Performing XRD analysis on Nile clay Nubian- and Egyptian-style samples from Attab and Ginis

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Exams never end, not just for humans but even for archaeological artifacts.

Already before the Christmas break, I had happily returned to the lab, this time to prepare a new bunch of ceramic samples to undergo X-ray powder diffraction (XRPD) analysis. Thanks to a new cooperation with the TU München, and especially with Prof. H. A. Gilg (Chair of Engineering Geology) we decided in fact to complement our iNAA and OM analyses with this new laboratory methodology, with the aim of expanding our knowledge on the composition, provenance and technology of production of our Nile clay samples. All in all, we preliminary selected 30 ceramic specimens, among Nubian- and Egyptian-style sherds from the 2022 and 2023 excavated sites at Attab West and Ginis East. To this sample, we added a replica in modern Nubian (from Abri) Nile clay manufactured by us during our last workshop in Asparn.

Generally speaking, X-ray powder diffraction analysis is a well consolidated analytical technique used in the field of archaeometry and ceramic technology to determine the mineral phases present in the pastes, including those clay phases which are typically not visible under the microscope. This technique also provides information on the firing process the pottery went through. Certain minerals (e.g., calcite as one of the most known) can in fact degrade, disappear or be altered at given temperatures because the crystalline structure collapses through the process of dehydroxylation (Magetti 1982; Rice 1987). The analysis itself based on the phenomenon of diffraction of electromagnetic radiation, by exploiting the fact that X-rays falling on crystalline planes in minerals are reflected at varying angles (Velde and Druc 1999; Quin 2013). Hence, each mineral type will produce a characteristic X-ray diffraction spectrum with diagnostic peaks placed at given angular distances (expressed in degrees 2θ), allowing the qualitative identification of the minerals present within the ceramic sample. The heigh of those picks permits otherwise a semi-quantitative estimation of the ratios in which minerals are more or less represented.

Figure 1 – Lab kit for the preparation of samples for XRD analysis. Photo by G. D’Ercole.

Sample preparation is pretty much straightforward although partially destructive. The procedure requires that a tiny portion of the sherd be ground up (about 1g of powder) by hands with an agate mortar and a pestle, alike those used for iNAA, pressed in the mounting smear slide, and then put into the instrument. Proper pulverization and homogenization are crucial to achieve highly quality XRD data.

Figure 2 – Pulverization of the sample by hands in the agate mortar. Photo by G. D’Ercole.

The sample needs to be as representative of the ceramic sherd as possible – for this reason, it is sometimes advisable to grind a larger quantity of powder and above all finely ground so as to prevent larger crystals (e.g., coarse quartz grains) from interfering with the measurement. This latter can be carried out with different timing and levels of accuracy depending on whether one wants only a rough semi-quantitative estimate of the mineral phases in the sample or more accurate information.

Figure 3 – First set of potsherds ground up and ready to be analysed by XRD analysis. Note the diverse powder colours from black (reduced fired Nubian samples) to reddish-brown (oxidized fired Egyptian sherds). Photo by G. D’Ercole.
Figure 4 – Samples ready in the mounting smear slides. Photo by G. D’Ercole.

In performing XRD analysis, our main archaeological questions were the following:

  • Can we recognize the use of different clay raw materials for the different sites/locations (e.g., Attab, Ginis…);
  • Can we differentiate between Nubian- (also Pan-Grave) vs. Egyptian-style samples;
  • Can we differentiate between the different ceramic types and wares;
  • Can we demonstrate the intentional addition of tempers (calcite and/or quartz and/or feldspar and/or mica) in particular samples?
  • Can we know more about the firing process (i.e., firing temperatures) the ceramics went through?

Currently, together with Prof. Gilg, we just started to interpret the results of the first diffractograms. The data are not always straightforward to read and the differences between the various samples look sometimes very subtle – on the other hand our Nile clay samples have used us to significant challenges for many years already!

Preliminary, we can say that, based on the diagnostic mineral phases in the various spectra, it was possible to recognise four distinct groups or types of samples. These groups do not depend on the main phases (quartz or feldspar) as these are present in nearly homogenous amounts in all samples. Rather, some differences can be spotted in the clay minerals. Whether these latter can be ascribed to different clay sources, preparation recipes, or eventually the pot production (i.e., firing) has yet to be fully assessed.

