REE concentrations of garnet and omphacite in eclogites from the Dabie Mountain, central China

Distributions of the rare-earth elements (REE) in omphacite and garnet and REE behaviors during metamorphic processes were discussed. The REE concentrations of garnet and omphacite in six eclogite samples from the Dabie Mountain, central China, were measured by inductively coupled plasma-mass spectrometry (ICP-MS). The correlation of δEu ratios between garnet and omphacite indicated that chemical equilibrium of REE distribution between garnet and omphacite could be achieved during ultra-high pressure (UHP) metamorphism. Most of the partition coefficients (Kd=CiOmp/CiGrt) of light rare-earth elements (LREE) are higher than 1. However the partition coefficients of heavy rare-earth elements (HREE) are lower than 1. This indicated that the LREE inclined to occupy site M2 in omphacite, but the HREEs tended to occupy eightfold coordinated site in garnet during the eclogite formation. The REE geochemistry of the eclogites indicated that LREE could be partially lost during the prograde metamorphic process of protolith, but be introduced into the rocks during the symplectite formation. LREE are more active than HREE during the UHP metamorphism. The results are favorable to highlighting the REE behavior and evolution of UHP metamorphic rocks.     

“寨背式”离子吸附型稀土矿床多类型稀土矿化及其成因

赣南寨背离子吸附型稀土矿床产于寨背复式花岗岩体的风化壳中,自20世纪80年代发现以来一直以轻稀土型开采,近年在轻稀土型花岗岩风化壳中发现了重稀土矿。为了探讨轻稀土型花岗岩风化过程中重稀土元素的迁移、分馏和富集机制,本文选择了区内三个具有代表性的风化壳钻孔(ZK1、ZK2和ZK4)对其进行了全相和离子交换相稀土元素地球化学研究。结果显示：钻孔ZK4中离子交换相稀土含量介于14.90×10^-6～835.8×10^-6之间,并富集轻稀土(LREE/HREE=2.28～10.78);钻孔ZK1中离子交换相稀土含量达1470×10^-6(9件样品均值),具有从轻稀土型向重稀土型过渡的配分特征(LREE/HREE=1.30～1.65),并且剖面自上而下显示轻、重稀土逐渐富集的趋势;钻孔ZK2中离子交换相稀土含量为492.4×10^-6(8件样品均值),自上而下稀土配分类型从轻稀土型过渡至重稀土型(LREE/HREE=0.43～2.25),且轻稀土富集在全风化层上部而重稀土则富集在下部。三个钻孔的Nb/Ta和Zr/Hf...     

REE Geochemistry and Mineralization Characteristics of the Zudong and Guanxi Granites,Jiangxi Province

Abstract The Zudong and Guanxi granites are original rocks of the ion adsorption-type HREE and LREE deposits in weathering crust of granites. The ∑REE ¹ ∑REE=REE+Y.
value and LREE ² LREE=∑(La-Eu) and HREE=∑(Gd-Lu)+Y.
/ HREE ratio of the Zudong granite are 264 ppm and 0.81-0.24 respectively, and the average Y/∑REE ratio is 35.8-54.5%. This is mainly due to magmatic crystallization and evolution and deuteric metasomatism (albitization, muscovitization and fluorite-doveritization). These alterations resulted in endogenic mineralizations of yttrium-group REE fluorine carbonates, silicates and arsenates. The Guanxi granite is characterized by LREE enrichment (the average LREE/HREE ratio is 2.43).     

Behaviour of REE and mass balance calculations in a lateritic profile over chlorite schists in South Cameroon

