Northwest Argentina Research Articles

Distribución de fragmentos cerámicos prehispánicos en abanicos aluviales de regiones áridas del noroeste argentino (valle de yocavil)

In this article we examine the effects of surficial runoff on the visibility, preservation and spatial distribution of pre-Hispanic pottery sherds (ca. 100-1.535 a.C.) in alluvial fans of the Sierra de Quilmes (Northwest of Argentina) to evaluate the validity of spatial patterns of occupation based in part on them. Archaeological surveys across the slope-foothill-bottom of the valley with surface collection and pits were made. Archaeological places were located and chronologically differentiated in geomorphological and hydrological maps. Finally, traces of hydric displacement in the ceramic fragments were macroscopically analyzed. The results show, that pottery sherds were mainly found in the proximal and distal parts of the fans, but they markedly decrease in the middle sectors, eliminated by runoff and channeled through the gullies after a short distance displacement. However, formal modifications of the sherds due to displacement are uniformly slight in all three sectors, and, importantly, there are spatial and chronological-stylistic correspondences between surface and pit assemblages. Consequently, the pottery distribution reflects the archaeological spatial structure at local and microregional scales, even under spatially differentiated water and wind erosion / sedimentation, favored by aridity, differences in slopes and vegetation cover.

A new remote-sensing-based volcanic debris avalanche database of Northwest Argentina (Central Andes)

A new remote-sensing-based volcanic debris avalanche database of Northwest Argentina (Central Andes)

Lost and found: the rediscovery of the lost fern species Asplenium achalense (Aspleniaceae) and assessment of its conservation status

Abstract The fern of Achala Asplenium achalense Hieron. (Aspleniaceae), endemic to north-west and central Argentina, was formerly considered a lost species. We describe its rediscovery in August 2022 in the Yungas biogeographical province, compile a map of all historical and current records of the species, and propose an IUCN Red List status. We estimated the fern of Achala's range using the area of occupancy of the rediscovered population, calculated as 4 km2 because it is located in a single 2 × 2 km grid square. The extent of occurrence cannot be calculated because only a single living population is known. These data suggest a provisional categorization of the fern of Achala as Critically Endangered based on criteria B2ab(i,ii,iii,iv,v). The species should be considered Regionally Extinct in its locus classicus in Comechingones biogeographical province. We recommend securing the conservation of the single known population (which does not lie within a conservation unit), further surveys for the species in the five protected areas where it was recorded historically, and restoration of the species in the wild. To support the latter, we are cultivating spores and gametophytes of the fern of Achala, in collaboration with colleagues from the National University of La Plata.

Contemporary Uses of Vilca (Anadenanthera colubrina var cebil): A Major Ritual Plant in the Andes.

Vilca or cebil (Anadenanthera colubrina var. cebil) is a species known for its psychoactive properties and its widespread use among the pre-Hispanic peoples who inhabited the southern Andean area (southern Peru, Bolivia, northern Chile and northwest Argentina). Studies on this species, as well as on medicinal, psychoactive, or magical plants in general, tend to consider its use in post-Spanish conquest times to be scarce or irrelevant in the Andes of South America. However, based on an in-depth review of the existing literature and on ethnobotanical research conducted in markets in Argentina, Bolivia, and Peru, this paper provides an updated overview affirming the continuity of the use of this species. The results indicate a significant diversity in terms of usage types, plant parts used, treatments, and conditions in which it is applied, along with new records of vernacular names. This paper also offers an interpretation from the perspective of Andean logics, highlighting the current therapeutic effectiveness of the seeds of this plant, facilitated through a series of "movements" that aim to restore the affected person's health.

