Carbon Dioxide Exchange Between the Atmosphere and an Alpine Shrubland Meadow During the Growing Season on the Qinghai-Tibetan Plateau

In the present study, we used the eddy covariance method to measure CO2 exchange between the atmosphere and an alpine shrubland meadow ecosystem (37°36'N, 101°18'E; 3 250 m a.s.l.) on the Qinghai-Tibetan Plateau, China, during the growing season in 2003, from 20 April to 30 September. This meadow is dominated by formations of Potentilla fruticosa L. The soil is Mol-Cryic Cambisols. During the study period, the meadow was not grazed. The maximum rates of CO2 uptake and release derived from the diurnal course of CO2 flux were -9.38 and 5.02 μmol•m-2•s-1, respectively. The largest daily CO2 uptake was 1.7 g C•m-2•d-1 on 14 July, which is less than half that of an alpine Kobresia meadow ecosystem at similar latitudes. Daily CO2 uptake during the measurement period indicated that the alpine shrubland meadow ecosystem may behave as a sink of atmospheric CO2 during the growing season. The daytime CO2 uptake was correlated exponentially or linearly with the daily photo synthetic photon flux density each month. The daytime average water use efficiency of the ecosystem was 6.47 mg CO2/g H2O. The efficiency of the ecosystem increased with a decrease in vapor pressure deficit.

LC-DAD-ESI-MS Characterization of Carbohydrates Using a New Labeling Reagent

A novel labeling reagent 1-(2-naphthyl)-3-methyl-5-pyrazolone (NMP) coupling to liquid chromatography with electrospray ionization mass spectrometry for the detection of carbohydrates from the derivatized rape bee pollen samples is reported. Carbohydrates are derivatized to their bis-NMP-labeled derivatives. Derivatives showed an intense protonated molecular ion at m/z [M+H](+) in positive-ion detection mode. The mass-to-charge ratios of characteristic fragment ions at m/z 473.0 could be used for the accurately qualitative analysis of carbohydrates. This characteristic fragment ion is from the cleavage of C2-C3 bond in carbohydrate chain giving the specific fragment ions at m/z [MH-CmH2m+1Om-H2O](+) for pentose, hexose and glyceraldehydes and at m/z [MH-CmH2m-1Om+1-H2O](+) for alduronic acids such as galacturonic acid and glucuronic acid (m = n - 2, n is carbon number of carbohydrate). No interferences for all aliphatic and aromatic aldehydes presented in natural environmental samples were observed due to the highly specific parent mass-to-charge ratio and the characteristic fragment ions. The method, in conjunction with a gradient elution, offered a baseline resolution of carbohydrate derivatives on a reversed-phase Hypersil ODS-2 column. The carbohydrates such as mannose, galacturonic acid, glucuronic acid, rhamnose, glucose, galactose, xylose, arabinose and fucose can successfully be detected.

Analysis of carbohydrates in a tibetan medicine using new labeling reagent, 1-(2-naphthyl)-3-methyl-5-pyrazolone, by HPLC with DAD detection and ESI-MS identification

A new labeling reagent, 1-(2-naphthyl)-3-methyl-5-pyrazolone (NMP), coupling with liquid chromatography (LC) with electrospray ionization mass spectrometry (ESI-MS) for the detection of carbohydrates from a famous Tibetan medicine is reported. Carbohydrates were derivatized to their bis-NMP-labeled derivatives. The method, in conjunction with a gradient elution, offered a baseline resolution of carbohydrate derivatives on a reversed phase Hypersil ODS-2 column. The carbohydrates such as mannose, galacturonic acid, glucuronic acid, rhamnose, glucose, galactose, xylose, arabinose, and fucose could be successfully detected by UV and ESI-MS. Derivatives showed intense protonated molecular ion at m/z [M+H]+ in positive ion mode. The mass to charge ratios of characteristic fragment ions at m/z 473.0 could be used for the accurately qualitative identification of carbohydrates; this characteristic fragment ion was from the cleavage of C2-C3 bond in the carbohydrate chain giving the specific fragment ions at m/z [MH-CmH2m+1Om-H2O](+) for pentose, hexose, and glyceraldehydes, and at m/z [MH-CmH2m-1Om+1-H2O](+) for alduronic acids, such as galacturonic acid and glucuronic acid (m=n-2, n is carbon atom number of carbohydrate). Compared with the traditional 1-phenyl-3-methyl-5-pyrazolone (PMP) reagent, currently synthesized NMP show the advantage of higher sensitivity to carbohydrate compounds with UV and ESI-MS detection.

Identification of phenolics and nucleoside derivatives in Gastrodia elata by HPLC-UV-MS

An HPLC-UV-MS method for simultaneous identification of predominant phenolics and minor nucleoside derivatives in Gastrodia elata was developed, which was based on their UV and MS characteristics summarized through a series of homemade reference standard experiments. Phenolics showed characteristic UV lambda(max) at 267 nm, [M + NH4](+) base peak in positive mode and [M - H](-) base peak in negative mode while nucleosides exhibited UV lambda(max) at 255 nm, [M + H](+), [M - H + 2H(2)O](-) or [M - H + CH3COOH](-). Phenolics conjugates mainly underwent the consecutive loss of gastrodin residue (- 268 U) and the combined loss of H2O and CO2 from the citric acid unit under negative MS/MS conditions whereas nucleosides simply lost the ribose (- 132 U) under positive MS/MS conditions. According to these characteristics, a special pattern under MS/MS conditions and reported compound data for G. elata in the literature, not only 15 phenolics were identified but also 6 nucleoside derivatives were identified. Among these compounds, seven phenolics and three nucleoside derivatives have not been reported yet from G. elata.

