Keywords

1 Introduction

As we mentioned in the abstract, in this chapter we propose to discuss the important contribution of non-invasive surveys, along with minimally invasive pedological analyses, in the evaluation, re-evaluation and documentation of buried archaeological heritage. We propose also an overview of the research background, especially by discussing some key moments in promoting these interdisciplinary methods and techniques in Romanian archaeology. Therefore, we consider a review of the contributions to geophysical research, as well as the main initiatives in the field of pedological studies applied to archaeological contexts. The aim is to highlight the indisputable need for such initiatives in a modest national historiographical landscape.

In support of our approach, we have chosen to focus on one of the most well-known and publicised prehistoric archaeological monuments in Romania, the eponymous site of the Chalcolithic Cucuteni Culture (toponym Cetățuie). The site has benefited from special attention over time, but still with multiple questions without an answer.

1.1 Brief Retrospective About Interdisciplinarity in Romanian Archaeology: The Role of Geophysical Prospection

The assertion of modern prospection techniques, starting with the second half of the last century, and the special impact on international archaeological research, have caused an echo among specialists in Romania as well. We recall here, from the pioneering phase, the resistivity survey of Richard Atkinson, conducted at Dorchester-on-Thames, in 1946 and published for the first time in the work edited by Annette Laming (1952), those of Martin Aitken and Eduard Hall from Oxford University (Aitken, 1958, 1986), Elizabeth Ralph at the Museum Applied Science Center for Archaeology (Ralph, 1964), Albert Hesse and Alain Tabbagh at the Center National de la Recherche Scientifique, Irwin Scollar at the Rheinisches Landesmuseum in Bonn, or Carlo Lerici and Richard Linington from the Lerici Foundation and the Milan Engineering School (Lerici, 1965; Clark, 1990; Gaffney & Gater, 2003).

Thus, in a paper published by Hadrian Daicoviciu in 1960 (Daicoviciu, 1960), inspired by the volume edited by Annette Laming in Paris (1952), the measurement of electrical resistance of the soil, one of the main methods of prospecting in archaeology to this day, is presented. The author highlights the indisputable quality of these type of studies and the need to standardise these applications in Romanian archaeology, emphasising the advantages that the archaeologist can benefit through these non-invasive interventions. In this regard, the following historiographical statements come from Aurelian Petre (1966a, b; Petre & Apostol, 1970), a good connoisseur of this subject, who, following the inauguration in 1964 of the annual international courses of archaeological prospecting, organised by the Milan Engineering School, takes part in one of these meetings. The first two articles of the above-mentioned author present synthetically, and in a manner accessible to the archaeologist, the methods debated during the course of 1965 that took place in Rome. The 1970 paper (Petre & Apostol, 1970) presents one of the first practical applications of magnetic and electrical methods in Romanian archaeology, more precisely the ones conducted in the perimeter of the ancient castrum of Beroe (Petre & Apostol, 1970).

In the following period, for various reasons, the application of recently developed techniques is manifested in Romanian archaeology only as a desideratum. References can be made, for the period of the ‘80s, to initiatives such as that of professor Gheorghe Lazarovici, who applied the method of electrical resistivity in the tumulus from Tureni (Dragomir et al., 1992) and took an interest in organising national seminars on archaeometry, in the period 1988–1992.

A new approach in archaeology, manifested during the ‘90s, directed mainly towards interdisciplinarity and driven, in particular, by numerous collaborations with specialists from abroad, encourages the intensification of the use of non-destructive methods in Romania, visible both by the appearance of scientific studies based on field applications—such as those from Scânteia, Dealul Bodești (Cucuteni culture) started in 1994 and 1995 (Ghiță et al., 2000) or the measurements of the same F. Scurtu (2014) for sites like Porolissum, Histria, Tropaeum Traiani, Orgame or Halmyris—as well as through the institutionalisation of research centres.

The problem that fundamentally characterises this period is the lack of an adequate logistical base, qualified staff and bibliographic material. The results, where they exist, do not exceed the scope of isolated tests. However, in 1996, at the initiative of a team from the National Museum of History of Romania, the National Centre for Multidisciplinary Research was established (Popovici et al., 2002). The University “1 Decembrie 1918” of Alba Iulia, with the help of a research grant, implemented in the period 2001–2003, starts the second attempt to establish an institutional body. Originally called Multi-Users Research Base and with the specific objective of developing a system of theoretical and practical training in the field of archaeology, conservation and restoration of archaeological materials and sites, it will be transformed in 2004 into the Institute of Systemic Archaeology, which currently bears the name of the initiator of this project, the late professor and archaeologist Iuliu Paul.Footnote 1 In Iași, interdisciplinarity was highly and early promoted. In this regard, mention should be made of the introduction, in 1987, of a section entitled “Interdisciplinary Research in Archaeology” in the prestigious journal Arheologia Moldovei, at the initiative of the journal’s founder, professor Mircea Petrescu-Dîmbovița. In 2000, under the auspices of the Department of Ancient History and Archaeology of the Faculty of History, within the “Alexandru Ioan Cuza” University of Iași, the Interdisciplinary Centre for Archaeological Studies (CISA) was created, aiming to “establish contacts and collaborations with all those who can and want to contribute to the progress of archaeological research through interdisciplinarity” (Ursulescu, 2006). The founding of this centre, as well as the subsequent activity dedicated to issues related to multi- and interdisciplinarity (language standardisation, explanation of terms, etc.) was the foundation on which, a few years later, the Platform for Training and Research in Archaeology—Arheoinvest will be based. The latter, set up after obtaining a research grant, comes to solve one of the most pressing problems in Romanian archaeology—the alignment of research standards with the European ones, by acquiring an appropriate logistical basis for the interdisciplinary approach, including modern instruments for archaeological prospection.Footnote 2