Recruitment responses of shade‐tolerant and heliophilous trees in degraded areas: The necessity of knowing the recruitment autecology of species for effective reforestation decisions

AbstractDirect seeding is a reforestation technique that allows introducing a great variety of tree species in degraded areas with less logistics, but tree establishment rates are usually low because developing plants do not tolerate the high sun exposure, extreme temperatures, and low soil moisture that prevail in these habitats. This leads to the proposal that seeds should be planted beneath shrubs or herbaceous plants that ameliorate harsh abiotic conditions, although this can also trigger interspecific competition and impair the performance of developing trees. This study aimed to test these proposals in dry forests in northwest Argentina. For this, seeds of two shade‐tolerant trees and a heliophilous tree, native to this region, were sowed beneath the canopy of pioneer shrubs and in open spaces with and without herbaceous plants. After 2 years, our findings indicated that shade‐tolerant trees performed better beneath shrub canopies, while the heliophilous tree achieved higher establishment rates in the open spaces. Nevertheless, it seems that herbaceous plants compete with the tree seedlings and, therefore, they should be removed before conducting reforestation programs. Thus, we propose that direct seeding could be an efficient reforestation strategy, but the regeneration autecology of the tree species selected for this task, as well as their competitive ability in the face of the pioneer vegetation, must be carefully evaluated before seeding.

Transnational corporate influence and local politics: how mining companies intervene in neighbouring communities

AbstractThis paper analyses how transnational mining companies influence decision-making processes and public policies in communities adjacent to industrial gold mines. Most social science research on mining focuses on the emergence and dynamics of social conflicts over mining and overlooks the political influence mining companies exert by implementing development programmes to gain social acceptance. This paper fills this gap and develops a refined understanding of the multiple layers of political influence of companies in mining areas. It finds that mining companies spatialise corporate interests, contribute to an informalisation of political decision-making, assume quasi-governmental functions and, in this way, intensify the privatisation of local politics. This paper draws on approaches from critical governance research, critical geography and participation theory. It analyses corporate influence by distinguishing between socio-spatial, political-institutional and political-developmental forms of influence that companies use to create social acceptance for their particular mining project. Empirically, this paper is based on a comparative case study of corporate influence in communities near industrial gold mines in the Argentine north-west and southern Patagonia. For conflict research, the article offers a novel framework for shedding light on the workings of corporate micropolitics in mining areas beyond manifest conflicts. This contribution illustrates that mining companies have the capacity to mould political institutions and public policies by implementing development programmes that are in fact designed to serve corporate purposes.

A new species of Porophyllum (Asteraceae: Tageteae) from the northwest of Argentina, and the first record of female plants of Porophyllum cabrerae

Porophyllum riparium, a new species of the genus Porophyllum, is described. Morphological details, illustration, geographical distribution, and photographs in its natural habitat are provided. This new species occurs in the northwest region of Argentina, in Salta, Jujuy and Tucumán Provinces, in the Yungas biogeographical province. It is usually found on rocky and sandy soils, as well as along riverbanks. Porophyllum riparium is characterized by being an annual or short-lived perennial, glaucous, odoriferous, monoecious herb, 15–80(–130) cm tall, with sessile or attenuate into a pseudopetiole, linear-elliptic leaves with submarginal and subapical semi-pellucid oil cavities, lemon-colored infundibuliform corollas and exserted brownish anthers. Additionally, female plants of Porophyllum cabrerae were documented for the first time, photographs and descriptions of their female florets are included. Also, a key to identify northwestern species of Porophyllum is provided.

Cis, Trans and Lesbian Women in Situations of Violence and Access to Justice in Northwest Argentina: From Diagnosis to Action

Cis, Trans and Lesbian Women in Situations of Violence and Access to Justice in Northwest Argentina: From Diagnosis to Action

Structure of compound and component communities of fleas parasitic on small mammals in six different regions as revealed by environmental‐based co‐occurrence geometry analyses

