Preliminary organic petrography of Palaeozoic rocks from the Grand Banks,Newfoundland

Samples of lower Palaeozoic bedrock from the Grand Banks of Newfoundland were examined using reflected light microscopy and Rock-Eval pyrolysis. These samples contained organic material which included bitumen (structureless organic material), acritarchs, chitinozoa, scolecodonts and graptolites. The reflectance of the organic material increased from acritarchs towards graptolites with bitumen showing a wide range of reflectance. Multiple phases of oil migration through one sample were inferred by examination of the bitumens: the lowest reflecting being more recent than the highest reflecting bitumen. Combined reflectance and Rock-Eval analysis indicate that these samples are mature to overmature. The two oldest samples (Arenig-Llanvirn, Ordovician) are assessed as mature and as having potential for generation of liquid hydrocarbons, but must be considered as mainly gas prone.     

Organic petrography of graptolite fragments from Turkey

The reflectance and bireflectance of graptolite fragments (Silurian-Ordovician) from southeast Turkey were examined and the morphology was described using reflected light microscopy. The dispersion of maximum and minimum reflectance of graptolites sectioned parallel and perpendicular to the bedding was also determined. The graptolites were anisotropic and the anisotropy was stronger for sections perpendicular to the bedding. The graptolite fragments show two types of surface morphology: granular and non-granular. The granular type had a rough surface and granular anisotropy, the non-granular fragments showed a smooth surface and basic anisotropy. The fine internal structure of graptolite was evident under crossed-polars. The reflectance of graptolite increased with depth and was higher than other organic material, e.g. bitumen, found in the same sediment. The present study indicates that the reflectance of graptolite in sediment can be used to determine the maturity of the dediment.     

Reflected light microscopy of chitinozoan fragments

Certain optical properties of some Silurian-Ordovician chitinozoans have been measured and their morphology described, using polished, block-mounted samples and polished thin sections. The chitinozoans were found to be optically isotropic and many fine details of their morphology were observed using reflected light microscopy. It has also proved possible to recognize chitinozoan fragments in sections made from kerogen concentrates and whole rock samples from early Palaeozoic sediments using reflected light microscopy, reflectance studies indicate their potential use as maturity indicators.     

The assessment of the hydrocarbon potential and maturity of Silurian intervals from eastern part of Moesian Platform – Romanian sector

The aim of this paper is the assessment of the hydrocarbon potential and maturity of Silurian intervals from the Călăraşi-Bordei Verde-Biruinţa perimeter – East Moesian Platform. All the information gathered from the wells drilled in the mentioned perimeter is used for the evaluation of the “shale gas” potential, too. This major sedimentary basin has all geological conditions for hydrocarbons generation, migration and accumulation. The main conclusions of the all geo-analyses are the following: the XRD analyses show that the samples consist of clay minerals with organic material, the organic matter contained in the samples of the wells shows widely distributed type of organoclasts. In absence of true vitrinite originating from higher plants in these Lower Paleozoic series, the various encountered organic remains consist of Tasmanites, microporous or homogeneous fragments, structured fragments of graptolites, oxidized or naturally rich in oxygen organoclasts inherited from the continent (phytoclasts, fungal remains). The maturity of the Silurian at Ţăndărei borehole is established taking into account the fluorescence of the Tasmanites and the reflectance of graptolites; the maturity increases with depth between 0.70 and 1% eq. VRo. The organic matter of Biruinţa and Călăraşi boreholes is overmature with maturity of around 1.40–1.55% at 400 m in Biruinţa and a maturity increase with depth between 1.85 and 2.05% eq. VRo in Călăraşi borehole. Those values are mainly deduced from vitrinite/graptolite correlation. According to the maturity trend deduced of Călăraşi and Ţăndărei boreholes, the high maturity of Biruinţa for such a low burial (around 400 m) indicates a possible erosion around 3400 m due to uplift. The Silurian studied samples consist of carbonated claystones with an organic matter of type II with relatively low residual TOC content: less than 1.2% weight for the overmature boreholes (Biruinţa and Călăraşi) and less than 1.6% weight in Ţăndărei borehole.     

