A three-dimensional large-scale cloud model: testing the role of radiative heating and ice phase processes     

J. L. LEE  K. N. LIOU  S. C. OU 《地球，A辑:动力气象学与海洋学》1992,44(3):197-216

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Parameterization of the Absorption of the H_2O Continuum,CO_2,O_2,and Other Trace Gases in the Fu-Liou Solar Radiation Program     

张凤  曾庆存  K.N.LIOU 《大气科学进展》2005,(4)

The absorption properties of the water vapor continuum and a number of weak bands for H2O, O2, CO2, CO, N2O, CH4, and O3 in the solar spectrum are incorporated into the Fu-Liou radiation parameterization program by using the correlated k-distribution method (CKD) for the sorting of absorption lines. The overlap absorption of the H2O lines and the H2O continuum (2500-14500 cm-1) are treated by taking the two gases as a single-mixture gas in transmittance calculations. Furthermore, in order to optimize the computation efforts, CO2 and CH4 in the spectral region 2850-5250 cm-1 are taken as a new single-mixture gas as well. For overlap involving other absorption lines in the Fu-Liou spectral bands, the authors adopt the multiplication rule for transmittance computations under which the absorption spectra for two gases are assumed to be uncorrelated. Compared to the line-by-line (LBL) computation, it is shown that the errors in fluxes introduced by these two approaches within the context of the CKD method are small and less than 0.48% for the H2O line and continuum in the 2500-14500 cm-1 solar spectral region, -1% for H2O (line) H2O (continuum) CO2 CH4 in the spectral region 2850-5250 cm-1, and -1.5% for H2O (line) H2O (continuum) O2 in the 7700-14500 cm-1 spectral region. Analysis also demonstrates that the multiplication rule over a spectral interval as wide as 6800 cm-1 can produce acceptable errors with a maximum percentage value of about 2% in reference to the LBL calculation. Addition of the preceding gases increases the absorption of solar radiation under all sky conditions. For clear sky, the increase in instantaneous solar absorption is about 9%-13% (~12 W m~2) among which the H2O continuum produces the largest increase, while the contributions from O2 and CO2 rank second and third, respectively. In cloudy sky, the addition of absorption amounts to about 6-9 W m-2. The new, improved program with the incorporation of the preceding gases produces a smaller solar absorption in clouds due to the reduced solar flux reaching the cloud top.  相似文献   

Low-Temperature Eclogites and Eclogitic Schists in Mn-rich Metabasites in Ward Creek, California; Mn and Fe Effects on the Transition between Blueschist and Eclogite   总被引：1，自引：0，他引：1  

OH  CHANG W.; LIOU  J. G.; MARUYAMA  S. 《Journal of Petrology》1991,32(2):275-302

In situ eclogitic schist lenses occur in the coherent low-gradeepidote-zone Ward Creek metabasite unit of the Central Franciscanbelt. They contain almandine garnet, clinopyroxene, and rutile.They have slightly higher Mn content (0–5–1–0wt.%) than the coexisting Type III metabasites (0–12–0–25wt%) which contain epidote + glaucophane + actinolite + chlorite+ omphacite + quartz + sphene ? aragonite? lawsonite ? pumpellyite+ albite. The in situ eclogitic schists (130–140 Ma) canbe distinguished from older tectonic eclogites (150–160Ma) in Ward Creek as follows: (1) they are medium grained, whereasType IV tectonic eclogites are coarse grained; (2) they haveunaltered spessartine-rich idioblastic (0–4–10 mm)garnets, whereas Type IV tectonic eclogites have larger xenoblasticto hypidiomorphic spessartine-poor garnets which were corrodedand chloritized along the rim during retrograde metamorphism;(3) clinopyroxenes are chloromelanite in in situ eclogitic schistsbut omphacite in Type IV tectonic eclogites; (4) barroisiticamphiboles occur both as inclusions in garnets and as matrixminerals in Type IV tectonic eclogites but not in in situ eclogiticschists; (5) albite is present in in situ eclogitic schistsbut not in Type IV tectonic eclogites; and (6) the estimatedP-T condition of in situ eclogitic schists is 290 ?C < T<350 ?C, P = 8–9 kb, whereas that of Ward Creek Type IVtectonic eclogites is 500?C< r<540?C, P< 10–11–5kb. Medium-grained eclogites occur as individual blocks in WardCreek; they are different from Type IV tectonic eclogites butare very similar to in situ eclogitic schists. They have unalteredidioblastic garnet with high almandine and spessartine content(Alm₄₇Sp₂3Gr₂₀Py10), and they have chloromel-anitic clinopyroxeneand quartz but no barroisite. Paragonite is also stable in theseeclogites. The blocks formed at 380 ?C< r<400?C, and 9–5kb<P< 14 kb. They are presumably in situ eclogites formedat the highest-temperature part of the Ward Creek metabasiteunit and may be younger than Type IV tectonic eclogites. Such low-temperature occurrences of eclogitic assemblages aredue to the compositional effect on reactions between blueschistand eclogite that are insensitive to pressure and shift towardslower temperatures as bulk-rock MnO content and X_Fe/(Fe+Mg)increase. The Mn/(Mn + Fe) ratio of bulk rock is an importantfactor in controlling the P-T positions of these reactions attemperatures below 450 ?C, whereas the Fe/(Fe + Mg) ratio ofbulk-rock becomes important at temperatures higher than 450?C.  相似文献   

