Lead Isotope Signatures Research Articles

Antlers as bioindicators of environmental pollution: principles, achievements, and future research directions

The periodically detached and regenerated antlers are a diagnostic trait of deer (family Cervidae) and represent the most rapidly growing bones of mammals. During their species-specific and seasonally fixed growth period of a few months, antlers can accumulate large amounts of ‘bone-seeking’ elements that are incorporated into the bone mineral. This makes antlers ‘naturally standardised’ environmental samples that can be used to monitor environmental pollution of deer habitats by these elements. The present contribution reviews studies utilising hard antlers as environmental archives to reconstruct temporal and spatial variation of contaminant levels in different geographic regions. We further discuss the use of lead isotope signatures in antlers for source apportionment of environmental lead and the impact of excess fluoride uptake on antler mineralisation. In addition, promising areas for future research using antlers as bioindicators are discussed.

Lead isotopic signatures in blood from incubating common eiders (Somateria mollissima) in the central Baltic Sea

The Christiansø colony of common eiders (Somateria mollissima) in the central Baltic Sea were exposed to high levels of Pb during the 2018 breeding season that were not present in 2017. Due to these high Pb blood levels, the present study investigated possible Pb sources and Pb dynamics within this vulnerable colony. We analyzed body mass and lead isotopic ratios (Pb-IRs) in blood taken from the same incubating eiders at the early (day 4) and late (day 24) stages of incubation during the 2018 breeding season (n = 23). Pb-IRs 208/207, 208/206, 206/207, and 207/206 were analyzed using high resolution inductively coupled mass spectrometry. We found largely similar Pb-IRs from the different stages of incubation indicating a predominantly constant endogenous source of Pb exposure. We suggest the increasing Pb levels come from pre-nesting and nesting foraging and from medullary bone release. The similar Pb-IRs also indicate continued metabolization of the medullary bone to meet the nutritional and energy demands of incubation. Comparisons to Pb-IR reports from the Baltic Sea showed multiple sources of pollution distinguished by a difference between Pb-IRs in individuals with Pb blood concentrations >500 μg/kg ww and <500 μg/kg ww. The most highly contaminated individuals in the present study had Pb-IRs similar to those of Pb ammunition indicating shot pellet uptake. This study further emphasizes the need for continued biomonitoring of the Christiansø colony, including fecal sampling and environmental field sampling to identify the origin and extent of dietary Pb exposure on Christiansø. As a representative unit of the Baltic Flyway population; the Christiansø colony provides an important opportunity for continued investigation into Pb contamination, population dynamics, and declines.

The provenance of Yin-Shang bronzes with highly radiogenic lead isotopes

Even if the lead isotope results are same, the significance of the lead isotopic signature is quite different for the provenance study of the Chinese bronzes. The published data show that the radiogenic lead signatures in the unalloyed copper and the Yin-Shang bronzes with the low lead content are contributed by the copper deposits, while those of the South Africa and Zimbabwe bronzes with highly radiogenic lead were contributed by tin deposits. Combined with the results of lead isotope analysis by LA-MC-ICP-MS and the recent archeological discoveries, it was possible that for the Yin-Shang bronzes with highly radiogenic lead contents, the copper material was derived from Zhongtiao Mountain copper deposits, while the lead material from Huojiagou and Zhenggou in the northern margin of North China Craton, but we prefer that the lead materials were from the southern margin of the North China Craton.

Use of Lead Isotopic Ratios as Geographical Tracer for Lambrusco PDO Wines.

In this study, the lead isotope signature was tested with the aim to verify its potential as geographic tracer for wine production and particularly for the Lambrusco PDO wines of the province of Modena (Italy). A solid phase extraction procedure, for separating lead from the investigated matrices, soil and wine, was optimized. Furthermore, different mathematical models, based on an exponential law and internal or external correction approach, were evaluated for the correction of instrumental mass dependent fractionation. The optimized analytical procedure yielded isotopic ratio data relative to the lead NIST 981 standard, 208Pb/206Pb = 2.16664 and 207Pb/206Pb = 0.914645, in good agreement both with the tabulated values and with the most recent literature data. Measured isotope ratio data highlight the contribute of multiple lead sources in bottled wine but different from the one present in soils.

