Primary alteration—oxidation of marine algal organic matter from oil source rocks of the North Sea and Norwegian Arctic: new findings

The presence of partially oxidized algal organic matter in oil-prone marine source rocks, is the rule rather than the exception. Partially oxidized, algal kerogen can still act as a significant source of liquid hydrocarbons. However, the corresponding peak of C₁₂ + hydrocarbon generation is shifted to a considerably lower maturity level compared with that of the classical Type II kerogen. The extent of primary alteration-oxidation of marine algal kerogen is monitored by means of solid state microfluorescence spectroscopy. A new parameter, the Primary Alteration Factor (PAF) is established, and the relationships between PAF and H/C, O/C, HI, TOC and between PAF and %₀δ¹³C are determined. The present data show large variations in the bulk chemistry of immature marine algal kerogens, and reveal evidence for gradational dehydrogenation/oxidation of the source organic matter. This contrasts with the recently proposed mechanism for kerogen formation. SEM analysis reveals a relationship between the physical breakdown of algal organic matter and the formation of liptodetrinite. FTIR analysis shows that the incorporation of primary oxygen in the kerogen macromolecules is not in the form of carbonyl or carboxyl functionalities. The presence of highly unreactive, stable oxygen, associated with aromatic structures in partially oxidized algal kerogen, is suggested by resistance of the kerogen to graphitization. The FTIR data also suggest the presence of aryl ether oxygen. The present findings raise fundamental questions regarding the mechanisms of kerogen cracking and kerogen formation, and have important implications for petroleum exploration.     

原生晕在深部成矿预测中的应用——以黑河地区永新金矿为例

原生晕法在长期大量的勘探实践中，已被证明是一种有效推测隐伏矿体，进行找矿预测的地球化学勘探方法.在永新金矿床的勘查基础上，通过采集永新金矿区内见矿效果最好的180号勘探线上的4个钻孔的岩石样品，开展了钻孔原生晕的分析.确定了该矿床前缘晕元素组合为As-Sb-Hg，近矿晕元素组合为Au-Ag-Cu-Pb-Zn，尾矿元素组合为W-Mo-Bi-Co-Ni-Cd.与前人总结的金矿经典分带模型相比，前缘晕出现了尾晕元素，同时尾晕序列中也有前缘晕的元素出现，显示了"反分带"的特征，说明在矿体的头部和尾部均有盲矿存在，而依据矿体发育形态来看，矿体头部继续往南东的盲矿已被剥蚀，而矿体尾部往北西方向是下一步勘查的重点.     

宝玉石的找矿标志

本文主要探讨宝石的找矿标志。包括在超基性岩、辉长岩—斜长岩中含虹彩长石、喷发岩、花岗伟晶岩中的宝石,还有变花岗岩云英岩中含海蓝宝石,镁矽卡岩中含尖晶石、红宝石、蓝宝石和青金石,风化壳中的宝石,砂矿中的宝石等。     

康定黄金坪金矿床原生晕分带特征及找矿意义

黄金坪金矿床以自然金(银金矿)—多金属硫化物—碲金银系列矿物—碲化物以及石英、黄铁矿等矿物组合为特征;典型元素组合为Au(Ag)-Te-Cu-Pb-Zn-Ba-As。本文应用数理统计方法研究Ⅰ号矿体的原生晕及其分带特征,结果表明侧向分带(矿体向围岩)趋势As-Zn-Pb-Au-Ag-Te-Cu-Ba,垂向分带(由上至下)为Pb-Ag-Au-Zn-As-Te-Cu-Ba。该分带模式对于深部矿化预测与其它矿化带的远景评价具有现实意义。     

Mid-chain ketocarboxylic acids in the remote marine atmosphere: Distribution patterns and possible formation mechanisms

In remote marine aerosol samples collected from the North Pacific ocean, Enewetak Atoll, American Samoa, and New Zealand, series of mid-chain ketocarboxylic acids in the range of C₆-C₁₈ were detected. All the positional isomers, except for the 2-oxo and 3-oxo species, were detected for major ketoacid families (e.g. C₉, C₁₁ and C₁₃). Higher ketoacid concentrations (up to 19 ng/m³) were obtained in the northern North Pacific aerosol samples, which generally showed an odd carbon-numbered predominance with 5-oxoundecanoic acid being the major species. By contrast, lower concentrations were obtained in the lower-latitude or subtropical aerosol samples, where even carbon-numbered ketoacids were relatively abundant.The distribution patterns of the odd carbon-numbered ketoacids could not be explained by the primary emissions from source materials including terrestrial higher plants, soil particles, and ocean surfaces. We consider that the isomeric ketocarboxylic acids are produced in the atmosphere by the photochemical oxidation of semi-volatile monocarboxylic acids, which are counterparts of the oxidative degradation of unsaturated fatty acids emitted from seawater surfaces. Atmospheric production of the ketoacids is seemingly enhanced in the northern North Pacific, probably due to an enhanced primary productivity.     

