Trapping and adsorption of CO₂ in amorphous ice: A FTIR study     

Óscar Gálvez  Belén Maté  Víctor J. Herrero  Rafael Escribano 《Icarus》2008,197(2):599-605

The interaction of carbon dioxide and amorphous water ice at 95 K is studied using transmission infrared spectroscopy. Samples are prepared in two ways: co-deposition of the gases admitted simultaneously or sequential deposition, in which amorphous water ice (ASW) is grown first and CO₂ vapor is added subsequently. In either case, a fraction of the CO₂ molecules is found to interact with water in a way that gives rise to shifts and splittings in the infrared bands with respect to those of a pure CO₂ solid. In co-deposition experiments, a larger amount of carbon dioxide is trapped within the amorphous water than in sequential deposition samples, where a substantial proportion of molecules appears to be trapped in macropores of the ASW. The specific surface area of sequential samples is evaluated and compared to previous literature results. When the sequential samples are heated to 140 K, beyond the onset temperature at which water ice undergoes a phase transition, the CO₂ molecules at the pores relocate inside the bulk in a structure similar to that found in co-deposited samples, as deduced by changes in the shape of the CO₂ infrared bands.  相似文献   

The long-term stability of a possible aqueous ammonium sulfate ocean inside Titan     

P.M. Grindrod  A.D. Fortes  D.L. Feltham  L. Vo?adlo 《Icarus》2008,197(1):137-151

We model the thermal evolution of a subsurface ocean of aqueous ammonium sulfate inside Titan using a parameterized convection scheme. The cooling and crystallization of such an ocean depends on its heat flux balance, and is governed by the pressure-dependent melting temperatures at the top and bottom of the ocean. Using recent observations and previous experimental data, we present a nominal model which predicts the thickness of the ocean throughout the evolution of Titan; after 4.5 Ga we expect an aqueous ammonium sulfate ocean 56 km thick, overlain by a thick (176 km) heterogeneous crust of methane clathrate, ice I and ammonium sulfate. Underplating of the crust by ice I will give rise to compositional diapirs that are capable of rising through the crust and providing a mechanism for cryovolcanism at the surface. We have conducted a parameter space survey to account for possible variations in the nominal model, and find that for a wide range of plausible conditions, an ocean of aqueous ammonium sulfate can survive to the present day, which is consistent with the recent observations of Titan's spin state from Cassini radar data [Lorenz, R.D., Stiles, B.W., Kirk, R.L., Allison, M.D., del Marmo, P.P., Iess, L., Lunine, J.I., Ostro, S.J., Hensley, S., 2008. Science 319, 1649-1651].  相似文献   

Response of sandstone to atmospheric heating during the STONE 5 experiment: Implications for the palaeofluid record in meteorites     

John Parnell  Darren Mark 《Icarus》2008,197(1):282-290

A 1 cm thick sandstone disk exposed to atmospheric re-entry on the heat shield of a spacecraft (the STONE 5 experiment) shows alteration of fluid inclusions compared to a control sample. The sandstone contained inclusions in quartz grains, feldspar grains and calcite cement before flight. After flight, inclusions in the feldspar were all decrepitated, few inclusions in calcite survived intact and they yielded widely varying microthermometric data, and the quartz inclusions also yielded disturbed microthermometric data. The quartz becomes less affected with depth below the surface, and extrapolation suggests would be unaffected at a depth of about 2 cm. These data show that fluid inclusion data from meteorites must be treated with caution, but that a genuine fluid record may survive in the interior portions. The possibility of thermal sterilization to 2 cm depth also implies that small meteorites may be unsuitable vehicles for the transfer of microbial life from one planetary body to another. As the interiors of larger meteorites tend to have very low porosity and permeability, microbial colonization would be difficult, and the potential for panspermia is accordingly low.  相似文献   

Study of a thermal drill head for the exploration of subsurface planetary ice layers     

P. Weiss  K.L. Yung  N. Kömle  E. Kaufmann 《Planetary and Space Science》2008,56(9):1280-1292

The recently discovered water vapor plumes on Saturn's moon Enceladus, the polar caps of planet Mars and the possible ice volcanism on the Jovian satellites call for suitable techniques to explore deep ice layers of the solar system bodies. This paper presents a novel approach to deliver scientific probes into deeper layers of planetary ice. Several existing locomotion concepts and techniques for such probes are presented. After studying the mathematical framework of the melting locomotion process, melting tests with different head forms were done to evaluate the influence of the head's geometry on the melting process. This work led to a novel concept of a thermal drill head, using heat and mechanical drill in combination to penetrate the ice. We compare the performance of such a hybrid concept versus the melting penetration alone by a mathematical model and tests in ice with a prototype of the melting drill head.  相似文献   