Enhancement of atmospheric pressure chemical ionization for the determination of free and glycine-conjugated bile acids in human serum

A highly sensitive and accurate method based on the precolumn derivatization of bile acids (BA) with a high ionization efficiency labeling reagent 1,2-benzo-3,4-dihydrocarbazole-9-ethyl-benzenesulfonate (BDEBS) coupled with LC/MS has been developed. After derivatization, BA molecules introduced a weak basic nitrogen atom into the molecular core structure that was readily ionized in commonly used acidic HPLC mobile phases. Derivatives were sufficiently stable to be efficiently analyzed by atmospheric pressure chemical ionization (APCI)-MS/MS in positive-ion mode. The MS/MS spectra of BA derivatives showed an intense protonated molecular ion at m/z [M + H](+). The collision-induced dissociation of the molecular ion produced fragment ions at [MH - H2O](+), [MH - 2H(2)O](+), [MH - 3H(2)O](+). The characteristic fragment ions were at m/z 320.8, 262.8, and 243.7 corresponding to a cleavage of N - CO, O - CO, and C - OCC, respectively, and bonds of derivatized molecules. The selected reaction monitoring, based on the m/z [M + H]+ -> [MH - H2O](+), [MH - H2O](+), [MH - 2H(2)O](+), [MH-3H(2)O](+), 320.8, 262.8, and 243.7 transitions, was highly specific for the BA derivatives. The LODs for APCI in a positive-ion mode, at an S/N of 5, were 44.36-153.6 fmol. The validation results showed high accuracy in the range of 93-107% and the mean interday precision for all standards was < 15% at broad linear dynamic ranges (0.0244-25nmol/mL). Good linear responses were observed with coefficients of > 0.9935 in APCI/MS detection. Therefore, the facile BDEBS derivatization coupled with mass spectrometric analysis allowed the development of a highly sensitive and specific method for the quantitation of trace levels of the free and glycine-conjugated BA from human serum samples.

Short-term variation of CO2 flux in relation to environmental controls in an alpine meadow on the Qinghai-Tibetan Plateau

[1] The alpine meadow ecosystem on the Qinghai-Tibetan Plateau may play a significant role in the regional carbon cycle. To assess the CO2 flux and its relationship to environmental controls in the ecosystem, eddy covariance of CO2, H2O, and energy fluxes was measured with an open-path system in an alpine meadow on the plateau at an elevation of 3,250 m. Net ecosystem CO2 influx (Fc) averaged 8.8 g m(-2) day(-1) during the period from August 9 to 31, 2001, with a maximum of 15.9 g m(-2) day(-1) and a minimum of 2.3 g m(-2) day(-1). Daytime Fc averaged 16.7 g m(-2) day(-1) and ranged from 10.4 g m(-2) day(-1) to 21.7 g m(-2) day(-1) during the study period. For the same photosynthetic photon flux density (PPFD), gross CO2 uptake (Gc) was significantly higher on cloudy days than on clear days. However, mean daily Gc was higher on clear days than on cloudy days. With high PPFD, Fc decreased as air temperature increased from 10degreesC to 23degreesC. The greater the difference between daytime and nighttime air temperatures, the more the sink was strengthened. Daytime average water use efficiency of the ecosystem (WUEe) was 8.7 mg (CO2)(g H2O)(-1); WUEe values ranged from 5.8 to 15.3 mg (CO2)(g H2O)(-1). WUEe increased with the decrease in vapor pressure deficit. Daily albedo averaged 0.20, ranging from 0.19 to 0.22 during the study period, and was negatively correlated with daily Fc. Our measurements provided some of the first evidence on CO2 exchange for a temperate alpine meadow ecosystem on the Qinghai-Tibetan Plateau, which is necessary for assessing the carbon budget and carbon cycle processes for temperate grassland ecosystems.

水-盐-气天然流体的物理化学性质模拟与流体包裹体应用研究

Natural fluids with water-salt-gas are often found in every sphere of the Earth, whose physicochemical properties and geochemical behaviors are complicated. To study these properties and behaviors turns out to be one of the challenging issues in geosciences. Traditional approaches mainly depend on experiments and observations. However, it is impossible to obtain a large number of data covering a large T-P space of the Earth by experimental methods in the near future, which will hinder the advance of the theoretical study. Therefore, it is important to model natural fluids by advanced theoretical methods, by which limited experimental data can be extended to a large temperature-pressure-composition space. Physicochemical models developed in this dissertation are not only more accurate, but also extend the applied T-P-m region of the experimental data of the multi-fluid systems by about two times. These models provide the new and accurate theoretical tools for the geochemical research, especially for the water-rock interactions and the study of the fluid inclusions. The main achievements can be summarized as follows: (1) A solubility model on components of natural gases is presented. The solubility model on the systems of CH4-H2O-NaCl, C2H6-H2O-NaCl or N2-H2O-NaCl takes advantage of modern physicochemical theory and methods, and is an improvement over previous models whose prediction and precision are relatively poor. The model can predict not only the gas solubility in liquid phase but also water content in the gas phase. In addition, it can predict gases (methane or nitrogen) solubility in seawater and brine. Isochores can be determined, which are very important in the interpretation of fluid inclusions. (2) A density model on common aqueous salt solutions is developed. The density models with high precision for common aqueous salt solutions (H2O-NaCl, H2O-LiCl, H2O-KCl, H2O-MgCl2, H2O-CaCl2, H2O-SrCl2 or H2O-BaCl2) are absent in the past. Previous density models are limited to the relatively small range of experimental data, and cannot meet the requirement of the study of natural fluids. So a general density model of the above systems is presented by us based on the international standard density model of the water. The model exceeds the other models in both precision and prediction. (3) A viscosity model on common aqueous alkali-chloride solutions is proposed. Dynamic viscosity of water-salt systems, an important physics variable, is widely used in three-dimension simulation of the fluids. But in most cases, due to the lack of viscosity models with a wide T-P range, the viscosity of aqueous salt solutions is replaced by that of the water, giving rise to a relatively large uncertainty. A viscosity model with good prediction for the systems (H2O-NaCl, H2O-LiCl or H2O-KCl) is presented on the base of the international standard viscosity model of water and the density model developed before. (4) Equation of State applied in fluid inclusions. The best Equations of State in the world developed by others or us recently are applied in the study of the fluid inclusions. Phase equilibria and isochores of unitary system (e.g. H2O, CO2, CH4, O2, N2, C2H6 or H2S), binary H2O-NaCl system and ternary H2O-CH4-NaCl system are finished. From these programs and thermodynamic equations of coexisting ores, the physicochemical conditions before or after the deposits form can be determined. To some extent, it is a better tool.