An in situ weathering profile overlying chlorite schists in the Mbalmayo-Bengbis formations (South Cameroon) was chosen for the study of the behaviour of REE and the evaluation of geochemical mass balance. After physical and mineralogical studies, the chlorite schists and the undisturbed weathered materials were chemically analyzed for major elements (X-ray fluorescence and titrimetry) and REE (ICP-MS). The behaviour of the REE in the Mbalmayo weathering system was established in comparison with the REE of the reference parent rock. Mass balance calculations were applied to both major elements and REE. The mineralogy of the materials was determined with the aid of a Philips 1720, diffractometer. The chlorite schists of the Mbalmayo sector show low REE contents (Σ=153.44 ppm). These rocks are relatively rich in LREE (about 125 times the chondritic value) and relatively poor in HREE (about 20 times the chondritic value). The REE diagram normalized to chondrites shows a slightly split graph ((La/Yb)_N=6.18) with marked enrichment in LREE (LREE/HREE=9.50) in relation to HREE. Moreover, these spectra do not present any Ce anomaly, but a slightly positive Eu anomaly. The imperfectly evolved profile, whose materials are genetically linked, shows an atypical behaviour of REE. In effect, the LREE are more mobile than the HREE during weathering ((La/Yb)NASC<1) with weak Ce anomalies. This has been rarely reported in lateritic profiles characterized by higher HREE mobility than LREE during weathering processes with high Ce anomalies. This is either due to the difference in the stability of REE-bearing minerals, or to the weak acidic to basic pH conditions (6.70<pH<7.80), or even due to the average evolution of the weathering materials. The pathway of the REE along the profile is as follows: (1) leaching in the saprolites and summit of the profile, except for Ce, which precipitates very weakly in the nodular materials and the coarse saprolite materials, (2) at the base of the profile, solutions come in contact with chlorite schist formations, at this level, the pH increases (pH=7.79), HREE and a part of LREE partially void of Ce precipitate and (3) the other part of LREE precipitates further up in the profile. The geochemical mass balance calculations reveal that these elements are leached in the same phases as the relatively high Si, Al, K and Fe²⁺ contents.     

鄂尔多斯盆地中东部奥陶系风化壳储层稀土元素配分特征及其油气地质意义

对鄂尔多斯盆地中东部奧陶系马家沟组风化壳岩溶储层的碳酸盐岩、硫酸盐岩和碎屑岩类岩石样品以及上覆层本溪组碎屑岩样品所作的稀土元素含量与配分特征分析表明,稀土元素分馏特征与富集特征明显,非可溶岩的稀土元素总含量与富集程度高于可溶岩。轻、重稀土元素关系分析表明,可溶岩的轻稀土元素迁移大于重稀土元素的分馏效应,揭示了可溶岩经历了不同的岩溶环境,马家沟组碎屑岩中的稀土元素与上覆层本溪组底部砂泥岩中的稀土元素是同源的。δEu与δCe分析表明,δEu的活化迁移,反映了表生期岩溶环境的存在,而δCe的相对富集,揭示了埋藏期岩溶的发育及其与天然气生成运聚的密切关系。     

Hydrothermal Redistribution of Rare—Earth Elements in Pingxiang Dacite,Guangxi

Distribution of the rare-earth elements (REE) in dacite has been studied so as to get a better understanding of the migration behavior of REE during alteration. Both unaltered and altered samples were collected in an unpolluted area of Guangxi Zhuang Autonomous Region, southwest China. The REE concentrations were analyzed by ICP-MS. It is concluded that the REE were enriched during dacite alteration in varying degrees. The chondrite-normalized REE patterns of altered samples approximately maintain the characteristics of unaltered samples. However, if we normalize the REE concentrations of altered samples with unaltered dacite, fractionation of REE will appear. The LREE are more enriched than HREE in all altered samples with the LREE possibly precipitated as carbonate minerals. Both positive and negative Eu anomalies exist. Enrichment, immobility and depletion are noticed for the element Lu. Heavy mineral alteration, difference in stability constant between carbonate LREE and HREE complexes, downward migration of weathering fluid and microenvironment change may be responsible for the fractionation of REE in the altered dacite.     

碳酸盐岩酸不溶物作为贵州岩溶区红色风化壳主要物质来源的证据

贵州岩溶区红色风化壳是中国南方红色负化壳的重要组成部分，本文根据部分红色风化壳剖面野外特征、矿物学、地球化学及土壤物理学等的研究结果，对其物源及成因进行了探讨。各剖面，尤其邻近剖面显著的矿物学、地球化学差异排除了远程风成沉积物、火山灰、上覆或者高处碎屑岩层作为统一且重要物源的可能。极低的石英含量表明贵州常见的长石石英砂岩不是其主要物源，具有中稀土（MREE）富集的特征也排除了粘土岩、页岩作为主要物源的可能。风化壳剖面间的差异性均可从基岩酸不溶物的差异性得到很好解释，表明它们是下伏碳酸盐岩风化、酸不溶物（准）原地堆积的结果。部分剖面甚至显示了典型风化壳剖面的一些特征，具有正常风化序列的剖面结构特征。     