A ‘match–no match‘ numerical and graphical kernel density approach to interpreting lead isotope signatures of ancient artefacts

A new method for interpreting lead isotope ratios of artefacts is presented: a numerical and graphical ‘match–no match‘ with possible raw materials. By calculating the definite integral under the kernel density estimate plot of different mining districts, using open‐access software and legacy data, the relative probability that an object is made of an ore is indicated. A match with the reference data set may indicate the true origin, while no match indicates an unknown origin, that is, not present in the data set of mineral resources. Likewise, the composite or recycled nature of artefacts can be investigated in a probabilistic manner.

Lead isotope ratios in Podzol profiles as a tracer of pollution source in the subalpine zone of the Karkonosze National Park, Sudety Mts (south-western Poland)

The Karkonosze National Park (south-western Poland) represent central European medium-elevation mountains. At the end of the twentieth century, an ecological disaster was observed in this nature reserve, resulting in the defoliation of large areas of spruce forest. One of the considered reasons for this phenomenon was contamination with heavy metals. The aim of this study was to determine the origin of lead (lithogenic versus several specific anthropogenic sources) occurring in the soils of the highest located parts of the Karkonosze Mts. Lead concentrations and its isotope ratios were investigated in nine Podzol profiles located in the subalpine zone (1200–1400 m a.s.L.) of the Karkonosze Mts. Concentrations of total lead and its isotopes were measured in particular genetic horizons; then lead isotope ratios were calculated. On the basis of lead isotope signatures known from literature data, different anthropogenic sources of this element have been assessed (emissions from coal combustion, mining, metallurgy, and fuel combustion). The results obtained revealed the highest Pb concentrations (121.0–353.0 mg kg−1) in the surface horizons. The podzolization process, differentiating soil profiles into eluvial (Es) and illuvial (Bh and Bs) horizons, has contributed to different concentration of lead through the profile. The concentrations of this element in eluvial, illuvial Bh, and parent material horizons were 15.5–28.4 mg kg−1, 25.8–55.6 mg kg−1, and 8.7–29.6 mg kg−1, respectively. The Pb isotope composition determined in the ectohumus horizons and eluvial horizons showed that about 86–95% of lead existing in these surface horizons originated from emissions resulting from the burning of coal exploited in Poland and the Czech Republic. The Pb isotope signatures of lead present in the illuvial horizon (Bs) and parent material (C) pointed to the lithogenic origin of this element. The results obtained indicated that higher-elevation areas of the Karkonosze National Park have been contaminated with lead from long distance emissions. Pollution with lead has been limited only to ectohumus and eluvial horizons, although the soil-forming process contributed to translocation of lithogenic lead down the soil profile to the illuvial Bh horizon.

Elevated lead exposure in Roman occupants of Londinium: New evidence from the archaeological record