内蒙古白云鄂博超大型REE-Nb-Fe矿床脉状矿化时代与成矿流体特征

Bayan Obo REE-Nb-Fe ore deposit is the largest REE deposit in the world. Owing to its unique type and tremendous economic value, this deposit has widely attracted interests from geological researchers and vast amount of scientific data have been accumulated. However, its genesis, especially ore-forming age and REE sources, have been under dispute for a long time. On the basis of previous research works, this paper mainly conducts studies on the Early Paleozoic ore-forming event in the Bayan Obo deposit. The following results and conclusions can be suggested: Sm-Nd isotopic analytical results of bastnaesite, beloeilite, albite and fluorite samples from a coarse-crystalline ore lode present an isochron age of 436±35Ma. Besides, Rb-Sr isotope dating of the coarse-crystalline biotite lode that intruded into banded ores gives an isochron age of 459±39Ma. The two ages verify the exist of Early Paleozoic ore-forming event at Bayan Obo, which characterized by extensive netted mineralization of REE fluorocarbonates, aeschynite and monazite, accompanied by widely fluorite-riebeckite-aegirine-apatite alteration. Sr-Nd isotope composition of vein minerals is located between EMI and ancient lower crust component in the ISr(t)-εNd(t) correlation diagram, indicating that there is a crustal contamination during veined mineralization. A large area late Paleozoic granitoids are distributed in the southeast region of east open pit of the mine. The granitoids intruded directly into the ore-bearing dolomite, and produced intense skarnization. Moreover, at 650-660m of the drill core on 22 line and 1598m level flat in the south of East Open Pit, we firstly found skarnization rocks. Single grain and low background Rb-Sr isochrone dating on phlogopite in skarn gives 309±12Ma. Considering the intruded contacting relationship, the late Paleozoic granitoids, already extended to the under part of REE ore bodies, must be posterior to the latest intense REE mineralization, and is only a destructive tectonic and magmatic activity. Fluid inclusion types of fluorite in the Bayan Obo deposit consist of multiphase daughter mineral-bearing inclusion, two or three phase CO2-bearing inclusion and two phase aqueous inclusion. Petrography, laser Raman analysis and microthermometry study indicate that the fluids involving in REE-Nb-Fe mineralization at Bayan Obo might be mainly of H2O-CO2-NaCl-(F-REE) system. The presence of REE-carbonate as a daughter mineral in fluid inclusions shows that the original ore-forming fluids are rich in REE elements.