Along with these three main examples, we can list the National Centre for Multidisciplinary Research at the “Valahia” University of Targoviște, the Department of Computerized Archaeology at the National Museum of Transylvanian History in Cluj-Napoca, the Applied Geomorphology and Interdisciplinary Research Centre at the Department of Geography at the West University of Timisoara (with a strong geoarchaeological component) or the Tulcea Eco-Museum Research Institute, involved through the project “Archaeological Research and Prospecting with Optoelectronic Means (CARPO)” in the mapping of all archaeological sites in the county.

All this contributed to significant progress in the field, putting the Romanian archaeological research to an ascending direction.

Thus, in the last two decades, we can see an obvious increase in the application of non-destructive techniques in prehistoric and classical archaeology, based, in particular, on collaborations with foreign groups, but also through the contribution of local specialists (Ardelean et al., 2017; Asăndulesei, 2011, 2015b; Asăndulesei et al., 2011; Bennett, 2006; Cosac et al., 2014; Dragoș et al., 2020; Drașovean & Schier, 2010; Gogâltan et al., 2019; Gridan et al., 2017; Heeb et al., 2012, 2015; Hegyi et al., 2019, 2020, 2021; Maillol et al., 2004; Micle et al., 2010a, 2010b; Mischka, 2008; Mischka et al., 2015; Opreanu et al., 2013; Pisz et al., 2019, 2020; Popa, 2017; Popa et al., 2009; Scurtu, 2005; Ștefan & Popa, 2017; Ștefan et al., 2010; Szentmiklosi et al., 2011; Țentea et al., 2018; Teodor & Dumitrașcu, 2019).

In direct connection with our case study, previous undertakings in the case of the Cucuteni culture include those carried out by our team from Arheoinvest Center (Asăndulesei et al., 2012, 2020a, b; Asăndulesei, 2014, 2015a, 2017), by teams of German researchers collaborating with Romanian specialists (Mischka, 2008; Hofmann et al., 2016; Mischka et al., 2016) or with groups from other Romanian academic or research centres (Dumitroaia et al., 2012; Micle et al., 2010a).

1.2 Short Overview About Pedo-archaeological Interaction

In Romania, although the relationship between archaeology and pedology has its roots in the late ‘50s, very few pedo-archaeological studies were carried out to date. The earliest attempts to study soils in archaeological contexts belong to Popovăţ (1957), which aimed to establish a relative age of soil horizons buried under several Bronze and Iron Age sites from south-eastern Romania, and to Nicolăescu-Plopşor (1958), which focused on developing a chronological scheme of the Upper Paleolithic using soil and archaeological data. Later on, Protopopescu-Pache (1969) and Mateescu (1971) conducted several pedogenetic studies within Neolithic settlements from south Romania.

During the ‘70s and ‘80s, the sporadic collaborations between soil scientists and archaeologists resulted in several papers published by Asvadurov et al. (1970, 1972), which focused on the Paleolithic chronology using soil data, and by Lupașcu et al. (1987), who analysed the physicochemical properties of the thick heterogeneous deposits from a tell settlement from eastern Romania.

Over the last decades, the increasing demand for soil information in archaeological studies led to a slightly growing of published papers focused on the detailed physicochemical and mineralogical characterisation of soils from various archaeological sites (Lupașcu, 1996; Gâță et al., 2000; Rogobete et al., 2011; Dicu et al., 2015). In recent years, emphasis has been drawn to the use of proximal soil sensors and digital soil morphometric techniques, together with the multivariate statistical methods in the pedo-archaeological studies (Pîrnău et al., 2014, 2020, 2022). An overview of literature related with Romanian pedo-archaeological research can be found in Asvadurov and Florea (2002).

As can be seen from the paragraphs above, only recently can be noticed an intensification of integrated archaeological studies. The generalisation of non-invasive investigations based on the integration in a GIS environment, alongside spatial analysis, of the main prospecting methods (air photography, LIDAR surveys, geophysical prospecting, pXRF) arise new opportunities for understanding the complex phenomenon on the evolution of these Cucuteni communities.

2 Rediscovering the Eponymous Site of the Cucuteni Culture

In 1884, at 50 km from Iași, the archaeological site of Cucuteni was discovered, a site which was to become one of the eponymous settlements of the most renowned prehistoric civilisations in Europe, Cucuteni-Trypillia, whose area of spread exceeded 350.000 km2 over nowadays Romania, Ukraine and the Republic of Moldova (Lazarovici et al., 2009).

The site (Lat: 47°17′55.12″N; Long.: 26°54′44.68″E) is located in North-East Romania (Fig. 1a), on the north-western part of Iași county (Fig. 1b) and in the upper sector of Valea Oii catchment (the last left tributary of the Bahluieț River), in a hilly area at the border between Moldavian Plain and Suceava Plateau (Fig. 1c). More specifically, can be found in the north-west of the Băiceni village (Fig. 2a, b) on a promontory east of the wide Laiu plateau (Petrescu-Dîmbovița & Văleanu, 2004).

