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In order to know better about the Phanerozoic lithosphere thinning process of Sino-Korea Plate, four Cretaceous intrusion complexes and their ultramafic xenoliths are investigated by this thesis, which are located in Laiwu, Shandong Province, Eastern China, a region far away from plate margin. The four complexes, Kuanshan, Jiaoyu, Jingniushan and Tietonggou, intruded into Archaeozoic granite gneiss and Paleozoic carbonate rocks with scam iron ore at their contact zone. The four complexes can be divided into two magma series, abyssal rocks for the early and hypabyssal rocks for the later. K-Ar dating show that the abyssal rocks intrusion began with 120 ��2 Ma and the hypabyssal rocks intruded about 113 Ma. Abyssal rocks, mainly made up of augite diorites, amphibole diorites and gabbros for the lesser, are chemically characterized with high-Mg (Mg#>0.5) high-K calcalklic rock, which are depleted with Nb, Ta and Ti related to LILE and extremely enriched with Sr and Pb. Comparatively, augite diorites are the most LREE enriched in abyssal rocks, and they show no Eu abnorrnity or weak positive Eu abnormity. Gabbros show the least LREE enrichment with a strong Eu abnormity relatively. In (~(87)Sr/~(86)Sr)_1 -�� Nd(T) diagram, the abyssal rocks show a mixing trend , a rapid change in �� Nd(T) with a relatively small change in (~(87)Sr/~(86)Sr)_1. Low radiogenic Sr and Pb composition with high radiogeic Nd composition indicate that the mixing processes happened in lower crust Melt-rock interactions in lower crust might be the most possible processes to produce these high-Mg and high-K calcalklic magmas. Hypabyssal rocks, mainly made up of granite porphyry and dioritic porphrite, show much higher �� Nd(T) than abyssal rocks. Granite porphyry are distinct with an adakite geochemical characteristics, high (La/Yb)_N, Sr/Y and low Rb/Sr ratio. The adakitic granite porphyry indicates a new lower crust produced by underplating within plate. Ultramafic xenoliths had been found only in augite diorites and amphibole diorites. Field investigations show that ultramafic xenoliths in augite diorites had been inherited from amphibole diorites, so ultramafic xenoliths had been only entrained by hydrous dioritic magma. Ultramafic xenoliths are mainly made up of dunite and harzburgite, orthopyroxenite and bistangite are the lessor. Coarse olivines in dunite often show many chromite exsolution lamellae. Opx in orthopyroxenite often show dense chromite exsolution lamellae. The presence of exsolution minerals indicates that ultramafic xenoliths had cooled before entraining. Metasomatism phenomenons are popular in dunite and harzburgite xenoliths, including two kinds of assemblage, cpx+phlogapite and opx+pl. The first metasomatism assemblage indicates an ancient enrichment. Rb-Sr dating of xenoliths shows that the ancient enrichment happened in 223 �� 7Ma. The second metasomatism assemblage indicates a recent, relatively not deep melt-rock interaction, which might be related with the genesis of the high-Mg high-K calcalklic rocks. Mineralogy and geochemistry indicate that these ultramafic xenoliths might sample the crust-mante transition zone (or the base of lower crust, moho). Investigation of high-Mg intrusions and their ultramafic xenoliths in Laiwu indicate that the thinning processes of Sino-Korea Plate can be divided into two stages. The first stage is lithosphere mantle thinning with crust thickening by underplating in lower crust. The second stage is that the thickened lower crust delaminated into the underlying mantle.