References

Maggetti, M. 1982. Phase Analysis and its Significance for Technology and Origin. In J. S. Olin and A. D. Franklin (eds.), Archaeological Ceramics: 121−133. Washington, Smithsonian Institution Press.

Quinn, P. S. 2013. Ceramic Petrography: The Interpretation of Archaeological Pottery & Related Artefacts in Thin Section. Oxford, Archaeopress.

Rice, P. M. 1987. Pottery analysis. A sourcebook. Chicago, University of Chicago Press.

Velde, B. and Druc, I. C. 1999. Archaeological Ceramic Material. Origin and Utilization. Berlin Heidelberg, Springer-Verlag.

Having fun with Virtual Reality

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This week we had a special teaching lesson – archaeological sites in VR – almost a real field trip to Egypt!

With the help of various digital models and 360-degree videos, the students were able to get a realistic picture of a huge variety of Egyptian sites and antiquities. Studying can be so much fun!

Thanks to recent digital developments, it is finally possible to get a good impression of temples and tombs, even outside of Egypt. In addition to the commitment of many colleagues and various large-scale projects (like the project of the factum foundation in cooperation with Basel University and the Egyptian Ministry of Antiquities), this development is a very positive outcome of the digitalization associated with the pandemic. Many 3D models are accessible free online and can be accessed using your own mobile phone, laptop or high-quality VR glasses (via YouTube, Matterport or Sketchfab, etc.).

In our class, we dared to experiment and integrate virtual reality into teaching Egyptology. And the happy faces show that it worked.

Digital models are particularly helpful for introductory courses to Egyptian archaeology. The impressive monuments can be seen in almost their full size, colour and shape. It is also possible to consider specific aspects in more detail based on the student questions. There are no longer any restrictions on the presentation of images.

After initial difficulties getting to grips with the cell phone settings and engaging with the virtual world, it soon became clear how easy it can be. A cardboard box, a mobile phone, an internet link and you’re ready to go. For all those who are unable to enjoy a VR experience due to visual impairment or vertigo, there was the option of viewing the 3D models on a laptop and joining without the 3D simulation in the virtual world. The variety of different models is huge. From the pyramids in Giza – inside or outside, to temples like Karnak or Abu Simbel, the tombs the Valley of the Kings, there is nearly no limit (e.g. Pyramids: https://www.youtube.com/watch?v=mOuvAJRknXk; https://my.matterport.com/show/?m=o5Ex5Xo7UkE; Karnak: http://www.aktiv-panorama.de/vr-touren/Karnak-Tempel_in_Luxor/; https://www.youtube.com/watch?v=VtI9debZPGU; Abu Simbel: https://matterport.com/discover/space/VxYAEMXh6dW; Tomb Ramses II https://ramsestheexhibition.com/3d-tomb/; Nefertari reconstruction: https://www.youtube.com/watch?v=PFAJcMzmMzQ).

By integrating the new technology into the syllabus, we hope to achieve the best teaching and learning results and offer students a fun immersive experience.

We hope to integrate new 3D models of the DiverseNile project in the future to enhance learning, teaching and archaeology.

Now published: our excavation report 2023

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Perfect timing – just before the holidays, the new issue of Der antike Sudan – Mitteilungen der Sudanarchäologischen Gesellschaft zu Berlin e.V. arrived in our office, hot off the press. It comprises a broad range of topics, including our 2023 excavation report.

Chloë, Kate and I summarised under the title “Cultural diversity in the Bronze Age in the Attab to Ferka region: new results based on excavations in 2023” the most important working steps and results of our field season in Attab and Ginis earlier this year. This work would not have been possible without our Sudanese workmen and the support of all authorities. We are in particular very grateful to Huda Magzoub Elbashir, our NCAM inspector and long-time collaborator and friend.

