Mineralium Deposita 

About: Mineralium Deposita is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Pyrite & Fluid inclusions. It has an ISSN identifier of 0026-4598. Over the lifetime, 3452 publications have been published receiving 91859 citations. The journal is also known as: Mineralium deposita (Print).

Major types and time–space distribution of Mesozoic ore deposits in South China and their geodynamic settings

Abstract: The ore deposits of the Mesozoic age in South China can be divided into three groups, each with different metal associations and spatial distributions and each related to major magmatic events. The first event occurred in the Late Triassic (230–210 Ma), the second in the Mid–Late Jurassic (170–150 Ma), and the third in the Early–Mid Cretaceous (120–80 Ma). The Late Triassic magmatic event and associated mineralization is characterized by peraluminous granite-related W–Sn–Nb–Ta mineral deposits. The Triassic ore deposits are considerably disturbed or overprinted by the later Jurassic and Cretaceous tectono-thermal episodes. The Mid–Late Jurassic magmatic and mineralization events consist of 170–160 Ma porphyry–skarn Cu and Pb–Zn–Ag vein deposits associated with I-type granites and 160–150 Ma metaluminous granite-related polymetallic W–Sn deposits. The Late Jurassic metaluminous granite-related W–Sn deposits occur in a NE-trending cluster in the interior of South China, such as in the Nanling area. In the Early–Mid Cretaceous, from about 120 to 80 Ma, but peaking at 100–90 Ma, subvolcanic-related Fe deposits developed and I-type calc-alkaline granitic intrusions formed porphyry Cu–Mo and porphyry-epithermal Cu–Au–Ag mineral systems, whereas S-type peraluminous and/or metaluminous granitic intrusions formed polymetallic Sn deposits. These Cretaceous mineral deposits cluster in distinct areas and are controlled by pull-apart basins along the South China continental margin. Based on mineral assemblage, age, and space–time distribution of these mineral systems, integrated with regional geological data and field observations, we suggest that the three magmatic–mineralization episodes are the result of distinct geodynamic regimes. The Triassic peraluminous granites and associated W–Sn–Nb–Ta mineralization formed during post-collisional processes involving the South China Block, the North China Craton, and the Indo-China Block, mostly along the Dabie-Sulu and Songma sutures. Jurassic events were initially related to the shallow oblique subduction of the Izanagi plate beneath the Eurasian continent at about 175 Ma, but I-type granitoids with porphyry Cu and vein-type Pb–Zn–Ag deposits only began to form as a result of the breakup of the subducted plate at 170–160 Ma, along the NNE-trending Qinzhou-Hangzhou belt (also referred to as Qin-Hang or Shi-Hang belt), which is the Neoproterozoic suture that amalgamates the Yangtze Craton and Cathaysia Block. A large subduction slab window is assumed to have formed in the Nanling and adjacent areas in the interior of South China, triggering the uprise of asthenospheric mantle into the upper crust and leading to the emplacement of metaluminous granitic magma and associated polymetallic W–Sn mineralization. A relatively tectonically quiet period followed between 150 and 135 Ma in South China. From 135 Ma onward, the angle of convergence of the Izanagi plate changed from oblique to parallel to the coastline, resulting in continental extensional tectonics and reactivation of regional-scale NE-trending faults, such as the Tan-Lu fault. This widespread extension also promoted the development of NE-trending pull-apart basins and metamorphic core complexes, accompanied by volcanism and the formation of epithermal Cu–Au deposits, granite-related polymetallic Sn–(W) deposits and hydrothermal U deposits between 120 and 80 Ma (with a peak activity at 100–90 Ma).

Discriminant diagrams for iron oxide trace element fingerprinting of mineral deposit types