The evolution of metallurgical practices over several millennia has resulted in human exposures to a diverse variety of toxic elements. These exposures were not just confined to the metalworkers, but in many cases broadly impacted the larger community and society. The role of lead in Roman civilization is particularly fascinating, where the available evidence of lead use in a myriad of applications by Roman civilization suggests the potential for elevated exposures. The present paper addresses the hypothesis that because of these practices, Roman occupants of ancient Londinium (43–410 ad) were exposed to levels of lead that far exceeded exposures in the preceding populations of Iron Age Britain (700 bc–43 ad). The elemental content and stable lead and strontium isotopic signatures of 30 femora from three Londinium cemeteries and radiocarbon‐dated representative burials were examined and the results then compared with 70 femora dating to the pre‐Roman Iron Age from the well‐known Iron Age hillfort of Danebury, Hampshire, and from three cemeteries in East Yorkshire. Extensive efforts were directed at the minimization of sediment and soil contamination, the assessment of contamination from burial artefacts and a careful review of the burial context of specimens. Data for lead and 20 additional trace and major elements were obtained by magnetic sector inductively coupled plasma mass spectrometry (ICPMS), after acid dissolution of pre‐cleaned bone cores. Lead isotope ratios in the bone core digests (and burial soils) were measured by multi‐collector ICPMS. It was found that concentrations of lead in the Roman/Londinium‐era femora were &gt; 70‐fold greater than those from pre‐Roman populations. This was confirmed by femoral data obtained from the analysis of a pre‐Roman burial from the early first century bc found adjacent to the Southern Cemetery. Several major and trace element metrics for diagenesis demonstrate that levels of lead in the bone are robust indicators of human exposure during life. Lead isotope data for the Roman population are consistent with previously identified widespread lead pollution. The pre‐Roman populations contain lead isotopic compositions consistent with highly localized, minor sources of lead. Together, these data provide unequivocal confirmation that the Romans in Londinium were exposed to elevated lead levels. Elevated blood lead levels would have resulted, negatively affecting their health and possibly contributing to declining birth rates.

Copper, zinc and lead isotope signatures of sediments from a mediterranean coastal bay impacted by naval activities and urban sources

Toulon bay is severely impacted by metal contamination induced by past and recent naval activities. In this work, Cu, Zn and Pb isotope compositions and elemental concentrations of fifty-five surface sediments were determined in order to map the spatial distribution of anthropogenic and natural sources along this land-sea continuum. Two sub-systems of Toulon Bay, the Small and Large bays, showed well-marked patterns on metal contamination levels and isotope signatures for Cu and Pb. The Small bay had the highest metal concentrations, and displayed average Pb and Cu isotope compositions of 1.1664 ± 0.0043 (1s, expressed as 206Pb/207Pb ratios) and −0.17 ± 0.19‰ (1s, expressed as δ65CuNIST values), respectively. It contrasted with the Large bay, with moderate to pristine metal concentrations and average Pb and Cu isotope compositions of 1.1763 ± 0.0079 (1s) and +0.08 ± 0.23‰ (1s), respectively. Lead isotope systematics indicated a binary source mixing process involving industrial and natural sources, while Cu isotope systematics showed a ternary mixing process involving two distinct anthropogenic signatures, interpreted as associated to new diffuse anthropogenic sources and old warfare material. In contrast, Zn isotope compositions in the Small and Large bays were practically the same: +0.06 ± 0.05‰ and +0.06 ± 0.11‰ (1s, expressed δ66ZnJMC values), respectively, denoting an overlap between isotope signatures of natural and anthropogenic sources. This study presents the first detailed spatial distributions of Cu and Zn isotope compositions for an aquatic system, and demonstrates the feasibility to use Cu isotopes as tracers of anthropogenic sources in coastal environments.

Laos' central role in Southeast Asian copper exchange networks: A multi-method study of bronzes from the Vilabouly Complex

The application of lead isotope-based provenance analysis in Southeast Asia over the last decade has strongly suggested a central role was played by the Lao PDR in regional copper production exchange networks for approximately 1500 years. The Vilabouly Complex, in central Lao's Savannakhet Province, has revealed major copper mining and smelting sites dated to the regional Iron Age (c. 400 BC – AD 500) and possibly Bronze Age (c. 1000 - 400 BC). Metallurgical practices at the Vilabouly Complex, and indeed for all of the Lao PDR, are unknown, and the propose of this paper is to provide a comprehensive analytical study of the Vilabouly Complex metal assemblage, including 60 copper-base artefacts of multiple typologies. Cut samples of these were subjected to morpho-stylistic, metallographic (OM), elemental (XRF, SEM-EDS) and lead isotope analyses (MC-ICP-MS) in order to reconstruct the range of forms, metalworking materials, techniques (alloying, casting and post-casting treatments) used at the Vilabouly Complex. The results revealed an assemblage composed of copper, bronze and leaded bronze alloys, with a majority consistent with the lead isotopic signature for the Vilabouly Complex copper. The consistent geochemical and technological signature of the majority of artefacts strongly corroborates the extensive onsite production evidence, and fits with the burgeoning regional copper-base metals database for copper metal demand being sated in large part by Lao PDR supply.