An update of our work in Kerma cemetery GiE 003 can be found in the article, highlighting the relevance of the Pan-Grave burials we discovered in Trench 5. The presence of cultural diversity (Pan-Grave Nubians, Kerma Nubians) and evidence for cultural exchange (with the Hyksos – see for example the royal scarab, with the Egyptians – especially through imported ceramics) is of key importance for the ERC DiverseNile Project.

An overview drone image of site AtW 002. Photo: K. Rose, © DiverseNile project.

Furthermore, a short section describes our work at site 2-S-54 which we recorded as AtW 002. The rectangular Structure 1 on this site can be dated through the ceramics to the early 18th Dynasty and I included in the new article the results from the C14 analysis of a charcoal sample from a fireplace in the lower stratum, presumably the primary usage horizon. The sample yielded with the highest probability the period of 1688-1517 BCE, supporting our hypothesis that AtW 002 and neighbouring sites were probably used from Classic Kerma times to the early New Kingdom. The site is located along a paleochannel which was documented in our 2023 season by Kate (who also describes her work in this article). This paleochannel was recently addressed by our colleagues Mat Dalton, Neal Spencer and others (Dalton et al. 2023) under the topic of the intriguing river walls (of which there are plenty in our concession).

The report includes an update on our 2023 excavation at AtW 001 which allows a better understanding of this site, also in terms of dating. The material found in the debris layers we excavated in 2023 is all mid-18th Dynasty in date, therefore an abandonment of the site under the late years of Thutmose III or one of the subsequent Egyptian kings is likely. The latest pottery found at the site seems to date to the reigns of Amenhotep II/Thutmose IV (e.g. imported bichrome decorated ware).

Finally, Kate describes in the article the two primary objectives carried out for the landscape work package during the 2023 field season: 1) the drone survey over the entire district of Attab West and other areas in the concession, including low flights over selected sites for the creation of detailed orthophotos and digital elevation models of the terrain, and 2) ground survey and mapping of dry-stone features in the landscape, using a Trimble Catalyst GPS receiver, and a TDC 6000 data collector. One of Kate’s nice drone photos also made it to the cover of the new issue of MittSAG!

Seeing results of our fieldwork in Sudan published is very ambivalent at the moment – it reminds us all too well of our friends and colleagues on site and the terrible situation in Sudan, which unfortunately continues to escalate. The hope remains that 2024 will bring rapid improvement for the country and its residents. Just as there will hopefully be peace in other parts of the world.

Reference

Dalton et al. 2023 = Dalton, M., Spencer, N., Macklin, M. G., Woodward, J. C., & P. Ryan. “Three thousand years of river channel engineering in the Nile Valley.” Geoarchaeology, 2023, https://doi.org/10.1002/gea.21965.

New dissemination article about our 2023 season

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With all the snow here in Munich, it is quite a good timing to see the new volume of the Project Repository Journal going live. It includes a new dissemination article about our season in Sudan earlier this year.

Check it out if you want to know more about our works at sites like the Kerma cemetery GiE 003, the domestic site AtW 002 along the major paleochannel in Attab West dating to the early New Kingdom and the larger New Kingdom settlement site AtW 001 which was located on a former island, close to the present Nile on the west bank of Attab.

As much as it is a joy to see such an outreach of our project, we are widely concerned about the risks the people and the cultural heritage of Sudan are currently facing – may this terrible war end soon. Hoping that peace will come as soon as possible, our thoughts are with all of our friends and colleagues.

Upcoming DiverseNile Seminar: how to conceptualise narratives of Napatan shabtis figurines using 3D print replicas

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I am excited to announce the next DiverseNile Seminar for Tuesday, 5 December. Amanda Ford Spora will talk about her research with replicas of Napatan shabti figurines.

Amanda is currently a PhD candidate at the University College London. She is a community archaeologist with fieldwork experience in Sudan, especially at Mograt Island.

Her exciting research is “about co-creative meaning making using digitally produced replicas, and the process that non-professionals and professionals engage with together, to manifest authentic narratives of the ancient past.” The shabti figurines she is using for this include Napatan shabtis, of which the originals are currently in the UK. Amanda has undertaken research with teenagers in Sudan, Australia and United Kingdom, last but not least also to raise more awareness of the rich and endangered Sudanese heritage.

