,sedimentary facies and biot a period of Xiangshan,Miboshan,Niushou Hill,Luoshan and Qing long shan etc.,and based on stratig raphic structure and identification of key interface,we divide the Ordovician period stratumint of our depo sitional system domains: the early highstand systems tract (HST1),low stand wedge (LSW),the transg ressive sytemstract (TST),and the late highstand systems tract (HST2),of which,HST1 and LSW are separated by Ⅰ type unconformity (SB1); TST and HST2 are separated by hunger parag raph (SS).
Regional data indicate that Xiangshan-Qinglongshan area was a shallow open mesa in the early Ordovician Period,and they accepted the platform facies carbonate deposition.To early Ordovician later period,because the Helan aulacogen crack fell again,the ancient geography appearance and the environment of deposition in this area had the remarkable change,the western Xiangshan region turned into continental slope-times of deep-sea,deep-sea basin,and the water depth of the eastern (Qinglongshan region) had more significantly increased than previous period,but it still inherited nature of the early plat form.By comparating and analyzing the charact eristics of Ordovician sediment ary strata,sedimentary facies and biot a period of Xiangshan,Miboshan,Niushou Hill,Luoshan and Qing long shan etc.,and based on stratig raphic structure and identification of key interface,we divide the Ordovician period stratumint of our depo sitional system domains: the early highstand systems tract (HST1),low stand wedge (LSW),the transg ressive sytemstract (TST),and the late highstand systems tract (HST2),of which,HST1 and LSW are separated by Ⅰ type unconformity (SB1); TST and HST2 are separated by hunger parag raph (SS).
2009, 42(4): 84-91.
Abstract：
Xiangfan-Zaoyang sag lies on the south of Nanxiang basin.Compared with the northern small but prolific Nanyang and Biyang sags,the breakthrough of exploration activity is always obtained in this area.Through the research on the characteristics of Cenozoic Hetaoyuan group source rock and the hydrocarbon resource evaluation,we know that the source rock is immature,and the quantity of hydrocarbon generation and resources is very little,the total quantity of hydrocarbon generation is 2.97×108t,the largest resources quantity is only 130×104t.Moreover,the wells of aiming at Hetaoyuan group don't obtain the hydrocarbon accomplishment in Xiangfan-Zaoy ang sag.Therefore,Hetaoyuan group can't be taken as the exploration objective formation.Some salt wells provided a little information on Cretaceous source rock,and soil geochemistry exploration also showed that Cretaceous has exploration prospect.The exploration of carbonate and mantle derived gas is the fields of being concerned bothat home and abroad over along period of time,and some breakt hroughs have been made.Some soil geochemistry exploration information has revealed that there are some exploration prospects of carbonate and mantle derived gas.Then based on multidisciplinary analyzing research accomplishment of salt exploration and soil geochemistry exploration,Mesozoic Cretaceous,mantle derived gas and Sinian-Cambrian carbonate are the new horizon and fields of hydrocarbon exploration in Xiangfan-Zaoyang sag.
Xiangfan-Zaoyang sag lies on the south of Nanxiang basin.Compared with the northern small but prolific Nanyang and Biyang sags,the breakthrough of exploration activity is always obtained in this area.Through the research on the characteristics of Cenozoic Hetaoyuan group source rock and the hydrocarbon resource evaluation,we know that the source rock is immature,and the quantity of hydrocarbon generation and resources is very little,the total quantity of hydrocarbon generation is 2.97×108t,the largest resources quantity is only 130×104t.Moreover,the wells of aiming at Hetaoyuan group don't obtain the hydrocarbon accomplishment in Xiangfan-Zaoy ang sag.Therefore,Hetaoyuan group can't be taken as the exploration objective formation.Some salt wells provided a little information on Cretaceous source rock,and soil geochemistry exploration also showed that Cretaceous has exploration prospect.The exploration of carbonate and mantle derived gas is the fields of being concerned bothat home and abroad over along period of time,and some breakt hroughs have been made.Some soil geochemistry exploration information has revealed that there are some exploration prospects of carbonate and mantle derived gas.Then based on multidisciplinary analyzing research accomplishment of salt exploration and soil geochemistry exploration,Mesozoic Cretaceous,mantle derived gas and Sinian-Cambrian carbonate are the new horizon and fields of hydrocarbon exploration in Xiangfan-Zaoyang sag.
2009, 42(4): 92-101.
Abstract：
Based on the geological data in recent years,by discussing the structural attribute,geodynamic mechanism,structural evolution course of the south and north boundary structural belts of Qiangtang Basin,we analyzed the evolution and structural attributes in the late Triassic of Qiangtang Basin.On the basis of researching the Upper Triassic lithology,lithofacies in different locations within the basin,we established sequence stratigraphic framework in the Upper Triassic by Identifying Sequence interface and systems tract interface under the different ancient geographical backg rounds,and discussed the location of coal-bed in the sequence stratig raphic framework,the coal accumulation characteristics and spatial distribution law.The results show that the Qiangtang basin was a complex superposition basin in the Upper Triassic,and experienced the passive continental margin basin at the early and mid-stage in Late Tr iassic,the Foreland Basin in the northern Qiangt ang and the passive continental margin rifting depression basin in the southern Qiangtang at the late-stage in Late Triassic.The coalbed was located in the middle-upside of the highstand systems tract,which was mainly controlled by high-frequency and lowgrade sea-level changes.