班公湖带多不杂超大型富金斑岩铜矿床的成岩成矿年代学、岩石学及高氧化岩浆¬流体-成矿作用

Duobuza copper deposit, newly discovered typical gold-rich porphyry copper deposit with superlarge potential, is located in the Tiegelong Mesozoic tectonic -magmatic arc of the southern edge of Qiangtang block and the northern margin of Bangonghu-Nujiang suture. Quartz diorite porphyrite and grandiorite porphyry, occurred in stock, are the main ore-bearing porphyries. As the emplacement of porphyry stock, a wide range of hydrothermal alteration has developed. Within the framework of the ore district, abundant hydrothermal magnetite developed, and the relationship between precipitation of copper and gold and hydrothermal magnetite seems much close. Correspondingly, a series of veinlets and network veinlets occurred in all alteration zones. Therefore, systematic research on such a superlarge high-grade Duobuza gold-rich porphyry copper deposit can fully revealed the metallogenic characteristics of gold-rich porphyry copper deposits in this region, establish metallogenetic model and prospecting criteria, and has important practical significance on the promotion of regional exploration. In addition, this research on it can enrich metallogenic theory of strong oxidation magma-fluid to gold-rich porphyry copper deposit, and will be helpful to understand the metallogenic characteristics in early of subduction of Gangdese arc stages and its entire evolution history of the Qinghai-Tibet Plateau, the temporal and spatial distribution of ore deposits and their geodynamics settings. Northern ore body of Duobuza copper deposit have been controlled with width (north-south) about 100 ~ 400 m, length (east-west) about 1400 m, dip of 200 °, angle of dip 65 °~ 80 °. And controlled resource amount is of 2.7 million tons Cu with grade 0.94% and 13 tons Au with 0.21g/tAu. Overall features of ore body are large scale, higher grade copper, gold-rich. Ore occurred in the body of granodiotite porphyry and quartz diorite porphyrite and its contact zone with wall rock. Through the detailed mapping and field work studies, some typies of alteration are identificated as follows: albitization, biotititation, sericitization, silication, epidotization, chloritization, carbonatization, illitization, kaolinization and so on. The range of alteration is more than 10km2. Wall alteration zone can be divided into potassic alteration, moderate argillization alteration, argillization, illite-hydromuscovite or propylitization from ore-bearing porphyry center outwards, but phyllic alteration has not well developed and only sericite-quartz veins occurred in local area. Moreover, micro-fracture is development in ore district , and correspondingly a series of veinlets are development as follows: biotite vein (EB type), K-feldspar-biotite-chalcopyrite-quartz vein, magnetite-antinolite-K-feldspar vein, quartz-chalcopyrite-magnetite veins (A-type), quartz-magnetite-biotite-K-feldspar vein, chalcopyrite veinlets in potassic alteration zone; (2) chalcopyrite occurring in the center vein–quartz vein (B type), chalcopyrite veinlets, chalcopyrite-gypsum vein in intermediate argillization alteration; (3) chalcopyrite- pyrite-quartz vein, pyrite-quartz vein, chalcopyrite-gypsum veins, quartz-gypsum- molybdenite-chalcopyrite vein in argillization alteration; (4) gypsum veins, quartz-(molybdenite)-chalcopyrite vein, quartz-pyrite vein, gypsum- chalcopyrite vein, potassium feldspar veinlets, Carbonate veins, quartz-magnetite veins in the wall rock. In short, various veins are very abundant within the framework of the ore district. The results of electronic probe microscopy analysis (EMPA) indicate that Albite (Ab 91.5~99.7%) occurred along the rim of plagioclase phenocryst and fracture, and respresents the earliest stages of alteration. K-feldspar (Or 75.1~96.9%) altered plagioclase phenocryst and matrix or formed secondary potassium feldspar veinlets. Secondary biotite occurred mainly in phenocryst, matrix and veinlets, belong to magnesium-rich biotite formed under the conditions of high-oxidation magma- hydrothermal. Chloritization developed in all alteration zones and alterd iron- magnesium minerals such as biotite and hornblende and then formed chlorite veinlets. As the temperature rises, Si in the tetrahedral site of chlorite decreased, and chlorite component evolved from diabantite to ripiolite. The consistent 280℃~360℃ of formation temperature hinted that chlorite formed on the same temperature range in all alteration zones. However, formation temperature range of chlorite from the gypsum-carbonate-chlorite vein was 190℃~220℃, and it may be the product of the latest stage of hydrothermal activity. The closely relationship between biotite and rutile indicate that most of rutiles are precipitated in the process of biotite alteration and recrystallization. In addition, the V2O3 concentration of rutile from ore body in Duobuza gold-rich porphyry copper deposit is >0.4％, indicate that V concentration in rutile has important significance on marking main ore body of porphyry copper deposit. Apatites from Duobuza deposit all are F-rich. And apatite in the wall rock contained low MnO content and relatively high FeO content, which may due to the basaltic composition of the wall rocks. The MnO in apatite from altered porphyry show a strong positive correlation with FeO. In addition, Cl/F ratio of apatite from wall rock was highest, followed by the potassic alteration zone and potassic alteration zone overprinted by moderate argillization alteration was the lowest. SO2 in Apatite are in the scope of 0 to 0.66%, biotite in the apatite has the highest SO2, followed by the potassic alteration zone, potassic alteration zone overprinted by moderate argillization alteration, and the lowest in the surrounding rocks, which may be caused by the decrease of oxygen fugacity of hydrothermal fluid and S exhaust by sulfide precipitation in potassic alteration. Magnetite in the wall rock have higher Cr2O3 and lower Al2O3 features compared with altered porphyry, this may be due to basalt wall rock generally has high Cr content. And magnetites have higher TiO2 content in potassic alteration than moderate argillization alteration overprinted by potassic alteration, argillization and wall rock, suggested that its formation temperature in potassic alteration was the highest among them. The ore minerals mainly are chalcopyrite and bornite, and Au contents of chalcopyrite, bornite, and pyrite are similar with chalcopyrite slightly higher. The Eu* negative anomaly of disseminated chalcopyrite was relatively lower than chalcopyrite in veinlets. Within a drill hole, the Eu* negative anomaly of disseminated chalcopyrite was gradually larger from bottom to top. Magnetite has the same distribution model, with obvious negative Eu* abnormal, and ΣREE in great changes. The gypsum has the highest ΣREE content and the obvious negative anomaly, and biotite obviously has the Eu* abnormal. Based on the petrographic and geochemical characteristics, five series of magmatic rocks can be broadly classified; they are volcanic rocks of the normal island arc, high-Nb basaltic rocks, adakites, altered porphyry and diorite. The Sr, Nd, Hf isotopes and geochemistry of various series of magmatic rock show that they may be the result of mixing between basic magma and various degrees of acid magma coming from lower crust melted by high temperature basic underplating from partial melting of the subduction sediment melt metasomatic mantle wedge. Furthermore S isotope and Pb isotope of the sulfide, ore-bearing porphyries and volcanic rocks indicated ore-forming source is the mantle wedge metasomatied by subduction sediment melt. Oxygen fugacity of magma estimated by Fe2O3/FeO of whole rock and zircon Ce4+/Ce3+ indicated that the oxidation of basalt-andesitic rocks is higher than ore-forming porphyry, and might imply high-oxidation characteristics of underplated basic magma. Its high oxidative mechanism is likely mantle sources metasomatied by subduction sediment magma, including water and Fe3+. And such high oxidation of basaltic magma is conducive to the mantle of sulfides in the effective access to melt. And the An component of dark part within plagioclase phenocryst zoning belong to bytownite (An 74%), and its may be a result of magma composition changes refreshment by basaltic magma injection. SHRIMP zircon U-Pb and LA-ICP-MS zircon U-Pb geochronology study showed that the intrusions and volcanic rocks from Duobuza porphyry copper deposit belong to early Cretaceous magma series (126~105Ma). The magma evolution series are as follows: the earliest diorite and diorite porphyrite → ore-bearing porphyry and barren grandiorite porphyry →basaltic andesite → diorite porphyrite → andesite → basaltic andesite, and magma component shows a evolution trend from intermediate to intermediate-acid to basic. Based on the field evidences, the formation age of high-Nb basalt may be the latest. The Ar-Ar geochronology of altered secondary biotite, K-feldspar and sericite shows that the main mineralization lasting a interval of about 4 Ma, the duration limit of whole magma-hydrothermal evolution of about 6 Ma, and possibly such a long duration limit may result in the formation of Duobuza super-large copper deposit. Moreover, tectonic diagram and trace element geochemistry of volcanic rocks and diorite from Duobuza porphyry copper deposit confirm that it formed in a continental margin arc environment. Zircon U-Pb age of volcanic rocks and porphyry fall in the range of 105~121Ma, and Duobuza porphyry copper deposit locating in the north of the Bangonghu- Nujiang suture zone, suggested that Neo-Tethys ocean still subducted northward at least early Cretaceous, and its closure time should be later than 105 Ma. Three major inclusion types and ten subtypes are distinguished from quartz phenocrysts and various quartz veins. Vapor generally coexisting with brine inclusions, suggest that fluid boiling may be the main ore-forming mechanism. Raman spectrums of fluid inclusions display that the content of vapor and liquid inclusion mainly contain water, and vapor occasionally contain a little CO2. In addition, the component of liquid inclusions mainly include Cl-, SO42-, Na+, K+, a small amount of Ca2+, F-; and Cl- and Na+ show good correlation. Vapor mainly contains water, a small amount of CO2, CH4 and C2H6 and so on. The daughter minerals identified by Laman spectroscopy and SEM include gypsum, chalcopyrite, halite, sylvite, rutile, potassium feldspar, Fe-Mn-chloride and other minerals, and ore-forming fluid belong to a complex hydrothermal system containing H2O-NaCl-KClFeCl2CaCl2. H and O isotopic analysis of quartz phenocryst, vein quartz, magnetite, chlorite and gypsum from all alteration zones show that the ore-forming fluid of Duobuza gold-rich porphyry copper deposit consisted mainly of magmatic water, without addition of meteric water. Duobuza gold-rich porphyry copper deposit formed by the primary magmatic fluid (600-950C), which has high oxidation, ultra-high salinity and metallogenic element-rich, exsolution direct from the magma, and it is representative of the typical orthomagmatic end member of the porphyry continuum. Moreover, the fluid evolution model of Duobuza gold-rich porphyry copper deposit has been established. Furthermore, two key factors for formation of large Au-rich porphyry copper deposit have been summed up, which are ore-forming fluids earlier separated from magma and high oxidation magma-mineralization fluid system.

