This study examines detrital garnet compositions from five samples spanning a Late Miocene–Pliocene section of Himalayan sedimentary rocks (Surai Khola, Siwalik Group and central Nepal) to assess provenance and tectonic implications. A total of 100 detrital garnets were analysed for edge-to-edge compositional zoning, revealing distinct groups linked to specific hinterland regions. Manual classification identified garnet Groups 1 and 2 as grossular, Group 3 as spessartine, and Groups 4 through 7 as almandine, varying in XCa, XMg and XMn. Most garnets exhibit low XMg and flat zoning, with Groups 6* and 7* containing slightly higher XMg. Statistical clustering aligns broadly with manual groupings, which strengthens provenance interpretations. Comparisons with hinterland garnet compositions expand provenance options to magmatic garnets and rocks outside the Himalayan core units. Eight Siwalik Group garnets were modelled for pressure–temperature conditions and paths. Group 4 and 6 garnets, potentially linked to blueschist/eclogites or metamorphosed arc/Himalayan core rocks, record conditions of 510–538°C and 4.6–6.8 kbar, with isothermal burial over 0.5–2 kbar. Group 2 garnet, resembling compositions from North Himalayan granitic enclaves, yields core conditions of 480°C and 6 kbar and an N-shaped pressure–temperature path. Two Group 5 garnets with zoning like those in the High Himalayan leucogranites yield 520–528°C at 3.2–3.6 kbar. These findings provide insights into Himalayan erosion dynamics, hinterland exhumation and sediment transport pathways. Integrating garnet compositional zoning with statistical clustering and thermodynamic modelling is valuable for provenance studies of garnet-bearing sedimentary sections.

Miocene lacustrine clay deposits formed in the Şile region of Türkiye rest unconformably on Cretaceous andesite, basaltic andesite, basalts and rare dacites. Factors controlling the genesis of this sequence include: (1) sediment provenance, (2) tectonic uplift and climatic regimes during syn- and post-depositional times, (3) burial diagenesis and (4) changes from surface weathering alterations (i.e. oxidation and hydrolysis reactions) in the critical zone. Clay minerals are dominated by kaolinite and illite, with their relative abundances varying in relation to the proximity of coal seams, stratigraphic sequence and in an overlying sand-rich fluvial deposit. Variations in the mineral abundances reveals cyclothem-like sequences with patterns of fining upwards (i.e. increasing clay mineral abundance) capped by thin coal seams. The Clay Mineral Alteration Index values for the Şile clay sequence indicate a slight trend of decreasing chemical weathering intensity up-section, which is consistent with regional geological data for terrain uplifting and a drying climate during the Miocene. Critical zone processes have modified the mineral and chemical assemblages, as evidenced by the appearance of iron oxides putatively formed from recent oxidation of the ferrous minerals siderite and pyrite, which are not found in the upper sections. Taken together, the evidence indicates that the clay minerals are derived from a combination of prior weathering of basement rocks, diagenesis after deposition and modern critical-zone weathering. The degree of each process is dependent on depositional history, stratigraphic position and depth below the land surface, all under the changing influences of tectonic uplift and regional climate. The Şile deposits provide an economical clay resource that could be important to the ceramics industry of Türkiye.

Alisha Sijapati and Erin Thompson’s article “Making a market for ‘The Art of Nepal’: Tracing the flow of Nepali cultural property into the United States” makes a series of unsubstantiated claims about the nature and scope of the Nepali antiquities market in the 1950s and 1960s based on the authors’ research of a single 1964 exhibition of Nepali antiquities in the United States. This critical response will contest these claims by examining the broader Nepali antiquities market as it existed prior to 1970, particularly within Nepal and in South Asia, while also locating the authors and their claims in the context of the recent repatriation campaign by Nepali activists. Finally, the response will conclude that if there is to be an ethical turn in voluntary repatriation, there must be greater consideration of contexts beyond the West and a refocusing of provenance research beyond Western collectors and institutions.

Multidisciplinary methods permit the first archaeometallurgical study of artefacts from five key first-millennium BC settlements in Poland: Grzybiany, Wicina, Kamieniec, Tarławki and Mołtajny. This project fills a lacuna in our understanding of technical ceramics, metal provenance and the role of settlements in the cultural landscape.

