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中国科学院地球环境研究所在砗磲超高分辨率Sr/Ca古气候古天气指示意义方面取得进展（图）
气候 同位素 元素
2024/11/14
砗磲，全球最大的双壳贝类，其壳体具有清晰的年生长纹层与天生长纹层，天纹层宽度约5-60μm，是优良的高分辨率古气候古天气研究载体。月分辨率砗磲Sr/Ca、δ18O已被证实是可靠的砗磲古气候代用指标，常被用于重建过去ENSO活动、海表面温度冬夏温差等，但是有关砗磲同位素、元素比值在小时-天分辨率上的探讨仍在起步阶段。
中国有三个主要的克拉通，分别是华北、华南和塔里木，它们在显生宙经造山过程聚集到一起。塔里木克拉通位于中国的西北部，面积超过60万平方千米，其北侧为中亚造山带，南侧为西昆仑造山带和阿尔金造山带。塔里木克拉通的前寒武纪岩石主要出露在其南北两侧边缘，包括库鲁克塔格、敦煌、阿尔金、铁克里克和阿克苏地块，它们记录了塔里木克拉通早期的构造演化。北阿尔金地块的阿克塔什塔格地区位于塔里木克拉通的东南边缘。该地区最...
显生宙棘皮动物骨骼均由高镁方解石组成，其骨骼的Mg/Ca比受海水Mg/Ca比、古海水温度、成岩作用等因素的影响. 研究以华南扬子区下奥陶统棘皮动物海百合化石为主要测试对象，通过能谱仪及波谱仪等微区原位分析方法，获得其骨骼可靠的Mg/Ca比. 化石骨骼显微构造和化学成分特征表明，扬子区下奥陶统海百合茎化石骨骼受到成岩作用的影响较弱，依旧保存有与壳体原始矿物有关的Mg含量特征. 测试结果显示，根据棘皮...
Coral growth-rate insensitive Sr/Ca as a robust temperature recorder at the extreme latitudinal limits of Porites
skeletal oxygen isotope in the coral Sr/Ca high latitudes coral growth rates
2017/4/11
Oxygen isotope values of low-growth coral (<5 mm/yr) skeletons may reflect kinetic effects, which is problematic for
sea surface temperature (SST) reconstruction. Here, we report a Sr/Ca-based SST re...
Effect of organic matrices on the determination of the trace element chemistry (Mg, Sr, Mg/Ca, Sr/Ca) of aragonitic bivalve shells (Arctica islandica) —Comparison of ICP-OES and LA-ICP-MS data
trace elements bivalve shell organics LA-ICP-MS ICP-OES sclerochronology
2017/8/9
The element chemistry of biogenic carbonates can provide important data on past environments. However, the Sr/Ca and Mg/Ca ratios as well as the Mg and Sr concentrations of biological carbonates, espe...
富Ca、Al包体(简称CAI)形成于太阳星云演化的最初始阶段，其成因模式主要包括：气—固凝聚、熔融结晶和部分熔融以及高温蒸发作用等。最近，通过对不同球粒陨石化学群中的CAI进行岩石学特征对比研究，发现不同化学群中的CAI具有相似的大小和类型分布特征，表明不同球粒陨石化学群中的CAI极可能具有相似的起源。该结果，与前人的氧同位素、Al—Mg同位素体系以及稀土元素等研究得到的结论一致。不同球粒陨石化学...
Mn/Ca ratio in planktonic foraminifer from ODP Site 1144, the northern South China Sea: A possible paleoclimate indicator
planktonic foraminifer Mn/Ca ratios paleoclimate proxy South China Sea ODP
2017/8/9
We report here high-resolution Mn/Ca ratios of planktonic foraminifer, Globigerinoides sacculifer from ODP Site 1144 in the northern South China Sea (SCS). The variation pattern of the Mn/Ca ratios of...
Oxyfertil?: the answer for a productive and environmentally friendly 6-element (N,P,K,Ca,Mg,S) fertilization
Oxyfertil? productive environmentally friendly 6-element (N,P,K,Ca,Mg,S) fertilization
2012/3/28
In recent years, we have seen a growing concern in the developed farming community towards a sustainable and more environmentally friendly agriculture. In parallel, soaring energy prices are directly ...
Simulations of Interlayer Methanol in Ca- and Na-Saturated Montmorillonites Using Molecular Dynamics
Methanol Molecular Dynamics Montmorillonite
2011/12/5
Abstract: Molecular dynamics computer simulations were used to study methanol molecules confined between the layers of 2:1 phyllosilicates. The model systems are based on natural Ca- and Na-rich montm...
Infrared Study of Water Sorption on Na-, Li-, Ca-, and Mg-Exchanged (SWy-1 and SAz-1) Montmorillonite
Exchangeable Cation FTIR Hydration Hysteresis Smectite Sorption Water
2011/12/2
Abstract: An environmental infrared microbalance (EIRM) cell was used to study H2O sorption on two montmorillonite samples as a function of water content and type of exchangeable cation. The vibration...
The self-diffusion of Ca and the tracer diffusion of Mg in calcite have been measured experimen-Mg and Ca. Natural single crystals of calcite were coated with atally using isotopic tracers of gas at ...
Local Ca-Mg distribution of Mg-rich pyrope-grossular garnets synthesized at different temperatures revealed by 29Si MAS NMR spectroscopy
Local Ca-Mg distribution Mg-rich pyrope-grossular garnets synthesized different temperatures revealed 29Si MAS NMR spectroscopy
2012/4/1
Pyrope-grossular solid solutions, (Mg,Ca) Al Si O , of composition Py Gr and Py Gr were3 2 3 12 85 15 75 25
synthesized at 1000, 1200, and 1400 ?C and 30 kbars in a piston-cylinder device. The synt...
Interlayer structure, anion dynamics, and phase transitions in mixed-metal layered hydroxides: Variable temperature 35Cl NMR spectroscopy of hydrotalcite and Ca-aluminate hydrate (hydrocalumite)
Cl -intercalated hydrotalcite Ca-aluminate hydrate Variable temperature
2012/3/31
The Cl NMR spectroscopy of Cl -intercalated hydrotalcite and the Ca-aluminate hydrate, the presence of
hydrocalumite (Friedel°Os salt) demonstrates dynamical behavior of interlayer C
dynamical orde...
Burbankite, a (Sr,REE,Na,Ca)-carbonate in fluid inclusions from carbonatite-derived fluids: Identification and characterization using Laser Raman spectroscopy, SEM-EDX, and synchrotron micro-XRF analysis
Burbankite synchrotron micro-XRF analysisp SEM-EDX Laser Raman spectroscopy
2012/3/31
Burbankite, ideally (Na,Ca) (Sr,REE,Ba) (CO ) , is a rare REE carbonate mineral that until now
had been encountered only at a few localities including highly alkaline silicate rocks, carbonatites,
a...
Effect of isovalent Si, Ti substitution on the bulk moduli of Ca(Ti1-xSix) SiO5 titanites
Si Ti bulk modulus
2012/3/30
Theequationsofstateof A2/a titanitephasesofCaTiSiO ,Ca(Ti Si )SiO ,andCaSi O5 0.5 0.5 5 2 5
havebeendeterminedfromhigh-pressureX-raydiffractionmeasurements.Theisothermal
bulkmoduliare K 131.4(7)GPa(...