Underwater Archaeology – Sanisera Field School

Ever wanted to combine a hobby you enjoy with work you are passionate about, like scuba diving and archaeology? In 2013 Vince and I did just that. Archaeologists tend to be naturally curious people, always wondering “what’s over there?” or “what’s under that?”, so its not surprising that many archaeologists also enjoy scuba diving. There are plenty of opportunities for the public to try their hands at archaeology right here in Alberta (such as at Bodo or Brazeau) but as avid scuba divers Vince and I decided to try our hands at underwater archaeology at a more exotic location.

For two weeks in April-May 2013 Vince and I attended the Sanisera underwater field school at the Cap de Cavalleria on the island of Menorca, Spain.  This field school was conducted by the Ecomuseum de Cap de Cavalleria (now called the Sanisera Archaeology Institute for International Field Schools).  This is a large field school with something for everyone and we met people from all over the globe who shared our interest in archaeology. In addition to the underwater fieldschool, there were two other fieldschools being held on land at the same site. One excavation was taking place at the Roman city (Sanisera), and the other was at one of the seven Roman necropolises located near the city. Our group was underwater investigating shipwrecks in the harbour. The site was diverse and included not only the areas mentioned above but also a Roman military camp which predated the Roman city, a quarry and an 18th century British watch tower.

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We started each morning by hopping into the van and driving to the dive site. On the beach before diving we would discuss which survey methods we were going to use that day and what our objectives would be (since we couldn’t speak once we were under). Then we would gear up and hit the water. Some days we would have to swim a fair distance before submerging and some days the sea was too stormy (or too many jellyfish) to dive at all.

Four different underwater survey strategies:

1. Snag line – two divers swim in the same direction with a weighted rope pulled tight between them dragging it along the bottom and stopping if it “snags” an object. When an object is snagged the ends of the rope are pinned to the bottom and the divers follow the rope to the object. If it is an artifact they record it, if it is something like a rock they unpin the rope and continue.

2. Circular search – to perform a circular search one end of rope is tethered to something that won’t move (a datum) then either multiple divers can space themselves out along the rope and survey a circle around the datum, or one diver can make multiple circles around the datum moving down the rope with each new circle to cover the same amount of space as the multi-diver scenario.

3. Swim-line search – a linear method, the swim-line search sees divers hold onto a rope to make sure they and maintain a consistent speed and keep their distance between each other as they move together in a line. A tug on the rope indicates that someone along the line found something and for everyone to stay put until it is recorded.

4. Jack-stay search – this type of survey is useful for carefully covering a predetermined area. Two parallel lines are fixed to the seabed (called jack-stays) and a movable rope is laid out spanning the distance between them. Divers then use the movable rope as a guide for their search starting at opposite ends, where it meets the parallel fixed jack-stay lines, and swim towards one another. When finished surveying the ground below the movable rope is adjusted along the length of the stationary jack-stays as the survey progresses slowly working from one end to the other effectively creating temporary survey corridors. When the search is midway through, the rope system will resemble a capital “H”. The two fixed jack-stay lines running parallel to each other form the vertical lines and the movable rope, perpendicular to the other two, would form the middle part of the “H”.

We practiced all of these survey techniques with the exception of the snag line and also practiced mapping artifacts underwater and taking photos. The artifacts we found were mostly amphorae that had spilled out of wrecked cargo ships, but we also found two anchors. We finished our dives around noon, got out of our gear, packed it back into the van and then returned to the Ecomuseum.

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Once at the museum we would have a debriefing about what we found, compare our notes and maps and have a short lecture. While we were doing this the students from the terrestrial field schools were cleaning and cataloging artifacts. We didn’t collect any artifacts from our underwater survey as keeping them underwater is the best way to preserve them at present. After our short lecture we would sometimes have a longer lecture that all three field schools would attend, these lectures were useful to all the groups as they usually discussed topics such as the history of the site, findings of previous excavations or focused on specific artifact types (for example how to tell where an amphora was manufactured based on vessel shape, temper type or colour of the clay).
We had a few days that we didn’t do any diving, lectures or excavation. On those days all three field schools were taken on tours of the island to visit other archaeological sites relating to the pre-Roman inhabitants of the island – the Talaiotic. We were also taken to the island’s capital city Mahon (Maó) to visit the museum where our instructors gave talks about some of the artifacts on display and we visited the back rooms to see some unique artifacts that were not currently on display. At the end of the field school each student gave a presentation to our specific field school group and to all the instructors.