This study concerns prehistoric amber networks in north-eastern Iberia, emphasizing its distinct exchange dynamics compared to other regions of the Iberian Peninsula. Baltic amber dominated assemblages in this area from the Late Neolithic to the Bronze Age, contrasting with the prevalence of Sicilian amber in southern Iberia, or Cretaceous Iberian amber in the northern region. The findings underscore the region’s connection to southern France, with the Pyrenees serving as a cultural conduit, unlike the river Ebro, which acted as a boundary. Here the authors present the results of a Fourier transform infrared spectrometry (FTIR) analysis of twenty-one amber beads, primarily from collective burials. Eighteen were made of Baltic succinite. Baltic amber may have begun to arrive as early as 3634–3363 cal bc, and continued to be used until the Late Bronze Age. Exceptions included a unique spacer-bead made of gum and two bolus pigments misidentified as amber. The results highlight Iberia’s regional diversity in raw material sourcing and exchange, reflecting distinct sociocultural dynamics and challenging linear narratives of Iberian prehistory.

Old collections, real or fake, are a basic part of the collection history of an antiquity or artwork. This article is a starting point for a study of the concept: how old collections are employed, what functions they have, and how fictitious old collections are chosen and constructed. To explore these concepts, the article considers the example of Cumberland Clark, an early 20th-century collector who serves as the putative origin of cuneiform tablets in a handful of present-day collections, most notably the Schøyen Collection. This article looks at the life and collections of Cumberland Clark, then argues that the Clark provenance for current collections is a fabrication, and concludes by looking at Clark in the context of other old collections in order to draw some lessons about fabricated provenance.

The earliest pottery vessels in the Arabian Gulf, appearing in the mid-sixth millennium BC, belong to two distinct traditions: Ubaid Ware was imported from Mesopotamia, but the origins of the Coarse Red Ware have remained obscure. Geochemical examination of pottery from Bahra 1, in modern-day Kuwait, and geological samples from the surrounding area reveal a regional origin for the clay. Further exploration of the Bahra 1 assemblage indicates that Coarse Red Ware was probably made at the site by low-skilled potters. This research provides insights into the organisation of pottery production and distribution in the Arabian Neolithic.

Numerous transport stirrup jars have been found at the site of Pefkakia. Most were manufactured in Crete with some from the Greek mainland. There were also at least two Canaanite jars from the Carmel coast. These finds and the first results of petrographic analysis attest to the site's role as a major Aegean harbour.

Measuring chemical weathering histories in submarine fan deposits is critical if the impact of orogenic erosion on atmospheric CO2 levels is to be understood, yet existing records are often noisy and hard to interpret. In this study, we selected mudstones from two International Ocean Discovery Program (IODP) sites from the Indus submarine fan and carefully removed the biogenic carbonate. The resulting records of chemical weathering show two trends, one of reducing chemical alteration since ∼8 Ma and which is associated with the Indus River, while a second trend is linked to sediment delivery from peninsular India. The second trend shows little temporal variation. Sediment deposited at IODP Site U1456 in the central Laxmi Basin is preferentially, but not exclusively, Indus-derived, while that at Site U1457 on the eastern flank of Laxmi Ridge is more peninsula-derived. Both trends show much less variability than seen in earlier studies in which various grain-size fractions were integrated together. The efficiency with which CO2 is removed from the atmosphere during chemical weathering has decreased over time in the Indus River-derived material. This reflects both lower degrees of alteration in the sediment since the late Miocene and increasing derivation of sediment from Himalayan sources, rather than more mafic Karakoram-Kohistan rocks. Previous estimates of CO2 consumption have overestimated the contribution that the Indus Basin has made to reducing atmospheric CO2 by ∼28–68%. This work emphasizes the importance of analysing appropriate largely silt-sized sediment when considering submarine fan records and in rigorously removing biogenic carbonate.

A growing number of institutions that hold cultural heritage artifacts are now considering voluntary repatriations in which they choose to return an artifact despite unfilled gaps in their knowledge of its ownership history. But how are institutions to judge whether it is more probable that such gaps conceal theft and illicit export or are innocuous? Attempting to answer this question for Nepal, we examine published and archival records to trace the history of the growth in collecting of Nepali cultural heritage in the United States, with special attention to a 1964 exhibition at New York’s Asia Society Gallery, “The Art of Nepal,” and the activity of the New York dealers Nasli and Alice Heeramaneck. We conclude that the majority of Nepali heritage items in America entered after Nepal prohibited their export.

In sediments, clay minerals are mainly detrital. Formed by continental weathering, they are carried by surface transport predominantly by rivers, glaciers and, to a lesser extent, winds to the adjacent sedimentary basins and then are redistributed by oceanic currents. In a sedimentary core, the variability in the clay mineral assemblages reflects either variable physical and chemical weathering conditions in the watershed, typically with a significant link to climatic conditions, or changes in the mineral source, the latter being associated with various transport agents. When different sources are involved, a combination of mineralogical and geochemical proxies allows us to trace the detrital provenance, but they also indirectly provide valuable information on transport pathways and palaeocurrents. This manuscript reviews several examples from the literature and ongoing research on clay mineral variability in marine or lacustrine sedimentary records and interprets them in terms of: (1) climate control at different timescales, from the Neogene to the Quaternary; and (2) transport paths. Examples are selected to review the various clay-derived proxies in existence.