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The Ultrahigh Pressure Metamorphic (UHPM) eclogite, which was resulted from deep subduction of crustal continent, is very significant due to its continental dynamic implications. Further more, this kind of rocks experienced great P-T, fluid and stresses changes during its forming and exhumation, causing mineral reactions occur intensively, which resulted in a lot of fantastic micro-texture. The micro-texture was preserved duo to a rapid exhumation of the eclogite. This PhD dissertation takes such micro-textures in 10 Donghai eclogite samples South Sulu UHPM terrene, as research object to reveal the transformation of the eclogite to amphibolite. Microscope and Scanning Electron Microscope were employed to observe the micro-texture. Basing on microprobe analysis of minerals, the ACF projections and iso-con analysis were used to uncover the mineral reactions during the transformation. Micro-texture observation (both of Microcopy and Electron Scanning Microscope), demonstrated: l.The peak mineral assemblage of the researched Donghai eclogites is garnet + omphacite + rutile (+ kyanite + aptite +coesite). 2.The transformation of the Donghai eclogite to amphibolite can be divided into two stages: The earlier one is Symplectization, resulting in the forming of diopside + albite (+magnetite) symplectite that occurred only along the boundary between two adjacent omphacite grains. Other minerals were not involved in such reaction. The latter stage is Fluid-Infiltration of the eclogite, which was caused by fluid-intrusion. The infiltration is demonstrated by amphibolization of the symplectite, decomposition of garnet and the forming of some hydrous minerals such as phengite and epidote, and resulted in an amphibole + plagioclase + phengite + epidote or ziosite assemblage. Basing on microprobe analysis of the minerals, ACF projections indicated: In the ACF diagrams, the two joint lines of peak Grt + Omp and Dio + Ab crossed at Omp projection-point, indicating that the garnet had not taken part in the forming reaction of the Dio + Ab symplectite, just like that had been pointed out by micro-texture observation. In the ACF diagrams, the hornblende + plagioclase + epidote + phengite quadrilateral intersected with Dio + Ab + Grt triangle, demonstrating that the hydrous mineral assemblage was formed by fluid infiltration through garnet, diopside and albite. Iso-con (mass-balance) analysis of the symplectization and infiltration reveals: 1.The symplectization of the omphacite has a very complex mass exchange: Some symplectite gained only silicon from its surroundings; and some one requires Ca, but provides Na to its surroundings; while other symplectite provides Ca, Mg and Fe to its surroundings. 2.The infiltration cause variable mass exchanges occurring among the garnet, diopside and albite: In some eclogite sample, no mass, except H2O, exchange occurred during the infiltration. Meanwhile, there was not any hydrous mineral except hornblende formed in the sample accordingly. In some samples, the mass exchange among the three minerals is complex: amphibolization of the diopside in a symplectite gained Al from garnet, and provided Si and Ca to its surrounding, resulting in a Si, Ca and Al-rich fluid. Correspondingly, there was a lot of phengite and ziosite occurred in the sample. In other samples, the amphibolization of a symplectite provided Fe and Mg besides Si and Ca to its surrounding while gained Al. In such kind of sample, epidote occurred within the hydrous mineral assemblage. Synthesizing the micro-texture observation, ACF analysis and iso-con analysis, we deduced the transformation procedure as following: 1. A symplectite after an omphacite was resulted by one, or two, or all of following mineral reactions together: Jd (Ca-Tsch) +SiO2=Ab (An) (1) 4NaA IS i.A+CaO=2NaAlS i308+Na20+CaAl2S 1208 (2) 2NaAlSi2OB (Jd in Omp)+CaMgSi;,0B(Dio in Omp)-2NaAlSi:,O"(Ab)+Ca0+Mg0 (3) 2(CaAl2Si0fi) (Ca-tsch in Omp)+CaFeSi2O6(Hed in 0mp)-H>2CaAl2Si208(An)+Ca0 + FeO (4) A CO2-rich fluid is suggested as cataclysm for the above reactions, which largely increased the mobility of Ca, Mg and Na resulted from reaction (2), (3) and (4). The immobile product Fe2* combined with rutile to form ilmenite, resulting in rutile + ilmenite symplectite. Or, the Fe was precipitated as hematite locally. A procedure of the fluid infiltration as following is suggested: I .A hydrous fluid intruded into the eclogite, and reacted first with garnet to form hornblende and extra Al, resulting in a hornblende film around the garnet grain and an Al-rich fluid. 2.The Al-rich fluid infiltrated through the symplectite, OH" and part of the Al in the fluid combined with Dio while some Si and Ca in the Dio were dissolved made the Dio transferred to amphibole. Meanwhile, plagioclase-type cation exchange occurred between the fluid and plagioclase in the symplectite, making the plagioclase have a higher An-content. 3.Above infiltration and cation exchange resulted in an Al, Si, Ca (and K, providing the primary hydrous fluid contain K)-rich fluid. 4.Under suitable conditions, the solute in the fluid precipitated to form phengite firstly. After the K element in the fluid was consumed up, ziosite or epidote was formed. If the fluid did not contain any K. element, only ziosite or epidote was precipitated. For those eclogites, where all omphacite had been replaced by symplectite before infiltration, neither element exchange occurred, nor did phengite or epidote form during the infiltration. At the last stage, the garnet was oxidized and breakdown: garnet + H2O = epidote + hornblende + hematite, due to more and more fluid intruding into the eclogite. At this time, all the peak minerals were replaced by amphibolite-phase ones, and the eclogite transformed to an amphibolite completely. Tentative pressure calculation indicates that the infiltration occurred at 3-6kbar (about 10-20km depth), where the deformation mechanics transformed from brittle to ductile yield. At such depth, the surface water can permeate the rocks through fault system, causing a rapid cooling.

