川东茅口组硅质岩地球化学特征及成因

川东地区中二叠统茅口组硅质岩广泛分布。通过野外剖面的详细研究和硅质岩主量、稀土和同位素的分析,认为茅口组硅质岩为沉积于台盆相中的热水硅质岩,其化学成分以SiO2为主,含量为80.09%～97.91%,富集Fe、Mn等元素,Al/(Al+Fe+Mn)平均值为0.30;REE总量平均值为8.72×10-6,δCe值为0.39～0.81,为负异常,δEu值为0.35～5.85,从Eu负异常到Eu正异常;δ30Si值为0.2‰～1.2‰,与热水来源石英较为接近;根据δ18O计算出硅质岩形成时古海水的温度为34～89℃。热水硅质岩的形成与火山活动和断裂有关,下渗的海水与岩浆热液混合,并被加温,溶解了大量SiO2等有关元素;然后以热泉形式通过断裂喷出,使附近海水中SiO2含量极大提高并沉淀。     

东昆仑山香日德南部白沙河岩组的岩石组合特征和形成年代的锆石Pb-Pb定年启示

柴达木盆地南缘香日德南部金水口岩群白沙河岩组的岩石组合自下而上为长英质片麻岩-钙质片麻岩 斜长角闪岩-大理岩组合.白沙河岩组和侵入该岩组的变质花岗岩的锆石逐层蒸发Pb-Pb定年结果表明:白沙河岩组的陆源碎屑来自一个具有2.1～1.9 Ga岩浆变质热事件的陆源区,当考虑现有的年龄资料时,该岩组的形成年龄可进一步约束在1.6～1.0 Ga间;柴南缘的晋宁期深成侵入活动可能推前到中元古代末.     

China''''s First Exploration of Chukchi Sea and Its Adjacent Waters in the ArcticA Study on Lead Geochemistry of Atmospheric Aerosol

1ＩｎｔｒｏｄｕｃｔｉｏｎＷｉｔｈｔｈｅｒａｐｉｄｄｅｖｅｌｏｐｍｅｎｔｏｆｈｕｍａｎｓｏｃｉｅｔｙ ,ｉｎｄｕｓｔｒｉａｌｉｚａｔｉｏｎｈａｓｂｅｅｎｓｐｅｅｄｅｄｕｐ .Ａｓａｒｅｓｕｌｔ,ｍｅｔａｌｍｉｎｉｎｇａｎｄｍｅｔａｌｌｕｒｇｙ ,ｃｏａｌａｎｄｇａｓｏｌｉｎｅｃｏｍｂｕｓｔｉｏｎａｎｄｃｈｅｍｉｃａｌｓｐｒｏｄｕｃｔｉｏｎｈａｖｅｇｉｖｅｎｏｆｆａｌｏｔｏｆＰｂ ｃｏｎｔａｉｎｉｎｇｉｎｄｕｓｔｒｉａｌｐｏｌｌｕｔａｎｔｓｗｈｉｃｈｈａｖｅｄｏｎｅｇｒｅａｔｈａｒｍｔｏｔｈｅｅｃｏｌｏｇ…     

0～6 h定量降雪(雨)预报技术及其在温哥华冬奥会中的应用

利用中尺度数值预报模式与雷达回波外推技术相结合,围绕SNOWV10项目的科学目标,在自动判识降水相态(雨、雪或雨雪混合物)基础上,利用雷达反演降雪(雨)关系,建立短时(0～6 h)定量降雪(雨)预报方法,并集成到GRAPES-SWIFT临近预报系统,为温哥华冬奥会提供实时场馆预报产品.从2010年2月冬奥会使用情况看,所建立的定量降雪(雨)预报技术,一定程度满足高纬度冬季降雪(雨)临近预报预警的需求,但降水(雨或雪)预报量级偏小,针对场馆的降水预报起止时间节奏偏差较大,各时次预报一致性有待改进.     

