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Geochemistry of intermediate to siliceous volcanic rocks of the Rooiberg Group, Bushveld Magmatic Province, South Africa 总被引：1，自引：1，他引：1
P. Buchanan W. Reimold C. Koeberl F. Kruger 《Contributions to Mineralogy and Petrology》2002,144(2):131-143
The volcanic Rooiberg Group represents the earliest phase of Bushveld-related magmatism and comprises, in some areas, the floor and roof rocks of the mafic-ultramafic intrusive units of the Bushveld Complex. The lower to middle Dullstroom Formation is composed of two interbedded series of low Ti and high Ti volcanic strata, which are predominantly basaltic andesites. Volcanic units above these strata range from andesites to dacites in the upper Dullstroom Formation and to predominantly rhyolites in the overlying Damwal and Kwaggasnek Formations. Compositional data suggest that these intermediate to siliceous volcanic rocks are petrogenetically related to the low Ti volcanic suite and suggest that the low Ti magmas resided in a shallow magma chamber where they experienced fractional crystallization and assimilation of crustal material. In contrast, the high Ti volcanic suite is petrogenetically unrelated. These data confirm previous suggestions that Bushveld-related magmas experienced significant amounts of assimilation of continental crust. 相似文献
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Alvaro Nivia Giselle F. Marriner Andrew C. Kerr John Tarney 《Journal of South American Earth Sciences》2006,21(4):423
The Quebradagrande Complex of Western Colombia consists of volcanic and Albian–Aptian sedimentary rocks of oceanic affinity and outcrops in a highly deformed zone where spatial relationships are difficult to unravel. Berriasian–Aptian sediments that display continental to shallow marine sedimentary facies and mafic and ultramafic plutonic rocks are associated with the Quebradagrande Complex. Geochemically, the basalts and andesites of the Quebradagrande Complex mostly display calc-alkaline affinities, are enriched in large-ion lithophile elements relative to high field strength elements, and thus are typical of volcanic rocks generated in supra-subduction zone mantle wedges. The Quebradagrande Complex parallels the western margin of the Colombian Andes’ Central Cordillera, forming a narrow, discontinuous strip fault-bounded on both sides by metamorphic rocks. The age of the metamorphic rocks east of the Quebradagrande Complex is well established as Neoproterozoic. However, the age of the metamorphics to the west – the Arquía Complex – is poorly constrained; they may have formed during either the Neoproterozoic or Lower Cretaceous. A Neoproterozoic age for the Arquía Complex is favored by both its close proximity to sedimentary rocks mapped as Paleozoic and its intrusion by Triassic plutons. Thus, the Quebradagrande Complex could represent an intracratonic marginal basin produced by spreading-subsidence, where the progressive thinning of the lithosphere generated gradually deeper sedimentary environments, eventually resulting in the generation of oceanic crust. This phenomenon was common in the Peruvian and Chilean Andes during the Uppermost Jurassic and Lower Cretaceous. The marginal basin was trapped during the collision of the Caribbean–Colombian Cretaceous oceanic plateau, which accreted west of the Arquía Complex in the Early Eocene. Differences in the geochemical characteristics of basalts of the oceanic plateau and those of the Quebradagrande Complex indicate these units were generated in very different tectonic settings. 相似文献
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西藏羌塘地区印支期火山岩主要分布在盆地北缘若拉岗日和羌塘中央隆起南缘肖茶卡—香琼火山岩地区。主要元素和稀土元素地球化学特征分析表明 ,若拉岗日区火山岩属富钠型的碱性系列玄武岩 ,肖茶卡—香琼火山岩为拉斑玄武岩。两区岩石系列和构造发育部位虽不同 ,却都是在海西期末闭合的裂陷带上再扩张过程中形成的 ,反映盆地北部和中央隆起处的两条板块缝合带有相似的演化特点。 相似文献
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New data on the chemical and rare-element composition and age of the rocks referred earlier to the Iruney suite of the Kamchatka Isthmus are received. In the recent structure these rocks compose the structural–strata complexes of the nappe-folded Lesnovsky Rise. Radiolarian analysis data substantiate that the deposits belonging to the Ening series and the middle and upper parts of the Iruney suite were formed in a single sedimentation basin in the Campanian time. The discovery of a new occurrence of Prunobrachidae representatives on the Kamchatka Peninsula allows us to draw wide interregional correlations and reconstruct the sedimentation conditions. The studied volcanites relate to different igneous series and were formed in geodynamic conditions of the marginal sea and the volcanic arc. The igneous rocks of the Ening stratum are similar to the N-MOR and OI basalts that were formed within the marginal sea (Iruney Marginal Sea) basin. The Upper Cretaceous formations of the eastern slope of the Sredinny Range were formed within the volcanic rise with the island-arc type of volcanism. The younger Eocene igneous rocks of the neo-autochthon (granites and granodiorites) and the volcanic rocks of the Kinkil suite mark a new orogenic stage of development of the Kamchatka margin. 相似文献