AbstractWe inferred the patterns of co‐occurrence of flea species in compound (across all host species) and component (across conspecific hosts) communities from six regions of the world (Mongolia, Northwest Argentina, Argentinian Patagonia, West Siberia, Slovakia, and South Africa) using the novel eigenvector ellipsoid method. This method allows us to infer structural community patterns by comparing species’ environmental requirements with the pattern of their co‐occurrences. We asked whether: (a) communities are characterized by species segregation, nestedness, or modularity; (b) patterns detected by the novel method conform to the patterns identified by traditional methods that search for non‐randomness in community structure; and (c) the pattern of flea species co‐occurrences in component communities is associated with host species traits. The results of the application of the eigenvector ellipsoid method suggested that the co‐occurrence of flea species was random in all compound communities except in South Africa, where this community demonstrated a tendency to be nested. Flea species co‐occurrences were random in many component communities. Species segregation was detected in the flea community of one host, whereas the flea communities of 14 hosts from different regions appeared to be nested. No indication of a modular structure in any community was found. The nestedness of flea component communities was mainly characteristic of hosts with a low relative brain mass. We concluded that the application of this novel method that combines data on species distribution and their environmental requirements allows better identification of the community structural patterns and produces more reliable results as compared with traditional methods.

Wastewater and Grey Water Footprint Assessment of the Olive Oil Production Process in Northwest Argentina

Argentina stands as the leading producer and exporter of olive products in the Americas, with the province of La Rioja as its main productive area. Since the 1990s, the olive grove cultivated area and related agro-industry in La Rioja have expanded. However, the resulting wastewater has generally been neglected. The water footprint (WF) provides information about the water volume consumed and polluted by a production process. Since the 1990s, agricultural and agro-industrial activities in La Rioja have experienced substantial growth. This study aims to analyze the generation, quality, and management of Oil Mill Wastewater (OMWW) using the grey WF of chloride and nitrate as an indicator and focusing on two olive mills (OM) in La Rioja. Additionally, it seeks to examine the relationship between the international trade of provincial olive oil and the estimated grey WF. For the diagnosis of OMWW generation, a description of the production process was made coupled with flow and physico-chemical characterization. The total grey WF was 8.69 and 45.5 L water/L olive oil for OM 1 and OM 2, respectively. Nitrate was identified as the critical pollutant. The grey virtual water export related to the export of olive oil was 5569 m3 for OM 1 and 28,000 m3 for OM 2. The provincial grey virtual water export related to olive oil was 161,955 m3 with major trade destinations including Spain, the United States, and Brazil. The article analyses for the first time the grey WF of olive oil industries and assess the related grey virtual water exports. This research represents a step forward in the knowledge of wastewater management in the olive oil sector and facilitates the search for solutions to minimize negative environmental impacts while promoting cleaner production.

Black paintings in the late Yocavil ceramics (11th–17th centuries): Applying micro X‐ray diffraction to the study of archaeological potteries in Northwest Argentina

AbstractThe black pigments used in Late Period (11th–17th centuries) painted pottery in the Yocavil Valley were characterized. Changes and continuities in the composition of this material over an extended span were evaluated. A regional sample of 47 potsherds from the Loma Rica, San José, and Santa María styles was collected, and for the first time micro wide‐angle X‐ray scattering was used in these ceramic styles. The results indicate the simultaneous presence of iron oxides (hematite) and solid solutions of manganese and iron oxides (jacobsite–magnetite). Besides, the paints were prepared by mixing the pigments with clay‐based binding materials.

Depositional and diagenetic processes in travertines: A comprehensive examination of Tocomar basin lithotypes, Northwest Argentina