Potential of lead elemental and isotopic signatures for authenticity and geographical origin of Bordeaux wines

Lead concentrations and lead isotope ratios of 43 authentic Bordeaux wines from prestigious châteaux and 14 suspicious Bordeaux origin were determined to evaluate their potential for authenticity and geographical origin assessment. Results have shown that the total Pb concentrations in Bordeaux wines drastically decreased over the previous 50 years with a clear shift of isotopic signatures towards geogenic values corresponding to an overall trend of European environmental lead monitoring. The Pb isotopic ratios determined in both series of samples clearly demonstrated that suspicious Bordeaux wines displayed Pb isotopic signatures statistically distinctive from those obtained for authentic wines. This observation was confirmed by the three-isotope mixing lines obtained between the geogenic and the anthropogenic Pb isotopes data that characterize European and Asian sources. The use these specific three-isotope plots allows a non-ambiguous discrimination between authentic Pauillac AOC and the counterfeited ones.

Trace elements and lead isotopic composition of copper deposits from the eastern part of the Internal Zone of the Betic Cordillera (SE Iberia): application to provenance of archaeological materials

This paper presents trace element compositions and lead isotope analyses by MC-ICP-MS of 34 copper ore samples from the Internal Zone of the Betic Range, Southeast Spain. Samples were collected during a fieldwork campaign in the mines of Cerro Minado, Pinar de Bedar, Sierra Cabrera and Sierra Almagrera/Herrerias. Most samples are copper oxide minerals from the near surface alteration of the sulfide ore deposits. The aim of the study is to supplement the existing reference data bank on lead isotopic compositions of ancient copper mines from the Iberian Peninsula, complementing this data with trace element compositions. The latter can be useful for discriminating when isotopic overlaps occur. This characterisation will be of great usefulness for provenancing further archaeological materials. Lead isotope ratios range from 18.603 to 20.327 (206Pb/204Pb); from 15.685 to 15.779 (207Pb/204Pb) and from 38.728 to 39.702 (208Pb/204Pb). Data from the literature analysed by TIMS have been also considered for comparison although the larger analytical error is highlighted, especially for isotope 204Pb. The lead isotopic signature of the analysed samples shows three separate isotopic fields. These fields are also consistent with differences in compositions evidenced by principal component analyses.

Source apportionment of Pb in a rice-soil system using field monitoring and isotope composition analysis

Annual inputs and isotope compositions of Pb were investigated to assess Pb pollution and source apportionment in a paddy field around a mining and smelting area. The concentrations of Pb in surface soils (0–20 cm) were significantly higher than those in deep soils (20–100 cm) and the mean concentration of Pb in rice grains exceeded the maximum acceptable level of Pb in food (0.20 mg/kg). These observations indicated that soils and rice in the study area were polluted by Pb. Lead input was higher than Pb output. The annual net input flux of Pb was approximately 18.7 mg/m2/year for the study area. Atmospheric deposition was the most predominant input pathway for Pb, accounting for 95.3% of the total Pb input. However, contributions of fertilizer and irrigation water were merely 3.11% and 2.57%, respectively. Lead isotopic signatures in surface soils and rice grains were different from those in possible sources. This difference suggested that Pb in surface soils and rice grains came from multiple sources. The calculation results from IsoSource program showed that geological background, atmospheric deposition, fertilizer, and irrigation water contributed between 20–84%, 16–42%, 0–42% and 0–28% to soil Pb, respectively. As for rice grains, 76–98% of Pb was derived from atmospheric deposition, whereas source contribution of soil Pb was only 0–26%. These results indicated that mining and smelting activities posed a higher risk to rice grains than soils. Field monitoring (FM) combined with isotope composition analysis (ICA) can provide more information for source identification of Pb than the separate methods.