Abstract: Magnetite and hematite are common minerals in a range of mineral deposit types. These minerals form partial to complete solid solutions with magnetite, chromite, and spinel series, and ulvospinel as a result of divalent, trivalent, and tetravalent cation substitutions. Electron microprobe analyses of minor and trace elements in magnetite and hematite from a range of mineral deposit types (iron oxide-copper-gold (IOCG), Kiruna apatite–magnetite, banded iron formation (BIF), porphyry Cu, Fe-Cu skarn, Fe-Ti, V, Cr, Ni-Cu-PGE, Cu-Zn-Pb volcanogenic massive sulfide (VMS) and Archean Au-Cu porphyry and Opemiska Cu veins) show compositional differences that can be related to deposit types, and are used to construct discriminant diagrams that separate different styles of mineralization. The Ni + Cr vs. Si + Mg diagram can be used to isolate Ni-Cu-PGE, and Cr deposits from other deposit types. Similarly, the Al/(Zn + Ca) vs. Cu/(Si + Ca) diagram can be used to separate Cu-Zn-Pb VMS deposits from other deposit types. Samples plotting outside the Ni-Cu-PGE and Cu-Zn-Pb VMS fields are discriminated using the Ni/(Cr + Mn) vs. Ti + V or Ca + Al + Mn vs. Ti + V diagrams that discriminate for IOCG, Kiruna, porphyry Cu, BIF, skarn, Fe-Ti, and V deposits.

In situ U-Pb zircon dating using laser ablation-multi ion counting-ICP-MS

Abstract: High resolution in situ U-Pb zircon geochronology on zoned grains can obtain isotope signatures from multiple growth or thermal events.We present a method using laser ablation-multicollector-inductively coupled plasma-mass spectrometry(LA-MC-ICP-MS) to overcome complications associated with intricately zoned zircon crystals through in situ sampling of zircon volumes as small as 12 μm,25 μm and 40 μm in diameter by about 10 μm in depth.High precision U-Pb age of a series of zircon standard covering a wide age range of 30 to 1 065 Ma was acquired using LA-MC-ICP-MS.The precision of measured Pb/U ratios in homogeneous zircon is about 2%(2σ),resulting in routinely achieved precision of U-Pb ages obtained by external calibration of～1%(2σ) or better.All masses of interest can be simultaneously recorded with a multi-ion counting system(MIC) operating in static mode,and the short ablation required to achieve such precision results in spatial resolution that is superior to comparable U-Pb zircon analyses by single collector ICP-MS.The resulting present U-Pb age for five zircon reference samples and two geological samples show an excellent agreement with the previously reported ID-TIMS or SHRIMP data.