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乡城弧间盆地在晚三叠世时受甘孜理塘洋由拉张到汇聚和金沙江洋由汇聚到碰撞的影响,先后堆积了由拉张沉降到汇聚抬升的火山岩系列组合,同时伴随着来自再旋回造山带物源区的复理石沉积。在上三叠统图姆沟组上部的中酸性火山岩中发现具呷村式大型矿床的成矿地质背景,是寻找呷村式大型矿床的重点靶区。 相似文献
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《International Geology Review》2012,54(14):1684-1708
Volcanic rocks that make up Faial Island, Central Azores, consist of four volcano-stratigraphic units, with ages between 730 ka and the present. Lavas range from alkali basalts to trachyandesites and belong to the alkaline-sodic series. The oldest unit is the Ribeirinha Volcanic Complex, generally characterized by low MgO contents. The Cedros Volcanic Complex is composed of basalts to benmoreites with low MgO contents. The Almoxarife Formation represents fissure flows, containing MgO contents similar to to slightly higher than those of the underlying Cedros Volcanic Complex. The youngest unit, the Capelo Formation, consists of mafic rocks with MgO values higher than those of the other units. Bulk-rock major and trace element trends suggest that differentiation of the three earliest units were dominated by fractional crystallization of plagioclase ± clinopyroxene ± olivine ± titanomagnetite. Capelo bulk-rock compositions are the most primitive, and are related to a period when volcanic activity was fed by deep magmatic chambers, and melts ascended more rapidly. Comparison among geochemical patterns of the trace elements suggests a strong similarity between the lavas from Faial and Pico islands. Corvo Island volcanism contrasts with the geochemistry of Faial and Pico lavas, reflecting its strong K and Rb depletion, and Th, U, Ta, Nb, La, and Ce enrichment. Absence of the Daly gap in the Faial volcanics is attributed to early crystallization of Ti-Fe oxides. The probable source of the Faial magma coincides with the MORB-FOZO array, which implies the presence of ancient recycled oceanic crust in the mantle source. Ratios of incompatible trace elements suggest the similarity of Corvo volcanic rocks with magmas derived from HIMU sources, whereas the Faial and Pico volcanic rocks could have been produced from sources very close to EMII-type OIB. 相似文献
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Evolution of the early devonian bindook volcanic complex,wollondilly basin,eastern lachlan fold belt
The Early Devonian Bindook Volcanic Complex consists of a thick silicic volcanic and associated sedimentary succession filling the extensional Wollondilly Basin in the northeastern Lachlan Fold Belt. The basal part of the succession (Tangerang Formation) is exposed in the central and southeastern Wollondilly Basin where it unconformably overlies Ordovician rocks or conformably overlies the Late Silurian to Early Devonian Bungonia Limestone. Six volcanic members, including three new members, are now recognised in the Tangerang Formation and three major facies have been delineated in the associated sedimentary sequence. The oldest part of the sequence near Windellama consists of a quartz turbidite facies deposited at moderate water depths together with the shallow‐marine shelf Windellama Limestone and Brooklyn Conglomerate Members deposited close to the eastern margin of the basin. Farther north the shelf facies consists of marine shale and sandstone which become progressively more tuffaceous northwards towards Marulan. The Devils Pulpit Member (new unit) is a shallow‐marine volcaniclastic unit marking the first major volcanic eruptions in the region. The overlying shallow‐marine sedimentary facies is tuffaceous in the north, contains a central Ordovician‐derived quartzose (?deltaic) facies and a predominantly mixed facies farther south. The initial volcanism occurred in an undefined area north of Marulan. A period of non‐marine exposure, erosion and later deposition of quartzose rocks marked a considerable break in volcanic activity. Volcanism recommenced with the widespread emplacement of the Kerillon Tuff Member (new unit), a thick, non‐welded rhyolitic ignimbrite followed by dacitic welded ignimbrite and air‐fall tuff produced