Lead (Pb) isotope signatures for silcrete sources from the Willandra Lakes region, Australia: A pilot study of a new method for provenancing silcrete artefacts

Silcrete was often used to make stone tools and the ubiquity of this material in the archaeological record has sparked considerable interest in developing techniques that can be used to trace its geographic origin. However, the highly variable physical and chemical properties of silcrete means that artefacts made from this raw material have proved difficult to provenance. This paper describes the use of Pb isotope analysis to characterize and differentiate silcrete sources in the Willandra Lakes region, a UNESCO World Heritage listed site in southeastern Australia. The sample collection strategy employed in the field has allowed Pb isotope variation both within and between the silcrete sources to be described. Pb isotope variation within each silcrete source does not exhibit spatial patterning, but Pb isotope signatures differ between silcrete sources in the Willandra Lakes region, and clear separation between more distant sources, is demonstrated. This represents a first step in being able to use isotope analysis to investigate how silcrete from different sources was used and how it was moved around the landscape.

Lead isotope and metal source of Shang bronzes: a response to Sun et al.’s comments

In this brief response to Sun et al.’s () comments on our paper, we re‐emphasize that archaeological, chemical and isotopic evidence are all relevant to the discussion about the metal source of the Shang period with highly radiogenic lead isotope ratios. The southern African bronzes have much lower lead contents and quite different lead isotopic signatures than the Shang bronzes. More importantly, there was no metallurgy of any kind in southern Africa before c.200 ce, so southern Africa cannot possibly be the source of Shang bronze, which date to about 1500 to 1000 bce.

Holocene provenance shift of suspended particulate matter in the Amazon River basin

The strontium (Sr), neodymium (Nd) and lead (Pb) isotope signatures of suspended particulate matter (SPM) in rivers reflect the radiogenic isotope signatures of the rivers’ drainage basin. These signatures are not significantly affected by weathering, transport or depositional cycles, but document the sedimentary contributions of the respective sources. We report new Sr, Nd and Pb isotope ratios and element concentrations of modern SPM from the Brazilian Amazon River basin and document the past evolution of the basin by analyzing radiogenic isotopes of a marine sediment core from the slope off French Guiana archiving the last 40 kyr of Amazon River SPM, and the Holocene section of sediment cores raised between the Amazon River mouth and the slope off French Guiana. The composition of modern SPM confirms two main source areas, the Andes and the cratonic Shield. In the marine sediment core notable changes occurred during the second phase of Heinrich Stadial 1 (i.e. increased proportion of Shield rivers SPM) and during the last deglaciation (i.e. increased proportion of Madeira River SPM) together with elsewhere constant source contributions. Furthermore, we report a prominent offset in Sr and Nd isotopic composition between the average core value (εNd: −11.7 ± 0.9 (2SD), 87Sr/86Sr: 0.7229 ± 0.0016 (2SD)) and the average modern Amazon River SPM signal (εNd: −10.5 ± 0.5 (2SD), 87Sr/86Sr: 0.7213 ± 0.0036 (2SD)). We suggest that a permanent change in the Amazon River basin sediment supply during the late Holocene to a more Andean dominated SPM was responsible for the offset.

Record of Anthropocene pollution sources of lead in disturbed peatlands from Southern Poland

