不同培养条件对三角褐指藻生长及其生物活性成分积累的影响

以三角褐指藻(Phaeodactylum tricornutum)为研究材料,比较了Na NO3、NH4HCO3和CO(NH2)2为氮源的两种培养基(m L1和ASW培养基)对其生长和生物活性成分(岩藻黄素、金藻昆布糖和二十碳五烯酸(C20:5,EPA))时相积累的影响,同时分析了脂肪酸组成和总脂含量的变化。结果表明:以m L1培养基培养时,三角褐指藻的生物质质量浓度明显高于ASW培养基培养时的生物质质量质量浓度,尿素优于其他两种氮源,最大生物质质量质量浓度为3.7 g/L。不同培养条件下岩藻黄素含量的时相变化规律一致,均随着培养时间的延长呈现先增加后减少的趋势,其最高积累量分别为:13.27 mg/g(Na NO3)、13.23 mg/g(CO(NH2)2)和13.89 mg/g(NH4HCO3)(m L1);13.2 mg/g(Na NO3)、14.92 mg/g(CO(NH2)2)和13.6 mg/g(NH4HCO3)(ASW),由此可知氮源对岩藻黄素积累量影响不大。金藻昆布糖含量随着培养时间延长逐渐增加,其最大积累量分别为9.82 mg/g(NH4HCO3)(m L1)和8.59 mg/g(Na NO3)(ASW)。不同培养条件下其总脂含量变化不显著,均在培养末期达到最大值,分别为24.18%(NH4HCO3)(m L1)和23.79%(Na NO3)(ASW);其主要脂肪酸组成为:豆蔻酸(C14:0)、棕榈酸(C16:0)、棕榈油酸(C16:1)、硬脂酸(C18:0)、油酸(C18:1)、亚油酸(C18:2)、花生一烯酸(C20:1)、木焦油酸(C24:0)和EPA,其中,EPA含量随着培养时间延长逐渐下降,尿素最有利于EPA的积累。     

Paratacamite from Gypsum Veins in Sandstones of the Kuqa Basin,Xinjiang, China: Implications for a New Epigenetic Cu Enrichment Mechanism

The Kuqa Basin filled with Paleogene evaporite series is located in the northeast of the Tarim Basin, Xinjiang, China. It is famous for sandstone‐hosted Cu deposits formed by synsedimentary processes. However, our recent studies reveal that there has been another Cu mineralization mechanism in this basin. Field investigations show that there is a close relationship among faults, salt domes, and brine. Cu deposits are mainly located in two east–west‐trending anticlinal belts in the basin, adjacent to salt domes in the belts. Cu minerals in gypsum veins of the Jidike and Kangcun formations have been investigated by SEM, EDS, and X‐ray diffraction methods. The occurrence of paratacamite in gypsum veins has been reported to coexist with glauberite and halite in the joint planes of sandstones. In addition, it occurs accompanying residual crystal salt encrustation in limestone fractures, or in sandstones in dendritic form. These features indicate that the surface‐Cu enrichment in the Kuqa Basin might have originated from Cu‐bearing brine in the underlying evaporite units, which migrated upward along fractures. In addition, the presence of H₂S in the east–west fault belt in the Kuqa Basin, and the discovery of surface sulfur, calcium carbonate, and covellite, suggest thermochemical sulfate reduction near salt domes in the deeper parts of the rock units. This process resulted in the generation of reduced brine and provided a favorable environment for Cu enrichment. Therefore, the surface‐Cu mineralization near salt domes is interpreted to be the result of Cu‐bearing brine migrating upward to the surface along faults (or joints) following the intrusion of deep salt domes. The geological evidence indicates the presence of reducing brine and Cu‐bearing brine near the salt dome in the deeper rocks of the Kuqa Basin, thus making the intrusive contact zone of the salt dome a favorable site for the epigenetic enrichment of Cu. Our study demonstrates that Cu enrichment in the Kuqa Basin resulted not only from synsedimentary deposition but also through epigenetic enrichment associated with salt dome intrusion and brine‐rich fluids.     

