Schlagwort-Archive: Sai Island

DiverseNile’s Explorations in 3D Printing Ancient Nubian Objects

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Digital technologies continue to inundate archaeology as a means of bridging scientific and humanistic approaches. More than merely an exercise in playing with flashy machines and fancy toys, 3D printing has wide-ranging implications for fostering education and outreach, the accessibility of archaeological heritage, and explorations in experimental archaeology.

In my first month as a postdoc with the DiverseNile project, I began looking into different strategies and methodologies for making 3D models and prints of small objects. First up, we looked into printing a seal impression from the AcrossBorders project’s excavations at Sai Island. This mid-18th dynasty mud seal impression bears the name of Nehi and the title “Overseer of the Gateway” and is intact apart from a finger smudge in the lower left corner.

We also decided to experiment with printing an inscribed stone heart scarab also from the AcrossBorders project at Sai Island (figure 1). This object was excavated from the 18th dynasty burial of Khnum-mes and is inscribed on the bottom with Chapter 30 from the Book of the Dead (Budka 2021). Check out a blog post from 2017 about this find here.

Figure 1: The large stone heart scarab from the burial of Khnum-mes

To create models, we use photogrammetric methods to align photos of the object in Agisoft’s Metashape to create a textured mesh (figure 2). The photos of this object were taken during a study season in Khartoum in 2017 by Cajetan Geiger.

Figure 2: The 3D model of the seal impression in the Metashape interface

For this project, we needed a printed object quickly for a television appearance (keep reading to find out more!) so I looked into commercial printing options. I came across Xometry, a Germany-based company offering on-demand manufacturing of industrial parts. I like to think that they were both confused and delighted when they saw the small, inscribed objects on their platform!

Pros of this service: Xometry has a well-designed, functional, and easy to use website. With their instant quoting engine, you can upload 3D models (.stl, .obj, and many other formats) and immediately receive a cost and shopping estimate. Also, if there are issues with your model the engine will detect them. You can also choose the specific color, material, weight, and finish of your print.

Cons: While the website has extensive options for types of printing materials, most of the options are obviously very light-weight industrial plastics, polycarbonates, silica glasses, and nylons. If you are aiming for realism in your 3D print, you will not come across colors or materials on this site that can replicate those of many archaeological objects. Also, it should be noted that for this company, the minimum order is €50. If you just want one or two prototypes of small objects, you will have to order A LOT of copies just to come close to this high of a minimum!

Given the drawbacks of working with large 3D printing companies like Xometry, I began to look into the possibility of collaborating with institutes on campus that may offer printers. After a bit of digging, I contacted the Medieninformatik Lab at LMU. Luckily, they have, not one, not two, but three (!) high quality, professional 3D printers; a Prusa Mini+ (PLA-3D printer), a Prusa i3 MK3S+ (PLA-3D printer), and the pièce de resistance, a Formlabs Form 3 (SLA-3D printer). The Prusa Mini+ and Prusa i3 models are some of the most ubiquitous printers (figure 3). They are extrusion-based printers which operate by heating a plastic material through a tube (filament) and distributing the heated material on a platform layer by layer, until it takes the full form of the object. The material is Polylactic acid (PLA) and can be heated at a low temperature. It is a robust, low-cost, and biodegradable material. Xometry prints using this method.

Figure 3: The Prusa Mini+ in action printing the heart scarab.

The Formlabs 3 printer operates with an entirely different method (figure 4). It uses stereolithography (SLA), which is a type of additive manufactory technology employing resin 3D printing. A light source like a laser or projector heats and cures liquid resin at a high temperature into hardened plastic in the shape of a 3D model. SLA printers have the ability to capture the highest resolution and most accurate details of objects, along with smoother surfaces and more complex geometries (size and shape of the print).

Figure 4: The Formlabs 3 printer preparing to cure resin for the print in the large orange vat.

Preliminary Results Printing with Xometry and the Medieninformatik Lab:

As apparent in figure 5, three different printing methods yielded three vastly different results. On the far left of the image is a print of the seal impression using a Prusa Mini+. As is evident, the fine details of the inscription of Nehi were too high resolution for the printer to capture with accuracy. The inscription is not legible and overall, the surface and geometry of the object are not clean. The middle print is of the seal impression from Xometry. Even though Xometry used a PLA printer (like the Prusa) the print is of a higher resolution, and the geometry of the object is more accurate. The surface is smoother and the inscription, while not perfect, is legible. Lastly, the far-right print is from the Formlabs 3 printer. This by far, is the highest quality and highest resolution print! The inscription is very legible, and the geometry of the object is extremely accurate. The surface is also smooth, extremely detailed, and shows no signs of lumps or imperfections in the raw material. While the Formlabs 3 printer is a more time-intensive and expensive process, the cured resin clearly is the superior material to capture intricate and complex details of smaller objects (figure 6).