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Chinese National Antarctic Research Expedition (CHTNARE) has collected 4480 meteorite specimens in the Grove Mountains, East Antarctica, from 1998 to 2003. According to the location characteristics and the diversity of the classification, the paper concludes that the Grove Mountains is another important meteorite concentration area in the Antarctica. The Concentration mechanisms at the site could be related to the last glacier activity and katabatic wind. An empirical model was proposed: 1) Probably during the Last Glacial Maximum, ice flow overrided the Gale Escarpment range in the area. Formerly concentrated meteorites were carried by the new glacier and stayed in the terminal moraine when the glacier retreated. 2) Blown by strong katabatic wind, Newly exposed meteorites on the ablation zone were scattered on the blue ice at the lee side of the Gale escarpment. Some of them would be buried when they were moved further onto the firn snow zone. Many floating meteorites stopped and mustered at the fringe of the moraine. The chemical-petrographic of 31 meteorites were assigned based on electron probe microanalyses, petrography and mineralogy, including 1 martian lherzolitic shergottite, 1 eucrite, 1 extreme fine grain octahedron iron meteorite, and 28 ordinary chondrites (the chemical groups: 7 H-group, 13 L-group, 6 LL-group, 2 L/LL group; the petrographic types: 6 unequilibrated type 3 and 22 equilibrated type 4-6). GRV99028 meteorite has the komatiite-like spinifex texture consisting of acicular olivine crystals and some hornblende-family minerals in the interstitial region. Possibly it has crystallized from a supercooled, impact-generated, ultramafic melt of the host chondrite, then experienced the retrogressive metamorphism. Four typical chondrule textures were studied: porphyritic texture, radiative texture, barred texture and glass texture. The minerals are characteristically enriched in MgO content.

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The Fanshan complex consists of layered potassic ultramafic-syenite intrusions. The Fanshan apatite (-magnetite) deposit occurs in the Fanshan complex, and is an important style of phosphorus deposit in China. The Fanshan complex consists of three (First- to Third-) Phases of intrusion, and then the dikes. The First-Phase Intrusive contains ten typical layered rocks: clinopyroxenite, biotite clinopyroxenite, coarse-grained biotite clinopyroxenite, pegmatitic orthoclase-biotite clinopyroxenite, variegated orthoclase clinopyroxenite, interstitial orthoclase clinopyroxenite, biotite rock, biotite-apatite rock, biotite rock and magnetite-apatite rock. This layered intrusive consists of nine rhythmic units. Each rhythmic unit essentially comprises a pair of layers: clinopyroxenite at the bottom and biotite clinopyroxenite at the top. The apatite (-magnetite) deposit is situated near the top of rhythmic Unit no. 6 of the First-Phase Intrusive. The Second-Phase Intrusive contains three typical rocks: coarse-grained orthoclase clinopyroxenite, . coarse-grained salite syenite and schorlomite-salite syenite. The Third-Phase Intrusive includes pseudo-trachytic salite syenite, porphyritic augite syenite, fine-grained orthoclase clinopyroxenite and fine-grained salite syenite. The origin of the Fanshan complex is always paid attention to it in China. Because most layered igneous intrusion in the world not only have important deposit in it, but also carry many useful information for studying the formation of the intrusion and the evolvement of magma. Two sketch maps were drawn through orebodies along no. 25 cross-cut on 425 mL and no. 1 cross-cut on 491 mL in the Fanshan mine. Through this mapping, a small-scaled rhythmic layering (called sub-rhythmic layering in the present study) was newly found at the top of the rhythmic Unit no. 6. The concept of sub-rhythmic layering is defined in this article. The sub-rhythmic layering is recognized throughout this apatite-rich part, except for magnetite-apatite rock. Presence of the layered magnetite-apatite rock is one of the characteristics of the Fanshan apatite (-magnetite) deposit. Thus, from this layer downwards six units of sub-rhythmic layering are recognized in the present study. Each unit consists of biotite clinopyroxenite (or biotite rock and biotite-apatite rock) layer at the bottom and apatite rock layer at the top. To study this feature in detail is an important work for understanding the origin of the Fanshan complex and apatite (-magnetite) deposit. The origin of the Fanshan complex and the relation of the formation of the apatite(-magnetite)deposit will be interpreted by