The use of travertines in active fault studies is known as travitonics. Their geobody shape, veins, faults and fractures, are commonly used as neotectonic proxies. The surficial travertines in the pull apart Tocomar Basin (Puna Plateau, Argentina) occur in the center of the Calama – Olacapato – El Toro (COT) transcurrent fault zone and have never been substantially buried. The Tocomar area exhibits complex tectonic with N–S thrust faults and NW-SE transfer faults, crucial in shaping its travertine deposits and geothermal activity. The travertine bodies are characterized in terms of geometry as a fissure ridge type, coexisting with ash tuff, siliciclastic sandstone, and conglomerate deposits. The travertines mainly consist of crystalline crusts, with occasional occurrences of granular, arborescent, and porous textures. Mineralogical analyses by X-ray diffraction (XRD) reveal the predominance of magnesian calcite, along with trace minerals identified as dolomite, anhydrite, gypsum, halite, fluorite, bassanite, and barite. Petrographic analyses, including cathodoluminerscence (CL), indicate intense diagenesis in the travertine samples. Isotopic signatures of C and O in these samples exhibit normally a negative trend, ranging from −6.38 to +2.45 ‰ VPDB for δ13C and from −20.48 to −11.21 ‰ VPDB for δ18O. Laboratory analysis and field observations allow to classify three distinct lithotypes in the Tocomar travertine: (1) crystalline crust, further divided into three sub-lithotypes: (1.1) laminated crystalline crust (LCC), (1.2) filamentous-like crystalline crust (FlCC) and (1.3) fiber-like crystalline crust (FbCC); (2) granular travertine (GT) and (3) porous travertine (PT). These different lithotypes likely reflect variations in fluid velocity during deposition, although some of them may result from diagenetic processes. The three lithotypes give rise to four facies association (steep slope, marshy/pools, drainage, and fracture-associated facies), forming two distinct depositional systems (slope and channel), which comprises the Tocomar travertine system.

UHPLC-MS/MS and GC-MS Metabolic Profiling of a Medicinal Flourensia Fiebrigii Chemotype.

The comparative metabolic profiling and their biological properties of eight extracts obtained from diverse parts (leaves, flowers, roots) of the medicinal plant Flourensia fiebrigii S.F. Blake, a chemotype growing in highland areas (2750 m a.s.l.) of northwest Argentina, were investigated. The extracts were analysed by GC-MS and UHPLC-MS/MS. GC-MS analysis revealed the presence of encecalin (relative content: 24.86 %) in ethereal flower extract (EF) and this benzopyran (5.93 %) together sitosterol (11.35 %) in the bioactive ethereal leaf exudate (ELE). By UHPLC-MS/MS the main compounds identified in both samples were: limocitrin, (22.31 %), (2Z)-4,6-dihydroxy-2-[(4-hydroxy-3,5-dimethoxyphenyl)methylidene]-1-benzofuran-3-one (21.31 %), isobavachin (14.47 %), naringenin (13.50 %), and sternbin, (12.49 %). Phytocomplexes derived from aerial parts exhibited significant activity against biofilm production of Pseudomonas aeruginosa and Staphylococcus aureus, reaching inhibitions of 74.7-99.9 % with ELE (50 μg/mL). Notably, the extracts did not affect nutraceutical and environmental bacteria, suggesting a selective activity. ELE also showed the highest reactive species scavenging ability. This study provides valuable insights into the potential applications of this chemotype.

Obsidian lithic technology: Chaîne opératoire and symbolic meaning in the Northern Hualfín Valley (Northwest Argentina) during the Late Inka period