山东省重要地质遗迹自然区划研究

地质遗迹区划是地质遗迹资源保护的基础,该文根据山东省重要地质遗迹资源的空间分异和山东省大地构造二级构造单元,划分出3个地质遗迹大区,再以其自然分布规律、遗迹形成时间、空间、成因和地质构造单元的关联性进一步划分出8个地质遗迹区和24个地质遗迹集中区,从而建立了山东省重要地质遗迹自然区划系统,亦为地质遗迹保护提供了可靠的科学依据。     

江西德兴铜矿区水系的Cu同位素地球化学特征及其地质意义

江西德兴铜矿水系样的δ65Cu值具有极大的变化范围(-5.8‰~+24.4‰),是迄今为止已报道发现的最大的Cu同位素分馏值。水体中铜的来源可分为黄铜矿源和黄铁矿源,二者具有明显不同的Cu同位素特征。根据水体的Cu同位素值分布特征,圈出了流经矿体(矿体上方)水、矿体外围水和尾矿库水3个源区。水体中的Cu主要以离子态和微粒态存在,二者具有明显不同的65Cu特征,尾矿库中黄铁矿65Cu对水体的Cu同位素组成具有较大的影响作用。Cu同位素在示踪找矿及地质环境监测方面具有良好的应用潜力。     

西藏改则县多龙矿集区发现岩墙岭蛇绿岩残片

西藏班公湖-怒江缝合带北缘多龙矿集区是青藏高原新近发现的具有超大型远景的、典型的富金斑岩型铜矿集区,其成岩成矿地质背景是解决班公湖-怒江洋构造演化的关键问题之一。近年来的区域地质调查研究发现,多龙矿集区南侧出露岩墙岭蛇绿岩残片,应该是班公湖-怒江蛇绿岩带的重要组成部分。岩墙岭蛇绿岩主要由席状岩墙群、枕状玄武岩和硅质岩组成,整体呈棱形或透镜体状断续分布于侏罗系复理石沉积内,构成典型的网结状构造。糜棱岩普遍发育在岩墙岭蛇绿岩和围岩的接触部位。综合前人研究成果,初步认为多龙矿集区早白垩世成岩成矿作用应该形成于增生楔之上伸展拉张的构造环境。岩墙岭蛇绿岩的发现和确定进一步约束了多龙矿集区成岩成矿地质背景,同时为班公湖-怒江缝合带的延伸及其构造演化的研究提供了新的线索。     

Metallogeny of the Baiyangping Lead‐Zinc Polymetallic Ore Concentration Area,Northern Lanping Basin of Yunnan Province,China

The Lanping Basin in the Nujiang‐Lancangjiang‐Jinshajiang (the Sanjiang) area of northeastern margin of the Tibetan Plateau is an important part of eastern Tethyan metallogenic domain. This basin hosts a number of large unique sediment‐hosted Pb‐Zn polymetallic deposits or ore districts, such as the Baiyangping ore concentration area which is one of the representative ore district. The Baiyangping ore concentration area can be divided into the east and west ore belts, which were formed in a folded tectogene of the India‐Asia continental collisional setting and was controlled by a large reverse fault. Field observations reveal that the Mesozoic and Cenozoic sedimentary strata were outcropped in the mining area, and that the orebodies are obviously controlled by faults and hosted in sandstone and carbonate rocks. However, the ore‐forming elements in the east ore belt are mainly Pb‐Zn‐Sr‐Ag, while Pb‐Zn‐Ag‐Cu‐Co elements are dominant in the west ore belt. Comparative analysis of the C‐O‐Sr‐S‐Pb isotopic compositions suggest that both ore belts had a homogeneous carbon source, and the carbon in hydrothermal calcite is derived from the dissolution of carbonate rock strata; the ore‐forming fluids were originated from formation water and precipitate water, which belonged to basin brine fluid system; sulfur was from organic thermal chemical sulfate reduction and biological sulfate reduction; the metal mineralization material was from sedimentary strata and basement, but the difference of the material source of the basement and the strata and the superimposed mineralization of the west ore belt resulted in the difference of metallogenic elements between the eastern and western metallogenic belts. The Pb‐Zn mineralization age of both ore belts was contemporary and formed in the same metallogenetic event. Both thrust formed at the same time and occurred at the Early Oligocene, which is consistent with the age constrained by field geological relationship.     

Ore-forming Fluid and Mineral Source of the Hongshi Copper Deposit in the Kalatage Area, East Tianshan, Xinjiang, NW China