Structure of a modulated narrow light beam in seawater: Monte Carlo simulation

Dispersion properties of photon density waves propagating in seawater from a unidirectional point source have been studied using the Monte Carlo technique. It is shown that the spatial distribution of irradiance of the photon density waves at high modulation frequencies is significantly different from that of the stationary light field. Principal dispersion effects predicted earlier in the approximation solutions of the nonstationary radiation transfer equation are confirmed. An increase in the wave decrement and a decrease in the transversal cross section of the initially narrow beam at the modulation frequency with the increase of the modulation frequency are demonstrated. Frequency dependencies of phase and group velocities of photon density waves are calculated. It is shown that seawater possesses anomalous dispersion in a wide frequency range with respect to these waves.     

Estimation of water quality parameters from irradiance reflectance using optical models

In order to evaluate near-surface water quality parameters from spectral irradiance reflectance observed just below the surface, models of both radiative transfer and optical properties of sea water are used. The computed water quality parameters are compared with those determined directly from concurrent surface water samples. In this comparison, efforts have been made to minimize the number of spectral irradiance reflectance used in the computation while ensuring that the computed water quality parameters fit well to the observed ones.The observed water quality parameters were found to be closely represented by those computed from the irradiance reflectance at wavelengths of 400 nm, 440 nm, 510 nm and 600 nm, and the fit is as good as the fit of observed water quality parameters to those computed from the irradiance reflectances at 151 wavelengths located between 400 nm and 700 nm at intervals of 2 nm. This implies that the water quality parameters can be evaluated from at least four radiances observed at high altitude, if the effects of the atmosphere and the sea surface can be correctly removed.     

舟山海域陆源溶解有机质变化及其对近岸羽状流的响应

2007年夏季在东海舟山海域河口锋区开展了陆源溶解有机质的调查研究。测定了有色溶解有机质(CDOM)在激发波长370 nm/发射波长460 nm处的荧光强度和在λ=355 nm处的吸收系数,用于代表陆源CDOM浓度,并测定了荧光指数以指示CDOM来源。结果表明,CDOM的荧光值和紫外吸收系数之间呈显著正相关性,陆源CDOM浓度大体有向海方向降低的趋势,但是纵向上存在一些"突跃"现象。在舟山海域东北角不时观测到表层水体含有高浓度的CDOM,但变异性很大,推测可能该海区受到长江口羽状流的影响。在连续观测站发现陆源CDOM浓度在低平潮时往往比高平潮时要高。河海水在混合过程中CDOM浓度与盐度呈显著的线性负相关关系。在低盐度的悬沙锋区(S<24)CDOM浓度明显低于理论稀释值,而在较高盐度的羽状锋区,CDOM浓度接近于理论稀释值。在盐度为24~31范围内,大部分水样的荧光指数在1.50上下波动,表明其中CDOM来源以陆地来源为主;在较低盐度(S<24)的水样中荧光指数在1.70至1.90以上,表明CDOM以海洋来源为主,这与其陆源组分在高浊度的低盐度区存在显著的去除过程有关。研究表明,舟山海域水质存在着显著的变异性,与近岸羽状流密切相关,陆源溶解有机质的分布特征对此有较好的响应。     

Regional maturity as determined by organic petrography and geochemistry of the Schei Point Group (Triassic) in the western Sverdrup Basin, Canadian Arctic Archipelago

Maturity and source rock potential of organic rich beds in the Triassic Schei Point Group in the Sverdrup Basin, Arctic Canada have been investigated using reflected light microscopy and the results are compared with other maturity parameters determined geochemically (i.e. Rock Eval, and biomarker maturation parameters). The samples evaluated belong to the Eden Bay Member of the Hoyle Bay Formation and contain a predominance of marine algal material, in the form of Tasmanales, and dinoflagellates, along with mixed terrestrial organics.The rock matrix is dominantly carbonate with some shaly input, indicating that the rocks were deposited in an iron-poor highly euxinic environment. With few exceptions there is good agreement between parameters,determined using microscopy; namely %R_o, λ_max and and geochemical parameters, T_max, HI,

Full-size image (<1K)

steranes, C₂₉ steranes. The ternary diagram showing the abundance of normalized C₂₇, C₂₈ and C₂₉ regular steranes indicates a mostly marine depositional environment for the Schei Point source rock. This is confirmed by the abundance of marine fauna and flora in these samples.Analytical results from several different techniques indicate that the source rocks become more mature from the margin towards the axis of the Sverdrup Basin. This is due, in part, to the increase in overburden of sediments in the axis of the basin. Also the high thermal conductivity of salt has strongly influenced the maturity of Schei Point source rocks over the crest of the salt cored structures, i.e. Well Hazen F-54, and the proximity of salt has enhanced maturation levels at Well Rock Point J-43. The sections investigated were also considered to have an excellent gas potential due to their higher than average TOC content.     