Mineralogy, O18/O16, and D/H ratios have been determined in five size fractions (<0.1, 0.1–0.5, 0.5–1.0, 1.0–2.0, and >2.0µm) of seven samples taken from 500 m of Pleistocene deep-sea sediments cored at Deep Sea Drilling Project Site 180 in the Aleutian Trench. The depositional age of the samples spans the last 300,000 years; the samples have been interpreted by others to be continental detritus weathered from a mixed igneous, metamorphic, and sedimentary source area and then deposited by ice-rafting and turbidity currents. The minerals present are quartz, feldspar, illite, chlorite and/or non-expandable vermiculite, and expandable vermiculite and/or mixed-layer illite/expandable vermiculite. The relative amounts of quartz, feldspar, and total clay vary with particle size, but are nearly constant from sample to sample for a given particle size. δO18 is values of the four coarser size fractions range from +9.7 to +12.0‰ with variations attributable to changes in quartz/feldspar and clay/(quartz + feldspar) abundances. Values of δO18 for the expandable vermiculite-rich <0.1-µm size fraction range from +12.1 to +16.3‰ which indicates some oxygen isotope exchange at surface temperatures between meteoric waters and the parent rock during vermiculite formation. Values of δD range from −46 to −74‰ with variations attributable to changes in amounts of different clay minerals present. There is no mineralogic or isotopic evidence of post-depositional reactions in the coarser size fractions, but a general change in δD of the vermiculite-rich, <0.1-µm size fraction from about −50‰ to about −70‰ with increasing depth may be due either to post-depositional isotopic exchange or to climatic changes in the terrestrial weathering environment.

The geochemistry of lake sediments provides valuable information on environmental conditions and geochemical processes in polar regions. To characterize geochemical composition and to analyse weathering and provenance, 26 lakes located in six islands of the South Shetland Islands (SSI) and James Ross Archipelago (JRA) were analysed. Regarding major composition, the studied lake sediments correspond to ferruginous mudstones and to a lesser extent to mudstones. The weathering indices indicate incipient chemical alteration (Chemical Index of Alteration = 52.6; Plagioclase Index of Alteration = 57.6). The La-Th-Sc plot shows different provenance signatures. SSI lake sediments correspond to oceanic island arcs, whereas those of JRA denote a signal of continental arcs with mixed sources. In James Ross Island lake sediments are of continental arcs (inland lakes), oceanic island arcs (coastal lakes) and a middle signature (foreland lakes). Multi-elemental analysis indicates that the sediments are enriched from regional basalts in Ba, Rb, Th, Cs and U (typical of silica-rich rocks) and depleted in Cr and Co due to mafic mineral weathering. The geochemical signals identified by principal component analysis enable us to group the sediments according to the studied islands and their geomorphological characteristics. This study underlines the importance of knowing the geochemical background levels in pristine lake sediments to evaluate potential future anthropogenic effects.

Clay mineralogy (including illite crystallinity) was studied in Pennsylvanian synorogenic sediments (Atoka Formation) in the subsurface of the Arkoma Basin and the adjacent Ouachita thrust belt. Vitrinite reflectance values range from ≥0.8% at the surface up to as high as 4.7% Ro at the base of the Atoka Formation. The mineralogy of the <2 µm fraction of the mudrocks is fairly monotonous and composed of illite (<10% interstratified smectite), Fe-chlorite, kaolinite, quartz, and traces of feldspars. Kaolinite is common at shallow levels and “disappears” in most wells at a thermal maturity of 1.9–2.1% Ro, suggesting its possible use as an independent paleothermal indicator in this basin. Illite crystallinity (IC) values are fairly high (0.3–0.5° 2θ) and show little variation throughout the entire maturity range. In addition, no relation was observed between vitrinite reflectance and illite crystallinity, indicating that IC is not a useful paleothermal indicator in these rocks. Illite is almost exclusively of the 2M1 polytype, suggesting a predominantly detrital origin. Incipient metamorphic and low-grade metamorphic mudrocks in the Ouachita thrust belt to the east of the Arkoma Basin are regarded as the source rocks for the clays of the Atoka Formation. Rapid transportation and deposition by turbidity currents probably played a key role in protecting these unweathered micas from pervasive alteration in the terrestrial environment.