Fig. 1
A map of the study area in north east Romania depicts the site located in the north-western part of Ia?i county. The D E M ranges from 50 to 425 meters and includes the Valea Oii catchment, Targu Frumos, and Podu Iloaiei on the Bahluiet River.

The location of the case study in North-East Romania (a), within Iași county (b), and Bahluieț river basin (c)

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Fig. 2
Two topographic maps depict the area of Cucuteni-Ceta?uia, situated northwest of the Baiceni village on a promontory east of the wide Laiu plateau, along with Petrescu-Dîmbovi?a and Valeanu.

Topographic maps (1984 and 1979 editions) of the area with settlement limit, scale 1:25000 (a) and 1:5000 (b)

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The geology of the studied area is characterised by Sarmatian sediments, consisting of clay and sands deposits of ca. 200–300 m thick, overlaid by thin layers of limestone and sandstones, up to 4–5 m thick (Grasu et al., 2002). The investigated site is situated at the eastern edge of a large structural plateau, at an elevation of 325 m a.s.l., on a promontory bordered by steep slopes facing north and east, and by a large gully, up to 20 m deep with nearly vertical slopes, to the south (Fig. 1a). Towards the west, the terrain has a gentle slope shaped on a marl deposit of 2–4 m thick, that overlays a sandstone layer. The climate is temperate continental with mean annual temperature of 8–9 °C and mean annual precipitation around 530–560 mm (Dumitrescu & Bîrsan, 2015).

The settlement benefited from a particular attention on behalf of the academic environment due to its location near the city of Iași. By the contribution of the national and foreign researchers, the results achieved over time here were capitalised, both locally and internationally, through numerous articles and monographs (Beldiceanu, 1885; Schmidt, 1932; Petrescu-Dîmbovița & Văleanu, 2004). At Cetățuie the research was considered practically completed. Over 50 years after the latest excavation campaign in the renowned site of Cucuteni, benefiting from the new directions of interdisciplinary research in the field of archaeology, we resumed the investigations on this site and its landscape to finalise the research began 140 years ago.

The main argument that determined us to go on with a new research campaign for the site, primarily based on a multi-disciplinary approach of modern non-intrusive techniques of archaeological prospection, has been engendered by a series of novel recent results concerning site’s planimetry achieved for other Chalcolithic (Cucuteni) settlements from North-East Romania, using similar field methods (Asăndulesei, 2017; Asăndulesei et al., 2020b; Mischka et al., 2016, 2019).

We direct the attention to the presence of an external habitation positioned outside of the main fortification/delineation works of the settlements and additionally to a diverse typology of the ditches. This was possible due to the enlargement of the areas measured in order to attain a broader general view and a close characterisation of the landforms on which the communities were settled.

The non-invasive surveys carried out in North-East Romania in recent years offered the possibility of prospecting much larger areas than had been covered by excavations, especially outside the anthropic boundaries. Rarely the archaeological trenches were positioned in order to prospect the outside areas adjoining the defensive works or, like in the present case, were placed, by mischance, in between of archaeological complexes.

Thus, as there were more validations in this regard for many other cucutenian sites (Asăndulesei, 2017; Asăndulesei et al., 2020b)—it was practically documented an initial fortified habitation followed by an extension outside of main enclosure works—the same question was raised up for the eponymous site as well, especially, as we will subsequently see, there were some assumptions according to which the habitation would be extensive. Settled on a high naturally defended promontory with steep slopes from three sides and only with a relatively flat area to the west, effortlessly accessible, supplementary argued a possible extension in this direction and a good reason for our endeavour.

In this study, complementary to magnetometer investigations, a soil survey consisting of seven auger cores carried out on the territory of Cucuteni-Cetăţuie settlement aimed to examine the morphological and geochemical characteristics of soil cover in relation to geophysical results and the archaeological site features.

2.1 Milestones of 140 Years of Research of the Cucuteni–Cetățuie

As stated above, the Cucuteni settlement was discovered in 1884, thanks to the ethnologist Theodor Burada (1901), who was aware of the importance of the ancient remains of Cetățuie, stopped the destruction caused by the site’s rock exploitation work. There followed, from 1885, surface surveys and small excavations conducted by Dimitrie Butculescu and Nicolae Beldiceanu (1885) (also, Gr. Tocilescu participated in the research of 1887). The first systematic researches took place since in 1888, due to the association of N. Beldiceanu with Grigore C. Buțureanu; George Diamandy also took part in the excavations, and later he presented two papers about the Cucuteni discoveries within the Society of Anthropology in Paris (Diamandy, 1889, 1890). The same year, Gr. Buțureanu participated with a paper at the International Congress of Anthropology and Prehistoric Archaeology in Paris (Buțureanu, 1891), where the discoveries made at Cucuteni were enthusiastically received by the European archaeologists. The excavations continued in 1889, 1890, 1892 and 1895, the death of N. Beldiceanu marking the end of this first stage of research.

The next period of intensive research is due to archaeologist Hubert Schmidt from the Ethnographic Museum of Berlin, which carried out two vast excavation campaigns in the years 1909 and 1910 (Fig. 3). His research focused on the settlement of Cetățuie but also made some test trenches at Dâmbul Morii—“the settlement from the valley”. In 1910, H. Schmidt was accompanied by Gerhard Bersu, who investigated the defensive system of the settlement. Based on the findings from Cucuteni, the German researcher published a series of articles (Schmidt, 1910, 1911, 1924) and the famous monograph (Schmidt, 1932), building the chronological scheme of the evolution of Cucuteni civilisation, valid even today, with some nuances and additions.