内蒙古龙头山Ag-Pb-Zn多金属矿床成矿模式及找矿模型

The recent years research indicated that middle-south section of Da Hinggan Mountains metallogenic belt has two periods(Hercynian and Yanshanian) characteristics of metallogenesis, as well as the most of ore deposits in the area closely relate to Permian strata. Longtoushan ore deposit discovered in 2004 is an Ag-Pb-Zn polymetallic ore deposit born in Permian and located in the east hillside of the metallogenic belt, which has considerable resources potentials. It has important research value for its good metallogenic location and blank research history. Base on the detail field geology studies, the geology characteristics of "two stages and three kinds of metallogensis" has established. According to further work through geochemistry research including trace element, REE, S, Pb and Sr isotope, as well as petrography, microtemperature measurement, Laser Raman analysis and thermodynamics calculation of fluid inclusion, origin and characteristic of the ore-forming material and fluid has been discussed. And a new technology of single pellet Rb-Sr isochrones has been tried for dating its born time. Bae on above work, study of ore deposit comparison has been carried out, and metallogesis controlling factor and geological prospecting symbol have been summarized. Finally, metallogenic model and prospecting model have been established. According to above, the next step work direction has been proposed. Main achievement of the paper are listed as follow: 1.Longtoushan ore deposit has experienced two metallogenic periods including hot-water sedimentation period and hydrothermal reformation period. There are three kinds of metallizing phase: bedded(or near-bedded) phase, vein-shaped phase and pipe-shaped phase. The mian metallogenic period is hot-water sedimentation period. 2.Ore deposit geochemistry research indicated that the metal sulfides have charcateristic of hot-water sedimentation metallogensis, but generally suffered later hydrothermal transformation. The barite mineral isotope content is homogenous, showing the seabed hot-water sedimentation origin characteristic. Wall rock, such as tuff is one of metallogenic material origins. Both of Pb model age and Rb-Sr isochrone research older age value than that of strata, possibly for been influenced by hydrothermal transformation, and interfusion of ancient basis material. 3.There are two kinds of main metallogenic fluid inclusion in barite of the Longtoushan ore deposit, which are rich gas phase( C type) and liquid phase (D type). Their size is 2～7um, and principal components is H2O. Both kinds of fluid inclusion have freezing point temperature -7.1～-2.4℃ and -5.5～-0.3℃, salinity 4.0～10.6wt% and 0.5～8.5wt%, homogeneous temperature 176.8～361.6℃ and 101.4～279.9℃, which peak value around 270℃ and 170℃, respectively. Density of the ore-forming fluid is 0.73～0.97g/cm3, and metallogenic pressure is 62.3×105～377.9×105Pa. Above characteristic of the fluid inclusion are well geared to that of ore deposit originated in seabed hot-water sedimentation. 4.Through the comparison research, that Longtoushan ore deposit has main characteristic of hot-water sedimentation ore deposit has been indicated. Ore-forming control factor and prospecting symbol of it has been summarized, as well as metallogenic model and prospecting model. Next step work direction about prospecting has also been proposed finally.