Figure 5: Three prints of the seal impression from left to right: Prusa Mini+, Xometry print, and the Formlabs 3 print.
Figure 6: Detail of the Formlabs 3 print

In terms of the heart scarab, the differences between prints are less stark but still significant. As evident in figure 7, the Xometry print (on the left) and the Prusa Mini+ print (on the right) are similar in shape and detail. The Prusa print has a smoother and cleaner surface, and slightly more legible details near the top of the scarab.

Figure 7: The Xometry print of the heart scarab (top) on the left and the Prusa Mini+ print on the right.
Figure 8: The Xometry print of the heart scarab (bottom) on the left and the Prusa Mini+ print on the right.

The bottom of the scarab demonstrates the biggest difference between the two prints (figure 8). The inscription was not captured at all on the Xometry print (left), due to the direction in which the print was oriented. If the print is rendered layer by layer with the bottom of the object flat on the printing platform, then any detail on the bottom of the object will not be captured. However, with the Prusa Mini+ print (right) the object was printed at an angle, and the result is a legible inscription (figure 9).

Figure 9: A detailed image of the inscription on the heart scarab in natural light

From these preliminary printing exercises, it was fascinating to see just how different prints of the same object can turn out given the variety of available printers, raw materials, and approaches. Clearly the various methods explored here have their pros and cons. 3D printing methods must be tailored to the specific goals of the project and qualities of the object/3D model. Trial and error, if you have the available resources and time, is a terrific way to start!

The Significance and Broader Impact of 3D Modeling and Printing

As an archaeologist who is interested in digital technologies, I am asked all the time (by fellow archaeologists and non-specialists alike), what is the purpose of making 3D models of artifacts that already exist? What keeps us from creating glorified toys that just sit and gather dust on shelves?

The truth is….3D modeling applications in archaeology is a means of addressing several unique problems of studying the ancient past. Firstly, 3D prints of archaeological objects that can be handled and shared without any risk of damage to the original artifact is invaluable. For objects that are restricted to museum collections or excavation archives, 3D models increase the accessibility of the archaeological record, not only to scholars in different regions, but also to members of the public. High quality 3D models that capture valuable information such as inscriptions and technological means of production can be used as tools in public outreach and education. In fact, our PI Julia Budka just demonstrated this during her recent appearance on the wildly popular children’s show, “1, 2, oder 3?” On a show dedicated to ancient Egypt, she brought our Xometry print of the seal impression to teach children that even objects made of seemingly quotidian materials like mud can be extremely important to archaeologists. 3D models expand and diversify the types of environments in which objects can be used in teaching.

Here is a link to the full episode if you would like to check it out!

Lastly, 3D printing can be used alongside other experimental archaeological approaches. For example, our graduate student Sofia Patrevita is studying goldsmithing techniques in Nubian jewelry making, including the lost wax technique. See her recent blog post here. The 3D printing lab at LMU has the ability to print objects in wax (among other materials), which could allow us to experiment with recreating jewelry in various stages of production, giving us insight into the chaîne opératoire of Nubian goldsmithing. Sofia and I are looking forward to exploring this possibility in future collaborations!

A huge thanks to the Medieninformatik Lab at LMU for access to their printers and resources, and especially to Boris Kegels for providing the access and printer training. Thanks also too Christine Mayer and Prof. Dr. Nicola Lercari of the Institute for Digital Cultural Heritage Studies at LMU for helping facilitate this collaboration!

Stay tuned for an update on our most ambitious 3D printing project yet, a to-scale reproduction of Khnum-mes’s shabti from Sai Island!

Reference:

Budka, Julia. 2021. Tomb 26 on Sai Island: a New Kingdom Elite Tomb and Its Relevance for Sai and Beyond. Leiden: Sidestone Press.

Conference hopping from Germany to Egypt

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November is usually one of the busiest months of the year. This holds especially true when one has just returned from fieldwork in Egypt and even more since some conferences are now organised as hybrid events, allowing in person attendance.

Though it will be quite a challenge, I am extremy grateful to have been invited to two events in the next days of which the topics are very close to my special fields and also to WP 3 Material culture of the DiverseNile project.

Today, I will be heading towards Mainz in Germany. Tomorrow and on Saturday the international workshop „Excavating the extra-ordinary 2. Challenges & merits of working with small finds“ will take place.

My own presentation on Saturday has the title: „What makes a pottery sherd a small find? Processing re-used pottery from settlement contexts“.