祁连南缘花岗岩和榴辉岩之间的关系：嗷唠山花岗岩SHRIMP锆石年龄证据   总被引：2，自引：1，他引：2  

吴才来  Jong  WOODEN 《地质学报》2002,76(1):106-106

祁连南缘嗷唠山花岗岩锆石的SHRIMP年龄变化于445～496Ma之间,平均为 473 Ma,属早奥陶世。年龄值的统计出现两个峰值,第一个峰值与区内榴辉岩的相同(495 Ma),可能反映花岗岩源岩的部分熔融时代,第二个年龄峰值可能反映了花岗质岩浆的冷凝结晶时代(465 Ma)。该花岗岩的岩石地球化学特征类似于Ⅰ型花岗岩,有关构造环境判别图解得出,该花岗岩类似于岛弧或活动陆缘环境。结合区域地质特征和花岗岩的锆石SHRIMP年龄特征,我们认为,早奥  相似文献   

On the origin of oriented rutile needles in garnet from UHP eclogites   总被引：4，自引：0，他引：4  

S. L. HWANG  T. F. YUI  H. T. CHU  P. SHEN  H. P. SCHERTL  R. Y. ZHANG  J. G. LIOU 《Journal of Metamorphic Geology》2007,25(3):349-362

Although oriented rutile needles in garnet have been reported from several ultrahigh‐pressure (UHP) rocks and considered to be important UHP indicators, their crystallographic features including growth habit and lattice correspondences with garnet host have never been properly characterized. This paper presents a detailed analytical electron microscopic (AEM) study on evenly distributed oriented rutile needles in garnet of two eclogitic rocks from Sulu. Some garnet in one UHP diamondiferous quartzofeldspathic rock from the Saxonian Erzgebirge, and in one high‐pressure (HP) felsic granulite from Bohemia also contain a few unevenly distributed oriented rutile needles. They have also been studied for the purpose of comparison. Despite different distribution patterns, AEM revealed that all rutile needles are oriented along the 〈111〉 directions of garnet with their lateral sides surrounded by the {110} planes of garnet, and that the growth directions of most needles are close to the normal of the {101} planes of rutile. No other specific crystallographic orientation relationships between rutile and garnet host were observed, and there is no pyroxene associated with rutile, as necessitated by the precipitation reaction of rutile in garnet as previously proposed. A simple solid‐state precipitation scenario for the formation of the rutile needles in garnet in these two eclogitic rocks is not justified. Three alternative mechanisms are considered for the formation of oriented rutile needles: (i) the rutile needles may be inherited from precursor minerals; (ii) the rutile needles may be formed by a dissolution–reprecipitation mechanism; and (iii) the rutile needles may be formed by cleaving and healing of garnet with rutile deposition. None of these mechanisms can fully explain the observations, although the first one is less likely and the third one is preferred. This study presents an example where the presence of oriented/aligned inclusions in minerals does not necessarily imply a precipitation origin.  相似文献   

Eclogite and carpholite-bearing metasedimentary rocks in the North Qilian suture zone, NW China: implications for Early Palaeozoic cold oceanic subduction and water transport into mantle   总被引：9，自引：0，他引：9  