Fig. 3
A schematic displays the excavation plan of the Ceta?uie archaeological site, featuring archaeological trenches from 1909 to 1910, archaeological trenches from 1961 to 1966, dwellings from 1961 to 1966, and excavated ditches.

Cetățuie archaeological site—excavation plan with the main archaeological complexes

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The systematic researches were resumed between 1961 and 1966 (Fig. 3) by a team headed by Mircea Petrescu-Dîmboviţa (excavation leader) and Marin Dinu (assistant), with Adrian C. Florescu, Attila László, Eugenia Popuşoi, and many others. The excavations were eventually published extensively, as a monograph, under the signature of Mircea Petrescu-Dîmboviţa and Mădălin Văleanu (Petrescu-Dîmbovița & Văleanu, 2004).

Beyond the intrinsic significance, as the eponymous settlement of the Cucuteni culture, the older and newer researches from Cetățuie contributed decisively to the establishment of the chronology of the Cucuteni civilisation, by combining Hubert Schmidt’s observations with the information obtained through the systematic excavations from the ‘60s.

On the Cetățuie there were attested all three main phases of the Cucuteni culture (A, A–B and B). There were sporadic traces of habitation from Horodiştea-Erbiceni culture, and others associated to with later periods (Early bronze age, La Tène period). The investigated dwellings did not provide exceptional construction details. Interesting and noteworthy are the dwellings dating from the beginning of sub-phase B1, with local stone (sandstone)-built platforms. They contained modest interior arrangements, mainly hearths and ovens, areas for household activities (grinders) and some cult structures, mostly destroyed, perhaps intentionally (Petrescu-Dîmbovița & Văleanu, 2004).

2.2 Extra muros—Old Assumptions

Researches, both the initial and the subsequent ones in the twentieth century, focused only on the prominent part of the terrain (the Cetățuie itself), naturally defended on three sides by steep slopes, and on the fourth (westward)—through a system of ditches and ramparts. Previous surveys presumed that the habitation has expanded beyond this system, on the western plateau.

The first clue in this respect is provided, even since the end of the nineteenth century, by one of the pioneers of the site’s research, the professor from Iași University, Gr. Buțureanu, who speaks about the extension of the habitation beyond Cetatuie, for about 500 m, but the topographical indications, as well as the cardinal directions, are very vague (Buțureanu, 1889). Moreover, he even considered that this extension might be true habitation, and the Cetățuie was only the refuge. His ideas were, more or less, taken over by the first German scholars who wrote about the discoveries of the Cucuteni (Bosshard, 1890; Hoernes, 1898).

One of the owners of the land at the beginning of the twentieth century, C.V. Gheorghiu, in the brochure he writes about Cucuteni (Gheorghiu, 1910), states that on the northern edge of the site there is a stone quarry and, in that area, where there is a forest, about 150 m from Cetățuie, several discoveries were made, including a two-edged blade of a copper dagger. The piece, of great archaeological importance, was given to H. Schmidt, who deposited it at the Berlin Museum.

The discovery is confirmed by the Berlin scholar Hubert Schmidt, who in the 1932 monograph about the excavations he made at Cucuteni in 1909–1910, also speaks of the traces of habitation beyond the fortifications. He states that, in the two test trenches he practised here, “a few discoveries of great importance” were made, but without nominating them, except for the dagger. The pottery found here dates the traces found in this extra muros area (including dwelling debris) in the Cucuteni B phase (Schmidt, 1932).

In the 1961–1966 excavations led by Professor Mircea Petrescu-Dimbovita, one of the four investigated areas (trench IV: 240 m2) was placed immediately after the defence ditches in the extra muros area, but no dwelling remains were found here, but only isolated ceramic fragments. However, in the presentation of the general model of habitation, it is stated that “when the ditch, by filling it, did not fulfil anymore its defence purpose, the habitation extended also on the plateau beyond it, in the Cucuteni B2 sub-phase, on a quite large area, then continuing, somewhere nearby, in the first stage of Horodiştea-Folteşti culture” (Petrescu-Dîmbovița & Văleanu, 2004). The authors of the Cucuteni monograph have attached some aerial photographs, some of which present the area beyond the western fortification system but without any comment, although they could have been edifying for the possible extension to the west of Cetățuie.

3 Materials and Methods

As Holliday et al. (1993) pointed out, soil science and archaeology are closely allied in their temporal and spatial scales, and among the earth sciences, pedology is most similar to archaeology in scales of operation and process. This similarity is also reflected at the methodological level, especially in recent years, when various methods and techniques have been adopted as standards in both archaeological and pedological research.

The case study has been visited with on many occasions by researchers, but, as we stressed above, both surface surveys and excavation have focused on the promontory area. As Binford (1982) said, a landscape archaeology is an archaeology of place, which is why we considered it useful to have a much broader approach to the landscape near the site on the Cetățuie. A multi-disciplinary approach of modern, non-intrusive or minimum invasive techniques of pedo-archaeological prospection and documentation were applied during the research.