Re-cut pot sherds are among my favourite small finds and they occur in great numbers at domestic sites in both Egypt and Sudan (e.g. Qantir, Elephantine, Amarna and Sai Island). As multi-functional tools they attest to material-saving recycling processes.

Re-used pottery sherds offer many intriguing lines of research, first because of the recycling process and questions related to objects biographies. Second, the multiple function of tools created from re-cut sherds allows to investigate diverse sets of tasks and practises in settlement contexts. Third, lids and covers created from pottery sherds illustrate the blurred boundaries between categories of finds in the archaeological documentation, especially between ceramic small finds and pottery. Lids are also commonly part of ceramic typologies when produced as individual vessels. Can we determine if it made a difference to the ancient users whether a lid was made from a re-used sherd or as a new vessel? I will use the nice example of a complete Kerma vessel found with a stone lid in situ in one of our tombs in cemetery GiE 003 as case study to discuss these points.

My lecture in Mainz mainly aims to address some terminological and methodological issues arising from processing re-used pottery sherds as small finds as well as dating problems. I will outline the recording procedure established in the framework of the ERC AcrossBorders project for New Kingdom Sai and how we have adapted this workflow for the ERC DiverseNile project.

On Sunday, I will be heading to Cairo for the next event, the conference “Living in the house: researching the domestic life in ancient Egypt and Sudan”. The conference is organized by Dr. Fatma Keshk on behalf of the Institut Français d’Archéologie Orientale and the Polish Centre of Mediterranean Archaeology, University of Warsaw, Research Center in Cairo. The main focus of this event is settlement archaeology in its multi- and interdisciplinary aspects in ancient Egypt and Sudan. Chloe will also join the conference and we are expecting much input for the DiverseNile project, especially WP 1, settlements.

At the “Living in the house” conference, my lecture on Monday will again focus on ceramics, but this time on cooking ware.

I will present some results from the ERC Project AcrossBorders comparing cooking practices in two contemporaneous sites of the New Kingdom, Elephantine in Egypt and Sai Island in Nubia. I will also show a few examples from the MUAFS concession and how they fit to the other evidence. Preliminary results from organic residue analysis from Egyptian-style and Nubian-style cooking pots allow us to ask questions about diet and culinary traditions. My aim is to illustrate that dynamic and diverse choices within the New Kingdom reflect a high degree of cultural entanglement and challenge previous assumptions, for example of the role of Nubian cooking pots as cultural markers.

I am very much looking forward to these two workshops and especially the exchange and discussion with many colleagues.

Presenting the DiverseNile Project at an international conference in Cairo

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After a very successful Ankh-Hor Project season in Luxor as well as a wonderful participation in the South Asasif Conservation Project, I arrived in Cairo yesterday. I have the pleasure to spend four more days here in this splendid city before heading back to Germany. This is not just some leisure time after the intense excavations, but today is the opening of the international conference „Gateway to Africa: Cultural Exchanges across the Cataracts (from Prehistory to the Mameluk era)“.

The event is hosted at the Institut Français d’Archéologie Orientale du Caire and was organised by Valentina Gasperini, Gihane Zaki and Giuseppe Cecere. I am very thankful to the organisers for giving me the opportunity to present the DiverseNile project in this context. I will be talking about “Cross-cultural dynamics in the Attab to Ferka region: reconstructing Middle Nile contact space biographies in the Late Bronze Age.”

I will present the material evidence for complex encounters of various Egyptian and Nubian groups in the region of Attab to Ferka in the hinterland of the New Kingdom urban sites of Sai Island and Amara West. The rich archaeological record of this part of the Middle Nile reveals new insights into the ancient dynamics of social spaces. I will give some case studies from both settlements and cemeteries and will focus on the intriguing domestic site AtW 001 and the Kerma cemetery GiE 003.

I will discuss our recent idea that the material culture and evidence for past activities at such sites suggest complex intersecting and overlapping networks of skilled practices, for example for pottery production – see here also the latest blog post by Giulia D’Ercole.

I will also argue that the evidence from cemetery GiE 003 supports the general picture emerging regarding cultural exchanges in the Kerma empire. There was no single Kerman cultural input to interactions with the Hyksos, Egyptians and nomadic people but we must consider various hierarchical local responses determined by different communities’ ability to consume, shaping what can be called marginal communities in the Kerma state (cf. Lemos & Budka 2021 and most recently Walsh 2022). We are making very good progress in understanding the communities in the Attab to Ferka region and I am much looking forward to the next days and the possibility to discuss cultural exchanges throughout the centuries in the Nile Valley (and beyond) with all the participants of this exciting IFAO conference.