基于Sentinel-2影像的围海养殖信息提取

为了能够利用遥感图像快速准确地提取围海养殖矢量信息,本文选取养殖水体、堤坝及育苗室等交错分布的海参围海养殖区域作为研究区域,根据研究区域Sentinel-2遥感影像的光谱特征,选用归一化差异水体指数（Normalized Difference Water Index,NDWI）、改进归一化差异水体指数（Modified Normalized Difference Water Index,MNDWI）和增强水体指数（Enhanced Water Index,EWI）三类水体指数,分别进行提取实验,利用同时期高空间分辨率的高分二号卫星（GF-2）影像作为参考,验证不同方法的提取精度,精度评价结果表明：相较MNDWI和EWI两类水体指数,NDWI的分类精度更高,且利用NDWI提取研究区域的围海养殖信息的效果更好,所以该方法可在养殖区域的动态监测和规划管理中发挥数据支撑作用。     

Organic petrology and RockEval analysis of the Lower Carboniferous Emma Fiord Formation in Sverdrup Basin,Canadian Arctic Archipelago

Samples of the Lower Carboniferous Emma Fiord Formation from two localities in the Sverdrup Basin of Arctic Canada were examined using reflected white and fluorescent light. The samples from Kleybolte Peninsula on Ellesmere Island show a relatively high level of thermal maturity. In contrast, those from Grinnell Peninsula on Devon Island are immature to marginally mature and include subbituminous coals and oil shales. Two types of oil shales are distinguished on the basis of liptinite content, mineral matrix, RockEval pyrolysis analysis, and concentration of boron. One is characterized by a liptinite-rich, clay-carbonate matrix with a relatively high hydrogen index and boron content, and the other by a liptinite-poor carbonate matrix with a relatively low hydrogen index and boron content. Hydrogen-rich components of these shales consist of alginite, matrix bituminite and minor amounts of exsudatinite and sporinite. Kerogen Types III and IV comprise only minor components of the organic matter.Thermal maturity of the Grinnell Peninsula oil shales increases with depth. Matrix bituminite in these oil shales has seeped into cavities and microfractures in the kerogen Types III and IV, forming exsudatinite.The distribution and character of the organic constituents and also the concentration of boron in these samples indicate a fresh to brackish water environment.     

南黄海陆架中部沉积物反射率光谱的影响因素分析

利用Minolta CM-2002光谱光度计对南黄海陆架136个短柱样品20~25cm段的沉积物进行了颜色反射率数据测量,通过化学元素、粒度、磁化率等来确定影响沉积物颜色反射率变化的成分和因素,介绍了反射率光谱的一阶导数和因子分析的方法。分析结果表明,南黄海陆架沉积物颜色反射率受控于沉积物中的铁氧化物、有机质以及粘土矿物和钙质生物碎屑含量。主因子F1指示氧化环境,并与陆源物质相关,F2指示弱氧化环境,F3指示弱还原环境,主因子的波长范围分别是405~445 nm和495~595 nm,605~695 nm,445~485 nm。     

基于Landsat遥感数据的长岛南部岛群景观格局演化研究

为了了解长岛南部岛群在经济发展背景下的景观格局及未来变化趋势,利用1990~2015年6景Landsat TM5、TM7和OLI8影像数据源,基于地理信息系统(GIS)平台采用决策树分类的方法对长岛南部岛群的景观类型进行了分类,并结合Frag-stats软件提取7种不同的景观格局指数,对长岛南部岛群的景观格局演化特征进行了系统分析。结果显示,人为活动是近年来长岛南部岛群景观格局演化的主要驱动力,该岛群景观类型变化以建设用地、水产养殖用地增加和林地减少为特征,建设用地斑块聚集度指数较高,斑块的聚集度指数逐年增加,整体上斑块的聚集度和连通性很好。不同景观指数(SHDI(景观斑块多样性)、PAFRAC(周长面积分维数)、PD(斑块密度指数)、LSI(斑块形状指数)、CA(斑块面积指数)、AI(景观聚集度指数)、COHESION(斑块结合度指数))对人为扰动因子均具有良好的表征。相关研究结论可为长岛南部岛群综合管理和生态红线划定提供有效依据。     

