The extent and nature of symbolic behavior among Neandertals are obscure. Although evidence for Neandertal body ornamentation has been proposed, all cave painting has been attributed to modern humans. Here we present dating results for three sites in Spain that show that cave art emerged in Iberia substantially earlier than previously thought. Uranium-thorium (U-Th) dates on carbonate crusts overlying paintings provide minimum ages for a red linear motif in La Pasiega (Cantabria), a hand stencil in Maltravieso (Extremadura), and red-painted speleothems in Ardales (Andalucía). Collectively, these results show that cave art in Iberia is older than 64.8 thousand years (ka). This cave art is the earliest dated so far and predates, by at least 20 ka, the arrival of modern humans in Europe, which implies Neandertal authorship.

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Rationale Boron isotope analysis of marine carbonates by laser ablation multi‐collector inductively coupled plasma mass spectrometry (LA‐MC‐ICP‐MS) offers the potential for rapid sample throughput, and the means to examine micron‐scale variations in the δ11B signatures of fossil skeletons and shells/tests of marine organisms. Existing studies demonstrate an acceptable level of reproducibility is achievable, but also typically show a level of accuracy outside the limits required by most applications. Here we investigate matrix interference effects as a cause of inaccuracy and imprecision. Methods Analyses were performed on a standard format Thermo Scientific Neptune Plus MC‐ICP mass spectrometer coupled to a New Wave Research 193 nm ArF laser ablation system. The effects of matrix interference on δ11B analysis were investigated through analyses of a set of reference materials with differing B/Ca ratios. Three approaches to correct for matrix‐induced effects were trialled: (1) use of matrix‐matched standards, (2) utilisation of the relationship between δ11B inaccuracy and11B/43Ca, 11B/40ArCa4+ or 11B/Cainterference from three reference materials with known δ11B values and varying B/Ca ratios, and (3) direct characterisation of the (sloping) interference itself. Results Matrix interference from scattered Ca ions on 10B can impede both the accuracy and the reproducibility of δ11B analysis by LA‐MC‐ICP‐MS. Based on analyses of two in‐house reference materials, deep sea coral PS69/3181 and inorganic calcite UWC‐1, we find approach 2, following the 11B/Cainterference relationship, gives the best mean accuracies (within 0.4‰ of solution values) and external reproducibilities (± 0.5‰ 2 SD for PS69/3181). This approach has been applied to analyses of an annual growth cycle of a Siderastrea siderea coral and eight Cibicidoides wuellerstorfi benthic foraminifera. Both coral and foraminifera data match solution MC‐ICP‐MS analyses within reported uncertainties. Conclusions LA‐MC‐ICP‐MS can produce accurate and precise δ11B data to a 0.5‰ (2σ) level on <0.3 ng B after correction for Ca interference effects.

Geomorphological and biological archives of relative sea-level change in the western North Atlantic-Caribbean region following the Last Glacial Maximum have traditionally supported the hypothesis of a punctuated rise towards the present sea level. Such records, however, are often at insufficient resolution to discern centennial-scale changes. In caves where the water table is closely controlled by sea level, active periods of speleothem growth constraining maximum sea level, used in combination with marine overgrowths constraining minimum sea level, are a promising alternative archive recording sea-level variability at higher resolution. Here, we present a U-Th-dated early–middle Holocene speleothem record from a submerged cave on the tectonically stable Yucatán Peninsula, Mexico. Our record shows that polychaetes (Annelida, Polychaeta) colonised a sub-aerially deposited stalagmite during four individual submergence events. Submergence events occurred at approximately 8.9, 8.6, 8.4 and 6.0 ka, which we attribute to previously unrecognised minor sea-level oscillation events (OE1–OE4) above and below −6.12 ± 0.1 m relative to present sea level (r.s.l.). Combining these results with mangrove-derived relative sea-level constraints from another submerged cave on the Yucatán Peninsula, we are able to suggest that OE1 and OE2 did not reach as high as −5.26 m r.s.l., but that OE3 and OE4 exceeded −5.22 m r.s.l. We conclude that subsidence of the North American ice-load bulge was the main cause of relative sea-level rise. Superimposed on the glacio-isostatic adjustment were periods of widespread northern hemisphere cooling and ice margin re-advance, resulting in a relative sea-level fall on four occasions during the early–middle Holocene.

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Boron isotopic and elemental analysis of coral aragonite can give important insights into the calcification strategies employed in coral skeletal construction. Traditional methods of analysis have limited spatial (and thus temporal) resolution, hindering attempts to unravel skeletal heterogeneity. Laser ablation mass spectrometry allows a much more refined view, and here we employ these techniques to explore boron isotope and co-varying elemental ratios in the tropical coral Siderastrea siderea. We generate two-dimensional maps of the carbonate parameters within the calcification medium that deposited the skeleton, which reveal large heterogeneities in carbonate chemistry across the macro-structure of a coral polyp. These differences have the potential to bias proxy interpretations, and indicate that different processes facilitated precipitation of different parts of the coral skeleton: the low-density columella being precipitated from a fluid with a carbonate composition closer to seawater, compared to the high-density inter-polyp walls where aragonite saturation was ~ 5 times that of external seawater. Therefore, the skeleton does not precipitate from a spatially homogeneous fluid and its different parts may thus have varying sensitivity to environmental stress. This offers new insights into the mechanisms behind the response of the S. siderea skeletal phenotype to ocean acidification.

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Lead isotope analyses have been performed on 109 gold and 23 sulphide samples from 34 Irish gold occurrences, including 27 placers, and used to shed light on the sources of mineralising fluids and metals associated with gold mineralisation hosted by orogenic belts. The Pb isotope ratios of lode and placer gold range from 206 Pb/ 204 Pb = 17. 287-18.679, 207 Pb/ 204 and 208 Pb/ 204 Pb = 37.517-38.635, consistent with the Pb isotopic data on previously reported Irish sulphide mineralisation. There is no evidence that gold mineralisation is associated with distinctive source regions, and it appears to have been derived from similar sources to those responsible for the widespread sulphide mineralisation in Ireland. It is inferred that the principal controls on the Au mineralisation are structural and not related to the distribution of Au in their source rocks. The range of Pb isotope ratios favours the interaction of multiple source reservoirs predominantly during the Caledonian Orogeny (c.475-380 Ma). Underlying basement was the primary control on two key sources of Pb. Gold occurrences located to the south-east of the Iapetus Suture are characterised by Pb compositions that derive predominantly from the Late Proterozoic crustal basement or overlying Lower Palaeozoic sediments, whilst those located north-west of the Iapetus Suture are characterised by less radiogenic Pb signatures derived predominantly from Late Proterozoic or older crustal basement. A third source, relatively enriched in radiogenic Pb, also played a role in the formation of a number of Irish gold occurrences, and may have been associated with syn-to postorogenic intrusives. Magmatic processes may therefore have played an important role in the formation of some gold occurrences located in orogenic settings.