References

Lemos and Budka 2021 = Lemos, R. and Budka, J., Alternatives to colonization and marginal identities in New Kingdom colonial Nubia (1550-1070 BCE), World Archaeology 53/3 (2021), 401-418, https://doi.org/10.1080/00438243.2021.1999853

Walsh 2022 = Walsh, C., Marginal communities and cooperative strategies in the Kerma pastoral state, JNEH 10 (2022), https://doi.org./10.1515/janeh-2021-0014

Upcoming DiverseNile Seminar: new thoughts on pottery production in Bronze Age Nubia

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The so-called „vorlesungsfreie“ (lecture-free) summer time is now over – the winter term at LMU will start on Monday. Next week is also the next DiverseNile Seminar – this time it will be given by our own Giulia D’Ercole, who has just returned from her maternity leave.

Giulia will speak about some core tasks of our work package 3, material culture and cultural diversity in the Attab to Ferka region. Under the title „Material meanings, technology and cultural choices: Pottery production in Bronze Age Nubia“ she will outline a number of theoretical and methodological aspects of her study of ceramics produced in the Middle Nile, including Nubian-style, Egyptian-style and also so-called hybrid vessels. Case studies from Sai Island but also from the new MUAFS concession will be presented.

I am very happy that Giulia is back in office and very much looking foward to her lecture on Oct. 18 – anyone interested in Bronze Age technology and/or pottery shouldn’t miss it!

The right lid for every pot?

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Summer term is approaching an end at LMU (finally!) and there is again some time for research. I am currently busy with processing the pottery from AtW 001, but I also managed to work on the Kerma cemetery GiE 003. Our two student assistants, Caroline and Iulia, have been very hard-working in digitalising the original pottery drawings.

A topic that concerns me at the moment is the question of lids or covers for pots. In Egypt, ceramic lids are well attested since the earliest time. During the New Kingdom, it is sometimes really tricky to decide whether a shallow small dish was used as a lid or as an actual dish. In addition, reused sherds are commonly utilized as covers for pottery vessels (see also evidence from Sai Island, Budka 2020, 250, fig. 117).

How much do we know about lids and covers of pottery vessels from Nubia? Not a lot I am afraid (ast least I don’t).

Brigitte Gratien included some special types of lids in her corpus of the pottery of the Classical Kerma period (Gratien 1978, 36, fig. 7; fig. 63, type 19 and type 32, decorated lid). These are all specific for the site of Kerma and haven’t been found elsewhere. Type 32 of Gratien is especially noteworthy. It is a series of painted vessels with covers, which were interpreted as imitation of basketry or even as representation of a hut (Bonnet 2004, 83). For me, the interpretation of an imitation of basketry is more convincing, also because such imitations in pottery already exist much earlier, though with incised decoration (for nice examples, including pots with lids, see Old Kingdom Elephantine, Raue 2014, fig. 182).

One of the stunning painted vases with cover from Kerma, SNM 1119 (Bonnet 2004)

Interestingly, other than these basketry imitations from Elephantine, I do not know of any lids or covers of Nubian pottery prior to the Classical Kerma age. Could pots have been covered with non-ceramic materials – like with basketry or some other organic materials? And could the increase in pottery lids at the capital in Kerma during the heyday of the empire maybe reflect an inspiration from the Lower Nile/Egypt? Or something else? Another possibility is that we simply missed pottery lids in the Nubian ceramic tradition because we interpreted dishes and cups wrongly (as dishes/cups and not as lids).

These are all intriguing questions, and I will try to investigate them in more detail soon. For now, I would like to present some interesting case studies from the newly excavated Kerma cemetery GiE 003.

Feature 20 in Trench 1 is a rectangular burial pit with rounded edges, vertical walls, and impressions/pits in the east (40cm x 10cm) and west (30cm x 10cm). Remains of a contracted burial were still found in place on a wooden funerary bed. A goat/sheep offering and three almost complete pottery vessels were found below the foot end of the bed on the west side. The complete set of a red-burnished Kerma pot with a stone lid found in situ on top of the vessel (MUAFS 61 and 62) is especially remarkable.

The Kerma pot MUAFS 61 with its stone lid MUAFS 62.

The lid is just a nicely shaped circular disc without any modelling of the interior as it is for example known from lids of kohl pots. With a diameter of 5.4cm it fits perfectly on the pot. Some of you will wonder: with an in situ lid on the pot – what did they find inside the vessel? Well, to my disappointment the pot was completely empty except for some dust.

