Elemental Scientific Lasers’ Scientific Publications

Silicified fossil shells are well known for their exquisite preservation of morphological features; but because they have undergone such diagenetic process, they have generally not been used for geochemical proxy-based palaeoenvironmental and palaeoclimate reconstructions. However, silicification is a variable and often incomplete process that frequently results in portions of fossil shells being preserved with morphologically pristine microstructures. Here, we assess the potential of such partially silicified brachiopod shells to preserve structurally and chemically pristine calcite fabrics. We combine petrographical analyses, scanning electron microscopy (SEM), cathodoluminescence (CL), energy dispersive spectroscopy (EDS), Raman spectros...

The Northern Highlands Terrane in northwestern Scotland preserves a polyphase metamorphic history dominated by Scandian (435-415 Ma) tectonism. Phase equilibria modeling, major and trace element compositions in metamorphic phases, and textural observations are used to construct a detailed pressure-temperature-time path for a garnet-staurolite-kyanite-mica schist from the Moine nappe. We employ a statistical method to evaluate the best-fit pressure-temperature conditions based on measured and modeled garnet compositions. This method yields a straightforward multistage P-T path and eliminates some of the ambiguity inherent in comparing thermodynamic models with measured phase compositions. Trace elements in garnet, ilmenite, and rutile, and t...

A key challenge in phosphorite geochemistry is distinguishing primary seawater-derived rare earth element (REE) signatures from redox-controlled enrichment during phosphogenesis and early diagenesis. Previous bulk-rock studies of the Pabdeh Formation phosphorites identified carbonate-rich fluorapatite (CFA) as the principal REEs host, but could not resolve mineral-scale variability. To address this gap, in situ laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) micro-analysis was applied to CFA grains from the Paleocene-Eocene Pabdeh Formation (Fm) (Khormuj Anticline, SW Iran) to resolve the enrichment histories of REEs and U. CFA grains preserve a seawater-derived signature, showing: (1) strong negative Ce anomalies (C...

The late Triassic Heqing Mn deposit, located in the Lijiang Basin on the western margin of the Yangtze Block, SW China, contains more than 3 million tonnes ores with 24.60 to 58.13 wt% Mn. Orebodies are hosted by sedimentary rocks of the Upper Triassic Songgui Formation. The ore layers are confined to a specific stratigraphic horizon, occur as stratiform to sub-stratiform bodies concordant with the host strata, and consist of massive, botryoidal, honeycomb, and banded ores. Ore minerals are mainly hausmannite, pyrolusite, and rhodochrosite, with calcite as gangue. Rhodochrosite grains are spherulitic and anhedral and commonly contain Mn oxides. LA-ICP-MS in-situ U-Pb dating of rhodochrosite yielded 227 ± 20 Ma, consistent with Songgui Form...

Heavy mineral sands (HMS) from the Senegalese Grande Côte host economically significant zircon and rutile concentrates, with detrital monazite as a minor but informative component. This study combines textural, geochemical, and geochronological signatures of monazite grains to constrain sediment provenance and decipher the long-term crustal evolution of the West African Craton (WAC). Backscattered electron imaging and EPMA reveal a spectrum of monazite textures, ranging from homogeneous to complexly zoned and hydrothermally altered grains. These textures reflect magmatic, metamorphic, and fluid-driven histories prior to sedimentation. U-Pb-Th geochronology (EPMA and LA-ICP-MS) defines four major age populations: Archean (2.6-3.1 Ga), Ear...

The Ighir Amellal-Tanna Izem area is located in the southwestern part of the Tighza-Jbel Aouam polymetallic district within the Moroccan Central Meseta, a region characterized by significant Variscan magmatism and Pb-Zn-Cu-Sb mineralization. Although numerous studies have focused on the late Variscan granitoids of the district (≈295-280 Ma), the petrogenesis and chronology of earlier magmatic events remain poorly constrained. In this study, we combined whole-rock geochemistry and U-Pb apatite geochronology (LA-ICP-MS) to characterize a mafic dyke exposed in the area. Geochemical data recalculated on a 100% anhydrous basis (correcting for Loss on Ignition, LOI ≈ 10 wt%; SiO2 ≈ 47.02-47.26 wt%, raw 41.59-42.28 wt%; Na2O ...

Though volcanogenic massive sulfide (VMS) deposits are major global sources of indium (In), the physicochemical mechanisms and key factors controlling its significant enrichment remain poorly understood. To address the issue, this study investigates the Tiemurt VMS Pb-Zn-Cu deposit, utilizing detailed petrography, in-situ LA-ICP-MS analysis, and thermodynamic modeling to reveal the In enrichment mechanisms in VMS deposits. Petrographic observations identified two distinct generations of sphalerite corresponding to different mineralization stages. The early-stage sphalerite (Sp1) is euhedral-subhedral, associated with pyrite, and displays darker colors (red to brown), whereas the late-stage sphalerite (Sp2) is anhedral, intimately intergrown...