The Hongshi copper deposit is located in the middle of the Kalatage ore district in the northern segment of the Dananhu-Tousuquan island-arc belt in East Tianshan, Xinjiang, NW China. This study analyses the fluid inclusions and H, O, and S stable isotopic compositions of the deposit. The fluid-inclusion data indicate that aqueous fluid inclusions were trapped in chalcopyrite-bearing quartz veins in the gangue minerals. The homogenization temperatures range from 108°C to 299°C, and the salinities range from 0.5% to 11.8%, indicating medium to low temperatures and salinities. The trapping pressures range from 34.5 MPa to 56.8 MPa. The δ18OH2O values and δD values of the fluid range from ?6.94‰ to ?5.33‰ and from ?95.31‰ to ?48.20‰, respectively. The H and O isotopic data indicate that the ore-forming fluid derived from a mix of magmatic water and meteoric water and that meteoric water played a significant role. The S isotopic composition of pyrite ranges from 1.9‰ to 5.2‰, with an average value of 3.1‰, and the S isotopic composition of chalcopyrite ranges from ?0.9‰ to 4‰, with an average value of 1.36‰, implying that the S in the ore-forming materials was derived from the mantle. The introduction of meteoric water decreased the temperature, volatile content, and pressure, resulting in immiscibility. These factors may have been the major causes of the mineralization of the Hongshi copper deposit. Based on all the geologic and fluid characteristics, we conclude that the Hongshi copper deposit is an epithermal deposit.     

塔里木陆块西北缘萨热克砂岩型铜矿床构造-流体演化对成矿的制约

塔里木陆块西北缘萨热克砂岩型铜矿床构造演化、流体演化与成矿之间具有密切关系,处于一个统一系统中。矿床成岩期方解石中包裹体水的δD值为-65.3‰~-99.2‰,改造成矿期石英包裹体水的δD值为-77.7‰~-96.3‰,成岩成矿期成矿流体δ~(18)OH_2O变化范围为-3.22‰~1.84‰,改造成矿期成矿流体δ~(18)OH_2O变化范围为-4.26‰~5.14‰,指示萨热克铜矿成岩期、改造期成矿流体主要为中生代大气降水及其经水岩作用而成的盆地卤水。矿石中辉铜矿δ~(34)S值为-24.7‰~-15.4‰,指示硫主要源自硫酸盐细菌与有机质还原,部分源于有机硫。构造与成矿流体演化对砂岩铜矿成矿起关键制约作用。盆地发展早期强烈的抬升运动使盆地周缘基底与古生界剥蚀,为富铜矿源层的形成提供了丰富物源,至晚侏罗世盆地发展晚期,长期演化积聚的巨量含矿流体在库孜贡苏组砾岩胶结物及裂隙中富集,在萨热克巴依盆地内形成具有经济意义的砂岩型铜矿床。     

Porphyry Copper Deposit Prognosis in the Middle Region of the Bangonghu–Nujiang Metallogenic Belt,Tibet, Using ASTER Remote Sensing Data

The B angonghu–N ujiang metallogenic belt is considered to be T ibet’s third copper belt after the Y ulong and G angdese copper belts. The D uolong gold‐rich porphyry copper deposit, located in the western part of the B angonghu–N ujiang belt was recently recognized as a superlarge prospect. The A dvanced S paceborne T hermal E mission and R eflection R adiometer (ASTER ) was used to characterize the D uolong porphyry deposit alteration area, and three methods, color enhancement, band ratio transformation, and spectral angle mapping, were utilized to extract the phyllic and argillic alteration zones, which are typically considered the most important predictors of porphyry copper. Seven prospecting areas, which match mapped alteration zones, were delineated in the D uolong deposit. In addition, an ASTER image of the eastern region of the B angonghu–N ujiang belt in the X iongmei area was used to extract alteration information, and an area with image characteristics similar to the D uobuza and B olong ore deposits was identified as a prospecting area. Numerous malachite outcrops were identified in the field, and both laboratory analysis and isotopic dating confirmed that the deposit had formed concurrently with the D uobuza deposit (119 M a). Geologic mapping at the 1:5000 scale was conducted in the area, and three types of ore‐bearing rocks were identified, indicating that this area has significant potential to host ore deposits. The discovery of the X iongmei copper mining area is significant for the B angonghu–N ujiang belt.     

庐枞火山岩盆地南部拔茅山铜矿深部找矿潜力分析

位于庐枞火山岩盆地南部的拔茅山铜矿,是细脉带蚀变岩型脉状铜矿的代表。研究表明,其深部具有斑岩型铜矿的勘探潜力。为了进一步明确其深部找矿潜力,针对研究区斑岩型、热液型铜多金属矿的岩体、断裂、接触带等主要控矿因素,利用高精度磁法和可控源音频大地电磁测深(CSAMT)成果,分别对拔茅山岩体的分布、产状和深部形态及其与围岩的接触带特征进行了剖析。在此基础上,通过与沙溪斑岩铜矿地质、物探异常特征的类比,指明了研究区的找矿方向和有利找矿部位,为进一步找矿提供了思路和依据。