However, the stone lid MUAFS 62 is not a singular piece from GiE 003. Another stone lid was found in a plundering layer, MUAFS 10. Although it was impossible to associate this piece with a proper burial or feature, it is more or less contemporaneous to MUAFS 62 and can be attributed to the Classical Kerma time. With a diameter of 6.2cm it is slightly larger than MUAFS 62.

Apart from these two stone lids used as covers for pottery vessels, Trench 1 of GiE 003 also yielded a pottery lid. An almost complete lid, MUAFS 312-1/2022, was found in Feature 10 (a rectangular burial pit with pits for the funerary bed, very similar to Feature 20). This pottery lid is wheel-made, was imported from Egypt and is made in a Nile clay B2 variant. Such vessels are very common in the 17th Dynasty in Egypt (e.g. at Elephantine). With a diameter of 10.7cm and its convex shape, it is markedly different to the stone lids mentioned above.

The only attested wheel-made pottery lid from GiE 003 (original drawing J. Budka, digitalisation I. Comsa).

Although proof is lacking, I would assume that this pottery lid was used as the cover for one of the few Marl clay vessels imported from Egypt attested from Trench 1. However, the pottery found inside of Feature 10 apart from the lid was all Kerma in style, including typical Black topped fine wares.

To conclude, it requires more in situ found assemblages like MUAFS 61 and 62 to answer broader questions about the use of lids in Nubia in general and Kerma cemeteries in more particular. For now, the evidence from GiE 003 suggests some intriguing variation, especially in the Classical Kerma age.  

References

Bonnet 2004 = C. Bonnet, Catalogue no. 57: Vase with cover, in: D.A. Welsby and J.R. Anderson (eds.), Sudan. Ancient Treasures. An Exhibition of recent discoveries from the Sudan National Museum, London 2004, 83.

Budka 2020 = J. Budka, AcrossBorders 2: Living in New Kingdom Sai. Archaeology of Egypt, Sudan and the Levant 1, Vienna 2020.

Gratien 1978 = B. Gratien, Les cultures Kerma. Essai de classification, Lille 1978.

Raue 2014 = D. Raue, Elephantine und Nubien im 4. – 2. Jahrtausend v. Chr., Habilitation thesis, Leipzig 2014 (published in 2018, Berlin).

Excavating on the west bank of the MUAFS concession – summary of week 4

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While the first weeks of our 2022 season focused on mortuary remains and excavations in cemeteries, first of all the Kerma cemetery GiE 003, we switched focus and location in our week 4.

Earlier this year during our MUAFS survey, I noted an extremely interesting site at Attab West, with loads of early 18th Dynasty potsherds as well as scatters of local schist pieces on the surface. This site, AtW 001, is a small almost circular mound (Fig. 1). Unfortunately, the new line of electricity runs right through the site and seems to have destroyed part of it. This week, we went back there and excavated one trench as a first check of whether stratigraphy is preserved and any structures are traceable.

Fig. 1: Work in Week 4 focused on site AtW 001 at Attab West. View of Trench 1 to the south, with the loose surface removed. The mound covered with potsherds and schist pieces on the surface is still visible in the back.

It was our first excavation on the west bank, which differs considerably from the east bank in terms of landscape and general conditions. Logistics are a bit more complicated as well, bringing the team and the equipment to the site by boat and through large sandy dunes with picturesque tamarisks.

In sum, the test excavation at AtW 001 was a challenge but also very rewarding – we found what can be classified as domestic rubbish, loads of ashy deposits, plant remains, animal bones and lots of pottery sherds as well as debris from fires and other everyday activities. The ceramics are nicely datable to the early 18th Dynasty to Thutmoside times. Interestingly, the amount of Nubian wares in the various horizons of fill was really high, accounting to ca. 30% of the ceramics. The lower fills only had very little ceramics inside and here the Nubian wares were more common than Egyptian style wheelmade pots – this is just a first impression and I will follow up on this with a more detailed assessment soon!

We seem to have at least two phases of activity in the New Kingdom period preserved, possibly an early phase and a slightly later one which can be dated to Thutmose III. Remains of collapsed mud bricks and overfired sherds indicate the former existence of buildings and possible also ovens or kilns, but no standing remains of architecture was identified up to now. There were several homogenous deposits of silt, partly showing some ash. The ashy spots of the earliest phase are directly on top of the natural alluvium, suggesting that we either have an open courtyard or maybe part of the periphery of a domestic site. Apart from ceramics, the finds included some grindstones and stone tools like pounders, testifying to some grinding and crushing activities. However, many questions about this site are still open and AtW 001 needs to be excavated on larger scale in the near future.

Fig. 2: Final status of Trench 1 at AtW 001 in 2022 – there is still much work waiting for us at this domestic site!