by a large magnitude eruption leading to caldera collapse in the central part of the Bindook Volcanic Complex, together with an additional small eruptive centre near Lumley Park. The overlying Kerrawarra Dacite Member (new unit) is lava‐like in character but it also has the dimensions of an ignimbrite and covers a large part of the central Bindook Volcanic Complex. The Carne Dacite Member is interpreted as a series of subvolcanic intrusions including laccoliths, cryptodomes and sills. The Tangerang Formation is overlain by the extensive crystal‐rich Joaramin Ignimbrite (new unit) that was erupted from an undefined centre in the central or northern Bindook Volcanic Complex. The volcanic units at Wombeyan and the Kowmung Volcaniclastics in the northwestern part of the complex are probably lateral time‐equivalents of the Tangerang Formation and Joaramin Ignimbrite. All three successions pre‐date the major subaerial volcanic plateau‐forming eruptions represented by the Barrallier Ignimbrite (new unit). The latter post‐dated folding and an extensive erosional phase, and unconformably overlies many of the older units in the Bindook Volcanic Complex. This ignimbrite was probably erupted from a large caldera in the northern part of the complex and probably represents surface expressions of part of the intruding Marulan Batholith. The final volcanic episode is represented by the volcanic units at Yerranderie which formed around a crater at the northern end of the exposed Bindook Volcanic Complex. 相似文献
9.
塔里木盆地二叠系划分对比与火山岩分布 总被引：3，自引：1，他引：2
根据全盆地钻井与露头剖面对比和地震剖面追踪解释,探讨了塔里木盆地覆盖区二叠系岩石地层的划分对比。二叠系自下而上由一个自然伽玛曲线加积段、三个自然伽玛曲线退积段组成,加积段为南闸组、退积段分别为库普库兹曼组、开派雷兹克组和沙井子组。南闸组是塔里木盆地最后一次海侵形成的滨浅海灰岩泥岩薄互层为主的沉积。库普库兹曼组和开派雷兹克组是两个基性火山岩-酸性火山岩的旋回或基性火山岩-砂泥岩的旋回。沙井子组是一个与区域构造运动有关的冲积扇、辫状河-曲流河沉积的异旋回。二叠系火山岩在和田河、塔中西部和顺托果勒地区厚度较大,库普库兹曼组火山岩一般0~60m,开派雷兹克组火山岩一般0~200m,局部可超过400m。与库普库兹满组火山岩相比,开派雷兹克组火山岩分布范围由塔西南朝塔东北方向有所迁移。中西部的库普库兹曼组火山岩可能喷发于水下。火山通道多沿着古隆起上的断背斜、断鼻构造分布。火山岩可形成油气藏遮挡,或本身形成储层,但火山活动改造或不同程度地破坏了早期已有油气藏。 相似文献
10.
Zircon U-Pb and muscovite 40Ar/39Ar isotopic ages have been determined on rocks from the southernmost Andes and South Georgia Island, North Scotia Ridge, to provide absolute time constraints on the kinematic evolution of southwestern Gondwanaland, until now known mainly from stratigraphic relations. The U-Pb systematics of four zircon fractions from one sample show that proto-marginal basin magmatism in the northern Scotia arc, creating the peraluminous Darwin granite suite and submarine rhyolite sequences of the Tobifera Formation, had begun by the Middle Jurassic (164.1 ± 1.7 Ma). Seven zircon fractions from two other Darwin granites are discordant with non-linear patterns, suggesting a complex history of inheritances and Pb loss. Reference lines drawn through these points on concordia diagrams give upper intercept ages of ca. 1500 Ma, interpreted as a minimum age for the inherited zircon component. This component is believed to have been derived from sedimentary rocks in the Gondwanaland margin accretionary wedge that forms the basement of the region, or else directly from the cratonic “back stop” of that wedge.Ophiolitic remnants of the Rocas Verdes marginal basin preserved in the Larsen Harbour complex on South Georgia yield the first clear evidence that Gondwanaland fragmentation had resulted in the formation of oceanic crust in the Weddell Sea region by the Late Jurassic (150 ± 1 Ma). The geographic pattern in the observed age range of 8 to 13 million years in these ophiolitic materials, while not definitive, is in keeping with propagation of the marginal basin floor northwestward from South Georgia Island to the Sarmiento Complex in southern Chile.Rocks of the Beagle granite suite, emplaced post-tectonically within the uplifted marginal basin floor, have complex zircon U-Pb systematics with gross discordances dominated by inheritances in some samples and Pb loss in others. Of eleven samples processed, only two had sufficient amounts of zircon for multiple fractions, and only one yielded colinear points. These points lie close to the lower concordia intercept for which the age is 68.9 ± 1.0 Ma, but their upper intercept is not well known. Inasmuch as this age is similar to the 40Ar/39Ar age of secondary muscovite growing in extensional fractures of pulled-apart feldspar phenocrysts in a Beagle suite granitic pluton (plateau age is 68.1 ± 0.4 Ma), we interpret the two dates as good time constraints for cooling following a period of extensional deformation probably related to the tectonic denudation of the highgrade metamorphic complex of Cordillera Darwin in Tierra del Fuego. 相似文献
11.