东海榴辉岩向斜长角闪岩的转化过程

The Ultrahigh Pressure Metamorphic (UHPM) eclogite, which was resulted from deep subduction of crustal continent, is very significant due to its continental dynamic implications. Further more, this kind of rocks experienced great P-T, fluid and stresses changes during its forming and exhumation, causing mineral reactions occur intensively, which resulted in a lot of fantastic micro-texture. The micro-texture was preserved duo to a rapid exhumation of the eclogite. This PhD dissertation takes such micro-textures in 10 Donghai eclogite samples South Sulu UHPM terrene, as research object to reveal the transformation of the eclogite to amphibolite. Microscope and Scanning Electron Microscope were employed to observe the micro-texture. Basing on microprobe analysis of minerals, the ACF projections and iso-con analysis were used to uncover the mineral reactions during the transformation. Micro-texture observation (both of Microcopy and Electron Scanning Microscope), demonstrated: l.The peak mineral assemblage of the researched Donghai eclogites is garnet + omphacite + rutile (+ kyanite + aptite +coesite). 2.The transformation of the Donghai eclogite to amphibolite can be divided into two stages: The earlier one is Symplectization, resulting in the forming of diopside + albite (+magnetite) symplectite that occurred only along the boundary between two adjacent omphacite grains. Other minerals were not involved in such reaction. The latter stage is Fluid-Infiltration of the eclogite, which was caused by fluid-intrusion. The infiltration is demonstrated by amphibolization of the symplectite, decomposition of garnet and the forming of some hydrous minerals such as phengite and epidote, and resulted in an amphibole + plagioclase + phengite + epidote or ziosite assemblage. Basing on microprobe analysis of the minerals, ACF projections indicated: In the ACF diagrams, the two joint lines of peak Grt + Omp and Dio + Ab crossed at Omp projection-point, indicating that the garnet had not taken part in the forming reaction of the Dio + Ab symplectite, just like that had been pointed out by micro-texture observation. In the ACF diagrams, the hornblende + plagioclase + epidote + phengite quadrilateral intersected with Dio + Ab + Grt triangle, demonstrating that the hydrous mineral assemblage was formed by fluid infiltration through garnet, diopside and albite. Iso-con (mass-balance) analysis of the symplectization and infiltration reveals: 1.The symplectization of the omphacite has a very complex mass exchange: Some symplectite gained only silicon from its surroundings; and some one requires Ca, but provides Na to its surroundings; while other symplectite provides Ca, Mg and Fe to its surroundings. 2.The infiltration cause variable mass exchanges occurring among the garnet, diopside and albite: In some eclogite sample, no mass, except H2O, exchange occurred during the infiltration. Meanwhile, there was not any hydrous mineral except hornblende formed in the sample accordingly. In some samples, the mass exchange among the three minerals is complex: amphibolization of the diopside in a symplectite gained Al from garnet, and provided Si and Ca to its surrounding, resulting in a Si, Ca and Al-rich fluid. Correspondingly, there was a lot of phengite and ziosite occurred in the sample. In other samples, the amphibolization of a symplectite provided Fe and Mg besides Si and Ca to its surrounding while gained Al. In such kind of sample, epidote occurred within the hydrous mineral assemblage. Synthesizing the micro-texture observation, ACF analysis and iso-con analysis, we deduced the transformation procedure as following: 1. A symplectite after an omphacite was resulted by one, or two, or all of following mineral reactions together: Jd (Ca-Tsch) +SiO2=Ab (An) (1) 4NaA IS i.A+CaO=2NaAlS i308+Na20+CaAl2S 1208 (2) 2NaAlSi2OB (Jd in Omp)+CaMgSi;,0B(Dio in Omp)-2NaAlSi:,O"(Ab)+Ca0+Mg0 (3) 2(CaAl2Si0fi) (Ca-tsch in Omp)+CaFeSi2O6(Hed in 0mp)-H>2CaAl2Si208(An)+Ca0 + FeO (4) A CO2-rich fluid is suggested as cataclysm for the above reactions, which largely increased the mobility of Ca, Mg and Na resulted from reaction (2), (3) and (4). The immobile product Fe2* combined with rutile to form ilmenite, resulting in rutile + ilmenite symplectite. Or, the Fe was precipitated as hematite locally. A procedure of the fluid infiltration as following is suggested: I .A hydrous fluid intruded into the eclogite, and reacted first with garnet to form hornblende and extra Al, resulting in a hornblende film around the garnet grain and an Al-rich fluid. 2.The Al-rich fluid infiltrated through the symplectite, OH" and part of the Al in the fluid combined with Dio while some Si and Ca in the Dio were dissolved made the Dio transferred to amphibole. Meanwhile, plagioclase-type cation exchange occurred between the fluid and plagioclase in the symplectite, making the plagioclase have a higher An-content. 3.Above infiltration and cation exchange resulted in an Al, Si, Ca (and K, providing the primary hydrous fluid contain K)-rich fluid. 4.Under suitable conditions, the solute in the fluid precipitated to form phengite firstly. After the K element in the fluid was consumed up, ziosite or epidote was formed. If the fluid did not contain any K. element, only ziosite or epidote was precipitated. For those eclogites, where all omphacite had been replaced by symplectite before infiltration, neither element exchange occurred, nor did phengite or epidote form during the infiltration. At the last stage, the garnet was oxidized and breakdown: garnet + H2O = epidote + hornblende + hematite, due to more and more fluid intruding into the eclogite. At this time, all the peak minerals were replaced by amphibolite-phase ones, and the eclogite transformed to an amphibolite completely. Tentative pressure calculation indicates that the infiltration occurred at 3-6kbar (about 10-20km depth), where the deformation mechanics transformed from brittle to ductile yield. At such depth, the surface water can permeate the rocks through fault system, causing a rapid cooling.

