中国盐湖沉积年代学研究进展

盐湖沉积记录了区域的气候和水文变化,是重要的古气候研究对象。年代学是盐湖古气候研究最重要的一项内容,是后续几乎所有工作的基础。盐湖沉积最常用的定年方法有₁₄C定年、铀系定年、光释光(OSL)定年、古地磁定年。受各种定年方法自身的局限性以及盐湖沉积特有的沉积特征,存在不同方法测出的年龄差异较大的现象。准确测定盐湖沉积的年代还较为困难,一定程度制约了盐湖古气候研究的发展。由于盐湖沉积有机质含量低,易受现代碳的污染,其₁₄C年代老于30 cal ka BP时,测出的年龄可能已饱和,需要谨慎对待。未来需要加强铀系定年和光释光定年等方法在盐湖沉积中的基础研究,并开发新的更好的测年方法,提高盐湖沉积测年的准确度,为深入开展盐湖古气候变化及成盐成矿规律研究提供坚实基础。     

深水稀井区天然气藏储盖组合定量预测方法研究:以琼东南盆地陵水凹陷为例

南海北部油气勘探表明天然气是本地区主要的资源类型。与石油相比,天然气藏的形成对盖层要求更为严格,因此开展天然气藏储盖组合研究对油气勘探具有重要意义。通过统计和调研的方法,将砂岩储层孔隙度12%定义为琼东南盆地天然气有效储层评价的下限参数,将泥岩排替压力1 MPa定义为天然气有效泥岩盖层评价的下限参数。利用测井资料开展了单井天然气藏储盖组合窗口定量预测,得出陵水凹陷W22-1井发育单个天然气藏储盖组合窗口。在此基础上,针对稀井或无井区,提出了基于地震反演速度剖面的天然气藏储盖组合定量预测方法,以琼东南盆地陵水凹陷主洼过井测线为例,开展了天然气藏储盖组合窗口地震预测,确定出该凹陷主洼发育单个天然气藏储盖组合窗口,大体上包括陵水组-莺歌海组上部多套地层,拓宽了陵水凹陷天然气勘探层系。这种方法对其它深水区和低勘探新区均有借鉴意义。     

柴达木盆地第三系咸水湖相生油岩古沉积环境地球化学特征

在系统分析柴达木盆地西部第三系咸水湖相生油岩样品的微量元素、有机物、粘土矿物组成的基础上,揭示了研究区生油岩的无机元素和有机质组成特征;并结合沉积环境的无机与有机地球化学指标,重建了生油岩沉积时的古沉积环境。生油岩的B、Cl-及伽玛蜡烷含量表明,沉积时的水介质条件是半咸水—咸水环境,并伴随湖盆沉积中心北迁过程各层位地层的盐度发生规律性时空]化;生油岩的Fe2 /Fe3 、S2-、Pr/Ph比值、藿烷碳数分布模式及黄铁矿含量反映其沉积时的沉积环境为强还原性;粘土矿物组合特征及含量揭示这些生油岩的沉积相带介于中心咸湖相和边缘咸湖相之间。     

Prediction of the calcium carbonate budget in a sedimentary basin: A “source-to-sink” approach applied to Great Salt Lake,Utah, USA

Most source-to-sink studies typically focus on the dynamics of clastic sediments and consider erosion, transport and deposition of sediment particles as the sole contributors. Although often neglected, dissolved solids produced by weathering processes contribute significantly in the sedimentary dynamics of basins, supporting chemical and/or biological precipitation. Calcium ions are usually a major dissolved constituent of water drained through the watershed and may facilitate the precipitation of calcium carbonate when supersaturating conditions are reached. The high mobility of Ca²⁺ ions may cause outflow from an open system and consequently loss. In contrast, in closed basins, all dissolved (i.e. non-volatile) inputs converge at the lowest point of the basin. The endoreic Great Salt Lake basin constitutes an excellent natural laboratory to study the dynamics of calcium on a basin scale, from the erosion and transport through the watershed to the sink, including sedimentation in lake's waterbody. The current investigation focused on the Holocene epoch. Despite successive lake level fluctuations (amplitude around 10 m), the average water level seems to have not been affected by any significant long-term change (i.e. no increasing or decreasing trend, but fairly stable across the Holocene). Weathering of calcium-rich minerals in the watershed mobilizes Ca²⁺ ions that are transported by surface streams and subsurface flow to the Great Salt Lake (GSL). Monitoring data of these flows was corrected for recent anthropogenic activity (river management) and combined with direct precipitation (i.e. rain and snow) and atmospheric dust income into the lake, allowing estimating the amount of calcium delivered to the GSL. These values were then extrapolated through the Holocene period and compared to the estimated amount of calcium stored in GSL water column, porewater and sediments (using hydrochemical, mapping, coring and petrophysical estimates). The similar estimate of calcium delivered (4.88 Gt) and calcium stored (3.94 Gt) is consistent with the premise of the source-to-sink approach: a mass balance between eroded and transported compounds and the sinks. The amount of calcium deposited in the basin can therefore be predicted indirectly from the different inputs, which can be assessed with more confidence. When monitoring is unavailable (e.g. in the fossil record), the geodynamic context, the average lithology of the watershed and the bioclimatic classification of an endoreic basin are alternative properties that may be used to estimate the inputs. We show that this approach is sufficiently accurate to predict the amount of calcium captured in a basin and can be extended to the whole fossil record and inform on the storage of calcium.     