3.1 Aerial Prospection and LiDAR Data

The 2004 monograph (Petrescu-Dîmbovița and Văleanu) includes some archival cadastral aerial photographs for the site from 1971 and 1981. The tip of the promontory is mainly focused here, but also a wide area with the surroundings of the site. Important things can be seen on the images concerning the old excavation trenches, fortification ditches or the open area from west and north disturbed by stone extraction.

Another aerial survey from a small aircraft was conducted in 2012 (Asăndulesei, 2014). In recent years (2017, 2021), many other flight missions were performed using UAVs (unmanned aerial vehicles) (DJI’s octocopter S1000+ or Phantom 4 Pro v.2) in order to acquire up to date oblique and perpendicular images for the site and its proximity.

The Digital Elevation Model (DEM) can provide important information regarding the micro-topography of the study area. For our project, in order to obtain a good terrain model, we used ALS (Airborne Laser Scanning) data with 4 points/m2 resolution (Stular et al., 2012; Doneus, 2013; Kokalj et al., 2013). Light Detection and Ranging (LiDAR) data were mainly used in RVT (Relief Visualisation Toolbox) to interpret the geomorphological parameters and some possible cultural anomalies.

3.2 Vertical Gradient Magnetometer Survey

One of the most intriguing characteristics of the Cucuteni settlements refers to the strongly burned archaeological structures. Most of the dwellings found in the excavation are burned, sometimes to vitrification. For this reason, we chose magnetometer survey as a main technique of prospection for this site, being known the efficiency of the method in similar contexts (Kvamme, 2006; Aspinall et al., 2008; Fassbinder, 2015). A 5 probe SENSYS gradiometer connected to a Leica GNSS receiver was used. The traverse spacing was set up to 0.5 m. The total area prospected with the use of magnetometer was about 5 ha (Fig. 6a). Magnetic data were processed using AGT (Archaeological Geophysics Toolbox) plugin in QGIS 3.18.1 and subsequently transferred in ArcMap 10.6.1 for integrated interpretation.

3.3 Soil Samples Collection and Geochemical Analysis

Portable X-ray fluorescence spectrometry (pXRF) has already shown strong capabilities for archaeological site prospection and in pedogenesis studies related with to past human activities and environmental conditions (e.g., Oonk et al., 2009; Dreibrodt et al., 2017; Horak et al., 2018; Smejda et al., 2017, 2018). Nevertheless, while pXRF became intensely used as a proxy for quantifying various soil physical and chemical properties, in Romania this technique has rarely been applied in pedo-archaeological studies (Pîrnău et al., 2020, 2022). In this study we attempt to identify the anthropogenic signatures at the Cucuteni-Cetățuie site by quantifying on-site and off-site enrichments or depletions of elements by means of employing pXRF measurements.

A transect of 300 m length, consisting in seven soil sampling points distributed in a range of altitudes of 325–338 m a.s.l., was established along the northeast-southwest direction, starting from the known archaeological site (P1), crossing the adjacent inhabited area revealed by the recent geophysical investigations (P2 and P3) and the off-site soils (P4, P5, P6 and P7) (Fig. 8a, b). A total of 72 soil samples were collected using a Dutch auger from each of the seven sampling points, at every 10 cm depth, from the surface to approximately 1.1 m depth, depending on the substrate (Fig. 8c).

A portable XRF device was used to perform a multi-elemental soil analyses in order to assess the geochemical signatures of past human occupation. Prior to pXRF analysis, all samples were air-dried in the laboratory and disaggregated to pass a 2 mm sieve and each sample was homogenised and compressed into a pellet using a 25-ton automated hydraulic press (Specac). The compressed pellets obtained were placed into cleaned plastic holders until the analysis was performed. Energy Dispersive X-ray Fluorescence (ED-XRF) analyses were performed using a portable Bruker Tracer S1 Titan spectrometer. This spectrometer uses a Rhodium (Rh) anode tube to generate an X-ray beam to probe the samples. The generated beam has a maximum energy of 50 keV, but was limited at to 40 keV. The incident beam is characterised by a spot with 8 mm in diameter on the selected samples. A Silicon Drift Detector (SDD), positioned backwards at an angle of approximately 45° with respect to the Rh-anode tube, is used to record characteristic X-ray spectra. One point randomly selected was analysed on each sample. Each point was exposed to the incident X-ray beam for 60 s. The spectrometer was used in soil workflow which provides measurements for 24 elements from which 12 elements (Si, Al, Ti, Zr, Ca, Sr, K, Rb, Fe, Mn, Cu, Zn) were retained for subsequent analysis due to non-detectability or the lower limit of detection of the other elements. The work-mode used to achieve the presented results was tested using NIST 1646a and NIST 679 standard reference material.

4 Results

Thus, it is noted that the extension of the settlement was postulated and even partially documented, but a thorough investigation of the problem has never been undertaken. In this context, the main purpose of our field evaluation was to open a much broader perspective on living near the most famous settlement of the Cucutenian civilisation.

4.1 Aerial Prospection and LiDAR Data

The old aerial photographs do not give indications regarding the planimetric extension of the site to the west, but they bring relevant information regarding the condition of the settlement in the 70s and 80s (Fig. 4a, b). Also, recent aerial images (Fig. 5a), as well as LiDAR data (Fig. 5b), provide information in this direction.

Fig. 4
Two aerial photos depict the excavation of the archaeological sites of Ceta?uie from 1971 to 1981. They highlight stone extraction disturbances and excavated ditches, which represent the main fortification system. It also exhibits the old excavation trenches.