庐山地区新元古代海相火山活动及岩石特征 总被引：1，自引：0，他引：1
庐山南麓发育一套变细碧－石英角斑岩系火山岩,岩性组合从早到晚反映了由基性到酸性的岩浆演化规律。火山活动具有由喷发相（喷溢亚相）→喷发－沉积相的特点,构成了具有韵律性的火山喷发特征。经同位素年代研究属晋宁期火山喷发产物,时代归属为新元古代早期。 相似文献
12.
准噶尔盆地石炭纪火山岩岩石地球化学特征及其构造环境意义 总被引：8，自引：0，他引：8
准噶尔盆地石炭纪发育区域性的火山岩建造,火山岩岩性以中基性为主,主要为玄武岩、玄武安山岩,同时发育少量酸性的流纹岩,基本属于钙碱性系列。样品全碱(Na_2O+K_2O=2.99%～8.07%)和TiO_2(0.30%～2.57%)含量较高,K_2O含量(0.13%～3.29%)较低,稀土元素含量(∑REE)中等。球粒标准化的REE配分表现轻稀土元素(LREE)相对于重稀土元素(HREE)富集((La/Yb)_N=2.47～7.45)、轻重稀土分异的特征,部分样品的Eu和大部分样品的Ce显示轻微的负异常(δEu=0.543～1.088,δCe=0.787～0.987)。微量元素具有大离子亲石元素(LILE)富集及高场强元素Nb、Ta亏损的特征,大部分样品(Rb/Yb)_N均远大于1。这些特征结合元素相关环境判别图解表明,准噶尔盆地石炭纪火山岩是原始岩浆经历了一定程度分异作用后的产物,以板内大陆环境为主,兼具有部分岛弧特征,形成于俯冲碰撞造山期后伸展背景下,火山岩所具有的岛弧特征是碰撞前混染弧组分的继承。 相似文献
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V. M. Grannik 《Doklady Earth Sciences》2016,470(2):1019-1022
It has been determined that the Rozhdestvenka Formation of the West Sakhalin Terrane composed of Late Mesozoic igneous rocks is a fragment of the accretionary prism of the Rebun–Kabato–Moneron–Samarga island-arc system. Volcanic eruptions, as well as destruction of the Rebun–Kabato–Moneron–Samarga island-arc and the East Sikhote-Alin volcano plutonic marginal continental belt, were the sources of pyroclastic and clastic material entering the sedimentary basin, where the Pobedinsk and Krasnoyarka suites of the West Sakhalin Terrane were formed. 相似文献
14.
The Guarguardz Complex, basement of the Cordillera Frontal, included in the proposed Chilenia Terrane, consists of metasedimentary rocks deposited in clastic and carbonatic platforms. Turbiditic sequences point out to slope or external platform environments. According to geochemical data, the sedimentary protoliths derived through erosion of a mature cratonic continental basement. Volcanic and subvolcanic rocks with N and E-MORB signature were interbeded in the metasedimentary rocks during basin development. A compressional stage, starting with progressive deformation and metamorphism, followed this extensional stage. Continuing deformation led to the emplacement of slices of oceanic crust, conforming an accretionary prism during Late Devonian. The Guarguardz Complex and equivalent units in western Precordillera and also in the Chilean Coastal Cordillera share common evolutional stages, widely represented along the western Gondwana margin. These evidences imply that Chilenia is not an allochthonous terrane to Gondwana, but a portion of its Early Paleozoic margin. Regional configuration indicates that the Guarguardz Complex and equivalent units represent the accretionary prism of the Famatinian arc (Middle Ordovician-Late Devonian). 相似文献
15.