The main objective of this research is to analyse the lithic technology applied to obsidian, a raw material popular amongst pre-Columbian populations from Northwestern Argentina (NWA) because of its social and symbolic value. The analysed assemblage comes from the archaeological site of Villavil 2 (VV2), located in the Hualfín Valley (Catamarca, Argentina) and distant ca. 100 - 200 kms from the nearest sources of this raw material. VV2 was discovered in 2015 by one of the authors and shows a particular presence of rock art which had not previously been registered in this area. The site was associated to the Late and Inka Period (ca. 10th - 16th centuries CE). So far, we suggest that this was a place of temporal, but periodical use that best fits with what we would call a ceremonial space.
 The assemblage comprises the totality of obsidian elements collected from both superficial and stratigraphic contexts. It was divided into three typological classes: tools (projectile points), flakes with natural sharp edges (FNSE) and waste products (WP). We did not identify the presence of cores. The analysis considered the following variables: knapping methods and techniques, size, amount of cortex, flake type and edge types.
 At VV2, points are the only retouched tools made of obsidian. They correspond to the triangular unstemmed concave-based type, very common during the Late-Inka Periods, and they were shaped using the perimetral bifacial pressure technique, possibly from flake blanks. FNSEs’ size is small, and they present scarce cortex. On the other hand, the abundance of very small-sized WPs is remarkable. They were found in the same stratigraphic context and attest a complete finish of the points (edge retouch).
 The results let us infer that the point-shaping tasks were carried out in situ. Moreover, the implemented technology involved both major production efforts and skills, that contrast with those involved in local raw material knapping. It is possible that this curated strategy was not related to the difficulty of accessing this allochthonous material. Instead, these choices could reflect social and symbolic meanings. According to linguistic and ethnohistoric information, the obsidian brightness and transparency are propitiatory to win the favour of the w'akas. Furthermore, in NWA the obsidian long-distance exchange is an ancient pre-Columbian tradition that lasted for a long time. Obtaining obsidian could display the ability of a social group to access distant resources and legitimize their political status. Nevertheless, we cannot forget that this raw material also was very important for making different artefacts for subsistence activities.

Ecosystems dynamics and environmental management: An NDVI reconstruction model for El Alto-Ancasti mountain range (Catamarca, Argentina) from 442 AD through 1980 AD

Vegetation dynamics play a crucial role in understanding the complex interactions between climate variability, ecosystem changes and human land use. In this study, we use the Hindcasting Ecosystems Model (HEMO) to reconstruct the paleo Normalized Difference Vegetation Index (paleo-NDVI), which provides valuable insights into the historical vegetation patterns. Our research focuses on the El Alto Ancasti mountain range, a region characterized by its rich environmental diversity, and archaeological evidence of pre-Hispanic agricultural village landscapes, showcasing the knowledge and management of diverse environments and their fluctuations.To reconstruct the paleo-NDVI, we employed a Neuronal Network trained with two datasets. First, we utilized NDVI data extracted from AVHRR/NOAA satellite images spanning from 1982 to 2015, representing 8 km pixels from the Global Inventory Modeling and Mapping Studies. Second, we incorporated growth ring chronologies from Northwest Argentina sourced from the International Tree Ring Data Bank, enabling the calibration of the NDVI-ring relationship. This methodology allowed us to reconstruct the paleo-NDVI back to 442 AD and to calculate anomalies.Our analysis revealed significant negative anomalies around 600 AD, coinciding with previous research conducted in the nearby Ambato valley. These anomalies may be attributed to the eruption of Tres Cruces volcano in Catamarca during that period. Additionally, extensive positive anomalies emerged from 1600 AD onwards, which align with anomalies detected in earlier studies. The eruption of Huaynaputina volcano in southern Peru in 1600 AD is a possible factor contributing to these positive anomalies.Ongoing investigations focusing on the paleoenvironment and human occupations in the El Alto-Ancasti area aim to provide further insights into how these detected changes could have influenced environmental management decisions. By integrating multidisciplinary approaches, we can better comprehend the complex relationship between vegetation dynamics, climatic events and human activities, ultimately enhancing our understanding of past environmental transformations and their implications for sustainable management strategies.

Experimental flintknapping with sandstones and prospection of lithic raw material sources from Cabra Corral area, Salta, Argentina

Within the framework of the project named Technological Variability and Social Interaction Networks in Northwest Argentina through the study of lithic technology strategies throughout the Formative period (Mercuri 2012) we collected samples of lithic raw materials in different portions of Las Conchas- Guachipas river area (Salta, Argentina) in order to create a reference collection. With part of this material we performed experimental lithic flintknapping with the aim to observe fractures and other characteristics that allow determining flintknapping quality so that we can understand and give a first reading to the selection of raw materials for making artifacts using local rocks.We present the results of these experiments conducted on sandstone, as it was the predominant raw material in the archaeological record. First results allow us to affirm that sandstone, given the availability and quality for flintknapping tasks constitutes an optimal raw material for the production of artifacts. We also note that the obtained edges are suitable for cutting work and the notches recorded in the artifacts are due probably to the characteristics of rock fracture.