The importance of human impacts on Earth has led to the proposal of a new geologic epoch called the Anthropocene. However markers, recognizable in all records, are required to define this period. Here we combine elemental geochemistry with stable lead (Pb) isotopes and mineralogical analyses to decipher the sources of lead in two exploited ombrotrophic peat bogs (Puścizna Mała and Puścizna Krauszowska) from Southern Poland. The most disturbed parts of the cores, distinguished using bulk density and age–depth models (22–45 cm in PM and 22–46 cm in PK), were excluded from the interpretation. The two studied cores record ca. 2000 years of variations in lead accumulation rates and isotopic compositions. In the lowest part of the cores (2nd to 4th century AD for Puścizna Mała and 2nd century BC to 2nd century AD for Puścizna Krauszowska), the 206Pb/207Pb ratios (1.188) are consistent with natural supplies from the erosion of the nearby Tatra Mountains. From the 9th to the 19th century AD, 206Pb/207Pb ratios (1.176–1.179) are similar to the signatures obtained from Polish galena ores. The highest Pb accumulation rates are found around 1950 AD and reflect the primary influence of bituminous coal combustion together with the secondary influence of leaded gasoline. This result agrees with the occurrence and abundance of spheroidal aluminosilicates, an unambiguous marker of human industrial activity and coal burning as well as with the acceleration of Zn, Cd and Fe accumulation rate. Our results provide evidence that similar geochemical patterns exist in both analysed cores despite differences in the history of peatland exploitation. Therefore, given that extra care is taken to identify the disturbed peat layers, exploited peatlands can be used to record past changes in lead isotopic signature during the Anthropocene.

Understanding the Influence of Open-waste Burning on Urban Aerosols using Metal Tracers and Lead Isotopic Composition

Open-waste burning (OWB) is one of the primary sources of urban aerosols in several developing countries. To better understand the influence of OWB emissions on urban aerosols, total suspended particles (TSP) and size-segregated samples were collected at an open-waste burning site (the Okhla landfill) and two urban sites in New Delhi. The TSP samples were analysed for selected metals (As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, Se, Sn, Sr, V and Zn) using ICP-MS. In general, among the metals, Fe and Zn were mostly dominant, and As, Cd and Se were found in trace concentrations in the majority of the samples. Additionally, Pb concentrations were ~5–8 fold higher in urban wintertime samples than other samples. Tin, a tracer for waste-burning aerosols, ranged between 0.055 and 0.675 µg m–3 in OWB aerosols. Interestingly, the concentration of Sn was significantly high in the urban wintertime aerosols, specifically, 0.082–0.284 µg m–3. Tin also showed a high enrichment factor in the urban wintertime aerosols, suggesting its anthropogenic origin, possibly because of enhanced OWB practices in winter. Waste burning was also found to be one of the primary sources of chromium, which ranged between 0.102 and 0.606 µg m–3 in OWB aerosols and between 0.114 and 0.574 µg m–3 in urban aerosols. Since Cr(VI) is of interest due to its impact on health, the soluble Cr(VI) concentration was determined and found to be 6.12–10.2 ng m–3 (~1–6% of the total Cr in OWB aerosols compared to 0.33–0.65 ng m–3 [< 1% of the total Cr]) in urban aerosols. The lead isotopic signatures of OWB aerosols, viz., the 208Pb/206Pb and 206Pb/207Pb ratios, were determined to be 2.1309 ± 0.0029 and 1.1316 ± 0.0035, whereas those of the urban aerosols were 2.1369 ± 0.0026 and 1.1243 ± 0.0024, respectively. However, the ranges of these values among the different aerosol types were not very distinct and showed discreet overlaps. This Pb isotopic study, along with metal fingerprints, suggests the increased influence of OWB emissions in winter on New Delhi aerosols.

Geochemical markers of human occupation in the lower Argens valley (Fréjus, France): from protohistory to Roman times