Detection of a dry-frozen boundary inside Martian regolith     

Fabio Gori  Sandra Corasaniti 《Planetary and Space Science》2008,56(8):1093-1102

The present work investigates the time oscillations of the temperature at several depths of a Martian soil analogue made of two layers of different physical properties. The maximum temperature-time oscillation inside the Martian soil analogue, DT, and its derivative with depth, d(DT)/dz or DDT, can be analysed to understand the presence of a boundary between dry and frozen soil. The maximum temperature-time oscillation, DT, reduces by about one order of magnitude at the boundary between dry and frozen soil if a frozen layer is present. The reduction of DT at the boundary between two dry soils with different porosity is much smaller. DDT decreases by more than one order of magnitude at the boundary between dry and frozen soil if a frozen layer is present. The reduction of DDT at the boundary between two dry soils with different porosity is much smaller.  相似文献   

Research Progress and Development Tendency About Thermal Physical Properties of Rocks     

Cheng Chao  Yu Wen&#x  gang  Jia Wanting  Lin Haiyu  Li Lianqing 《地球科学进展》2017,32(10):1072-1083

The fundamental researches about thermal physical properties of rocks have much concern in oil and gas field. They go through four stages and are applied in thermal structure of lithosphere, thermal evolution of sedimentary basins, geotechnical engineering and geothermal area. This article summarized the current research progress on the basis of thermal physical properties of rocks and proposed the development of tendency for the future. Moreover, some cylindrical heat pipe, disc heat pipe, spherical heat pipe based on in-situ measurement method and prediction model based on mathematical statistics have been developed. The scholars discuss the internal relation between thermal conductivity parameter of rocks and other physical properties by a large number of experiments. The researches show that the thermal conductivity of rocks is affected by many factors, and the petrologic characteristic is the most important factor. The porosity of rocks, filled fluid properties, acoustic characteristics are also related to thermal conductivity, which is affected by temperature, pressure and anisotropy. In consideration of the study of thermal physical properties of rocks, we proposed the following tendency for the future. First of all, shale gas is regarded as a hot spot in oil-gas exploration and the formation mechanism and the formation of shale gas reservoir are under the control of thermal physical properties of shale gas, but the relationship among thermal conductivity and organic porous, organic carbon content, gas content, fractured characteristics remains unknown. Therefore, exploring the thermal physical properties of gas-bearing shale is an important research direction in oil and gas field. Secondly, the study of big data represents the general trend. Though the database of rocks thermal parameter is continually expanding, measuring in-situ thermal conductivity continuously in well is the best method to get the accurate in-situ thermal conductivity of rocks. Hence, the development of logging method principle and logging instruments based on thermal physical properties of rocks is a necessary trend for the future.  相似文献   

Analysis on variation characteristics of geothermal response in Liaoning Province          下载免费PDF全文

ZHU Wei  TANG Wen  LIU Qiang  ZHANG Mei-gui 《地下水科学与工程》2017,5(4):336-342

Due to energy shortage and increasing environmental awareness, resources in shallow underground space have been rapidly exploited and utilized. So that studying variation characteristics of geothermal response in gneiss is necessary for effective and rational use of underground heat. Based on field test of thermal response in gneiss under hydrogeological survey project carried out in shallow geothermal energy development zone in Liaoning Province, this thesis analyzes mathematical statistics of geothermal response characteristics in main gneiss of Laoning Province. The initial formation temperature ranges from 10.80℃ to 15.80℃ according to field test. The statistical results show that in the condition of natural water content, the average thermal conductivity of Quaternary loose rocks comes as clay silty silty fine sand medium sand coarse sand gravelly sand. This order is consistent with thermal conductivity characteristics of gneiss obtained in the laboratory. Formation temperature recovery in different strata follows as granite medium sand clay. This order is opposite to the absolute value of temperature recovery curve slope of corresponding lithology, which shows that the stratum with higher temperature recovery rate has lower temperature recovery curve slope.  相似文献   