Excito-repellent and Pesticide-Likeness Properties of Essential Oils on Carpophilus dimidiatus (Fabricius) (Nitidulidae) and Oryzaephilus mercator (L.) (Silvanidae).

Carpophilus dimidiatus (Fabricius) (Nitidulidae) and Oryzaephilus mercator (L.) (Silvanidae) are insect pests that cause severe damage in important walnut growing regions in the northwest of Argentina. The current management approaches for these pests involve the use of unsafe phosphorus pesticides whose overuse have led to farmworker poisoning, pest resistance issues, and environmental contamination. Plant extracts, particularly essential oils, are an alternative source of insect control agents. Excito-repellent essential oils can be used to develop ecofriendly tools for managing the pest population without affecting quality and visual appearance of the stored walnuts. Laboratory studies were conducted to assess the excito-repellent effects of C. dimidiatus and O. mercator of 12 essential oils derived from aromatic plants used as food additives and traditional medicine in Argentina: Aloysia citrodora (AC), Aloysia gratissima (AG), Aloysia gratissima var. Gratissima (AGG), Blepharocalyx salicipholius (BS), Hyptis mutabilis (HM), Lippia junelliana (LJ), Lippia turbinata (LT), Mentha x piperita (MP), Minthostachys mollis (MM), Minthostachys verticillata (MV), Origanum vulgare(OV), and Rosmarinus officinalis (RO). The most bioactive EOs (ERijk ≥ 70%) were Aloysia gratissima var. Gratissima (AGG), Minthostachys verticillata, and Lippia junelliana. Their bioactivity profile and chemical space, characterized from GC-MS measures, Generalized Estimating Equations, and Hierarchical Cluster Analysis, revealed that they are mixtures of very functionalized molecules with physicochemical properties similar to those of insecticides with low residual property that enter the insect body through the respiratory system by inhalation. The AGG, MV, and LJ oils are promising as protective agents of walnut products. In our laboratory, studies of their formulations for use in integrated pest management programs are still ongoing.

Geological and geochronological implications of U–Pb dating in apatite from the Late Devonian/Early Carboniferous Sauce Guacho granite, Sierra de Ancasti, NW Argentina

The Sierra de Ancasti is located in the southeastern part of Catamarca province in northwest Argentina. It belongs to the easternmost sector of the Eastern Sierras Pampeanas geological province. The crystalline basement of the Sierra de Ancasti consists mostly of granitoids of two different ages -Early/Middle Ordovician and Late Devonian/Early Carboniferous periods-that intrude medium to high-grade metamorphites. The Sauce Guacho (SG) granite, which corresponds to the second period mentioned above, is one of them, and it intrudes banded schists. The SG granite has similar geological and geochemical characteristics to other coetaneous granitic bodies scattered throughout the Eastern Sierras Pampeanas. To get geochronological information on SG granite and contribute to the understanding of the Upper Paleozoic magmatism developed in the pre-Andean margin of SW Gondwana, we carried out U–Pb apatite dating on this granitic body of the Sierra de Ancasti. Several transparent, green, idiomorphic, and subidiomorphic apatite crystals were separated from the SG granite. They were used to obtain U–Pb apatite ages using LA-ICP-MS methodology. The results yielded concordia ages between 346 and 363 Ma. Due to the relatively low closure temperature of the U–Pb system in apatite (∼350°-570 °C), the result is considered a cooling age marking the end of the high-temperature magmatism that would have given rise to the SG granite. This revalidates a magmatic episode of the Middle Devonian-Early Carboniferous age, corresponding to the so-called ‘Early Gondwanan’ orogeny in the Sierra de Ancasti. An initial cooling rate has been estimated at ∼4 °C/Ma for the SG intrusive.