Cetățuie archaeological site—Aerial images from 1971 (a) and 1981 (b) (Petrescu-Dîmbovița & Văleanu, 2004); on the northern part of the upper image the stone extraction disturbances can be seen; excavated ditches representing the main fortification system can be observed on the lower image

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Fig. 5
An aerial photograph of the Ceta?uie site exhibits lush green forests with trees and shrubs covering the mountains, along with visible ditches. Additionally, a hypsometric map of the site displays archaeological trenches and natural disturbances.

Oblique aerial image of the Cetățuie site with the known ditches marked (a); hypsometric map of the site where archaeological trenches and other anthropic or natural disturbances can be observed (b)

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We can clearly see the area disturbed by the stone extraction from the north, apart from the main defence ditches (Fig. 4a). Here, the northern half of the external habitation is completely erased. Similar recent anthropic interventions can be correspondingly observed on the northern edge of the promontory itself (Fig. 5a, b). Also, the old excavation trenches are well outlined (Fig. 4b and 5a). To the south of the main habitation an active gully affects the integrity of the settlement (Fig. 5b).

4.2 Vertical Gradient Magnetometer Survey

The magnetometer measurements (Fig. 6a, b) on the large plateau highlighted the existence of a much different planimetry than what was known to date. Although excavations have taken place outside the known ditches (Fig. 3), it seems that the bad luck has made the planned sections to fall into the free space (without archaeological structures) between two rows of dwellings. This area lacking constructions is probably one of the two access ways in the settlement, which separates the rows of dwellings (Fig. 7). Only the southern row remains entirely today, but the layout of disturbed structures towards the centre and north of the external habitation suggests the presence of three alignments of Chalcolithic dwellings (Fig. 6b).

Fig. 6
Two magnetic maps of the R V T hillshade depict magnetic field strength ranging from negative 5 to 5 nanoteslas. The second map exhibits a scale from negative 10 to 10 nanoteslas and includes features such as test trenches and kilns.

Results of the magnetometer survey superimposed on multi-direction (16) RVT hillshade (a); a detail of results of the magnetometer survey where two possible kilns can be observed (b)

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Fig. 7
An aerial view of the archaeological excavation sites exhibit access ways, western enclosure ditches, unburnt features, burnt dwellings, ditches, excavated ditches, excavated dwellings, and a central row of dwellings.

Interpretation of the results of the magnetometer survey together with the excavated features

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The initial settlement was fortified with two defensive ditches, confirmed by the archaeological excavation. They are followed by another ditch, well individualised, with an average width of about 2.5 m, whose filling has, in certain sectors, a high degree of magnetic susceptibility (Fig. 7).

The southern row consists of at least 12 heavily burned dwellings (with values that may even exceed ±100 nT), some of which are visibly disturbed (Fig. 6b). Most seem to be north-northwest—south-southeast oriented, with a few exceptions. The latter may be a category of special constructions. Here too we can include the anomaly at the western end of the row which, although deranged, seems to have a surface that exceeds 300 m2 (Figs. 6b and 7). Structures on both sides of the accessways could also be classified as “bastions” or observation points.

The settlement also has a system of ditches arranged in a circular arc, narrow (not more than 1.5 m wide) and not very deep, which delimits the western side. The interruptions on their route, alongside the space without dwellings, suggest access areas in the settlement. We can probably talk about the ditches of a palisade system (Fig. 7).

Positive anomalies with relatively high dynamics, are visible outside the western ditches in the vicinity, but without a clear arrangement. Further on, to the west, a set of many positive, burned or unburned anomalies, possibly pits, is still visible. It is difficult to tell whether they have any connection to the Cucuteni habitation. There are also two circular anomalies in this sector, which exhibit a thermoremanent magnetism (signal intensity of about 35–55 nT), which may suggest the presence of kilns (Fig. 6b).

4.3 Soil Morphology

Among the seven sampling points, P1 and P2 occur within the inhabited area of the site, P3 intersects the rampart of the second ditch of the settlement, whilst P4–P7 occur off-site on the soils from the middle and upper parts of the catena sequence (Fig. 8a).

Fig. 8
A magnetic map of the study area displays the auger holes, with the scale ranging from negative 5 to 5. Additionally, a line graph depicts the elevation versus distance, showing a gradual decrease in the line. An illustration showcases the mollic horizons, which are rich in soil organic matter and buried under recent colluvial layers in the lower part of the catena.

Location of the investigated auger holes on the magnetometer survey results (a); topographic profile (b); simplified stratigraphy of the investigated profiles (c)

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P1 has a very dark brown to black A chernic horizon (10 YR 2/1–2/2) in the upper 40 cm, followed by a buried A mollic horizon (10 YR 3/2), which gradually changed at ca. 70 cm depth to a thin Bw horizon having a very dark greyish brown colour (10 YR 3.5/2). The Bw horizon is rich in coarse limestone fragments and is followed by a continuous limestone layer at 90 cm depth. Small fragments of potsherds and other artefacts are common from the topsoil to the bottom, with a maximum content at 30–90 cm depth (Fig. 8c).

P2 occur in the adjacent inhabited area, recently revealed by the geophysical investigations, and exposes similar characteristics with P1 in the upper and middle part, but a more developed Bw horizon formed on a marly calcareous parent material that overlay the limestone layer. The topsoil is characterised by a thin colluvial layer mixed with the buried Ah horizon, both having a black colour (10 YR 2/1). The artefact content reaches a maximum in the 20–50 cm interval (Fig. 8c).