浑浊介质光学特性参数测量方法的研究

浑浊介质光学特性参数的精确测量对于介质中成分的确定具有重要意义。文章设计了单积分球系统测量浑浊介质的光学特性参数。系统中采用了自行设计的准直光路以使系统更好地符合逆倍增法(IAD)的模拟边界条件。采取双光路补偿及光源调制的方法以提高系统的测量精度及信噪比。测量得到了不同浓度浑浊介质在632.8nm及1064nm波长处的光学特性参数，并据之由漫射理论计算得到的光径向分布与漫反射系统实际测量结果符合很好。     

Correction of atmospheric effect on ADEOS/OCTS ocean color data: Algorithm description and evaluation of its performance

This paper first describes the atmospheric correction algorithm for OCTS visible band data used at NASDA/EOC. Sharing a basic structure with Gordon and Wang’s Sea WiFS algorithm, it uses 10 candidate aerosol models including the “Asian dust model” introduced in consideration of the unique feature of aerosols over the east Asian waters. Based on the observations at 670 and 865 nm bands, the algorithm selects a pair of aerosol models that account best for the observed spectral reflectances, and synthesizes the aerosol reflectance used for the atmospheric correction. Two different schemes for determining the value of the parameter for the aerosol model selection are presented and their anticipated estimation error is analyzed in terms of retrieved water reflectance at 443 nm. The results of our numerical simulation show that the standard deviation of the estimation error of the “weighted average” scheme is mostly within the permissible level of ±0.002, reducing the error by 18% on average compared to the “simple average” scheme. The paper further discusses the expected error under the old CZCS-type atmospheric correction, which assumes constant aerosol optical properties throughout the given image. Although our algorithm has a better performance than the CZCS algorithm, further analysis shows that the error induced by the assumption taken in the algorithm that the water-leaving radiance at 670 nm band is negligibly small may be large in high pigment concentration waters, indicating the necessity for future improvements.     

Nematode community structure in relation to metals in the southern of Caspian Sea

Spatial distribution and structure of nematode assemblages in coastal sediments of the southern part of the Caspian Sea were studied in relation to environmental factors. By considering metals, organic matter, Shannon diversity index(H), maturity index(MI) and trophic diversity(ITD), ecological quality status of sediment was also determined. Fifteen nematode species belonging to eleven genera were identified at the sampling sites. Average density of nematode inhabiting in sediment of the studied area was 139.78±98.91(ind. per 15.20 cm~2). According to redundancy analysis(RDA), there was high correlation between metals and some species. Based on biological indicators, the studied area had different environmental quality. Generally, chemical and biological indices showed different results while biological indices displayed similar results in more sites.     

Analysis of ocean color spectra (II)

A method for evaluating the radiance due to sky light reflected by the sea surface and radiance emerging from the sea is described. The calculation is made as a function of the sun altitude, sky condition and sea state for varying optical properties of sea water. As a result of the contribution of reflected sky light, the shape of the spectral distribution for radiance just below the surface is considerably distorted above the surface, especially when chlorophyll concentrations are high. Special attention is paid to the ratio of radiance emerging from the sea to total upwelling radiance at the wavelength of 670 nrn. The variation in the ratio with wind-speed is small and the ratio decreases with increase in the atomospheric turbidity factor.     

养殖方式、光照强度对哲罗鱼稚鱼生长与存活的影响

采用生态学方法,研究了养殖方式、光照强度对哲罗鱼稚鱼生长与存活的影响。结果表明:在养殖方式实验中,哲罗鱼稚鱼体长、体质量均以室内静水组为最高,室内流水组其次,室外流水组最低。存活率以室内流水组为最高,室外流水组次之,室内静水组最低。统计分析表明养殖方式对哲罗鱼稚鱼终末体长、体质量、特定生长率、体长生长参数以及体长、体质量变异系数的影响均达到极显著水平(P0.01)。在光照实验中,哲罗鱼稚鱼的存活率、体长、体质量及特定生长率、体长生长参数均随光照强度的增加而增加,说明在哲罗鱼稚鱼室内培育阶段,适当地增加部分光照有利于其存活、摄食与生长。本研究结果为哲罗鱼高效养殖提供了科学依据。     