New insights on black carbon in pelagic Atlantic sediments

Black carbon (BC) is ubiquitous in pelagic sediments and presumed to have an older radiocarbon age due to long ocean residence times and pre-aging in terrestrial soils. Here, we analyzed sediments from five regions in the subtropical Atlantic Ocean to quantify the black carbon fraction of the total organic carbon pool. Black carbon, derived from the chemothermal oxidation method, comprised between 17 ± 6% of the sedimentary organic carbon in the Northwest Argentina Basin and 65 ± 18% in the Amazon Delta. Black carbon sediment accumulation rates were six times greater in the Sierra Leone Rise (8.4 ± 4.1 mg cm−2 kyr−1) compared to the remote Northwest Argentina Basin (1.3 ± 0.4 mg cm−2 kyr−1), possibly due to enhanced regional atmospheric deposition from annual African grassland fires. The radiocarbon age for BC from subtropical Atlantic sediments were more modern compared to the bulk total organic carbon, and BC source was apportioned as biomass burning byproducts from their stable carbon isotopic signatures and characteristic ratios of polycyclic aromatic hydrocarbons. This study demonstrated that subtropical Atlantic Ocean sediments serve as an important sink for young BC.

The interplay between magma source and geodynamic evolution in porphyry Cu-Au fertility of the Farallon Negro Volcanic Complex, Argentina

Zircon U-Pb, O, Lu-Hf and trace element systematics are used to track the magmatic-hydrothermal evolution and metallogenic potential of porphyry intrusions and associated Cu-Au deposits. We apply this analytical approach to unveil the poorly constrained geological history of the Farallon Negro Volcanic Complex in the Central Andes of northwest Argentina. This complex contains the world-class Au-rich Cu-Au Bajo de la Alumbrera deposit (here dated at 6.9 ± 0.1 to 6.8 ± 0.2 Ma; U-Pb SHRIMP) and a series of barren to weakly mineralized satellite porphyry intrusions, including El Durazno (8.0 ± 0.3 Ma; U-Pb SHRIMP), San Lucas (7.4 ± 0.1 to 7.3 ± 0.1 Ma; U-Pb SHRIMP) and Las Pampitas (7.2 ± 0.2 to 7.0 ± 0.1 Ma, U-Pb SHRIMP). Zircon Hf and O isotope data record a change in magma source from El Durazno (δ18O = 5.7 ± 0.3‰; εHf = −0.3 ± 1.8) to San Lucas, Las Pampitas and Bajo de la Alumbrera (δ18O > 6.7‰, εHf = − 4.0 ± 0.5 to −2.2 ± 1.0). This reflects a switch from a predominantly mantle-derived magma source to a mixed mantle-derived and supracrustal source that homogenized in a lower-crustal magma assimilation, segregation and homogenization (MASH) zone. All intrusions have a hydrous (Eu/Eu* > 0.5, Dy/Yb < 0.3), oxidized (ΔFMQ >1.0, Ce/Ce* > 100) and, therefore, ‘fertile’ zircon trace element signature, despite having variable Cu and Au grades. Likewise, ore-barren extrusive units in the FNVC have an overlapping ‘fertile’ zircon signature, reinforcing the view that zircon-based proxies for fertility may not be useful for mineralization targeting at a district scale. The magmatic evolution of the FNVC was significantly influenced by the tectonic setting, as the onset of regional transpression at ∼8 Ma after a period of localized extension caused pooling of mantle-derived magmas in a lower-crustal MASH zone and build-up of volatiles and metals. The petrogenetic model proposed for the FNVC emphasizes the role of the geodynamic environment and magma evolution in the Cu-Au endowment of Bajo de la Alumbrera