S. G. SONG  L. F. ZHANG  Y. NIU  C. J. WEI  J. G. LIOU  G. M. SHU 《Journal of Metamorphic Geology》2007,25(5):547-563

Low‐temperature eclogite and eclogite facies metapelite together with serpentinite and marble occur as blocks within foliated blueschist that was originated from greywacke matrix; they formed a high‐pressure low‐temperature (HPLT) subduction complex (mélange) in the North Qilian oceanic‐type suture zone, NW China. Phengite–eclogite (type I) and epidote–eclogite (type II) were recognized on the basis of mineral assemblage. Relic lawsonite and lawsonite pseudomorphs occur as inclusions in garnet from both types of eclogite. Garnet–omphacite–phengite geothermobarometry yields metamorphic conditions of 460–510 °C and 2.20–2.60 GPa for weakly deformed eclogite, and 475–500 °C and 1.75–1.95 GPa for strongly foliated eclogite. Eclogite facies metasediments include garnet–omphacite–phengite–glaucophane schist and various chloritoid‐bearing schists. Mg‐carpholite was identified in some high‐Mg chloritoid schists. P–T estimates yield 2.60–2.15 GPa and 495–540 °C for Grt–Omp–Phn–Gln schist, and 2.45–2.50 GPa and 525–530 °C for the Mg‐carpholite schist. Mineral assemblages and P–T estimates, together with isotopic ages, suggest that the oceanic lithosphere as well as pelagic to semi‐pelagic sediments have been subducted to the mantle depths (≥75 km) before 460 Ma. Blueschist facies retrogression occurred at c. 454–446 Ma and led to eclogite deformation and dehydration of lawsonite during exhumation. The peak P–Tconditions for eclogite and metapelite in the North Qilian suture zone demonstrate the existence of cold subduction‐zone gradients (6–7 °C km^?1), and this cold subduction brought a large amount of H₂O to the deep mantle in the Early Palaeozoic times.  相似文献   

Stability relations of Mn–Fe–Al piemontite     

MARY KESKINEN  J.G. LIOU 《Journal of Metamorphic Geology》1987,5(4):495-507

Abstract Comparison of the stability relations of Fe-piemontite, Pm₁₇Ps₁₇Cz₆₆ (Ca₂Al₂Mn_0.5 Fe_0.5Si₃O₁₂(OH)), with similar experimentally determined results on Pm₃₃Cz₆₇ suggests that, at moderate f_o2, addition of Fe to piemontite raises its thermal stability and slightly decreases its sensitivity to oxygen fugacity. Reversal study of the reaction: Fe-piemontite + quartz = garnet (Gr₃₃Sp₂₇And₄₀) + anorthite + fluid at P_fluid= 2 kbar in cold-seal apparatus using solid oxygen buffers was completed. The data indicated breakdown of Pm₁₇Ps₁₇Cz₆₆ at 645°± 10° C along the Cu₂O–CuO buffer, 477°± 10° C along the Cu–Cu₂O buffer, and 365°± 10° C for the hematite-magnetite buffer. Mn-free clinozoisite and epidote have been shown to be stable to much higher temperatures than piemontite at moderate f_o2 (< Cu–Cu₂O). At very high f_o2, however, the presence of Mn⁺³ in a distorted octahedral site may permit persistence of piemontite to higher temperatures than Mn-poor epidote minerals. The compositional range of natural Fe–Mn–Al piemontites supports these results. Cation partitioning from piemontite-bearing parageneses also indicates crystallization at high f_o2, but application of the cited results should be made with caution. Synthetic phases were too fine-grained for optical or microprobe analysis, and reaction was often incomplete. The assumption that all Fe + Mn was contained in piemontite and garnet, respectively, in the low- and high-temperature assemblages is supported by the cell dimensions for these synthetic minerals, which are close to predicted values. The reaction is pseudo-univariant, as solid solution in garnet and piemontite would be f_o2-dependent in a more complex chemical system. Although bulk rock and fluid compositions may also have a marked effect on the stability of natural epidote–piemontite, f_o2 is the major control on Fe : Mn : Al in epidote minerals.  相似文献   

Partial transformation of gabbro to coesite-bearing eclogite from Yangkou, the Sulu terrane, eastern China   总被引：18，自引：2，他引：18  