K-Ar measurements were used in this study of upland Savannah River Site soils to distinguish between sorbed K and the K remaining in remnants of primary minerals. Study of sorbed K contributes to understanding further the interaction of alkali metals (Cs in particular) with the soils. Primary mineral K and the associated radiogenic Ar were studied to characterize soil mica with respect to its provenance and its relationship to hydroxy-interlayered vermiculite. K-Ar age values of Na-saturated clay fractions from five samples of these soils range in age from 270 to 370 Ma. After a moderate acid treatment (6% HNO3 v/v, ~1 mol dm-3, 3 h, 80°C) of the clay fractions, K-Ar age values (270-325 Ma) were little changed on the whole, but they were more closely grouped near 300 Ma. Earlier work had shown that most of the K in these soils is found in material resistant to moderate acid extraction. The K-Ar age values show that this acid-resistant material is much older than any pedogenic minerals could be, even much older than the sedimentary parent rocks from which the soils were derived. These observations support earlier inferences by others that the K in these well leached soils is largely in remnants of primary muscovite from the parent sediments. Age values near 300 Ma suggest that the muscovite is largely from proximal Piedmont terranes of the Appalachian orogen, where the K-Ar relationship in most micas was set by Alleghanian tectonic processes late in the Paleozoic Era. The structural location of the K within mica, shown by the retention of the associated radiogenic Ar, is in contrast to the sorption-dominated behavior of the Cs and most of the Rb in these soils during pedogenesis. Stronger acid treatment (~6 mol dm-3 HNO3, 3 h, 100°C) extracted substantial fractions of both the K and the radiogenic Ar from bulk-soil portions, indicating destruction of some of the primary mica. K-Ar age values for the sand-rich bulk soils were not useful for this study because the sand contains excess radiogenic Ar, probably in sand-sized vein quartz.

The Kamieniec Metamorphic Belt (KMB) and the Doboszowice Metamorphic Complex (DMC) expose a fragment of the pre-Variscan volcano-sedimentary cover preserved in the Fore-Sudetic Block in the NE part of the Bohemian Massif. We present the age of detrital and magmatic zircon grains and the bulk rock chemical composition of rock samples from the KMB and the DMC to better understand the evolution of the early Palaeozoic Gondwana margin. The zircon age spectra were acquired by U–Pb LA–ICP–MS dating and represent two groups that differ by maximum depositional age (MDA). The paragneiss from the DMC displays the MDA at 456 Ma, whereas the mica shist from the KMB displays the MDA at 529 Ma. Older age peaks in both groups of samples are represented by the Neoproterozoic and less frequent the Paleoproterozoic and Archean. The data presented indicate that the rock successions were sourced from the Cadomian orogen and deposited in the basins that developed on the Gondwana margin. Our results support the suggestion that the crystalline basement in the eastern part of the Fore-Sudetic Block has an affinity to the Trans-Saharan Belt or West African Craton and was part of a Gondwana shelf. The final stage of evolution of the studied successions was related to the Variscan thermal overprint. Based on presented data, we support the idea that the suture separating the Brunovistulian domain from the rest of the Gondwana-derived terranes is not related to the closure of the Rheic Ocean and represents a local feature.

The Upper Permian sedimentary successions in the northern Sydney Basin have been the subject of several stratigraphic, sedimentological and coal petrographic studies, and recently, extensive U-Pb zircon dating has been carried out on tuffs in the Newcastle Coal Measures. However, detailed petrographic and geochemical studies of these successions are lacking. These are important because a major change in tectonic setting occurred prior to the Late Permian because of the Hunter-Bowen Orogeny that caused the uplift of the Carboniferous and Devonian successions in the Tamworth Group and Tablelands Complex adjacent to the Sydney Basin. This should be reflected in the detrital makeup of the Upper Permian rocks. This study provides data that confirms major changes did take place at this time. Petrographic analysis indicates that the source area is composed of sedimentary, felsic volcanic and plutonic and low-grade metamorphic rocks. Conglomerate clast composition analysis confirms these results, revealing a source region that is composed of felsic volcanics, cherts, mudstones and sandstones. Geochemical analysis suggests that the sediments are geochemically mature and have undergone a moderate degree of weathering. The provenance data presented in this paper indicate that the southern New England Orogen is the principal source of detritus in the basin. Discrimination diagrams confirm that the source rocks derive from an arc-related, contractional setting and agree with the provenance analyses that indicate sediment deposition in a retroarc foreland basin. This study offers new insights on the provenance and tectonic setting of the Northern Sydney Basin, eastern Australia.