Overall, our site finds a perfect parallel in the nearby site 2-R-18 in the desert hinterland of Amara West (Stevens and Garnett 2017, previously documented by Vila in the 1970s). As highlighted by Anna Stevens and Anna Garnett, there were also rubbish deposits above homogenous deposits of silt and ash, which seem to have accumulated directly on top of the natural surface. Similar to our site, no traces of architecture were preserved at 2-R-18. The material culture, especially of the pottery and the stone tools, is extremely well comparable to our finds. The dating to the early 18th Dynasty is also almost identical.

Thus, the results of our trench are clearly promising and work at AtW 001 will continue in the near future. Especially the function and duration of use of this site will make a considerable impact to our aims of addressing seasonal sites as well as sites connected with gold working (as suggested by Stevens and Garnett 2017 for 2-R-18 and other desert hinterland sites) and other activities in the 18th Dynasty periphery of Sai Island.

With the final day of work at AtW 001 yesterday, our fieldwork with workmen and excavation has come to an end – just in time before Ramadan starts tomorrow. Part of the team – all of them fully recovered from the corona infection by now – has already left and is heading back to Vienna and Munich. A small team will continue with processing finds here at Ginis and documenting the rich material culture from our very successful excavations in 2022.

Fig. 3: Group picture of the DiverseNile 2022 fieldwork team.

Many thanks go to all team members of 2022 – it has been a challenging season with so much wind, cold weather, covid-19 and a dense excavation programme at four different sites. The results are clearly remarkable and I am very grateful to all! For now, I am really keen to process the new material in more detail in the upcoming week.

Reference

Stevens and Garnett 2017 = Stevens, A. and Garnett, A. 2017. Surveying the pharaonic desert hinterland of Amara West, 287‒306, in: N. Spencer, A. Stevens and M. Binder (eds.), Nubia in the New Kingdom. Lived Experience, Pharaonic Control and Indigenous Traditions. British Museum Publications on Egypt and Sudan 3. Leuven.

Upcoming DiverseNile Seminar: The significance of black ritual liquids

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I am excited to announce the next DiverseNile Seminar which will take place tomorrow. Kate Fulcher is going to speak about the mysterious ‘black goo’ – black ritual liquids applied to coffins and cartonnage.

This topic is extremely exciting and in recent years, the use of bitumen in funerary contexts in the Middle Nile has received some new attention. For example, one of the contents from a vessel found in Tomb 26 was analysed by Kate using a GC-MS method and was shown to be bitumen. Where are the local sources for bitumen in ancient Sudan? Or was it imported? And more importantly, how was bitumen and other black substances used in rituals with coffins and cartonnage?

Be sure to join us tomorrow as Kate will address these important questions – as usual, last-minute registration via email is still possible.

Survey results 2021/2022 at Ginis East: an important Abkan site

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During our short season in December 2021/January 2022, we were able to record 14 sites on the East bank of the district of Ginis. These are 12 sites previously recorded by Vila as well as two new MUAFS sites (Fig. 1).

Fig. 1: Recorded sites in Ginis East, Dec. 2021/Jan. 2022. Map: C. Geiger.

One particularly noteworthy site is the Abkan occupation site 2-T-21 at Ginis East, on a hill above the modern asphalt road (Fig. 2). According to the current chronologies, the Abkan period is dated to between c. 5500 and 3700 cal BCE (see D’Ercole 2021 with discussion and references).

Fig. 2: Overview of site 2-T-21. Photo: J. Budka.

We could note that the meticulous documentation by Vila (1977) for 2-T-21 was correct (Fig. 3). Many diagnostic pottery sherds are still scattered on the surface. This site is clearly worth a more detailed investigation, although it has recently suffered from modern destruction like car tracks running through the site.

Vila’s sketch map of site 2-T-21 (Vila 1977, 60, Fig. 23).

Significant traces of Abkan occupation were recently documented by Elena Garcea on the island of Sai (Garcea 2020, 50 and 94 with references). The contemporaneous sites in our concession, of which several were documented on both riverbanks in Attab and Ginis, hold much potential and have received until now only little attention. Especially the relations of the Neolithic Abkan sites to Khartoum Variant sites in the region between the Dal Cataract and Sai Island needs to be explored in detail, not only regarding the chronology and possible overlaps but also in terms of subsistence strategies of these prehistoric communities as semi-sedentary hunter-gatherers and/or herding groups. This ties in with general questions about changes in the settlement strategies by Mesolithic groups compared to Neolithic communities (see D’Ercole 2021). Furthermore, until today, no cemeteries of the Abkan cultural complex have been identified – a highly unusual feature for a Neolithic culture in Sudan and something worth investigating in the future. Maybe the region between Attab and Ferka will provide some answers in this respect.