Understanding magmatic-hydrothermal conditions, redox-halogen controls, and fluid evolution is essential for deciphering porphyry Cu-Mo genesis and assessing mineralization potential. The Mujicun porphyry deposit, a major intra-continental Cu-Mo system in the North Taihang Mountain region of the North China Craton, has been studied for magma sources and post-ore thermal events, but its physicochemical conditions, magmatic-hydrothermal evolution processes, and magmatic fertility remain poorly understood. This study integrates in situ major and trace element analyses of biotite, apatite, and zircon from the ore-hosting diorite porphyry to constrain these factors. Magmatic biotite records the highest crystallization temperatures (782.6-879.6 �...

The Jinchanggou gold deposit (JGD) is a typical quartz vein-type deposit found in the Maoling ore field, which is mainly composed of altered-rock-type gold deposits. The genesis of the JGD is still not clearly known. We conducted hydrothermal monazite Usingle bondPb dating, fluid inclusion microthermometry, in situ trace-element and S-Pb-isotope analysis of pyrite to constrain the metallogenic process of the JGD. Four metallogenic stages were identified: Stage I features pure white quartz veins with subordinate fine-grained pyrite; Stage II exhibits greater pyrite and pyrrhotite precipitation; Stage III constitutes the dominant metallogenic period for Au precipitation, concurrent with significant lead-zinc mineralization; Stage IV primarily...

This study presents new in situ laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb ages of coexisting garnet and hydrothermal apatite from the Miaoshan Cu deposit in the Yunkai region. Garnet yields a U-Pb isochron age of 111.3 ± 2.1 Ma and a weighted mean age of 110.8 ± 1.7 Ma, while hydrothermal apatite—closely associated with chalcopyrite mineralization in copper orebodies—gives a lower intercept age of 116.9 ± 6.1 Ma. These results tightly constrain the timing of Cu mineralization at Miaoshan to between ca. 111 and 117 Ma, confirming it as part of an Early Cretaceous metallogenic event that also includes the Shilu Cu-Mo-W skarn and Tiantang Cu-Mo-Pb-Zn porphyry-skarn deposits. Garnet compositions are dom...

The Dongping gold deposit in the Zhang-Xuan district is the most significant alkaline pluton hosted gold deposit in the North China Craton (NCC). However, the complex cooling history and exhumation of the ore bodies and the adjacent plutons, including the Shangshuiquan (SQG) complex and the Shuiquangou (SSQ) granite are still poorly constrained. In this research, a suite of geochemical and geochronological techniques upon apatite were present to model and elucidate the multi-stage thermal evolution since the Devonian. Elements concentrations and Sr isotope ratios reveal two groups of apatite grains within the SQG complex showing three groups of different Usingle bondPb ages. The youngest group is characterized by depleted rare earth element...

Graphite, a predominant form of refractory solid carbon in high-grade metasedimentary rocks, serves as a critical indicator for tracing carbon sources and reconstructing deep Earth carbon cycling. Here, we focus on the Luanchuan crystalline graphite deposit hosted by the Palaeoproterozoic Taihua Complex along the southern margin of the North China Block (NCB). An integrated approach combining petrography, electron probe microanalysis (EPMA), laser Raman spectroscopy (LRS), organic carbon‑oxygen (Csingle bondO) isotope analysis, and zircon Usingle bondPb geochronology was employed to elucidate the genesis of the graphite. Raman spectroscopy of carbonaceous materials (RSCM) thermometry indicates the graphite crystallised at 550-630 °C. Str...

Lithium (Li) is a critical raw material for the new energy industry, and its demand has been steadily rising in recent years. Recovering Li from coal gangue not only helps alleviate the supply pressure of Li resources but also aligns with the environmental concept of solid waste resource utilization. This study proposes a novel method for the efficient recovery of Li via low-temperature roasting with potassium pyrosulfate followed by water leaching. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis reveals that kaolinite is the dominant carrier mineral for Li in coal gangue. The effects of various process parameters on Li recovery during potassium pyrosulfate roasting were systematically investigated. Under th...

Archean cratons are at the core, in terms of both their geographical position and geological processes, of the first long-lived lithospheric units. Shedding light on the temporality of craton formation is hence central to establishing geodynamic models accounting for the raising of emerged land masses and the consequential development of emerged life. To this extent, the Kaapvaal craton (KC), mostly exposed in South Africa and eSwatini, is ideally suited since it shows well-preserved rocks of both low and high-grade metamorphic rocks reflecting sedimentary, burial, metamorphic and magmatic processes occurring from ca . 3.5 Ga to ca . 2.5 Ga. In this study, we focus on meta -sedimentary rocks exposed in the northern edge of the KC (an area a...