基于原生晕三维数据体模型的深部矿产预测

三维原生晕矿产预测方法可以作为原生晕地球化学的有效补充。探讨了基于原生晕的地球化学深部矿产预测方法,通过三维建模技术构建了一种三维原生晕矿产预测方法,应用该方法在湖北铜绿山铜铁矿圈定了22个预测靶位,部分靶位已在矿区的实际勘探中得到验证。三维原生晕数据体模型可以在深部矿产预测中取得较好的效果。     

连续两次台风过境对东海北部水环境及初级生产力的影响

台风是影响东海最严重的自然灾害之一。本文在现场观测基础上,结合遥感与模型数据,研究了连续两个台风过境对东海北部水环境及初级生产力的影响。研究结果表明:连续两个台风过境情况下,虽然前面台风有助于后续台风对海洋上层进行垂直混合作用,但它对后续台风过后海洋表层温度(SST)的降低以及初级生产力的增加却起到了削弱作用;除了加强垂向混合过程,台风也可以改变海洋上层的平流输运过程,受此影响,部分海区上层温度、盐度以及叶绿素在台风后重新分布;台风对海区次表层叶绿素浓度的改变程度明显高于表层,某些站位次表层叶绿素最大值(SCM)在台风刚过后被破坏,一段时间后SCM又重新出现,而且层内叶绿素浓度远高于台风前水平。     

Species composition,abundance and biomass of microphytoplankton in the KwaZulu-Natal Bight on the east coast of South Africa

Nearshore marine environments are influenced by an array of variables that can either be land-derived or of marine origin, and nearshore phytoplankton communities may differ in their taxonomic composition and biomass in response to such variables. The KwaZulu-Natal Bight (hereafter referred to as ‘the bight’) is an oligo-mesotrophic, nearshore oceanic environment, that is influenced by both terrestrial run-off and upwelling. A microphytoplankton survey of the bight conducted over several stations and depths and two seasons was conducted in order to ascertain species composition, abundance and biomass. Microphytoplankton abundance was generally low (a maximum of 180 000 cells l–1 was recorded) but differed considerably between sites and seasons. A total of 99 taxa of mainly Bacillariophyceae and some Dinophyceae, Prymnesiophyceae and Cyanophyceae were identified in the present study. In the central bight, higher abundance and biomass were measured in February (wet season), which may be a possible consequence of terrestrial nutrient inputs. In the northern and southern bight we measured higher abundance and biomass in August (dry season). Upwelling was not detected during the study, but an influence of terrestrial nutrient sources was detected at the coastal stations. Turbid conditions were specific to the site near the Thukela River mouth and possibly influenced abundance, biomass and species composition at this site. Historic data on microphytoplankton composition are scarce, but comparisons with surveys from the 1960s reveal that around 60% of the common diatoms recorded then also occurred in the present study. Small taxa [20–200 µm] dominated the microphytoplankton community. Community composition was fairly uniform throughout the bight in both seasons, dominated in general by Chaetoceros species, and on occasion co-dominated by Thalassionema nitzschioides and Dactyliosolen fragilissimus.     

查格勒布鲁剖面CGS3a层段主元素记录的巴丹吉林沙漠35 000~25 000 a B. P.季风环境变化

对巴丹吉林沙漠东南缘查格勒布鲁剖面该层段的CGS3a层段（Chagelebulu Section 3a）139个样品的主元素——SiO₂、Al₂O₃、TOFE（Fe₂O₃+FeO）进行分析,划分出与地层旋回对应的5.5个化学元素旋回。研究认为：沙丘砂和黄土中SiO₂呈现的峰和Al₂O₃、TOFE、(TOFE+Al₂O₃)/SiO₂和CIA呈现的谷是类似于现代干冷的冬季风在过去多次作用的结果,而嗣后的湖相SiO₂呈现的谷和Al₂O₃、TOFE、(TOFE+Al₂O₃)/SiO₂和CIA的呈现的峰是类似于现代暖湿的夏季风在过去多次作用的结果。即35 000~25 000 a B. P.该沙漠经历了5次冬季风和6次夏季风交替的气候波动,这些气候事件与GRIP冰芯氧同位素记录的D/O（Dansgaard/Oeschger）事件相对应,Heinrich事件也在其中有很好体现。CGS3a层段所记录的千年尺度的气候波动可能是受到了北大西洋气候突变的影响。