Kilometer-scale fault-related thermal anomalies in tight gas sandstones     

《Marine and Petroleum Geology》2017

Upper Carboniferous sandstones make one of the most important tight gas reservoirs in Central Europe. This study integrates a variety of geothermometers (chlorite thermometry, fluid inclusion microthermometry and vitrinite reflection measurements) to characterize a thermal anomaly in a reservoir outcrop analog (Piesberg quarry, Lower Saxony Basin), which is assumed responsible for high temperatures of circa 300 °C, deteriorating reservoir quality entirely. The tight gas siliciclastics were overprinted with temperatures approximately 90–120 °C higher compared to outcropping rocks of a similar stratigraphic position some 15 km to the west. The local temperature increase can be explained by circulating hydrothermal fluids along the fault damage zone of a large NNW-SSE striking fault with a displacement of up to 600 m in the east of the quarry, laterally heating up the entire exposed tight gas sandstones. The km-scale lateral extent of this fault-bound thermal anomaly is evidenced by vitrinite reflectance measurements of meta-anthracite coals (VR_rot ∼ 4.66) and the temperature-related diagenetic overprint. Data suggest that this thermal event and the associated highest coalification was reached prior to peak subsidence during Late Jurassic rifting (162 Ma) based on K-Ar dating of the <2 μm fraction of the tight gas sandstones. Associated stable isotope data from fluid inclusions, hosted in a first fracture filling quartz generation (T ∼ 250 °C) close to lithostatic fluid pressure (P ∼ 1000 bars), together with authigenic chlorite growth in mineralized extension fractures, demonstrate that coalification was not subject to significant changes during ongoing burial. This is further evidenced by the biaxial reflectance anisotropy of meta-anthracite coals. A second event of quartz vein formation occurred at lower temperatures (T ∼ 180 °C) and lower (hydrostatic) pressure conditions (P ∼ 400 bars) and can be related to basin inversion. This second quartz generation might be associated with a second event of illite growth and K-Ar ages of 96.5–106.7 Ma derived from the <0.2 μm fraction of the tight gas sandstones.This study demonstrates the exploration risk of fault-bound thermal anomalies by deteriorating entirely the reservoir quality of tight gas sandstones with respect to porosity and permeability due to the cementation with temperature-related authigenic cements. It documents that peak temperatures are not necessarily associated with peak subsidence. Consequently, these phenomena need to be considered in petroleum system models to avoid, for example, overestimates of burial depth and reservoir quality.  相似文献   

Controls of hydrocarbon generation on the development of expulsion fractures in organic-rich shale: Based on the Paleogene Shahejie Formation in the Jiyang Depression,Bohai Bay Basin,East China     

《Marine and Petroleum Geology》2017

The development of expulsion fractures in organic-rich shale is closely related to hydrocarbon generation and expulsion from kerogen. Organic-rich shales from the upper part of the fourth member and the lower part of the third member of the Paleogene Shahejie Formation in the Jiyang Depression, Bohai Bay Basin, East China, are used as an example. Based on thin sections, SEM and thermal simulation experiments, the characteristics of hydrocarbon generation and the conditions supporting the development of expulsion fractures were explored. The key factors influencing these fractures include the presence of kerogens, their distribution along laminae and around particle boundaries, their exposure to heat and the build-up in pressure due to confinement by low permeability. The development of excess pore fluid pressures and intrinsic low rock fracture strength are the main influencing factors. Pressurization by rapid generation of hydrocarbon provides impetus for fracture initiation and cause bitumen to migrate quickly. The shale laminae results in distinctly lower fracture strength laminae-parallel than laminae-normal and this directs the formation of new fractures in the direction of weakness. When pore fluid pressure increases, maximum and minimum principal effective stresses decrease by different proportions with a larger reduction in the maximum principal effective stress. This increases the deviatoric stress and reduces the mean stress, thus driving the rock towards failure. Moreover, the tabular shape of the kerogen aids the generation of hydrocarbon and the initiation of expulsion fractures from the tip and edge. The resulting fractures extend along the laminae when the tensile strength is lower in the vertical direction than in the horizontal direction. Particle contact boundaries are weak and allow fractures to expand around particles and to curve as the stress/strength regime changes. When pore fluid pressure fields at different fracture tips overlap, fractures will propagate and interconnect, forming a network. This paper could provide us more detailed understanding of the forming processes of expulsion fractures and better comprehension about hydrocarbon expulsion (primary migration) in source rocks.  相似文献   

基于热红外光谱的干旱区土壤盐分监测研究     

买买提&#  沙吾提  吐尔逊&#  艾山  塔西甫拉提&#  特依拜  如则麦麦提&#  米吉提  麦尔耶姆&#  亚森  依力亚斯江&#  努尔麦麦提 《干旱区地理》2017,40(1):181-187

土壤盐渍化是新疆最常见的土地退化过程,已经严重威胁到了当地的农业生产、生态稳定和经济发展。通过对渭库绿洲土壤含盐量和土壤热红外光谱分析,探讨了土壤含盐量与热红外发射率之间的定量关系。结果表明：（1）盐渍化土壤的发射率随着含盐量的变化而发生变化,当土壤盐分增加时,发射率也随之增大。（2）土壤含盐量与热红外发射率光谱数据相关性在8.5～9.5 μm波段范围内表现尤为显著,相关系数超过0.8,最高为0.90,对应波段范围9.259～9.271 μm。（3）运用回归模型一阶导数变换形式下建模效果和预测精度都是最优的,R²达到了0.899,RMSE最小为1.734。热红外光谱技术可以反演土壤含盐量,为利用热红外遥感识别土壤盐分信息提供技术支撑。  相似文献