Compositional characteristics of wolframite in tin deposits,Dupangling, Guangxi

Statistical data on major, trace and rare-earth elements in wolframite from the quartz vein-and greisen-type tin deposits in the Dupangling orefield reveal: (1) The components in wolframite can be divided into two relatively independent groups: the WO₃-Nb-Ta-Sc-REE group, in which WO₃ is negatively correlated with the others and the FeO-MnO-Sn group, in which MnO is negatively correlated with the other two; (2) In general, REE fractionation is not significant, reflected mainly by the separation of Eu from other REE’s. LREE and HREE increase or decrease simultaneously, with HREE being more variable; (3) Nb, Ta, Sc, REE substitute for W, and Sn may enter into wolframite lattice accompanied by Fe-Mn substitution; (4) In contrast to wolframite in quartz veins, which is poor in REE, Nb, Ta and Sc and has highδ Eu values and LREE / HREE and Nb/Ta ratios, wolframite in greisen is rich in REE, Nb, Ta, Sc and has lowδ Eu values and LREE/HREE and Nb/Ta ratios; and (5) The contents and ratios of trace elements and REE partitioning parameters of wolframite can be used as guide for prospecting.     

云南兰坪盆地古近系细碎屑岩地球化学特征及其地质意义

采用电感耦合等离子体质谱(ICP-MS)方法对兰坪盆地古近系104件细碎屑岩样品进行了稀土元素及微量元素分析,结果显示∑LEE含量较高,轻稀土含量较富集、重稀土含量较亏损,显示出明显的"右倾"型配分模式。根据稀土元素和微量元素特征、w(Zr)-w(Th)、La-Th-Sc、Th-Sc-Zr/10等多种沉积构造背景判别图解及多种交叉分析方法,对兰坪盆地古近系细碎屑源岩构造背景进行了详细研究。利用La/Th-Hf和La/Yb-∑REE判别图解对兰坪盆地古近系源岩属性进行了分析,结果表明:兰坪盆地古近系碎屑源岩主要以上地壳长英质岩石为主,并混有少量基性岩,反映其物源区构造背景为早期为大陆岛弧构造背景,至晚期逐渐过渡为被动大陆边缘构造背景。     

The Behaviour of Rare—Earth Elements（REE） During Weathering of Granites in Southern Guangxi,China

The behaviour of the rare-earth elements(REE)during the weathering of granites was studied in southern Guangxi,China.Based on the study of the weathering profiles,the soil,weathered and sub-weatereb zones are identified with different REE geochemical behaviours throug the weathering profiles of granite.The Ce anomalies of the weathering profiles cover a large range of values with most falling between 1.02 and 1.43in the soil zone and 0.16and 0.40in the weathered and sub-weathered zones.Light rare-earth elements(LREE) and heavy rare-earth elements(HREE)are enriched to varying degree in the weathering profiles as compared to host granites.In the soil zone,more HREEs are leached than LREEs,and HREEs are more enriched than LREE in the weathered and sub-weathered zones.It is considered that infiltration and adsorption on clays are two processes controlling the enrichment and formation of REE deposits in the weathering profiles of granite.     

The Mobility of Rare—Earth Elements During Hydrothermal Activity：A Review

The mobility of the rare-earth elements(REE)during hydrothermal activities is increasingly documented.Geological and experimental evidence suggests that REE may be mobile in solutions rich in F^-,Cl^-,HCO3^-,CO^2- 3,HPO4^2-,PO4^3-,or in combinations of the above ligands,even though little has been known about which ligand or which combination is most effective in mobilizing REE. The fractionation of REE resulting from hydrothermal activities is inconsistent.One set of field data implies the prererential mobility of the light rare-earth elements(LREE).whereas another set of field observations indicates the dominant mobilization of the heavy rare earth elements(HREE),and some theoretical prediction is comtradictory to the field evidence.The Eu anomalies due to hydrothermal activities are complex and plausible explanation is not available.The existing experimental approaches dealing with REE are not adequate for explanation ofREE behaviour in aqueous solutions.Systematic experimental approaches are suggested.     