Titanium Isotope Analysis of Igneous Reference Materials using a Double-spike MC-ICP-MS Method

Ti separation was achieved by ion-exchange chromatography using Bio-Rad AG 1-X8 anion-exchange and DGA resins. For high-Fe/Ti and high-Mg/Ti igneous samples, a three-column procedure was required, whereas a two-column procedure was used for low-Fe/Ti and low-Mg/Ti igneous samples. The Ti isotopes were analysed by MC-ICP-MS, and instrumental mass bias was corrected using a 47Ti-49Ti double-spike technique. The 47Ti-49Ti double-spike and SRM 3162a were calibrated using SRM 979-Cr, certificated value 53Cr/52Crtrue = 0.11339. Isobaric interference was evaluated by analysing Alfa-Ti doped with Na, Mg, Ca, and Mo, and results indicate that high concentrations of Na and Mg have no significant effect on Ti isotope analyses; however, Ca and Mo interferences lead to erroneous δ49/47Ti values when Ca/Ti and Mo/Ti ratios exceed 0.01 and 0.1, respectively. Titanium isotopic compositions were determined for 12 igneous reference materials, BCR-2, BHVO-2, GBW07105, AGV-1, AGV-2, W-2, GBW07123, GBW07126, GBW07127, GBW07101, JP-1, and DTS-2b. Samples yield δ49/47Ti (‰) of ?0.035 ± 0.022, ?0.038 ± 0.031, 0.031 ± 0.022, 0.059 ± 0.038, 0.044 ± 0.037, 0.000 ± 0.015, 0.154 ± 0.044, ?0.044 ± 0.018, 0.010 ± 0.022, 0.064 ± 0.043, 0.169 ± 0.034, and ?0.047 ± 0.025 (relative to OL-Ti, ±2SD), respectively; of which isotopic compositions of DTS-2b, JP-1, GBW07101, GBW07105, GBW07123, GBW07126, and GBW07127 are reported for the first time. Standard Alfa-Ti was analysed repeatedly over a ten-month period, indicating a reproducibility of ±0.047 (2SD) for δ49/47Ti, similar to the precisions obtained for geochemical reference materials.     

塔里木盆地塔中地区志留系塔塔埃尔塔格组潮坪沉积中的遗迹化石

在塔里木盆地塔中地区志留系塔塔埃尔塔格组中共发现遗迹化石 11属 12种,包括Skolithoslinearis、Skolithosverticalis、Ophiomorphanodosa、Arenicolitesisp.、Cylindrichnusisp.、Thalassinoidessuevicus、Diplocraterionparallelum、Taenidi umsatanassi、Macaronichnussegregatis、Palaeophycustubularis、Planolitesbeverlegensis和Cochlichnusanguineus。这些遗迹化石主要是无脊椎动物的居住迹、进食迹和觅食迹,其中大部分呈全浮痕保存,少数呈上浮痕或下浮痕保存。按其古生态和沉积学特征,可划分出三个遗迹组合:①Skolithos-Thalassinoides遗迹组合,代表了平坦底型条件下的砂坪沉积环境;②Planolites-Palaeophycus遗迹组合,反映了潮间带砂泥坪沉积环境;③Cochlichnus-Planolites遗迹组合,代表了平均低潮线附近的泥坪沉积环境。     

珠江口盆地珠三坳陷文昌组有机质碳同位素异常成因

部分中国近海湖盆和大西洋裂谷盆地发现了腐泥型有机质碳同位素偏重的现象,并伴随异常高总有机碳含量和生烃潜力。本文依据泥岩有机碳测试、孢粉分析、主微量元素、泥岩和原油碳同位素及饱和烃色质色谱资料,并结合现代湖泊盘星藻发育特征,从有机质来源、古环境条件和有机质保存改造三个方面探讨了珠江口盆地珠三坳陷古近系文昌组碳同位素正偏移的成因机制。珠三坳陷文昌组碳同位素异常与气候、古生产力、古水深和藻类勃发等古环境因素有关。然而,从三级层序尺度看,古水深可能是一个不可忽视的重要因素：指示水深的Rb/K比值随深度加深而增加,与碳同位素和TOC含量变化趋势一致。同时现代湖泊研究也证实了盘星藻分布于不同水深范围,因此“深水型盘星藻”的繁盛很可能是珠三坳陷文昌组二段烃源岩碳同位素偏重的根本原因。