References

D’Ercole, G. 2021. Seventy Years of Pottery Studies in the Archaeology of Mesolithic and Neolithic Sudan. Afr Archaeol Rev 38, 345–372. https://doi.org/10.1007/s10437-021-09432-y

Garcea, E. 2020. The Prehistory of the Sudan. Springers Briefs in Archaeology. Cham.

Vila, A. 1977. La prospection archéologique de la Vallée du Nil, au Sud de la Cataracte de Dal (Nubie Soudanaise). Fascicule 5: Le district de Ginis, Est et Ouest. Paris.

Update on Raman Spectroscopy analysis on Nubian and Egyptian style samples

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At the beginning of June, we have announced the launch of a new pilot study – as part of the WP 3 of the DiverseNile project – implementing and testing the potential of the Raman Spectroscopy technique on a selection of ceramic samples coming from our reference collection from the sites of Sai Island (SAV/S-samples) and Dukki Gel, Kerma (DG-samples).

This study is currently in progress as part of our cooperation with the Department of Earth and Environmental Sciences of the LMU, and namely with Fabian Dellefant, co-author of this post, who is a geoscientist and doctoral student under the supervisors of Prof. Dr. Trepmann and Prof. Dr. Gilder.

Due to fast measurements and its non-destructive approach with only little sample preparation, Raman spectroscopy can be easily applied to ancient ceramic materials, answering various technological questions, in particular on the manufacturing stages of production and firing of the pots.

For our investigation, we analysed so far a total number of 8 samples/thin sections (namely samples DG-18, DG-23, DG-29, DG-35, SAV/S 02, SAV/S 14, SAV/S 17, and SAV/S 51). Of all these, micro photos were primarily taken under the petrographic microscope with both transmitted and reflected light in order to select the areas of the sample to be examined with Raman Spectroscopy (normally two different spots including the clay matrix and particular organic components, both within the inner portion or core of the sample and on the rim area).

These samples are either locally produced cooking pots or other local ware manufactured both according to the so-called Nubian (DG-18, DG-23, DG-29, and SAV/S 02) and Egyptian style (DG-35, SAV/S 14, SAV/S 17, and SAV/S 51).  All of them consist of a non-calcareous optically active clay matrix with dark cores and red or buff oxidised surfaces. In some specimens, the oxidised margins are narrow and well defined, while in others the red-black zonation appears larger and less regular. The Egyptian style samples normally show a kind of “sandwich” structure consisting of a dark core enclosed, both above and below, by red oxidised surfaces (Fig. 1).

Fig. 1 Photos of the fractures from thin section scanning of samples SAV/S 02 (left) and SAV/S 17 (right). Note the large amount of organic inclusions which have been totally or partially carbonized and are surrounded by voids. Both samples show a dark core due to insufficient penetration of oxygen during firing.

All these samples contain, in a different extent, organic matter either plant remains (chaff, straw, grass and possibly various cereals components), and probably herbivore manure (those finely divided straw particles). The organics are either totally or partially carbonized so that the plant inclusions are often preserved as black carbonized relics into the voids.

The carbonaceous core (dark-grey zone in the center of the ceramic samples) can be the result of insufficient firing under oxidizing conditions. It is also related to the use of a paste of high organic component. During the firing of the pot, the combustion of the organics acts indeed as a reducing agent, taking away oxygen from the firing environment (Velde and Druc 1999: 126-127, see also Quinn 2013).

In organic chemistry, the process of thermal decomposition, obtained by the application of heat and in the complete absence of an oxidizing agent is known as pyrolysis or graphitization.

Pyrolysis-GC/MS to ceramics which are conspicuously black or exhibit a black inner core from incomplete burn-out has been applied for the assessment of molecular properties of organic matter in archaeological pottery matrix (see Kaal et al. 2013).

In Raman Spectroscopy, vibrational modes of specific crystallographic components are used to determine a specific crystallographic structure. In our case, the temperature-dependent formation of graphite is used to quantify the highest temperature the sample has experienced.

The lab setup consists of an optical microscope with different magnifications and a computer software, which handles data acquisition (Fig. 2). Measurements are conducted by using a laser with a 532 cm-1 wavelength directly on the thin section which has been first well-polished and cleaned with ethanol. In the lab, temperature is kept constant at 18° C degrees with the lights turned off so as not to interfere with the measurement.

Fig. 2 Lab of the Museum Mineralogia in Munich with the optical microscope (right) and the computer (left), which were used for the investigation.