Rare Earth Element Geochemistry of Late Palaeozoic Coals in North China

Instrumental Neutron Activation Analysis (INAA) was done to determine the abundances of rare earth elements (REE) of 58 samples of Late Palaeozoic Carboniferous-Permian coals and related rocks in North China. Detailed study of REE geochemistry shows that the ∑REE of most coals studied in this paper is in a normal range between 30×10-6 and 80×10-6 with a mean of 56×10-6. The REE in the Taiyuan Formation in the northern part of North China are much richer than those in the southern part. This is due to the shorter distance to the source area in the north. Moreover, the IREE is in positive correlation to coal ash, especially closely related to the content of clay minerals <2μm in size. This reveals that most REE were carried by terrigenous clastic materials, especially fine clay minerals. In the coals the light REE (LREE) are much richer than the heavy REE (HREE), and the LREE/HREE ratio in coals generally varies from 2 to 8. The LREE/HREE ratio of high-ash, low-sulphur coals is higher than that of lo     

Geochemical and mineralogical characteristics of ion-adsorption type REE mineralization in Phuket, Thailand

Geochemical and mineralogical studies were conducted on the 12-m-thick weathering profile of the Kata Beach granite in Phuket, Thailand, in order to reveal the transport and adsorption of rare earth elements (REE) related to the ion-adsorption type mineralization. The parent rock is ilmenite-series biotite granite with transitional characteristics from I type to S type, abundant in REE (592 ppm). REE are contained dominantly in fluorocarbonate as well as in allanite, titanite, apatite, and zircon. The chondrite-normalized REE pattern of the parent granite indicates enrichment of LREE relative to HREE and no significant Ce anomaly. The upper part of the weathering profile from the surface to 4.5 m depth is mostly characterized by positive Ce anomaly, showing lower REE contents ranging from 174 to 548 ppm and lower percentages of adsorbed REE from 34% to 68% compared with the parent granite. In contrast, the lower part of the profile from 4.5 to 12 m depth is characterized by negative Ce anomaly, showing higher REE contents ranging from 578 to 1,084 ppm and higher percentages from 53% to 85%. The negative Ce anomaly and enrichment of REE in the lower part of the profile suggest that acidic soil water in an oxidizing condition in the upper part mostly immobilized Ce⁴⁺ as CeO₂ and transported REE³⁺ downward to the lower part of the profile. The transported REE³⁺ were adsorbed onto weathering products or distributed to secondary minerals such as rhabdophane. The immobilization of REE results from the increase of pH due to the contact with higher pH groundwater. Since the majority of REE in the weathered granite are present in the ion-adsorption fraction with negative Ce anomaly, the percentages of adsorbed REE are positively correlated with the whole-rock negative Ce anomaly. The result of this study suggests that the ion-adsorption type REE mineralization is identified by the occurrence of easily soluble REE fluorocarbonate and whole-rock negative Ce anomaly of weathered granite. Although fractionation of REE in weathered granite is controlled by the occurrence of REE-bearing minerals and adsorption by weathering products, the ion-adsorption fraction tends to be enriched in LREE relative to weathered granite.     

Major Element Compositions and Rare—earth Element Abundaces of Cenozoic Basalts in Eastern China：Implications for a Pressure Control over LREE／HREE Fractionation in Continental Basalt

Major element compositions and rare-earth element (REE) and transition element(Ni,Cr and V) abundances have been determined on 44 basalt samples from eastern China.These basalts have SiO2 contents ranging from 38.63 to 55.24(wt.%),and Na2O K2O from 3.1 to 9.4(wt.%).Ni and Cr abundances are largely variable,respectively falling in ranges 60-605 and 78-1150 ppm.REE abundances,especially light rare-earth elements(LREE), are highly variable.La/Sm and La/Yb ratios vary 2.8 to 7.6 and 1.8 to 8.1. Although the segregation mainly of olivine and clinopyroxene is requested to account for the vari-able and low MgO,CaO/Al2O3,Cr and Ni characteristic of these basalts studied here,the differ-ences in REE composition of the basalts are still related mainly to the partial melting process.Obvious varations in REE abundances could be principally attributed to the partial melting process.Obvious variations in REE abundances could be principally attributed to the partial melting processes that took place at different depths,in spite of some variations caused by the fractional crystallization processes.REE abundances and La/Sm and La/Yb ratios systematically decrease with increasing SiO2,which probably indicated that the basaltic magma derived from a deeper level has higher LREE and LREE/HREE ratios than that from a shallower level.As viewed from the fact that the D^Yb/D^La ratios of clinopyroxenes in the basaltic system increase with increasing pressure,the increase of LREE/HUEE ratios with increasing melting depth can be interpreted as the pressure dependence of bulk D^HREE/D^LREE ratios of silicate minerals,in addition to the pressure control over the melting degree.     