Evaluation of burial history, thermal maturity and source-rock assessment of the Upper Paleozoic succession of the eastern Taurus region, southern Turkey

The regional burial history pattern, thermal maturity variations and source rock assessment of the sedimentary succession in the eastern Taurus region, in the southern part of Turkey, have been studied on surface samples collected from the six different sections which represent the entire region. Organic petrography (Thermal Alteration Index) and geochemical data (TOC content, T_max and HI values) were obtained from transmitted-light microscopy and Rock-Eval pyrolysis.The Lower Paleozoic (Cambrian, Ordovician and Silurian) strata were not investigated and modeled in terms of the maturity and hydrocarbon source rock potential, because of their poor organic matter content and their over maturity resulting from great burial depth (more than 7630 m). Other Paleozoic strata, except the Lower Devonian Ayitepesi Formation, generally have the values of more than 0.5% TOC. Organic matter of the Middle Devonian Safaktepesi sediments are composed of highly terrestrial organic material (type III kerogen), while samples from other three formations (Gumusali, Ziyarettepe and Yigilitepe Formations), while samples from other organic matter (type II and type III kerogen). The average TAI values are as high as 3.4 (equivalent to 1.42 of R₀%) for Ayitepesi and as low as 2.75 (equivalent to 0.77 of R₀%) for Yigilitepe Formations. Time-temperature index values (TTI) indicate that Ziyarettepe and Yigilitepe sediments are marginally mature to mature, while the Devonian strata are overmature. There are minor discrepancies between ΣTTI values and geochemical data in terms of the organic maturity for Devonian strata. In contrast, the e is a consistency between those values for the Ziyarettepe and the Yigilitepe Formations. The onset of oil generation time in the region was initiated from as early as the Norian (216 Ma) to as late as the Lutetian (45 Ma).Regional variations in the level of thermal and source-rock maturities of the Upper Paleozoic sediments in the eastern Taurus region largely depend on burial depth.     

Application of integrated vitrinite reflectance and FAMM analyses for thermal maturity assessment of the northeastern Malay Basin,offshore Vietnam: Implications for petroleum prospectivity evaluation

Several exploration wells have intersected a Cenozoic coal-bearing, fluvial-deltaic mudstone and sandstone succession in the northeastern Vietnamese part of the Malay Basin, and have successfully tested seismically identified direct hydrocarbon indicators (DHIs). The oil and gas/condensate discovery well 46-CN-1x encountered a ∼55 m thick section of lacustrine mudstones having considerable potential as an oil source. Vitrinite reflectance (VR) measurements from these alginite-bearing rocks introduce several problems in thermal maturity evaluation, including associated VR suppression and delineation of cavings and bitumens. Reliable thermal maturity gradients, however, may be established using a combination of conventional VR measurements and ‘equivalent VR’ (EqVR) values derived from the fluorescence alteration of multiple macerals (FAMM) technique. These measurements, performed on dispersed organic matter (DOM) in cuttings from 46-CN-1x, allow separation of low-reflecting bitumens and vitrinite in cavings from indigenous vitrinite and the FAMM results indicate VR suppression of 0.14% in an alginite-bearing mudstone with a high Hydrogen Index value. On the basis of available ‘raw’ VR data, a highly irregular maturity trend is determined, with the deepest sample (2675–2680 m) having a VR of ∼0.4%R_o. The EqVR value, however, for the deepest sample is 0.70%. The maturity trend determined from the FAMM data (and VR data, omitting samples having suppressed VR) indicates that the top of the oil window (VR of 0.75%R_o) is located at about 2800 m depth. Modelling the geothermal gradient using the EASY%R_o algorithm yields ∼40 °C/km for both of the two maturity profiles; this is in the low end of the range for the Malay Basin. Modelled temperature histories indicate onset of hydrocarbon generation for the uppermost Oligocene source rocks between 2 Ma and present-day, which post-dates trap formation. Seismic facies patterns suggest that lacustrine oil-prone units are in the oil window in the same graben complex a few km NW of the investigated well, and these rocks are likely to be the source of the hydrocarbons found in the well. A more widespread occurrence of hydrocarbons sourced from this kitchen is indicated by other discoveries and mapping of DHIs in the area.