In the investigated ceramics, the precursor of the measured graphite can be either organic material, such as grass and straw, or dung of herbivores, which was mingled into the clay before heating. Furthermore, in some samples firing ash could have been added as well. Our preliminary results show that graphite can be clearly detected in the sample material. Interestingly, a group of samples showed graphite formation only within the organic components, which is interpreted as being the relicts from plant inclusions. Other samples clearly show graphite spectra also within the clay matrix, which could have been added to the clay as ash in the first place (see e.g., SAV/S 02, Fig. 3).

Fig. 3 Optical microphotograph with reflected light of sample SAV/S 02. Datapoint 12 (pink) marks an organic component in a void and refers to the Raman spectra SAV_2_1-r12 in Fig. 4. Datapoint 22 (blue) characterizes the ceramics matrix and refers to the Raman spectra SAV_2_1-r22 in Fig. 4.
Fig. 4 Raman spectra of a datapoint from the matrix and an organic component. The spectrum of the matrix refers to datapoint 22 and the spectrum of the organic component refers to datapoint 12 of Fig. 3.

The interpretation of the maximum temperature the sample experienced is based on the ratio of two Raman peaks, which have a wavenumber of ~1390 cm-1 and 1606 cm-1. Given the dataset shown in Fig. 4, the maximum temperature can be estimated to ~600 °C after Guizani et al. 2017.

In the following weeks, we will proceed to the data processing and potential grouping based on the various Raman spectra collected from our pottery samples (we measured on average up to 20-25 datapoints for each sample). This will allow us to develop our preliminary interpretations and come to more specific conclusions on the quality of the organic material added to the paste and the heating temperatures reached during the firing. Eventually we might get insights on the type of clay sources selected to make the pots.

We can maybe spoil a bit things for you, anticipating that possibly some of the examined samples experienced a more homogeneous firing than others, these latter showing otherwise varying temperatures!

References

Guizani, C., Haddad, K., Limousy, L., and Jeguirim, M. 2017. New insights on the structural evolution of biomass char upon pyrolysis as revealed by the Raman spectroscopy and elemental analysis. Carbon 119:519–521. http://dx.doi.org/10.1016/j.carbon.2017.04.078.

Kaal, J., Lantes-Suárez, O., Martínez Cortizas, A., Prieto, B., and Prieto Martínez, M. P. 2013. How Useful is Pyrolysis-GC/MS for the Assessment of Molecular Properties of Organic Matter in Archaeological Pottery Matrix? An Exploratory Case Study from North-West Spain. Archaeometry 56 (S1): 187–207. https://doi.org/10.1111/arcm.12057.

Quinn, Patrick S. 2013 Ceramic Petrography. The Interpretation of Archaeological Pottery and Related Artefacts in Thin Section, Oxford.

Velde, Bruce and Druc, Isabelle C. 1999. Archaeological Ceramic Material. Origin and Utilization, Berlin.

Of identities and bodies: new DiverseNile Seminar on mortuary diversity

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According to the cold and rainy weather here in Munich, summer has long past – fittingly, our short summer break of the DiverseNile Seminar is now officially over. It is my pleasure to announce the upcoming lecture on Tuesday, August 31: Michele Buzon will be talking about „Intersectional Identities and Bodies: Exploring Biological, Geographic, and Mortuary Diversity in the Ancient Nile Valley“.

Michele is bioarchaeologist and Professor of Anthropology at Purdue University in Indiana, USA. I have the pleasure knowing her since many years, having met her both in Sudan and at conferences. She is the codirector of the important excavations at Tombos and we were therefore always in close contact during my AcrossBorders project. Our assessment of the strontium isotope analysis from Sai could nicely built on data published by her and co-authors. As I outlined in an earlier post, only common efforts will allow us to establish a strontium isoscape for New Kingdom Nubia and much work is still waiting for all of us.

Michele is one of the key figures in modern Nubian bioarchaeology conducting contextualized interpretations that combine skeletal evidence with settlement, environmental, and mortuary data. This approach allows to create a more nuanced picture of life and death in ancient Nubia (see also her recent summary of Bioarchaeology of Nubia in the Oxford Handbook of Ancient Nubia, Buzon 2021).

I am very much looking forward to her presentation and hope that many of you will be joining us – without doubts, Michele is going to show exciting material, fresh data and will offer much food for thought! As usual, late registration for our DiverseNile seminar is still possible via email.

Reference

Buzon, Michele R. 2021. Bioarchaeology of Nubia, in: The Oxford Handbook of Ancient Nubia, edited by Geoff Emberling and Bruce Beyer Williams, Oxford, DOI: 10.1093/oxfordhb/9780190496272.013.55