Petrological and geochemical characteristics of Zhaibei granites in Nanling region,Southeast China: Implications for REE mineralization

Mineralization with ion adsorption rare earth elements (REEs) in the weathering profile of granitoid rocks from Nanling region of Southeast China is an important REE resource, especially for heavy REE (HREE) and Y. However, the Jurassic granites in Zhaibei which host the ion adsorption light REE (LREE) ores are rare. It is of peraluminous and high K calc-alkaline composition, which has similar geochemical features of high K₂O + Na₂O and Zr + Nb + Ce + Y contents and Ga/Al ratio to A-type granite. Based on the chemical discrimination criteria of Eby [Geology 20 (1992) 641], the Zhaibei granite belongs to A1-type and has similar source to ocean island basalts. The rock is enriched in LREE and contains abundant REE minerals including LREE-phosphates and halides. Minor LREE was also determined in the feldspar and biotite, which shows negligible and negative Eu anomalies, respectively. This indicates that the Zhaibei granite was generated by extreme differentiation of basaltic parent magmas. In contrast, granites associated with ion adsorption HREE ores contain amounts of HREE minerals, and show similar geochemical characteristics with fractionated felsic granites. Note that most Jurassic granitoids in the Nanling region contain no REE minerals and cannot produce REE mineralization. They belong to unfractionated M-, I- and S-type granites. Therefore, accumulation of REE in the weathering profile is controlled by primary REE mineral compositions in the granitoids. Intense fractional crystallization plays a role on REE enrichment in the Nanling granitoid rocks.     

Rare earth element studies of surficial sediments from the southwestern Carlsberg Ridge,Indian Ocean

The rare earth element (REE) contents of sixteen surficial calcareous sediments from the southwestern Carlsberg Ridge, Indian Ocean, have been determined. The total REE vary from 35 ppm to 126 ppm and are inversely related to the calcium carbonate content. REEs show a strong positive correlation with Al + Fe + K + Mg + Na (r ²= 0.98) and Mn + Fe + Cu + Ni (r ²= 0.86) suggesting that the REE is associated with a combined phase of clays (mainly illite) and Mn-Fe oxyhydroxides. The aeolian input into these sediments is suggested from the weak positive Eu/Eu* anomaly. Shale-normalized (NASC) pattern along with La_(n)/Yb_(n) ratio suggest enrichment of heavy REE (HREE) relative to the light REE (LREE) with a negative Ce/Ce* anomaly implying retention of a bottom water REE pattern. An erratum to this article is available at .     

Rare-earth elements as source indicators of Pan-African granites from Obudu Plateau,Southeastern Nigeria

The rare-earth element （REE） concentrations of representative granite samples from the southeast of the Obudu Plateau, Nigeria, were analyzed with an attempt to determine the signatures of their source, evolutionary history and tectonic setting. Results indicated that the granites have high absolute REE concentrations （190×10^-6-1191×10^-6; av.=549×10^-6） with the chondrite-normalized REE patterns characterized by steep negative slopes and prominent to slight or no negative Eu anomalies. All the samples are also characterized by high and variable concentrations of the LREE （151×10^-6-1169×10^-6; av.= 466×10^-6）, while the HREE show low abundance （4×10^-6-107×10^-6; av.=28×10^-6）. These are consistent with the variable levels of REE fractionation, and differentiation of the granites. This is further supported by the range of REE contents, the chondrite-normalized patterns and the ratios of LaN/YbN （2.30-343.37）, CeN/YbN （5.94-716.87）, LaN/SmN （3.14-11.68） and TbN/YbN （0.58-1.65）. The general parallelism of the REE patterns, suggest that all the granites were comagmatic in origin, while the high Eu/Eu＊ ratios （0.085-2.807; av.=0.9398） indicate high fo2 at the source. Similarly, irregular variations in LaN/YbN, CeN/YbN and Eu/Eu＊ ratios and REE abundances among the samples suggest behaviors that are related to mantle and crustal sources.     