R. Y. ZHANG  & J. G. LIOU 《Journal of Metamorphic Geology》1997,15(2):183-202

An ultra-high-pressure (UHP) metamorphic slab at Yangkou Beach near Qingdao in the Sulu region of China consists of blocks of eclogite facies metagabbro, metagranitoid, ultramafic rock and mylonitic orthogneisses enclosed in granitic gneiss. A gradational sequence from incipiently metamorphosed gabbro to completely recrystallized coesite eclogite formed at ultra-high-pressures was identified in a single 30 m block; metagabbro is preserved in the core whereas coesite eclogite occurs along the block margins. The metagabbro contains an igneous assemblage of Pl+Aug+Opx+Qtz+Bt+Ilm/Ti-Mag; it shows relict magmatic textures and reaction coronas. Fine-grained garnet developed along boundaries between plagioclase and other phases; primary plagioclase broke down to Ab+Ky+Ms+Zo±Grt±Amp. Augite is rimmed by sodic augite or omphacite, whereas orthopyroxene is rimmed by a corona of Cum±Act and Omp+Qtz layers or only Omp+Qtz. In transitional rocks, augite and orthopyroxene are totally replaced by omphacite, and the lower-pressure assemblage Ab+Ky+Phn+Zo+Grt coexists with domains of Omp (Jd_70–73)+Ky±Phn in pseudomorphs after plagioclase. Both massive and weakly deformed coesite-bearing eclogites contain Omp+Ky+Grt+Phn+Coe/Qtz+Rt, and preserve a faint gabbroic texture. Coesite inclusions in garnet and omphacite exhibit limited conversion to palisade quartz; some intergranular coesite and quartz pseudomorphs after coesite also occur. Assemblages of the coronal stage, transitional and UHP peak occurred at about 540±50 °C at c. 13 kbar, 600–800 °C at ≥15–25 kbar and 800–850 °C at >30 kbar, respectively. Garnet from the coronal- through the transitional- to the eclogite-stage rocks show a decrease in almandine and an increase in grossular±pyrope components; garnet in low-grade rocks contains higher MnO and lower pyrope components. The growth textures of garnet within pseudomorphs after plagioclase or along grain boundaries between plagioclase and other phases are complex; the application of garnet zoning to estimate P–T should be carried out with caution. Some garnet enclosing quartz aggregates as inclusions shows radial growth boundaries; these quartz aggregates, as well as other primary and low-P phases, persisted metastably at UHP conditions due to sluggish reactions resulting from the lack of fluid during prograde and retrograde P–T evolution.  相似文献   

Long Wave Reflection and Transmission over A Sloping Step     

Hsien-KuoCHANG Jin-ChengLIOU 《中国海洋工程》2004,18(3):371-380

This investigation examines long wave reflection and transmission induced by a sloping step. Bellman and Kalaba‘s (1959) invariant imbeddlng is introduced to find wave reflection. An alternative method matching both the surface elevation and its surface slope of each region at the junction is applied to the determination of wave reflection and transmission.The proposed methods are compared with the accurate numerical results of Porter and Porter (2000) and those of Mei (1983) for a vertical step. The wave reflection obtained for a mildly sloping step differs significantly from the result of Mei. The wave reflection is found to fluctuate owing to wave trapping for the ntild sloping step. The height and the face slope of the step are important for determining wave reflection and transmission coefficients.  相似文献   

Metamorphic P–T conditions and thermal structure of Chinese Continental Scientific Drilling main hole eclogites: Fe–Mg partitioning thermometer vs. Zr-in-rutile thermometer     

R. Y. ZHANG  Y. IIZUKA  W. G. ERNST  J. G. LIOU  Z.-Q. XU  T. TSUJIMORI  C.-H. LO  B.-M. JAHN 《Journal of Metamorphic Geology》2009,27(9):757-772

Core rocks recovered from the main hole (5158 m deep) of the Chinese Continental Scientific Drilling (CCSD‐MH) project, southern Sulu UHP terrane, east‐central China, consist of eclogites, various gneisses and minor metaperidotite cumulates; this lithological section underwent subduction‐zone UHP metamorphism. Coesite‐bearing eclogites are mainly present between the depths of 100–2000 m, but below 2000 m, mafic eclogites are rare. Selected elements (Zr, Nb, Cr, Fe, Si, Mg, Al & Ti) in rutile from 39 eclogite cores from 100 to 2774 m, and major elements of minerals from representative eclogites were analysed by electron microprobe. Zirconium and Nb concentrations of rutile cluster ～100–400 and 200–700 ppm respectively. However, Zr and Nb contents in rutile from strongly retrograded eclogites show larger variations than those of fresh or less retrograded eclogites, implying that somehow fluid infiltration affected rutile chemistry during retrograde metamorphism. Zr contents in rutile inclusions in garnet and omphacite are slightly lower than those of the matrix rutile, suggesting that the rutile inclusions formed before or close to the peak temperature. The P–T conditions of the CCSD‐MH eclogites were estimated by both Fe–Mg exchange and Zr‐in‐rutile thermometers, as well as by the Grt–Cpx–Phn–Ky geothermobarometer. The maximum temperature range of 700–811 °C calculated at 40 kbar using the Zr‐in‐rutile thermometer is comparable with temperature estimates by the Fe–Mg exchange thermometer. The temperature estimates of eclogites in a ～3000 m thick section define a continuous gradient, and do not show a distinct temperature gap, suggesting that the rocks from 100 to 3000 m depth might belong to a single, large‐scale UHP slab. These data combined with P–T calculations for CCSD‐MH peridotites yield a low geotherm (～5 °C km^?1) for the Triassic subduction zone between the Sino‐Korean and Yangtze cratons; it lies ～30–35 mW m^?2 conductive model geotherm.  相似文献