青藏高原东部贡觉盆地新生代火山岩特征及其构造意义 总被引：5，自引：0，他引：5
藏东贡觉盆地古近纪火山岩形成于印度-欧亚板块碰撞造山后的伸展环境中,火山活动受水平剪切-走滑断裂带控制。火山岩以高Si O2、Al2O3、K2O、Na2O和低MgO、Ti O2为特征,属高钾钙碱性中酸性火山岩。火山岩中富集大离子亲石元素(LILE)、轻稀土元素(LREE),亏损高场强元素(HFSE)和一部分相容元素(Co、Ni、V、Sc);无Eu异常但有弱的Ce负异常。火山岩源区可能是经历了壳源混合作用的富集交代地幔。富集组分来自壳源,它们沿古俯冲带以再循环方式进入地幔楔,并与地幔发生交代作用。 相似文献
16.
M. Suárez A. Demant R. De La Cruz C.M. Fanning 《Journal of South American Earth Sciences》2010,29(3):731-737
Surtseyan tuff cones of the Baño Nuevo Volcanic Complex erupted in shallow marine water during the waning stage of the Aisén Basin, the northern part of the Austral Basin of the Central Patagonian Cordillera. This volcanic complex was emplaced within the Hauterivian to early Aptian Apeleg Formation, the youngest sedimentary unit of this basin, whilst the sediments were still wet. Three new Ar/Ar dates (amphibole) and one U–Pb SHRIMP date (zircon) from this complex yielded concordant early Aptian ages of 122–121 Ma. These data agree with the contact relationships between the Apeleg Formation and the tuff cones. These dates also agree with those of early Aptian ammonites collected from the Apeleg Formation 100 km south of the study area, which represent the youngest fossils identified in this unit. Aptian to Albian subaerial volcanic rocks of the Divisadero Group, paraconformably overlie the Apeleg Formation. The emplacement of the Baño Nuevo Volcanic Complex pre-dates the disappearance of the Aisén Basin. 相似文献
17.
Uwe Hoffmann Christoph Breitkreuz Karel Breiter Sergey Sergeev Klaus Stanek Marion Tichomirowa 《International Journal of Earth Sciences》2013,102(1):73-99
Nine SHRIMP U/Pb ages on zircon and two Pb/Pb single zircon ages have been determined from Late Paleozoic volcanic rocks from Saxony and northern Bohemia. Samples came from the Teplice-Altenberg Volcanic Complex, the Meissen Volcanic Complex, the Chemnitz Basin, the Döhlen Basin, the Brandov-Olbernhau Basin, and the North Saxon Volcanic Complex. The Teplice-Altenberg Volcanic Complex is subdivided into an early Namurian phase (Mikulov Ignimbrite, 326.8 ± 4.3 Ma), thus older than assumed by previous studies, and a late caldera-forming phase (Teplice Ignimbrite, 308.8 ± 4.9 Ma). The age of the latter, however, is not well constrained due to a large population of inherited zircon and possible hydrothermal overprint. The Leutewitz Ignimbrite, product of an early explosive volcanic episode of the Meissen Volcanic Complex yielded an age of 302.9 ± 2.5 Ma (Stephanian A). Volcanic rocks intercalated in the Brandov-Olbernhau Basin (BOB, 302 ± 2.8 Ma), Chemnitz Basin (CB, 296.6 ± 3.0 Ma), Döhlen Basin (DB, 296 ± 3.0 Ma), and the North Saxon Volcanic Complex (NSVC, c. 300–290 Ma) yielded well-constrained Stephanian to Sakmarian ages. The largest Late Paleozoic ignimbrite-forming eruption in Central Europe, the Rochlitz Ignimbrite, has a well-defined middle Asselian age of 294.4 ± 1.8 Ma. Ages of palingenic zircon revealed that the Namurian-Westphalian magmatism assimilated larger amounts of crystalline basement that formed during previous Paleozoic geodynamic phases. The Precambrian inherited ages support the chronostratigraphic structure assumed for the Saxo-Thuringian Zone of the Variscan Orogen. The present results help to improve the chronostratigraphic allocation of the Late Paleozoic volcanic zones in Central Europe. At the same time, the radiometric ages have implications for the interbasinal correlation and for the geodynamic evolution of the Variscan Orogeny. 相似文献
18.