Her research fits perfectly into the agenda of the ERC DiverseNile project – as Kate Rose outlined in a previous blog post, we are also using the rich potential of 3D printing ancient artifacts. We are in particular interested in the implications these replicas hold for education and outreach, the accessibility of archaeological heritage, and explorations in experimental archaeology.

Speaking about education, I would once more like to advertise the fantastic recent volume “African Archaeology in Support of School Learning” – these contributions and also the splendid introduction are very inspiring and underline the wide-ranging relevance of our research (see also our article on the reconstruction of lived experiences in Sai City during the New Kingdom).

However, we must not forget the current challenges of school education in Sudan after more than 7 months of war. With an estimated 19 million children out of school, the country is facing a major education crisis. In a recent blog post, solutions to revive the education sector were proposed – I heartfully wish that the wonderful and amazingly resilient people of Sudan will achieve the revival of their educational sector by means of collaborative efforts. For this, they should receive as much international support as possible – and maybe also archaeology in Sudan and especially community archaeology can help a little bit to overcome this crisis.

Copper alloy production and use: upcoming DiverseNile Seminar

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I am delighted that our next DiverseNile Seminar is approaching. Frederik Rademakers will be speaking about brand-new research on copper production in the New Kingdom.

Frederik is currently employed at the British Museum, Department of Scientific Research as a metals specialist. His core research focus lies on ancient copper metallurgy in the Nile Valley and central Africa. Frederik’s approach is a combination of analytical studies of archaeological remains (from museum collections as well as ongoing excavations, e.g. Kerma and Amara West in Sudan) and experimental archaeology. Through the latter, we have been frequently in contact in the last years, and I can very highly recommend his seminal publications, e.g. Rademakers et al. 2022.

I am especially happy that the upcoming presentation by Frederik on November 21, 2023 will nicely connect to our previous DiverseNile Seminar 2022, focusing on landscape and resource management. In general, the procurement of materials and management of resources are topics which have gained popularity in archaeology in recent years, also in Egyptian and Sudanese archaeology. Modern multidisciplinary approaches enable us to investigate objects’ complete chaîne opératoire. An excellent example for these new advances is the study of copper in Egypt and Nubia (see Odler 2023) and in particular copper production at Kerma, a topic Frederic is an expert in (Rademakers et al. 2022). From the New Kingdom town of Amara West, a recent study in which Frederik was one of the main persons involved has provided important insights into the complexity of production chains, the question of material availability and supply in colonial Nubia and the direct comparison with Egypt (Rademakers et al. 2023).

In the upcoming DiverseNile Seminar, Fredrik will discuss unpublished material and data for the New Kingdom – nothing you want to miss if you are interested in archaeometry, copper production and interdisciplinary approaches to the topic.

References

Older, M. 2023. Copper in ancient Egypt: before, during and after the pyramid age (c. 4000-1600 BC), Culture and History of the Ancient Near East 132, Leiden; Boston.

Rademakers, F. W., Verly, G., Degryse, P., Vanhaecke, F., Marchi, S. and C. Bonnet. 2022. Copper at ancient Kerma: a diachronic investigation of alloys and raw materials, Advances in Archaeomaterials 3 (1), 1−18.

Rademakers, F., Auenmüller, J., Spencer, N., Fulcher, K., Lehmann, M., Vanhaecke, F. and Degryse, P. 2023. Metals and pigments at Amara West: Cross-craft perspectives on practices and provisioning in New Kingdom Nubia, Journal of Archaeological Science 153, 105766. 10.1016/j.jas.2023.105766.

One paper out, a new exciting Raman spin-off project just launched

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About two years ago, at the height of the Covid pandemic, the idea was born to initiate a scientific cooperation with our colleagues Fabian Dellefant and Melanie Kaliwoda from the Department of Earth and Environmental Sciences of the LMU and test together a new analytical methodology for archaeological ceramic material, namely Raman Spectroscopy.

Specifically, we aimed to first perform Raman spectroscopy towards carbon-bearing pottery and yields insights on the application of this technique for estimating maximum firing temperatures of Late Bronze Age vessels from Upper Nubia, comparing two site-specific data sets of samples, from the 18th Dynasty (1550–1290 BCE) at Sai Island and Dukki Gel (Kerma).

