The mineral exploration industry requires new methods and tools to address the challenges of declining mineral reserves and increasing discovery costs. Laser-induced breakdown spectroscopy (LIBS) represents an emerging geochemical tool for mineral exploration that can provide rapid, in situ, compositional analysis and high-resolution imaging in both laboratory and field and settings. We demonstrate through a review of previously published research and our new results how LIBS can be applied to qualitative element detection for geochemical fingerprinting, sample classification, and discrimination, as well as quantitative geochemical analysis, rock characterization by grain size analysis, and in situ geochemical imaging. LIBS can detect elements with low atomic number (i.e., light elements), some of which are important pathfinder elements for mineral exploration and/or are classified as critical commodities for emerging green technologies. LIBS data can be acquired in situ, facilitating the interpretation of geochemical data in a mineralogical context, which is important for unraveling the complex geological history of most ore systems. LIBS technology is available as a handheld analyzer, thus providing a field capability to acquire low-cost geochemical analyses in real time. As a consequence, LIBS has wide potential to be utilized in mineral exploration, prospect evaluation, and deposit exploitation quality control. LIBS is ideally suited for field exploration programs that would benefit from rapid chemical analysis under ambient environmental conditions. Minerals 2019, 9, 718 2 of 45 government to search for additional mineral resources in green-field (i.e., remote) and brown-field (i.e., near mine) exploration environments [7][8][9]. However, the global trends of declining mineral reserves for many commodities and increasing discovery costs [3,4,10] suggest that exploration investment is insufficient and/or is not being deployed in the most effective manner possible. Both trends are also occurring at a time when new mineral deposit discoveries tend to be deeper, covered, and/or more remote, which are unlike near-surface mines that were often found, at least initially, by prospectors [4,[7][8][9]11].To address increasing demand and declining mineral reserves from deeper and more challenging deposits, the mineral exploration industry had to evolve and innovate by adopting new, cost-effective methodologies and technologies. For example, new conceptual models provide a predictive framework to identify the kinds of large-scale geological environments that should be considered the most prospective for finding additional mineral resources in greenfield areas of sparse geological data [12-15]. The ore system concept, which includes all of the geological processes required to transport and concentrate ore components from source to ore (i.e., drivers, sources, pathways, and traps), is one such predictive framework [12][13][14]16]. Because each of the required ore-forming components is manifested in the rock record as chan...

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(2013) 'Lithogeochemistry, geochronology and geodynamic setting of the Lupa Terrane, Tanzania :implications for the extent of the Archean Tanzanian Craton.', Precambrian research., 231 . pp. 174-193. Further information on publisher's website:http://dx.doi.org/10. 1016/j.precamres.2013.02.012 Publisher's copyright statement: NOTICE: this is the author's version of a work that was accepted for publication in Precambrian Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reected in this document. Changes may have been made to this work since it was submitted for publication. A denitive version was subsequently published in Precambrian Research, 231, July 2013, 10.1016/j.precamres.2013 Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Terrane was a continental margin during the Paleoproterozoic onto which the other Ubendian litho-25 tectonic terranes were accreted. Our model implies at least a 150 km SW extension of the currently 26 accepted position of the Tanzanian cratonic margin. U-Pb zircon ages constrain Ubendian tectono-27 magmatic models and provide new evidence to support the protracted nature of the 1.9-1.8 Ga 28Ubendian accretionary history. Lu-Hf zircon model ages provide evidence for ≥3

The gold endowment of the western Churchill Province is conventionally attributed to reworking and attendant metamorphism during the Trans-Hudson Orogeny (1.9-1.8 Ga). The Meliadine gold district is regarded as a type example of this inferred Paleoproterozoic gold metallotect and also represents one of Canada's largest emerging orogenic greenstone-and banded iron formation (BIF)-hosted gold districts (2.8 Moz contained Au in reserves and total resource of 5.8 Moz Au). The largest gold deposits are cospatial with the Pyke fault and associated quartz (± ankerite) veining, which cuts Neoarchean (ca. 2.66 Ga) plutonic and supracrustal rocks comprising the Rankin Inlet greenstone belt.Meliadine gold occurs as inclusions within idioblastic arsenopyrite crystals, at sulfide crystal boundaries, and/ or as sulfide fracture fills in hydrothermally altered, sulfidized, and veined BIF. Clusters of gold, Bi-Mo telluride, chalcopyrite, and galena inclusions characterize high-grade ore zones and are spatially associated with sieve-textured arsenopyrite domains. These microtextural relationships suggest that incipient sulfide recrystallization liberated gold, which, along with other precious and base metals, was redistributed during late, fluidassisted and deformation/metamorphic-driven remobilization. Late precious and base metal enrichment is also demonstrated by in situ laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) arsenopyrite mapping. Hydrothermal xenotime crystals occur with gold in low-strain microtextural sites and yield U-Pb ages at ca. 1.86 Ga, suggesting that remobilization was concomitant with Trans Hudson orogenesis.New Re-Os arsenopyrite model ages range from 2.3 to 1.8 Ga and document a hitherto unrecognized, pre-1.86 Ga hydrothermal activity. The range of Re-Os model ages tends to support partial open-system behavior and/or mixing of disparate arsenopyrite generations that are evident from microtextural observations and in situ LA-ICP-MS element mapping. Replicate analyses of the two most rhenium rich arsenopyrite samples yield reproducible Re-Os model ages at ca. 2.27 and 1.90 Ga. These rhenium-rich samples are also gold poor and likely yield ages that predate gold remobilization and subsequent enrichment along arsenopyrite crystal boundaries and fractures. We suggest that pre-1.86 Ga hydrothermal activity was likely critical to the gold endowment of the district, but is obscured by reworking during the later stages of the Trans-Hudson Orogeny at 1.86 Ga. If correct, these new ages imply that the Paleoproterozoic gold metallotect, which is recorded across the western Churchill Province, in fact comprises multiple, temporally distinct gold events. Differentiating between disparate Paleoproterozoic gold events represents a critical step for effective mineral exploration in the western Churchill Province and at other reworked Archean terranes.

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