Sediments deposited in the lower Argens valley at Fréjus, a well-known Roman Imperial harbor in northwestern Mediterranean, reveal pollutant metal imprints since the Iron Age. Lead, copper and zinc concentrations in sediments above a facies transition from sand (lower) to silt (upper) at 1820–1946cal.BP (65–130cal.CE) are four times higher than in the non-contaminated geochemical background unit at the bottom of the core. These correlated chemical and sedimentological shifts in the ancient marine bay follow the growth of the Augustan city subsequent to the building of the Roman harbor during the late first century BCE. Trace metal enrichment factors (calculated from background concentrations) display a slight but significant increase (1.3 to 1.5) in sediments deposited during the Fréjus protohistoric period, just below the facies transition. This enrichment is corroborated by mean 206Pb/207Pb isotope ratios that vary from 1.179 (±0.002) to 1.193 (±0.002) and 1.202 (±0.002) in the Roman, protohistoric and background units respectively. These findings are the first evidence of pollutant metal release into the lower Argens ria during the protohistoric period, as far as 2600years ago. Lead isotope signatures in the protohistoric sediment layers shed light on several possible geographic origins for ores from which accumulated pollutant metals may originate. These include copper mines in the Alps or the Languedoc regions. Cyprus may also be isotopically invoked as a source that is not supported by archaeological findings and would constitute, if proven true, a new insight regarding metal trades in protohistoric Gaul.

Copper-base metallurgy in Late Iron Age Cambodia: Evidence from Lovea

In this paper we present the study of the copper-base assemblage of the Late Iron Age (c. 100–400BC/AD) moated site of Lovea in north-western Cambodia. Fourteen artefacts, approximately 20% of the metals assemblage, including bracelets, rings and earrings, were analysed for their elemental and lead isotopic composition, and these data compared with existing Southeast Asian archaeometallurgical databases. Results indicate the presence of bronze, leaded bronze, and possibly high-tin bronze alloys on-site. The unleaded-bronzes exhibit a strong consistency with the lead isotope signature of Sepon in central Laos, a major prehistoric copper production centre. We propose that the apparent presence of a sole copper source, when others were available, may be linked to economic and/or cultural factors during a period of increasing social complexity.

Lead isotopic evidence for interaction between plume and lower crust during emplacement of peralkaline Lovozero rocks and related rare-metal deposits, East Fennoscandia, Kola Peninsula, Russia

The Lovozero alkaline massif—an agpaitic nepheline syenite layered intrusion—is located in the central part of the Kola Peninsula, Russia, and belongs to the Kola ultramafic alkaline and carbonatitic province (KACP) of Devonian age. Associated loparite and eudialyte deposits, which contain immense resources of REE, Nb, Ta, and Zr, constitute a world class mineral district. Previous Sr, Nd, and Hf isotope investigations demonstrated that these rocks and mineral deposits were derived from a depleted mantle source. However, because the Sr, Nd, and Hf abundances in the Kola alkaline rocks are significantly elevated, their isotopic compositions were relatively insensitive to contamination by the underlying crustal rocks through which the intruding magmas passed. Pb occurring in relatively lower abundance in the KACP rocks, by contrast, would have been a more sensitive indicator of an acquired crustal component. Here, we investigate the lead isotopic signature of representative types of Lovozero rocks in order to further characterize their sources. The measured Pb isotopic composition was corrected using the determined U and Th concentrations to the age of the crystallization of the intrusion (376 ± 28 Ma, based on a 206Pb/204Pb versus 238U/204Pb isochron and 373 ± 9 Ma, from a 208Pb/204Pb versus 232Th/204Pb isochron). Unlike the previously investigated Sr, Nd, and Hf isotopes, the lead isotopic composition plot was well outside the FOZO field. The 206Pb/204Pb values fall within the depleted MORB field, with some rocks having lower 207Pb/204Pb but higher 208Pb/204Pb values. Together with other related carbonatites having both lower and higher 206Pb/204Pb values, the combined KACP rocks form an extended linear array defining either a ~2.5-Ga secondary isochron or a mixing line. The projection of this isotopic array toward the very unradiogenic composition of underlying 2.4–2.5-Ga basaltic rocks of the Matachewan superplume and associated Archean granulite facies country rock provides strong evidence that this old lower crust was the contaminant responsible for the deviation of the Lovozero rocks from a presumed original FOZO lead isotopic composition. Evaluating the presence of such a lower crustal component in the Lovozero rock samples suggests a 5–10% contamination by such rocks. Contamination by upper crustal rock is limited to only a negligible amount.