The encounter between natural sciences and archaeology was successful and from this idea an inspiring project developed, culminating in the publication of the paper: “Differentiation of Late Bronze Age Nubian- and Egyptian-style ceramics from northern Sudan by manufacturing firing temperatures using Raman spectroscopy”, in Journal of Archaeological Science: Reports, as part of the Special Issue Materiality of Earth edited by Pamela Fragnoli, Elisa Boccalon, Susanna Cereda, and Giovanna Liberotti, whom we all deeply thank for inviting us to contribute to this SI.

In testing Raman spectroscopy, our principal aims were to search for differences in producing technique and firing temperatures between the Nubian- and Egyptian-style samples; between the samples from Sai Island and those from Dukki Gel; and eventually among the different ceramic wares and types.

Now, as it is often the case, one idea leads to another and while some of the archaeological questions posed in the initial objectives of the work have not yet been fully answered, new exciting questions have arisen during the research and led us to further expand our Raman project into a new spin-off project focused on the investigation of the effects of oxidative weathering in relation to site-specific depositional environment and time.

Generally speaking, oxidative weathering is known to cause significant alteration modifications of the ceramic body after deposition resulting in distorting Raman spectra and potentially leading to an overestimation of the firing temperatures (Deldicque et al., 2023). Although all archaeological ceramics experienced oxidative weathering, our case study showed that the weathering effect was possibly more intense on the Dukki Gel than on the Sai Island samples hence to affect maximum firing conditions.

The new set of samples for which thin-sections were produced to perform Raman Spectroscopy.

In the coming months, together with Fabian Dellefant, we will particularly focus on this aspect of our research and perform Raman Spectroscopy on new samples, including ceramic sherds that have undergone extremely intensive oxidative weathering and experimental replica which were never exposed to any depositional and post-depositional processes.

Stay tuned to know more about the development of our work!

Reference

Deldicque, D., Rouzaud, J., Vandevelde, S., Medina-Alcaide, M.A., Ferrier, C., Perrenoud, C., Pozzi, J., Cabanis, M., 2023. Effects of oxidative weathering on Raman spectra of charcoal and bone chars: consequences in archaeology and paleothermometry. Comptes Rendus. Geoscience 355, 1–22. https://doi.org/ 10.5802/crgeos.186.

In focus: Jebel Barkal and Kushite urban sites

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Today, winter term has started in Munich and another DiverseNile Seminar is approaching.

Although we are still very concerned about the current situation in Sudan, with the terrible conflict ongoing since more than 6 months, threatening and endangering civilians and also cultural heritage, we are delighted to host our next event dedicated to Sudanese archaeology.

Tomorrow’s speaker will be Geoff Emberling, Associate Research Scientist of the Kelsey Museum at the University of Michigan.

Geoff is well known for his comparative perspectives on ancient cities, states, empires, and ethnicity. Originally a Near Eastern Archaeologist by training, he has conducted fieldwork in Sudan since 2007 and has become an internationally renowned expert on the Kerma period and the Naptan empire.

His talk for the DiverseNile Seminar will give insights into his current project at one of the most impressive landmarks of Sudan: Jebel Barkal. This holy mountain has an amazing history throughout the ages and the site incorporates temples, pyramids and palaces. The Jebel Barkal Archaeological Project (JBAP), co-directed by Geoff and El-Hassan Ahmed Mohamed, started its work in 2016. This new project aims to unearth Jebel Barkal as an ancient city—the “lost city” of Napata, the urban backbone of all the known palaces and temples.

I am very much looking forward to hear more about the latest research at a fascinating site in Sudan. Although Jebel Barkal and questions about Kushite capital cities are beyond our DiverseNile Bronze Age perspectives, this case study has much potential to address crucial questions about urban sites, their infrastructure, organization and hinterland.

Archaeology for Education: African Archaeological Review vol. 40, issue 3, September 2023 is now published

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It’s my great pleasure to announce that the special issue of the African Archaeological Review vol. 40, 3 edited by Ann B. Stahl Allison Balabuch, Kathy Sanford, Amanda Logan, Kate Grillo and Thiaw Ibrahima is now published!