松辽盆地含CO_2火山岩气藏的形成和分布 总被引：2，自引：0，他引：2
松辽盆地特有的深部构造背景和裂谷演化特征,造成盆地内含CO_2火山岩气藏的形成和富集。松辽裂谷盆地中新生代火山岩浆活动发育,总体上具有多期喷发、分布广泛和储集条件良好的特点。火山活动以中心式喷发为主,主要发育中基性-酸性火山岩,发育流纹岩、凝灰岩等多种岩石类型,爆发相和溢流相2种火山岩相。中生代火山岩在盆地内分布广泛,营域组构成深层有利储层,新生代火山岩在盆地外围出露较多,而在盆内出露较少。盆地高含量的二氧化碳为无机幔源成因,由青山口期和新生代幔源岩浆脱气形成。含CO_2火山岩气藏的形成主要受深部构造背景、深大断裂和中新生代火山岩控制。已发现含CO_2火山岩气藏主要分布于古中央隆起带及其两侧断陷的营城组火山岩中,具有点状、带状分布,局部富集的特点。根据主控因素分析,预测了5个CO_2富集区带。 相似文献
19.
准噶尔盆地的类型和构造演化 总被引：35，自引：1，他引：34
准噶尔盆地的早二叠世属于裂谷还是前陆盆地 ,存在意见分歧 ;晚二叠世—老第三纪盆地的性质也不确定。文中通过对盆地构造几何学、沉降史、热史及火山岩的综合分析研究 ,对盆地类型和构造演化获得了一些新的认识 :( 1)准噶尔盆地在早二叠世为裂谷 ,晚二叠世为热冷却伸展坳陷 ,三叠纪—老第三纪为克拉通内盆地 ,新第三纪至今 ,由于印度板块与亚洲大陆碰撞才形成陆内前陆盆地。 ( 2 )对石炭纪—早二叠世的岩浆活动结合区域构造资料的研究表明 ,准噶尔地区古生代的板块运动和造山作用具软碰撞特点 ,早二叠世的裂谷盆地是在软碰撞背景下造山带伸展塌陷的产物。 ( 3)地幔热对流作用可能是软碰撞造山后伸展塌陷的主要深部动力学机制。 相似文献
20.
Phillip L. Blevin 《Mineralium Deposita》2002,37(1):87-99
Mineralised igneous complexes of Ordovician age from New South Wales range in composition from quartz-rich medium-K dacites (e.g. Copper Hill), to quartz-poor, high-K to 'shoshonitic' monzodioritic to monzonitic complexes (Goonumbla and Cadia). Despite Ordovician igneous suites being considered mostly 'shoshonitic' by some authors, only the Cadia Igneous Complex is potassic in the sense of having molecular K/Na greater than unity. A feature of the intrusive complexes is that each is spatially associated with volcanic rocks of similar compositional character, and that these relationships may occur over long periods of time within local regions (e.g. Goonumbla Volcanic Complex), or show progressive compositional evolution over probably shorter time periods as in the case of the Cadia District. The igneous suites are variably enriched in K and LILE elements, with uniformly high K/Rb ratios, low mantle-compatible element abundances and marked depletions in Ti, Nb and Ta, which is consistent with a subduction-related tectonic setting. Patterns of enrichment and depletion between each suite are similar, and are consistent with the magmas having been derived from sources variably enriched by slab derived materials prior to fusion. Recent dating results from the Goonumbla Volcanic Complex suggest that this enrichment was not progressive over time, and that the oldest intrusions in the Ordovician are not necessarily the least compositionally evolved. These results confirm the overall 'calc-alkaline' nature of Ordovician magmatism and do not support models that argue against contemporaneous subduction on the grounds that Ordovician magmatism was almost exclusively shoshonitic in character. Economic size and significance of associated deposits increase with the degree of K-enrichment (but not total alkali contents) observed in the associated igneous complexes, and supports conceptual models that link mineralisation potential and fertility with processes related to the production of K-enriched protoliths. 相似文献