矾山杂岩体成因及其与磷（铁）矿的成矿关系

The Fanshan complex consists of layered potassic ultramafic-syenite intrusions. The Fanshan apatite (-magnetite) deposit occurs in the Fanshan complex, and is an important style of phosphorus deposit in China. The Fanshan complex consists of three (First- to Third-) Phases of intrusion, and then the dikes. The First-Phase Intrusive contains ten typical layered rocks: clinopyroxenite, biotite clinopyroxenite, coarse-grained biotite clinopyroxenite, pegmatitic orthoclase-biotite clinopyroxenite, variegated orthoclase clinopyroxenite, interstitial orthoclase clinopyroxenite, biotite rock, biotite-apatite rock, biotite rock and magnetite-apatite rock. This layered intrusive consists of nine rhythmic units. Each rhythmic unit essentially comprises a pair of layers: clinopyroxenite at the bottom and biotite clinopyroxenite at the top. The apatite (-magnetite) deposit is situated near the top of rhythmic Unit no. 6 of the First-Phase Intrusive. The Second-Phase Intrusive contains three typical rocks: coarse-grained orthoclase clinopyroxenite, . coarse-grained salite syenite and schorlomite-salite syenite. The Third-Phase Intrusive includes pseudo-trachytic salite syenite, porphyritic augite syenite, fine-grained orthoclase clinopyroxenite and fine-grained salite syenite. The origin of the Fanshan complex is always paid attention to it in China. Because most layered igneous intrusion in the world not only have important deposit in it, but also carry many useful information for studying the formation of the intrusion and the evolvement of magma. Two sketch maps were drawn through orebodies along no. 25 cross-cut on 425 mL and no. 1 cross-cut on 491 mL in the Fanshan mine. Through this mapping, a small-scaled rhythmic layering (called sub-rhythmic layering in the present study) was newly found at the top of the rhythmic Unit no. 6. The concept of sub-rhythmic layering is defined in this article. The sub-rhythmic layering is recognized throughout this apatite-rich part, except for magnetite-apatite rock. Presence of the layered magnetite-apatite rock is one of the characteristics of the Fanshan apatite (-magnetite) deposit. Thus, from this layer downwards six units of sub-rhythmic layering are recognized in the present study. Each unit consists of biotite clinopyroxenite (or biotite rock and biotite-apatite rock) layer at the bottom and apatite rock layer at the top. To study this feature in detail is an important work for understanding the origin of the Fanshan complex and apatite (-magnetite) deposit. The origin of the Fanshan complex and the relation of the formation of the apatite(-magnetite)deposit will be interpreted by the study of sub-rhythmic layering on the basis of previous research works. The magma formed the Fanshan complex was rich in K2O, early crystallized pyroxene, and after this phase more biotite crystallized, but no amphibole appeared. This indicated that the activity of H2O in the magma was low. Major element compositions of biotite and clinopyroxene (on thin sections) in the sub-rhythmic layering were analyzed using electron microprobe analyzer. The analytical results indicate Mg/(Mg+Fe*+Mn) atomic ratios (Fe*, total iron) of these two minerals rhythmically changed in sub-rhythmic layering. The trends of Mg/(Mg+Fe*+Mn) atomic ratio (Fe*, total iron) of biotite and clinopyroxene indicate that the magma evolved markedly from relatively magnesian bottom layer to less magnesian top layer in each sub-rhythmic unit. A general trend through the sub-rhythmic layering sequence is both minerals becoming relatively magnesian upwards. The formation temperatures for sub-rhythmic layering yield values between 600 and 800 ℃, were calculated using the ratio of Mg/(Mg+Fe+Mn) in the salite and biotite assemblage. The equilibrium pressures in the rhythmic layers calculated using the contents of Al in the salite were plotted in the section map, shown a concave curve. This indicates that the magma formed the First-Phase Intrusive crystallized by two vis-a-vis ways, from its bottom and top to its centre, and the magnetite-apatite rock was crytallized in the latest stage. The values of equilibrium pressures in the sub-rhythmic layering were 3.6-6.8(xlO8) Pa with calculated using the contents of Al in the salite. The characteristics of geochemistry in various intrusive rocks and the rocks or apatite of sub-rhythmic layers indicated that the Fanshan complex formed by the comagmatic crystallization. The contents of immiscible elements and REEs of apatite rock at the top of one sub-rhythmic unit are more than biotite clinopyroxenite at the bottom. The contents of immiscible elements and REEs of apatite of biotite clinopyroxenite at the bottom of one sub-rhythmic unit are higher than apatite rock at the top. The curves of rocks (or apatite) in the upper sub-rhythmic units are between two curves of the below sub-rhythmic unit in the primitive mantle-normalized trace element abundance spider diagram and the primitive mantle-normalized REE pattern. The trend for the contents of immiscible elements and REEs inclines to the same contents from the bottom to the top in sub-rhythmic layering. These characteristics of geochemistry of rocks or apatites from sub-rhythmic layering indicate that the latter sub-rhythmic unit was produced by the residual magma after crystallization of the previous sub-rhythmic unit. The characteristics of petrology, petrochemistry, geochemistry in the Fanshan complex and sub-rhythmic layers and the trends of Mg/(Mg+Fe+Mn) atomic ratio of biotite and clinopyroxene in sub-rhytmic layering rejected the hypotheses, such as magma immiscibility, ravitational settling and multiple and pulse supplement of magma. The hypothesis of differentiation by crystallization lacks of evidences of field and excludes by this study. On the base of the trends of formation temperatures and pressures, the characteristics of petrology, petrochemistry, geochemistry for the Fanshan complex and the characteristics of geochemistry for the rocks (or apatites), the trends of Mg/(Mg+Fe+Mn) atomic ratio of biotite and clinopyroxene in sub-rhytmic layering, and the data of oxygen, hydrogen, strontium and neodymium isotopes, this study suggests that the magma formed the Fanshan complex was formed by low degree partial melting of mantle at a low activity of H2O, and went through the differentiation at the depth of mantle, then multiply intruded and crystallized. The rhythmic layers of the First-Phase Intrusive formed by the magma fractional crystallized in two vis-a-vis ways, from the bottom and top to the centre in-situ fractional crystallization. The apatite (-magnetite) deposit of the Fanshan complex occurs in sub-rhythmic layering sequence. The the origin of the sub-rhythmic layering is substantially the origin of the Fanshan apatite (-magnetite) deposit. The magma formed the rhythmic layers of First-Phase Intrusive was rich in H2O, F and P at the later stage of its in-situ fractional crystallization. The Fanshan apatite (-magnetite) deposit was formed by this residual magma in-situ fractional crystallization. The magnetite-apatite rock was crystallized by two vis-a-vis ways at the latest stage in-situ fractional crystallization in the rhythmic layers. The result was light apatite layer below heavy the magnetite-apatite layer, formed an "inversion" phenomenon.