The topsoil layers of the P3 are similar with P2 to 30–40 cm depth, where abruptly change to a buried A molic horizon, with colour shifting from 10 YR (2/1–2/2) to 10 YR 3.5/2. The horizon sequence is followed by a Bw horizon with a dominant paler yellowish-brown colour (10 YR 5/4–5/6), mixed with mollic colours (10 YR 3/2). The morphological characteristics indicate that this profile cut through the rampart remains of the adjacent to the second ditch of the settlement. Artefacts are present in the middle and bottom part of the profile, with elevated accumulation at 50–60 cm and 90–100 cm.

In the case of P4, a colluvial layer of 40 cm thick, having a very dark greyish brown colour (10 YR 3/2), underlying a buried A chernic horizon (10 YR 2/1) to 70 cm depth. The underlaying Bw horizon has a dark yellowish colour (10 YR 4/4) and contain a small number of artefacts at 80–90 cm depth (Fig. 8c).

In the middle and upper parts of the catena (P5–P7), soils display some features different from all other profiles, like the presence of mollic surface horizons (10 YR 3/3–3/4) instead of chernic ones and a low content of artefacts fragments. Moreover, in the highest part of the catena (P7), the subsurface Bw (cambic) horizon gradually changes to Bt (argic) horizons characterised by clay coatings observed on some aggregates and stagnic properties shown by the presence of the redoximorphic features. In the case of P5, due to its location on the steepest slope, the surface horizon is strongly affected by erosion.

Taxonomically, the soils distribution along the analysed catena shows a succession of Technosols (Archaic, Cernic), in the case of P1–P3 profiles, followed by Cambic Phaeozems (P4–P6), in the transitional zone, and by Argic Phaeozems (P7) in the upper part of the slope (soil names according to IUSS Working Group WRB, 2015).

4.4 Results of the pXRF Elemental Analysis

The depth distribution of measured element values by pXRF is presented in Fig. 9. The results of the pXRF elemental analysis show clear differences in element concentrations in archaeological site areas compared to the off-site soils. Overall, the concentration of Si, Al, Ti, K, Rb, Fe, Mn, Cu and Zn are elevated in P1–P3, from topsoil to the bottom part, except for some values of P1 that can be attributable to the soil disturbance caused by the previous archaeological excavation.

Fig. 9
12 multi line graph plots the depth versus element concentration for Si, Al, Ti, Zr, Ca, Sr, K, Rb, Fe, Mn, Cu, and Zn. The lines are P1 to P7. The graphs has a decreasing trend.

Concentrations of elements measured by pXRF

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The ratio of Si, Ti, Zr and Mn show a similar distribution and a decreasing trend down to the soil profiles. In the case of P3, concentrations of the Si and Al decrease sharply at 30–40 cm depth, indicating a threshold between the upper part and the middle part of the soil. Due to the position of the sampling point in the proximity of the western ditches of the settlement, revealed by the magnetometer investigation, it can be presumed that this threshold reflects the contact between the remains of a possible ditch rampart and the buried soil beneath it.

The Fe and Al concentrations are relatively constant down the profile, in the case of archaeological soils, but have slightly elevated values in the B horizons of the off-site soils, which reflects the accumulation of clay by argilluviation processes, in the case of P7, or by in situ clay formation, for the other analysed soils with Bw horizons.

The depth distribution of Rb and K elements, which are strongly correlated with the clay content, as shown by numerous studies (Zhu et al., 2011; Tóth et al., 2019; Croffie et al., 2021, among others), demonstrates also increased values in the B horizons of the off-site soils. In the case of the soils situated within the archaeological site (P1–P3), the higher values of K and Rb are more likely related with to ancient anthropic influence and catena processes that led to the concentration of these elements at lower elevations.

As expected, Ca and Sr show a similar behaviour with depth, being highly correlated with the presence of calcium carbonates. Due to the leaching processes, both elements’ concentrations are uniformly low throughout the upper and middle parts of the analysed profiles. The elevated concentrations below the 80–90 cm depth are consistent with the presence of the carbonate marls. In the case of P5, which is located on the steepest slope of the catena, the concentrations of Ca and Sr increase from 60 cm, due to the erosional processes which removed the upper part of the soil.

In the case of Cu and Zn, a prominent spike occurs in the topsoil of all analysed points, which is related to the recent anthropogenic activities. A second spike in Cu and Zn content is characteristic only for the P1 profile, at 0.6–0.7 m depth, which is related to the presence of a consistent layer with artefacts fragments, reflecting the ancient anthropogenic influence.

5 Discussion

The catchment area or the exploited territory of a settlement is understood as an area where the Chalcolithic communities carried out their everyday activities, from where they ensured their food and resources. In the absence of a precise chronology that would make it possible to understand the contemporaneity of the settlements, their territoriality can only be determined by an attempt to analyse the type of habitation, which will subsequently show indications of their functionality. Analysing closely the characteristics of the place where the communities sat (geomorphological parameters, soils, etc.), we have seen that areas with a high concentration of settlements can be detected (Asăndulesei, 2015b). Of these, the long-standing settlements, such as Cetățuie, where all three major phases of the Cucuteni culture are present, have definitely been key positions in the development of the proximity and population dynamics. Through its position, dominates the upper course of the Valea Oii creek, benefiting from a high potential of visibility, polarising at the same time many settlements situated on low relief near the watercourses, with which has intervisibility relations.