It comprises, in open access format, 15 articles around the general topic of African Archaeology in Support of School Learning, including our piece on A Day Along the Nile. Once again, I am very grateful to Ann for inviting us to be part of this project with is fabulous accomplishment! I am thankful to my co-authors Chloe and Carl. We all hope this special issue of AAR will be much appreciated by a large and diverse community of both scholars and educators.

Digitally Documenting a Fortified Islamic House in Attab East

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This past season in Sudan, our drone program took flight (pun-intended) in more ways than one. We dedicated most of our efforts to flying programmed missions over large areas of the landscape mainly in Attab West, to collect data for the generation of Digital Elevation Models (DEMs) and orthophotos. In addition, we found time to make targeted flights of standing architecture for 3D modeling and visualization purposes. Digital recording of archaeological sites using the methods and principles of photogrammetry has immense implications for cultural heritage preservation.

I was able to spend an entire day in Attab East documenting an extremely interesting, and remarkably well-preserved Islamic house, located just south of the Nile. The structure was identified and recorded by André Vila as site 2-S-57, a fortified Islamic house. It was built on a small raised rocky plateau, east of a small drainage channel.  

Image of the Islamic house 3D model in Drone2Map, facing north.

The house is especially interesting in that many of its walls are still very well preserved, along with evidence of a second story, multiple small staircases, and a larger staircase in the northwestern corner of the house, leading to a tower-like structure. Several walls have also collapsed in recent years, and the collapsed building material remains in situ in the southeastern corner of the structure.

The house itself is designed with a large central courtyard surrounded by relatively small interior rooms. These rooms are all roughly rectangular in shape, seem to be similar sizes, and are mostly oriented east to west. Some rooms contain interior sub-divisions, as well as windows and doorways preserved along the northern exterior wall. The rooms form a cellular pattern around the central courtyard, a common architectural pattern in Islamic houses (Abu-Lughod 1987; Petruccioli 2008; Zolfagharkhani and Ostwald 2021). It would certainly be interesting to consider the use of domestic space in this house, as activity areas and movement patterns are surely present.

Current challenges exist to the house’s preservation, including erosion, flooding, and modern use of the house’s rooms as animal pens. It is interesting that there is continuity in the use of this structure for subsistence activities. However, it is extremely important to have the opportunity to digitally document well-preserved, at-risk sites such as this one. I collected approximately 700 images using our Phantom 4 drone of the site and processed a 3D model in Drone2Map.

Given the high-quality model, the site can be virtually “visited” on open-access sites like Sketchfab. This gives diverse publics the opportunity to engage with and experience the site. Furthermore, systematic analyses such as space syntax can be conducted to further understand the use of the site with the data from the model. Digital representations of archaeological sites are especially valuable during periods of political turmoil when cultural heritage may come under threat. Given the on-going conflict and humanitarian crisis in Sudan, and the enduring impact of the Covid 19 pandemic on research disciplines in general, archaeologists must continue to develop innovative solutions to critical problems of cultural heritage management and preservation.

Check out the model of the Islamic house for yourself on MUAFS’s Sketchfab profile:

https://sketchfab.com/muafs\

Here you can play with the model, manipulate the view, zoom in on rooms and features, and experiment with the size of the model. Sketchfab is a completely free educational platform for all users. Be on the lookout for more models from the project in the future!

References:

Abu-Lughod, J.L. (1987). “The Islamic City–Historic Myth, Islamic essence, and Contemporary Relevance”, International Journal of Middle East Studies, 19(2), pp. 155-176.

Petruccioli, A. (2008). “House and Fabric in the Islamic Mediterranean City” in S.K. Jayyusi, R. Holod, A. Petruccioli, and A. Raymond (eds.), The City in the Islamic World: Volume 1. Leiden: Brill: pp. 851-876.  

Zolfagharkhani, M. and Ostwald, M.J. (2021). “The Spatial Structure of Yazd Courtyard Houses: A Space Syntax Analysis of the Topological Characteristics of the Courtyard”, Buildings, 11(262), pp. 1-22.