Based on the geological data in recent years,by discussing the structural attribute,geodynamic mechanism,structural evolution course of the south and north boundary structural belts of Qiangtang Basin,we analyzed the evolution and structural attributes in the late Triassic of Qiangtang Basin.On the basis of researching the Upper Triassic lithology,lithofacies in different locations within the basin,we established sequence stratigraphic framework in the Upper Triassic by Identifying Sequence interface and systems tract interface under the different ancient geographical backg rounds,and discussed the location of coal-bed in the sequence stratig raphic framework,the coal accumulation characteristics and spatial distribution law.The results show that the Qiangtang basin was a complex superposition basin in the Upper Triassic,and experienced the passive continental margin basin at the early and mid-stage in Late Tr iassic,the Foreland Basin in the northern Qiangt ang and the passive continental margin rifting depression basin in the southern Qiangtang at the late-stage in Late Triassic.The coalbed was located in the middle-upside of the highstand systems tract,which was mainly controlled by high-frequency and lowgrade sea-level changes.
Abstract：
The application of scientific groundwater exploration is most important to improve efficiency of well construction and water supply for hydrogeological survey of groundwater exploration in water-shortage areas.In this paper,we introduced practices of groundwater exploration which were carried out in more than 300 water-shortage villages and towns over the past decade,and summarized the successive approximation method on groundwater exploration.There were five main steps for this method.The first was confirming the groundwater exploration direction by pre-research with prevenient survey data.The second was delineating underground water-bearing area with remote sensing techniques.The third was confirming water-rich aquifers by medium surface investigation with simple fast geophysical exploration methods.The forth was designing the well with further detailed surface investigation and combined geophysical techniques.The last was selecting drilling methods and well construction technologies according to characteristics of groundwater aquifers.We also supplied technical out lines on data source selecting of remote sensing,application of simple fast geophy sical methods and combined exploration of effective geophysical methods.
The application of scientific groundwater exploration is most important to improve efficiency of well construction and water supply for hydrogeological survey of groundwater exploration in water-shortage areas.In this paper,we introduced practices of groundwater exploration which were carried out in more than 300 water-shortage villages and towns over the past decade,and summarized the successive approximation method on groundwater exploration.There were five main steps for this method.The first was confirming the groundwater exploration direction by pre-research with prevenient survey data.The second was delineating underground water-bearing area with remote sensing techniques.The third was confirming water-rich aquifers by medium surface investigation with simple fast geophysical exploration methods.The forth was designing the well with further detailed surface investigation and combined geophysical techniques.The last was selecting drilling methods and well construction technologies according to characteristics of groundwater aquifers.We also supplied technical out lines on data source selecting of remote sensing,application of simple fast geophy sical methods and combined exploration of effective geophysical methods.
2009, 42(4): 109-118.
Abstract：
We summarize the characteristics of sedimentary cycles,cycle interface types of some stalagmites and related significances in climatic,environmental and geological sciences.Before that,the components and structures of some typical large stalagmite in southern China were studied.Also 210 isotopic samples of δ18C,δ18O,20 samples for Useries dating in D10 and some related trace elements were analyzed comparatively.According to the colors reflected by different impurities in carbonate,the lamina features and isotopic components of stalagmite in D10,three cycling features which are accordant parallel,unaccordant parallel and unaccordant unparallel can be divided.19 sediment arycycles can be identified.The average δ13C,δ18O value -3.91‰PDB and -6.97‰PDB respectively represent the threshold values which indicate the evolution of cold and warm climate.Consequently,if the isotopic value is higher than the threshold value,it means the climate is in favor of cold conditions.According to the isotopic and cycle characteristics of the sedimentary,it is considered preliminarily that the 19 cycles deposited during the years from 352 930 to 99 410 in Libo area indicate a relatively complete process of the climate evolution in the fifth Ice Age of the Quaternary Ice Age series in China.The 50 000 years which is calculated from cycle 10 to cycle 15 is surmised as a continuous freezing glacial maximum.The cycle 1 and cycle 16 represents probably interg lacial period which was relative warmer.Furthermore,there also existed 50 000 or 100 000 years scale climatic cycle during the period.
We summarize the characteristics of sedimentary cycles,cycle interface types of some stalagmites and related significances in climatic,environmental and geological sciences.Before that,the components and structures of some typical large stalagmite in southern China were studied.Also 210 isotopic samples of δ18C,δ18O,20 samples for Useries dating in D10 and some related trace elements were analyzed comparatively.According to the colors reflected by different impurities in carbonate,the lamina features and isotopic components of stalagmite in D10,three cycling features which are accordant parallel,unaccordant parallel and unaccordant unparallel can be divided.19 sediment arycycles can be identified.The average δ13C,δ18O value -3.91‰PDB and -6.97‰PDB respectively represent the threshold values which indicate the evolution of cold and warm climate.Consequently,if the isotopic value is higher than the threshold value,it means the climate is in favor of cold conditions.According to the isotopic and cycle characteristics of the sedimentary,it is considered preliminarily that the 19 cycles deposited during the years from 352 930 to 99 410 in Libo area indicate a relatively complete process of the climate evolution in the fifth Ice Age of the Quaternary Ice Age series in China.The 50 000 years which is calculated from cycle 10 to cycle 15 is surmised as a continuous freezing glacial maximum.The cycle 1 and cycle 16 represents probably interg lacial period which was relative warmer.Furthermore,there also existed 50 000 or 100 000 years scale climatic cycle during the period.