If you know anyone who is interested in giving archaeology a try it is definitely possible to get your hands dirty no matter where in the world you live. Joining your local Alberta Archaeological Society chapter is the best way to hear about great (and often free or kid friendly!) ways to get involved and to learn from the experts.

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Publicly Reported Sites

In 2016 two members of the public contacted Tree Time Services to report archaeological sites that they had discovered. Our Archaeological Roadshow was being hosted by the Sundre Museum, during which we were approached by the first person who had found a side-notched projectile point while planting her garden. We arranged to meet her at her home to record the site. We took photos of her garden and recorded the location using a hand-held GPS unit of where she recalled finding the projectile point. We also took photos of the projectile point itself. Our time with her allowed us to collect the data we needed to report the site as EkPp-18. While the site is highly disturbed due to the construction of the subdivision it is still important to record the location of her site and what was found. This information will help future archaeologists to predict where other similar sites in the area can be found.

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Side-notched point found in the garden.

The second community member to contact us got in touch with Kurtis to let him know about six sites he found while hiking and hunting in the region. Teresa and I took a day off from working for our client to spend with him visiting the sites he had found. While we were there, we recorded the locations of where he had found artifacts, took photos and conducted surface inspections resulting in the identification of additional artifacts. The artifact collection is being catalogued by Tree Time so that we can record data to the standards required by the Royal Alberta Museum. This way we can submit site forms to the government of Alberta, just as we did for the previous person’s site. These site forms will have a detailed description of the archaeological sites found and a full listing of the number and types of artifacts found at each site. A copy of these catalogues will be sent to the Royal Alberta Museum when we have completed the reporting process. The museum needs a copy of the catalogue so that if any future work is completed at these sites they will be able to provide the researchers with a starting catalogue number, avoiding duplicates in the database. This way it is easy for researchers to know how many and what kinds of artifacts have come from a particular site, even if the museum doesn’t have the artifacts themselves.

Bifacial fragment found while hiking.

We are always happy when people are willing to share their archaeological finds with us because the government cannot protect sites they don’t know exist. Researchers also need this information to build predictive models and to choose what areas would be interesting to conduct more research at.

If you have found an archaeological site and would like help to record it please contact Kurtis at 780-472-8878 or email [email protected].

Projectile Point

Projectile points come in many shapes and sizes ranging from large paleolithic spear points to small protohistoric arrow heads to even smaller “toy arrow heads”. This artifact type is a stone that has been shaped using flint knapping techniques to create a sharp triangular and aerodynamic tip that is attached to a wooden shaft that can be propelled through the air by throwing by hand, atlatl, or bow, to hunt game. This is an important artifact type as over time the styles of points changed allowing us to use the style to estimate the time period a site was occupied.  This particular point is a Besant style dart point, which dates to approximately 2,500 -1,350 BP.

Surface Exposure

Surface exposures are areas where there is no vegetation and the mineral soils are visible. These can occur naturally (areas of slumping, beaches, blow-out, or other natural erosional processes), or be caused by human activity (ATV trails, furrows created for site prep and skid trails just to name a few). Surface exposures can be great for covering a lot of ground during survey.


Obsidian is commonly known as volcanic glass. It forms when a volcano erupts and the lava is cooled extremely quickly, such as when it flows into a water body. In Alberta obsidian is considered to be an “exotic material” because it does not occur here naturally. When we find it here it tells us that people in the past engaged in long distance trade, usually with people in British Columbia or the Yukon. In 2016 Teresa found this lovely obsidian flake at site FaPr-6 located near the community of Caroline.

What is Mitigative Excavation?

Mitigative excavation is the process of digging an archaeological site that is threatened either by development or natural erosion. Mitigative excavations have different goals than academic excavations. The goal of mitigative excavations is is to save as much information about the site before it is destroyed, whereas in academic digs the goal is to answer specific questions about how people were using the site in the past.

When a planned development is in direct conflict with a significant archaeological site our normal first recommendation is for a project redesign in order to avoid impacting the site. When a project redesign is not a viable option a mitigative excavation might be required.