Intrusion-related gold systems: the present level of understanding

Abstract: This volume presents new data on a group of gold deposits that are hosted primarily within or in the immediate wall rocks to intrusions, and which have recently been suggested to comprise a distinct class of magmatic-hydrothermal system. These deposits have been called 'porphyry gold deposits' (Hollister 1992; Bakke 1995), 'intrusion-related stockwork-disseminated deposits' (Sillitoe 1991), 'plutonic-related gold deposits' (Newberry et al., 1988; McCoy et al., 1997) and 'intrusion-related gold deposits' (Thompson et al. 1999). Lang et al. (2000) preferred the term 'intrusion-related gold systems' because it reflects a tendency common to all magmatic-hydrothermal environments to form ores that manifest multiple styles, metal assemblages and spatial associations with their related intrusive centres. Although in its infancy, investigation and exploration of intrusion-related gold systems has accelerated markedly in the last five years, due in part to their global distribution and to the large number of deposits that contain a gold resource of >30 metric tons (Fig. 1). Major deposit examples include Fort Knox (~210 t Au), Donlin Creek (~315 t Au), Pogo (~160 t Au), and Dublin Gulch, True North and Brewery Creek (~40 t Au each) in Yukon and Alaska, as well as Mokrsko, Czech Republic (~120 t Au), Vasilkovskoe, Kazakstan (~300 t Au), Salave, Spain (~30 t Au), Korri Kollo, Bolivia (~160 t Au) and Kidston, Australia (~140 t Au). A paucity of detailed descriptions of individual intrusion-related gold systems, the plutonic provinces that host these systems, and the genetic processes critical to their formation currently limits our ability to either develop precise criteria for their definition or to formulate well-constrained geological and exploration models. The principal discussions (Sillitoe 1991; Hollister 1992; Newberry et al. 1988 and 1995; Lang et al. 1997; McCoy et al. 1997; Thompson et al. 1999; Lang et al. 2000; Goldfarb et al. 2000; Newberry 2000) suggest that there are several features common to most intrusion-related gold deposits and provinces, including: 1) metaluminous, subalkalic intrusions of intermediate to felsic composition that span the boundary between ilmenite- and magnetite-series, 2) carbonic hydrothermal fluids, 3) a metal assemblage which variably combines Au with elevated Bi, W, As, Mo, Te and/or Sb and low concentrations of base metals, 4) a low sulphide content (<5 volume %) with a reduced ore mineral assemblage that typically comprises arsenopyrite, pyrrhotite and pyrite, and which lacks magnetite or hematite, 5) areally restricted, commonly weak hydrothermal alteration, except in systems formed at the shallowest depths spanned by these deposits, 6) a tectonic setting of continental magmatism well-inboard of inferred or recognized convergent plate boundaries, and which commonly contains coeval intrusions of alkalic, metaluminous calc-alkalic and peraluminous compositions, and 7) a location in magmatic provinces best or formerly known for W and/or Sn deposits. Deposits that can be confidently included in the group formed during much of the Phanerozoic, but inclusion of some Proterozoic and even Archean deposits has also been proposed (e.g., Robert, this volume). The defining criteria as presently recognized show that intrusion-related gold systems and their associated plutonic provinces are globally widespread (Fig. 1), but adequate descriptions of the contained deposits are only now beginning to emerge. The Tintina Gold Belt of Alaska and the Yukon Territory in the northern part of the North American Cordillera (Fig. 1) is thus far the most extensively studied intrusion-related gold systems province. This belt is ~1000 km in length and contains gold deposits of Early Cretaceous to Eocene age (McCoy et al. 1997; Newberry et al. 1995; Lang et al. 2000; Goldfarb et al. 2000) that, as a group, span much of the globally recognized variation among these systems. As such, the Tintina Gold Belt is currently the primary standard against which deposits in other provinces can be compared, and is therefore emphasized in this introduction. This paper briefly considers the status of our knowledge of intrusion-related gold systems, and is intended only as an introduction to the major characteristics of these deposits rather than a comprehensive description. The discussion emphasizes the nature of the associated igneous rocks and their tectono-magmatic setting, the styles of deposits and their spatial distribution, the characteristics and evolution of hydrothermal fluids, and structural controls. It concurrently highlights some of the important gaps in our understanding of these systems that will be fruitful areas of investigation in ongoing and future research programs. The paper concludes with comments on deposit classification and the relationship of intrusion-related gold systems to other types of magmatic-hydrothermal systems.

The crustal continuum model for late-Archaean lode-gold deposits of the Yilgarn Block, Western Australia

Abstract: Most Archaean gold ores belong to a coherent genetic group of structurally controlled lode-deposits that are characteristically enriched in Au with variable enrichments in Ag, As, W, Sb, Bi, Te, B and Pb, but rarely Cu or Zn, and are surrounded by wallrock alteration haloes enriched in K, LILE and CO2, with variable Na and/or Ca addition. Evidence from the Yilgarn Block of Western Australia, combined with similar evidence from Canada and elsewhere, indicates that such deposits represent a crustal continuum that formed under a variety of crustal regimes over at least a 15 km crustal profile at PT conditions ranging from 180°C at <1 kb to 700°C at 5 kb. Individual deposits, separated by tens to hundreds of kilometres, collectively show transitional variations in structural style of mineralisation, vein textures, and mineralogy of wallrock alteration that relate to the PT conditions of their formation at varying crustal depths. Specific transitions within the total spectrum may be shown also by deposits within gold camps, although nowhere is the entire continuum of deposits recorded from a single gold camp or even greenstone belt. Recognition of the crustal continuum of deposits implicates the existence of giant late-Archaean hydrothermal systems with a deep source for the primary ore fluid. A number of deep fluid and solute reservoirs are possible, including the basal segments of greenstone belts, deep-level intrusive granitoids, mid-to lower-crustal granitoidgneisses, mantle lithosphere, or even subducted oceanic lithosphere, given the probable convergent-margin setting of the host greenstone terranes. Individual stable and radiogenic isotope ratios of fluid and solute components implicate fluid evolution from, or equilibrium with, a number of these reservoirs, stressing the potential complexity of pathways for fluid advection to depositional sites. Lead and strontium isotope ratios of ore-associated minerals provide the most persuasive evidence for fluid advection through deep-level intrusive granitoids or granitoid-gneiss crust, whereas preliminary oxygen isotope data show that mixing of deeply sourced fluid and surface waters only occurred at the highest crustal levels recorded by the lode gold deposits.