分子水平上研究地质流体的物理化学性质

Geological fluids exist in every geosphere of the Earth and play important roles in many processes of material transformations, energetic interchanges and geochemical interactions. To study the physicochemical properties and geochemical behaviors of geological fluids turn Girt to be one of the challenging issues in geosciences. Compared with conventional approaches of experiments and semi-theoretical modeling, computer simulation on molecular level shows its advantages on quantitative predictions of the physicochemical properties of geological fluids under extreme conditions and emerges as a promising approach to find the characteristics of geological fluids and their interactions in different geospheres of the Earth interior.This dissertation systematically discusses the physicochemical properties of typical geological fluids with state-of-the-art computer simulation techniques. The main results can be summarized as follows: (1) The experimental phase behaviors of the systems CH4-C2H6 and. CO2 have been successfully reproduced with Monte Carlo simulations. (2) Through comprehensive isothermal-isobaric molecular dynamics simulations, the PVT data of water hia^e been extended beyond experimental range to about 2000 K and 20 GPa and an improved equation of state for water has been established. (3) Based on extensive computer simulations, am optimized molecular potential for carbon dioxide have been proposed, this model is expected to predict different properties of carbon dioxide (volumetric properties, phase equilibria, heat of vaporization, structural and dynamical properties) with improved accuracies. (4) On the basis of the above researches of the end-members, a set of parameters for unlike interactions has been proposed by non-linear fitting to the ab initio potential surface of CO2-H2O and is superior to the common used mixing rule and the results of prior workers vs/Ith remarkable accuracies, then a number of simulations of the mixture have been carried out to generate data under high temperatures and pressures as an important complement to the limited experiments. (5) With molecular dynamics simulations, various structural, dynamical and thermodynamical properties of ionic solvations and associations have been oomprehensively analyzed, these results not only agree well with experimental data and first principle calculation results, but also reveal some new insights into the microscopic ionic solvation and association processes.

地幔流体及其成矿作用

地幔流体及其成矿作用的研究是当前地学界倍受关注的前沿课题。地幔流体是一种以CO2和H2O为主，同时含有一定量的溶质成分、相对富集大离子等不相容元素的超临界流体，具有独特的溶解和输运能力，主要来源于俯冲板板的脱水、脱气作用和地核及地幔脱气作用。地幔流体在许多大型－超大型金属、非金属、油气矿床和矿集区形成过程中具有重要意义。地幔流体成矿作用主要表现为本身成矿、提供成矿物质、成矿流体和成矿热动力。地质构造背景、岩浆活动、矿床地质、矿床地球化学等方面的研究均可提供地幔流体成矿作用的证据。地幔流体成矿作用的主要特征是矿床具有深大断裂构造背景、伴随幔源岩浆活动、成矿物质和成矿流体具有幔源性、往往形成大型－超大型矿床和矿集区。

骑田岭A型花岗岩流体包裹体地球化学特征——对芙蓉超大型锡矿成矿流体来源的指示

南岭中段骑田岭A型花岗岩与芙蓉超大型锡矿床具有密切的时间和空间关系。流体包裹体地球化学研究表明,骑田岭A型花岗岩石英斑晶中的流体包裹体类型主要有熔融包裹体、流体-熔融包裹体和流体包裹体。流体-熔融包裹体的显微测温学研究结果显示,骑田岭A花岗岩在岩浆演化过程中可以分异出流体,且岩浆分异出的流体与芙蓉超大型锡矿床流体包裹体所反映的高温和高盐度的CaCl2-NaCl-KCl-H2O流体体系的特征相吻合。综合分析表明,芙蓉超大型锡矿床成矿流体中的高盐度流体应为骑田岭黑云母二长花岗岩结晶过程中分异出的富含Cl等挥发份和成矿物质的高盐度热流体。