Understanding the tectonic nature and evolution of ancient oceanic basins is essential for reconstructing orogenic geodynamic processes, yet it remains highly controversial in many regions. The Hegenshan Ophiolite Belt (HOB) in the eastern Central Asian Orogenic Belt (CAOB) represents a key example of this uncertainty, with its tectonic setting and evolution remaining debated, and proposed origins ranging from a mid-ocean ridge to a back-arc basin or an intra-continental rift setting. To address these issues, we conducted detailed petrographic, microstructural, and in-situ elemental analyses of cherts from the HOB to reconstruct the Ocean Plate Stratigraphy (OPS) succession of the Hegenshan Ocean and evaluate its tectonic significance. Our ...

The Yangtze Block occupies a key paleogeographic position during the Ediacaran-Cambrian period. Nevertheless, its paleogeographic location and tectonic setting in global plate reconstructions for this timespan remain controversial. In this study, Ediacaran-lower Cambrian siliciclastic samples from the northwestern Yangtze Block were analyzed using detrital zircon U-Pb geochronology and trace element composition, complemented by regional geochronological datasets. Our results suggest a tectonic regime transition from extension to compression at Ediacaran-early Cambrian time. The appearance of ∼1.0 Ga and 0.7-0.5 Ga zircon age groups in the lower Cambrian strata records changing sediment provenance during Gondwana amalgamation. Provenance s...

Trace element variations in pyrite are invaluable for reconstructing fluid evolution and ore-forming processes of mineral deposits. While microtextural detection is fundamental for such studies, resolving textures associated with subtle compositional variations remains a challenge. Here, we apply infrared (IR) microscopy on pyrite from four deposits (Zhuangzi Au, Linglong Au, Dexing Cu, Yinjiagou S-Cu-Mo) to evaluate its potential as an imaging tool in detecting compositional heterogeneity. All the pyrite grains show zoned textures, characterized by alternating dark bands with low IR transmittance and bright regions with high IR transmittance. LA-ICP-MS trace element mappings reveal pronounced spatial correlations between IR dark zones and ...

The Esperanza granitoids unit is composed of an assemblage of metamorphic lithologies that belong to a high-pressure suite of the Acatlán Complex, the largest Paleozoic basement in Mexico, that records a continuous tectonic history spanning from the opening and closure of the Rheic Ocean. The Esperanza granitoids include megacrystic K-feldspar, amphibolite facies mylonitic augen gneisses. We studied deformed granitoids that vary from protomylonitic to ultramylonitic augen gneisses and strongly foliated pegmatites, obtaining U-Pb zircon and apatite ages and apatite chemistry, intending to better understand the thermotectonic events that affected the Esperanza granitoids from their crystallization to metamorphism. The zircon U-Pb geochronolo...

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The polar regions strongly influence the energy balance of the Earth, and contribute to large uncertainties in current Earth system models. This is due in part to the complex interplay of radiative, chemical, and dynamical processes active in the region, but also to the lack of observational capability. This thesis is focused on analysis of longwave radiation in the Arctic and Antarctic, and has three scientific objectives: to maintain year-round measurements of downwelling thermal emission with an Extended-range Atmosphere Emitted Radiance Interferometer (E-AERI) at the Polar Environment Atmospheric Research Laboratory (PEARL) in Eureka, Canada (80° N), to leverage acquired spectra to derive information on atmosphere composition and cloud...

The relationships between the environment and an organism can be traced through stable isotope and trace element geochemistry. This thesis explores the stable oxygen and carbon isotopic composition of fossil vertebrate assemblages in pursuit of revealing the relationships between dinosaurs and their archosaur relatives with the environment in which they lived during the Cretaceous. The Cretaceous Period of North America experienced some of the hottest intervals in the Phanerozoic Eon and the continental vertebrate taxa that existed during this time recorded these periods within the stable isotopic composition of their skeletal bioapatite. Oxygen isotopes in the bioapatite of vertebrates reflect their dietary source of water. The hydroclimat...

University of Minnesota Ph.D. dissertation. April 2026. Major: Earth Sciences. Advisors: Donna Whitney, Christian Teyssier. 1 computer file (PDF); xi, 252 pages....

V diplomskem delu se osredotočamo na analizo vsebnosti in porazdelitve slednih elementov v sfaleritu iz rudišča Ledina. Cilj predloženega dela je bil določiti vsebnost slednih elementov v sfaleritu in na podlagi geokemičnih kazalcev določiti fizikalno kemične pogoje mineralizacije ter postaviti genetski model nastanka rudišča Ledina. Podatki o vsebnostih slednih elementov so bili pridobljeni in-situ z uporabo metode induktivno sklopljene plazme masne spektroskopije z vzorčenjem z lasersko ablacijo (LA-ICP-MS). Sfalerit iz rudišča Ledina smo na podlagi različnega stila mineralizacije in vsebnosti slednih elementov razdelili na tri glavne tipe: tip A, tip B in tip C. Sfalerita tipa B in C, sta se izločila v zgodnji (primarni) f...

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