the study of sub-rhythmic layering on the basis of previous research works. The magma formed the Fanshan complex was rich in K2O, early crystallized pyroxene, and after this phase more biotite crystallized, but no amphibole appeared. This indicated that the activity of H2O in the magma was low. Major element compositions of biotite and clinopyroxene (on thin sections) in the sub-rhythmic layering were analyzed using electron microprobe analyzer. The analytical results indicate Mg/(Mg+Fe*+Mn) atomic ratios (Fe*, total iron) of these two minerals rhythmically changed in sub-rhythmic layering. The trends of Mg/(Mg+Fe*+Mn) atomic ratio (Fe*, total iron) of biotite and clinopyroxene indicate that the magma evolved markedly from relatively magnesian bottom layer to less magnesian top layer in each sub-rhythmic unit. A general trend through the sub-rhythmic layering sequence is both minerals becoming relatively magnesian upwards. The formation temperatures for sub-rhythmic layering yield values between 600 and 800 ���, were calculated using the ratio of Mg/(Mg+Fe+Mn) in the salite and biotite assemblage. The equilibrium pressures in the rhythmic layers calculated using the contents of Al in the salite were plotted in the section map, shown a concave curve. This indicates that the magma formed the First-Phase Intrusive crystallized by two vis-a-vis ways, from its bottom and top to its centre, and the magnetite-apatite rock was crytallized in the latest stage. The values of equilibrium pressures in the sub-rhythmic layering were 3.6-6.8(xlO8) Pa with calculated using the contents of Al in the salite. The characteristics of geochemistry in various intrusive rocks and the rocks or apatite of sub-rhythmic layers indicated that the Fanshan complex formed by the comagmatic crystallization. The contents of immiscible elements and REEs of apatite rock at the top of one sub-rhythmic unit are more than biotite clinopyroxenite at the bottom. The contents of immiscible elements and REEs of apatite of biotite clinopyroxenite at the bottom of one sub-rhythmic unit are higher than apatite rock at the top. The curves of rocks (or apatite) in the upper sub-rhythmic units are between two curves of the below sub-rhythmic unit in the primitive mantle-normalized trace element abundance spider diagram and the primitive mantle-normalized REE pattern. The trend for the contents of immiscible elements and REEs inclines to the same contents from the bottom to the top in sub-rhythmic layering. These characteristics of geochemistry of rocks or apatites from sub-rhythmic layering indicate that the latter sub-rhythmic unit was produced by the residual magma after crystallization of the previous sub-rhythmic unit. The characteristics of petrology, petrochemistry, geochemistry in the Fanshan complex and sub-rhythmic layers and the trends of Mg/(Mg+Fe+Mn) atomic ratio of biotite and clinopyroxene in sub-rhytmic layering rejected the hypotheses, such as magma immiscibility, ravitational settling and multiple and pulse supplement of magma. The hypothesis of differentiation by crystallization lacks of evidences of field and excludes by this study. On the base of the trends of formation temperatures and pressures, the characteristics of petrology, petrochemistry, geochemistry for the Fanshan complex and the characteristics of geochemistry for the rocks (or apatites), the trends of Mg/(Mg+Fe+Mn) atomic ratio of biotite and clinopyroxene in sub-rhytmic layering, and the data of oxygen, hydrogen, strontium and neodymium isotopes, this study suggests that the magma formed the Fanshan complex was formed by low degree partial melting of mantle at a low activity of H2O, and went through the differentiation at the depth of mantle, then multiply intruded and crystallized. The rhythmic layers of the First-Phase Intrusive formed by the magma fractional crystallized in two vis-a-vis ways, from the bottom and top to the centre in-situ fractional crystallization. The apatite (-magnetite) deposit of the Fanshan complex occurs in sub-rhythmic layering sequence. The the origin of the sub-rhythmic layering is substantially the origin of the Fanshan apatite (-magnetite) deposit. The magma formed the rhythmic layers of First-Phase Intrusive was rich in H2O, F and P at the later stage of its in-situ fractional crystallization. The Fanshan apatite (-magnetite) deposit was formed by this residual magma in-situ fractional crystallization. The magnetite-apatite rock was crystallized by two vis-a-vis ways at the latest stage in-situ fractional crystallization in the rhythmic layers. The result was light apatite layer below heavy the magnetite-apatite layer, formed an "inversion" phenomenon.