Before the excavation begins additional shovel testing may be required to ensure that the boundaries of the site have been confidently established and to identify the most important or valuable part of the site. Using what we have learned from the shovel testing we select areas for excavation blocks. We try to target the places where we’ll get the best return, in scientific information, for the investment of time. These excavation blocks are usually excavated in 1×1 m units. During the excavation layers of a predetermined depth are carefully removed. The sediment is screened and artifacts are collected. While excavating each layer is carefully described and locations of artifacts within the layer are recorded. Any changes in the soils or unusual staining is also described in detail. As each layer is removed photos are taken to further document the process. Once the unit is excavated to its final depth photos and drawings are taken of the unit walls. These photos and drawings will help us to understand the natural formation of the site area by studying the statigraphy. Looking at the layers of the soil can help us to determine if some artifacts in the site are older than others and can help us to understand how long or often the site was used by people in the past.

Mitigative excavations in Alberta typically do not involve excavation of the entire site as you might see in academic research excavations; instead archaeologists first consult with the developer and the government and excavate a sample of the site that focuses on the area of impact, and maximizes the information value of the dig.

Once the mitigative excavation is complete and the final report describing the project has been approved by the government the development will be allowed to proceed.

Mitigative excavations usually move along at a faster pace than academic excavations. This is related to time restrictions associated with development planning and budgetary concerns, as well as our focus on efficiency, and maximizing the return on investment. Academic excavations often take place over many field seasons but mitigative excavations have to be completed before the developer begins construction.

Mitigative excavation is our best tool to preserve archaeological heritage when avoidance isn’t an option, but it’s still a net loss in heritage value. Archaeological sites are non-renewable resources, once they have been destroyed, whether by excavation or development, no more information can be collected about the site.

HRV 4C – What Happens Now?

You have made a plan for a development and reviewed your plan against the Listing of Historic Resources. You’ve found that you have a conflict on your land parcel, it is listed with an HRV of 4C. What does that mean?

An HRV of 4C indicates that an historic resource site is located on that parcel of land, and that one or more First Nations groups have reported that the site is of cultural significance to them. These sites are usually Traditional Use Sites with a historic component, or spiritually significant or religious sites. Some examples include historic cabins or trails, community campsites, prayer trees or other spiritual sites, burials, cemeteries, rock art sites, and mission sites.

Before you can proceed you or your historic resource consultant must submit a Historic Resource Application through OPAC (the Online Permitting And Clearance system) to the Aboriginal Heritage Section of Alberta Culture & Tourism. Aboriginal Heritage will review the development plans against their confidential records of the site and determine whether impacts are likely. If impacts to the HRV 4C site are likely, Aboriginal Heritage will issue site-specific Consultation requirements.

This means you may have to Consult with the First Nations who have Listed the site. More than one group may have an interest in the site because of shared history and land use. Be sure to consult with all interested parties in this matter. Consulting with only one group on overlapping Listings is not sufficient. Alberta Culture will inform you if Consultation is required or not, and with which groups site specific Consultation is required (Listing of Historic Resources, Instructions for Use). It’s very important to understand that any Site-Specific Historic Resource Consultation requirements are separate from and in addition to any other standard Consultation requirements regarding Treaty rights and land use. You may have to go back to First Nations you’ve already Consulted about your project in general, and may have to Consult with different groups or individuals.

Whether you are required to Consult with First Nations groups or not, an HRV of 4C may also result in a requirement for an Historic Resources Impact Assessment. The fact that a specific historic resource has been identified within your land parcel does not mean that the rest of the area has been surveyed and that there is only the one site there. It only indicates that an historic resource site has been reported. An historic resources impact assessment requirement is likely because areas that are considered culturally significant today usually have been considered important for centuries, or millennia. Areas with an HRV of 4C have a high potential to contain additional historic resources such as archaeological sites.

You may be required to redesign your project to avoid the HRV 4C historic resources site. If the site can’t be avoided, mitigation may be required. Mitigation of archaeological and historic sites typically requires extensive shovel testing, detailed block excavations proportional to the percent of the site to be impacted and detailed mapping of the site. Mitigation of impacts to a Culturally Significant site would likely be site-specific, and determined in collaboration with the affected communities.

Our recommendation for HRV 4C conflicts is to identify them early, discuss them with communities in advance, avoid them at the planning stage.

If you don’t know where to start, or would like someone to help you Consult with First Nations contact Kurt or Madeline at 780-472-8878 or toll free at 1-866-873-3846 or email us at [email protected]. We are happy to help.