国内盐湖卤水硼资源提取专利分析

基于中国盐湖硼资源开发动态,选择国家知识产权局专利数据,从盐湖卤水硼资源提取相关专利申请时间、地域分布、主要方法等方面进行分析。发现中国专利包含多种盐湖硼资源提取方法,并且逐步走向成熟,其中萃取法已成为研究重点。近期关于多种伴生资源综合开发的专利越来越受到关注。对国内盐湖硼资源提取技术后续开发和产业发展提出了建议。     

柴达木盆地盐尘暴及其资源生态环境影响

在干旱和半干旱地区,盐尘暴是一种常见的极端气象灾害。柴达木盆地频发的沙尘暴实质上就是盐尘暴。柴达木盆地盐尘暴已经对区域大气、土壤、植被、人类健康乃至全球气候变化都产生了不同程度的影响。由于柴达木盆地盐尘暴中可溶盐成分来源复杂,尽管目前对其形成过程和机制还缺乏深刻理解,但人类的资源开发活动对盐尘暴显然具有促进作用。有必要从系统的角度来考虑柴达木盆地盐尘暴对区域乃至全球的影响,这对于区域生态环境的正确评估和后期恢复治理具有重要意义。     

Hydrodynamics of salt marsh creek systems: Implications for marsh morphological development and material exchange

Integrated ebb-aligned drainage systems are a feature of tide-dominated marshes, and are generally regarded as major conduits for material exchange. In north Norfolk, highly unsteady creek flows exhibit well-developed velocity and stress transients which result from the discontinuous nature of the tidal prism and the interaction of shallow water tidal inputs with hydraulically rough vegetated surfaces. Marsh morphological development is governed by a form-process feedback, in the sense that the marsh surface acts as a topographic threshold separating the depositional regime of below-marsh tides from the erosional (ebb-dominated) regime of over-marsh tides. Vertical marsh growth results in increasing intermittency of creek sediment transport. Furthermore, velocity transients are associated with large discharges which must be allowed for in material flux computations. Creek flux measurements are not in themselves sufficient to estimate total material budgets, since a large proportion of tidal exchange may take place via the marsh edge. Such studies should focus instead on direct measurement of marsh surface processes. These findings have relevance beyond this back-barrier setting to marshes of different geometry, occupying a broad range of the tidal energy spectrum.     

论中国古代地缘战略制定中的“权衡”——以《盐铁论》为例

《盐铁论》是记录汉朝时期关于盐铁酒榷均输及对匈奴关系的辩论的一部重要著作,能够较典型地反映中国古代地缘战略制定中的“权衡”过程。构建中国古代地缘战略制定中的“权衡”理论分析框架,继而基于该分析框架对《盐铁论》中的地缘战略辩论进行详细解读。《盐铁论》中辩论双方“权衡”的要点包含匈奴对汉朝产生的威胁程度、领土扩张所带来的收益大小和相应地缘战略的合法性3个方面。从思想、方法、目的等比较中西方地缘政治研究差异,指出“权衡”思想为西方主导的地缘政治理论提供新视角。     

西台吉乃尔盐湖原卤水历年来钾硼锂镁等元素品位变化及未来变化趋势预测

研究统计了西台吉乃尔盐湖(以下简称西台)自开发以来原卤水中钾硼锂镁各元素品位变化,利用K+,Na+,Mg2+/Cl-,SO2-4-H2 O五元体系298K介稳相图研究了主要元素之间相对含量的变化关系.根据西台开发现状建立数学模型,预测了未来10年钾硼锂元素品位变化趋势,为西台盐湖钾硼锂镁等资源的开发和综合利用提供依据.     

Implementation of baroclinic terms in a three-dimensional hydrodynamic model and its application to Anzali Port, Iran

Baroclinic terms have been implemented in a three-dimensional fully hydrodynamic model developed by Badiei et al. [2008. A three-dimensional non-hydrostatic boundary fitted model for free surface flows. International Journal for Numerical Methods in Fluids, 56(6), 607-627] modifying its momentum equations to account for density gradients and utilizing the scalar (salinity, temperature, etc.) conservation equation (SCE) and a state equation for the calculation of density. In the solution of advection-diffusion terms of the governing Navier-Stokes equations (NSE) and SCE, a symmetric splitting method was applied to ensure the long-term stability of simulations. Correction terms proposed by Ruddic et al. (1995) were applied to SCE to ensure the conservation of the scalar quantity. In the presence of baroclinic terms, the zero gradient pressure in the vertical direction in the vicinity of surface and bottom boundaries assumed by Badiei et al. [2008. A three-dimensional non-hydrostatic boundary fitted model for free surface flows. International Journal for Numerical Methods in Fluids, 56(6), 607-627] created spurious currents. This problem was solved by assuming a hydrostatic pressure variation at those boundaries. The ability of extended model was validated by comparing its results with an experimental test case. The simulation of hydrodynamic and salt intrusion at Anzali Port located at the southern coasts of Caspian Sea in Iran was carried out by the model with both barotropic and baroclinic modes. The simulated results with baroclinic mode show a better agreement with measured data as compared to the results of barotropic mode that clearly demonstrate the significance of baroclinic terms in the simulation of cyclic intrusion of salt wedge into the Port Basin.