Rationale Complete decomposition of silicate rock matrices is crucial in determining their isotopic compositions, but acid dissolution in a high‐pressure steel‐jacketed bomb, which has been the only powerful, effective technique thus far, is time‐consuming and expensive. Rock dissolution using ammonium bifluoride (ABF), as described here, is a viable alternative. Methods Geological reference materials (GRMs) were digested using ABF in closed Teflon beakers at temperatures of 220/230°C in a convection oven and subsequently treated with HNO3. Hf‐Sr‐Nd were separated and purified using ion‐exchange chemistry columns calibrated for 50–2 mg samples. The isotopic compositions of Sr‐Nd were measured by Thermal Ionization Mass Spectrometry, while that of Hf by Multi‐Collector Inductively Coupled Plasma Mass Spectrometry, both with normal 1011 Ω and gain calibrated 1013 Ω amplifiers. Results Total procedural blanks of our protocol are 0.5 ng for Sr, 0.2 ng for Nd and <25 pg for Hf. Test runs with GRMs, ranging in composition from basic to felsic and dissolved in ABF, yield accurate 87Sr/86Sr, 143Nd/144Nd and 176Hf/177Hf isotope ratios as compared with those obtained with the bomb dissolution technique. Reproducibilities were comparable, on the order of 10–20 ppm. Our technique allows combined Hf‐Sr‐Nd isotope analyses of low‐mass (50–2 mg) samples. Conclusions The ABF digestion is an alternative technique to high‐pressure bomb dissolution in matrix decomposition for accurate and reproducible Hf‐Nd‐Sr isotope analyses of geological samples within a reasonable time (3–4 days), with high sample throughput and low costs in geochemistry and environmental sciences.

Abrupt and large‐scale climate changes have occurred repeatedly and within decades during the last glaciation. These events, where dramatic warming occurs over decades, are well represented in both Greenland ice core mineral dust and temperature records, suggesting a causal link. However, the feedbacks between atmospheric dust and climate change during these Dansgaard–Oeschger events are poorly known and the processes driving changes in atmospheric dust emission and transport remain elusive. Constraining dust provenance is key to resolving these gaps. Here, we present a multi‐technique analysis of Greenland dust provenance using novel and established, source diagnostic isotopic tracers as well as results from a regional climate model including dust cycle simulations. We show that the existing dominant model for the provenance of Greenland dust as sourced from combined East Asian dust and Pacific volcanics is not supported. Rather, our clay mineralogical and Hf–Sr–Nd and D/H isotopic analyses from last glacial Greenland dust and an extensive range of Northern Hemisphere potential dust sources reveal three most likely scenarios (in order of probability): direct dust sourcing from the Taklimakan Desert in western China, direct sourcing from European glacial sources, or a mix of dust originating from Europe and North Africa. Furthermore, our regional climate modeling demonstrates the plausibility of European or mixed European/North African sources for the first time. We suggest that the origin of dust to Greenland is potentially more complex than previously recognized, demonstrating more uncertainty in our understanding dust climate feedbacks during abrupt events than previously understood.

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Highlights► We report new Sm–Nd and Rb–Sr data from metamorphic wedges in the NW-Himalayas. ► Melting during the Eohimalayan event is constrained by Sm–Nd ages around 40 Ma. ► Peak metamorphism and initial exhumation of the core is dated around 29 Ma. ► Intrusion of plutons above the wedges around 19 Ma clearly postdate the main fabric. ► 7 Ma old pegmatite dykes constrain melting of the crust during ongoing collision.

Combined Sr‐Nd‐Hf isotopic data of two reference materials (AGV‐1/BCR2) and 50, 10, and 5 mg aliquots of carbonate‐free fine grain (<10 μm) separates of three loess samples (Central Europe/NUS, China/BEI, USA/JUD) are presented. Good agreement between measured and reference Sr‐Nd‐Hf isotopic compositions (ICs) demonstrate that robust isotopic ratios can be obtained from 5 to 10 mg size rock samples using the ion exchange/mass spectrometry techniques applied. While 87Sr/86Sr ratios of dust aluminosilicate fractions are affected by even small changes in pretreatments, Nd isotopic ratios are found to be insensitive to acid leaching, grain‐size or weathering effects. However, the Nd isotopic tracer is sometimes inconclusive in dust source fingerprinting (BEI and NUS both close to ɛNd(0) –10). Hafnium isotopic values (<10 μm fractions) are homogenous for NUS, while highly variable for BEI. This heterogeneity and vertical arrays of Hf isotopic data suggest zircon depletion effects toward the clay fractions (<2 μm). Monte Carlo simulations demonstrate that the Hf IC of the dust <10 μm fraction is influenced by both the abundance of zircons present and maturity of crustal rocks supplying this heavy mineral, while the <2 μm fraction is almost unaffected. Thus, ɛHf(0) variations in the clay fraction are largely controlled by the Hf IC of clays/heavy minerals having high Lu/Hf and radiogenic 176Hf/177Hf IC. Future work should be focused on Hf IC of both the <10 and <2 μm fractions of dust from potential source areas to gain more insight into the origin of last glacial dust in Greenland ice cores.