The determination of a territory exploited by the communities of this culture should not be done through a steep delimitation of areas around the settlements without a prior proper interpretation of planimetry, a rigorous cultural analysis of artefacts, ecofacts or natural resources in their proximity. The delimitation of a reservoir of resources must be made from the inside of the site towards the dynamic habitat of interaction between the Chalcolithic communities.

As it can be seen, the recent research from Cucuteni—Cetățuie provided new interesting data worth of a thorough future investigation. It is about the existence of habitation in a much larger area than the one that was researched 50 years ago, with many new interesting archaeological situations (double fortifications, dwellings, possible kilns).

It seems that the tip of the promontory constituted the initial nucleus of the settlement, which probably developed to the west in several stages, in the context of demographic growth. Several stages of evolution of the Cucutenian site can be distinguished, for which we cannot define chronological intervals, in the given state of research (Fig. 7). Similar situations are known e.g., Războieni—Dealul Mare (Asăndulesei, 2017), Fulgeriș—La trei cireși (Asăndulesei et al., 2012), Ghelăiești—Nedeia (Mischka et al., 2016), Drăgușeni—Cetățuie (unpublished) constituting solid arguments, especially in case of high promontories settled habitations, for a possible existence of some particular patterns. Correspondingly, the lower situated settlement could have such an extension of habitation: Cucuteni—Dâmbul Morii (Asăndulesei et al., 2020a, b), Ripiceni—Holm (Asăndulesei et al., 2020a, b).

From a pedological point of view, overall, the variation of elements content with depth is consistent with the geophysical results and soil morphology. The results of pXRF measurements shown the enrichment of all measured elements at the lower part of the investigated area, which coincides with the archaeological site occurrence. Although a significantly higher concentrations of anthropogenic elements, such as Cu and Zn, was expected in the case of archaeological soils, the increased values of the geogenic elements can be explained by the post-Chalcolithic catena processes that led to the formation of a colluvial layer above the site and implicitly the concentration of these elements at lower elevations. Moreover, the depth distribution of elemental contents in the settlement area, highlighted a pedogenic threshold at ca. 40 cm depth, at the transition between the colluvial deposit and the buried chernic horizons developed at the Chalcolithic land surface. For the off-site soils, the vertical distribution of most elements shown a sharp change at the same depth, which is related with to the presence of B horizons and a second threshold at 80–90 cm depth, coincident with the depth occurrence of the parent material, consisting mostly in carbonate marls. The carbonate-rich parental material had a strong impact on soil development, leading to the formation of deep chernic/mollic horizons on the Chalcolithic land surface, which can also explain the preference of Chalcolithic inhabitants for this area. The colluvial cover explains the good preservation of buried soils and the relatively limited degree of soil evolution, despite a recent relatively humid climate.

The specificity of the investigated area is given by the dominance of the Cambic Phaeozems at the lower slopes, linked with the prehistoric habitation, that gradually changes to Argic/Stagnic Phaeozems and Haplic/Stagnic Luvisols, which occur in the upper hill region, outside the investigated area. The soil distribution suggests an open landscape at the archaeological site and its proximity, bordered at the west by a forested area, that favoured the development of the Bt (argic) horizon.

6 Conclusions

The Cucuteni-Cetățuie site has been the focus of much archaeological research over the last hundred years. Nevertheless, the non-invasive investigations carried out in this study allowed the identification of some previously unknown features related to site boundaries and the characteristics of the proximity area.

The results obtained are extremely important because they offer the possibility of a new, more efficient, approach to site research strategy given that it is increasingly threatened by anthropogenic, but especially natural, destructive factors.

With a total area of around 3.5 ha, the Cetățuie site belongs to the small settlements category, but with a dense and complex internal spatial organisation of archaeological features. Apart from the two main excavated ditches, on the magnetometer survey results a third one having the same size and orientation can be observed. This delineation could be interpreted as one of the first extensions of the settlement. Other two small ditches enclose the western side of the site; these remains here could have been generated probably by a palisade system. Two interruptions on the way of these anomalies could be interpreted as entrance into the settlement through some possible alleys situated in between the dwelling rows. At least 12 dwellings are visible in the western enlargement of the settlement, on the southern row, and many other small positive anomalies attesting the presence of pits (Fig. 7).

A test trench excavated in late November 2017 was intended to partially frame chronologically the extension of the eponymous settlement from Cetățuie. For this purpose, we have partially investigated a section (S I – 2 × 2 m), located at the centre of a magnetic rectangular anomaly that suggested a typical Cucuteni burned dwelling. About 25 cm below the ground surface, we have already reached the destruction layer of a dwelling, with wattle and daub fragments from its collapsed walls. The few painted pottery fragments indicate the Cucuteni B1 phase.

It was found that the soil morphological features and quantitative data of elemental contents measured by pXRF may add further information to geophysical results due to their ability to offer an insight on the vertical variation of soil properties and to address the complex issues of stratigraphical relationships between in-site and off-site area. The integration of results of magnetometer and soil survey may provide more answers for a better understanding of the extent and function of Chalcolithic sites. Furthermore, this approach has implications in archaeological sampling strategy by constraining the requirements for further excavation.