REE and HFS element behaviour in the alteration facies of the Erenler Dağı Volcanics (Konya,Turkey) and kaolinite occurrence

Mainly high-K, calc-alkaline, Late Miocene to Pliocene volcanic rocks cropped out of the Konya area in Central Anatolia, Turkey. The volcanic rocks are predominantly andesitic to dacitic in composition and rarely basalt, basaltic andesite, basaltic trachyandesite and pyroclastics. Kaolinite, illite, Ca-montmorillonite, alunite, jarosite, minamiite and silica polymorphs were formed by widespread and intense hydrothermal alteration in or around the volcanic products. To investigate the effects of hydrothermal alteration on the chemistry of volcanic rocks, the whole rock chemical composition (major and trace elements, including rare-earth elements (REE) was analysed. The results of the study demonstrate notable differences in the REE behaviour in the different sample groups. REE trends of fresh parent rocks to weakly-, moderately-altered, kaolinitic and alunitic rocks are characterised by strong LREE enrichment ((La/Lu)_cn = 14.57, 11,8 to 15.20, 4.54 to 13.30, 12.5 to 24.2 and 34.6 to 47.26, respectively). Most of the samples have pronounced negative and/or weakly-negative Eu anomalies ranging from 0.75 to 0.98 while three samples have weakly-positive Eu anomalies. LRE element contents are higher than those of HREE in the samples. The LRE elements were strongly enriched in the kaolinitic and alunitic alteration; in weakly- and moderately-altered rocks. LREE are nearly immobile whereas HRE elements show different behaviour in different rock groups. The HFS and TRT elements are slightly mobilised in weakly-altered rocks, but enriched in other alteration types. Elements commonly assumed to be immobile (e.g. Y, Zr, Nb, Hf, TiO₂, Al₂O₃, REE) show variation in mass calculation. LIL elements showed enrichment over LREE and MREE, and similar behaviour, in contrast with HFSE. A clear increment of trans-transition elements (TRTE) was found mainly in alunitic and partly in kaolinitic samples.     

Geochemical and mineralogical characteristics of recent clastic sediments from lower Godavari river: Implications of source rock weathering

The major, trace and rare earth elements geochemistry and clay mineral compositions in the river bed sediments from lower reaches of Godavari river suggest that they are derived from weathering of felsic rocks. Trace and rare earth elemental compositions indicate evidence of sedimentary sorting during transportation and deposition. Lower concentrations of transition elements, such as V, Ni and Cr imply enrichment of felsic minerals in these bed sediments. The REE pattern in lower Godavari sediments is influenced by the degree of source rock weathering. The light rare earth elements (LREE) content are indicating greater fractionation compared to the heavy rare earth elements (HREE). A striking relationship is observed between TiO₂ and gZREE content suggesting a strong control by LREE-enriched titaniferous minerals on REE chemistry. Shale-normalized REE pattern demonstrate a positive Eu anomaly, suggesting weathering of feldspar and their secondary products, which are enriched in Eu. Chondrite-normalised REE pattern is characteristic of felsic volcanic, granites and gnessic source rocks. Trace elemental compositions in sediments located near urban areas suggest influence of anthropogenic activity. Chemical Index of Alteration (CIA) is high (avg. 65.76), suggesting a moderate chemical weathering environment. X-ray diffraction analysis of clay fraction shows predominance of clay minerals that are formed because of the chemical weathering of felsic rocks.     

赣南峰山离子型稀土矿床成矿机理探讨

以赣南大埠岩体西部峰山钻孔风化壳剖面为研究对象,在风化壳剖面各层地质特征研究的基础上,对风化壳剖面各层中含稀土矿物开展了扫描电镜和电子探针分析,探讨了风化壳剖面各层主、微量（包括稀土）元素和离子相稀土元素特征。研究表明,风化壳中稀土元素呈“弓背式”分布,矿体位于风化壳剖面2~9 m,w(REE)平均为516.8×10^-6,离子相稀土元素浸出率为51%~84%,离子相与全项稀土元素总量分布特征一致。风化壳中稀土元素主要以离子吸附态形式和独立矿物（次生方铈矿和风化残余的磷钇矿、褐钇铌矿）形式存在,以离子吸附态形式为主。峰山风化壳离子吸附型稀土矿为轻、重稀土元素共生型稀土矿,以重稀土元素占主导,矿体上部相对富集轻稀土元素,下部相对富集重稀土元素。风化壳剖面中稀土元素的富集分异主要受轻重稀土元素地球化学行为的差异性、风化程度和黏土矿物含量联合控制。