While we always prefer to survey areas prior to any impacts, the identification of artifacts in post-impact contexts can be easier because of large areas of exposed sediments. Instead of targeted shovel tests that excavate a very small percentage of a high potential area, we can potentially see everything that is under the ground. However, the context of anything we find must be taken into account because heavy equipment can break cobbles and create things that look very similar to lithic debitage. If we find an artifact in the track of heavy machinery we need to be careful we are not misidentifying what we call a “tractorfact.”
In spring of 2017, we surveyed a proposed Associated Aggregates gravel pit that was being planned in a recently harvested cutblock . We identified several sites that were within the proposed gravel pit boundary, most of which were first identified by spotting artifacts on the ground. It’s not always easy, as vegetation can trick you into thinking you’ve found something, only to realize it was just a leaf.
If you want to try your eye, try to spot the flakes in the above picture!
How many did you find? Give up?
Keep scrolling for the answer…
It can be pretty difficult to spot because of the leaves on the ground but when you really take the time to look you can see five pieces of quartzite debitage.
A core is a larger piece of stone from which many smaller flakes are removed. These flakes are then turned into tools or are utilized as they are. There are many different types of cores, but a common way to describe them is by the direction(s) flakes were removed, or by the shape of the core. For example, unidirectional cores have flakes removed all in the same direction. That has had many stone flakes removed to make other tools.
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.
Specializing in forestry archaeology in Alberta, I haven’t had much opportunity to work in winter conditions. One of the nice things about forestry is its relatively long planning horizon and the flexibility to schedule our work.
Unfortunately, in fall 2012, a variety of factors conspired to push some of our fieldwork into late October, and then we got an unusually early and heavy snowfall in northwestern Alberta. The heavy snow prevented the ground from freezing, so we went ahead with our planned surveys of forestry cutblocks, conducting landform evaluation and shovel testing as normal.
Trudging through 50 cm of fresh powder gave me some perspectives on moving and living in the boreal forest under winter conditions that I hadn’t previously gained. I had wondered what effect snow cover would have on mobility patterns. Summer travel in the forest tends to follow linear features like river and stream valley margins, but I’d wondered if under winter conditions that would still be the case. This week it certainly was. We were working on the Chinchaga River valley, and found that travel along the valley margin was much easier than cutting cross country or on the slopes or lower terraces. I’d say the advantage was even greater than under summer conditions. The level backcountry had deeper snow than the exposed margins, and the snow on the slopes was even deeper than that. The grey overcast sky and falling snow also obscured the sun, which made it very hard to maintain a bearing cross-country without a compass. Without a landform to follow, I could have been walking in circles and wouldn’t know until I hit my tracks.
If I was camping under those conditions, however, I think I’d be choosing very different locations than I would in the summer. The distinct valley margins, corners and points that we tend to focus our surveys on had great views of the river and were on our preferred walking paths. But they were also very exposed to the biting wind coming out of the northwest. Even the south-facing edges were exposed. The most comfortable locations we found to break for coffee were just back from the edge, sheltered in stands of immature spruce. For the last couple seasons, I’d been suspecting that our focus on exposed corners and points was only finding one class of sites, and this experience reinforces that suspicion. I think that winter camps in particular, and possibly all larger camps, would be located back from the sharp landform edges that we’re targeting most. Drainage is still a factor, especially on warm winter days when the snow turns to mush, so we should still be looking for local elevation. But maybe we should be testing some less distinct elevated landforms a little back from the edges if we want to find sites occupied during less than ideal weather.
(This brief article was originally published in the Archaeological Society of Alberta Newsletter Vol. 1, January 2013)
Debitage, or flakes, are bits of stone chips that are left behind while making or modifying a stone tool. This artifact type has distinctive features that make them easily recognizable to archaeologists and clearly distinguish them from naturally occurring broken rocks.
“Archaeological heritage is an essential element in the affirmation of our Canadian identity and a source of inspiration and knowledge. It is the policy of the Government of Canada to protect and manage this heritage.1”
This sentiment is echoed through all levels of government and most provinces2, territories, and municipalities have either a piece of legislation, regulation, policy, or official plan in place that enables the government to protect heritage resources on lands within its jurisdiction.
For example, it’s stated in Alberta’s Historical Resources Act that when the Minister thinks a proposed operation or activity is likely to alter, damage, or destroy a historic resource, the Minister may order that person to undertake an HRIA3. This means that the Minister of Alberta Culture and Tourism (ACT) has the authority to require developers to conduct studies that assess the potential impacts of their development on historic resources. In Alberta, these studies are called “Historic Resources Impact Assessments” or HRIAs.
If the HRIA determines that there are historic resources located within the development footprint that may be impacted by the proposed development, ACT may require that the impacts be mitigated before the project will receive development approval (i.e. through modification of the development plan or the completion of a Historic Resource Impact Mitigation / HRIM). The goal of HRIA and HRIM studies is to ensure that significant historic resources are preserved through the development and land use planning processes. As such, the Minister may require the authority responsible for approving the proposed development (such as Alberta Environment and Parks, Agriculture and Forestry, or the Alberta Energy Regulator) to withhold or suspend the approval (or licence/permit/etc.) until the HRIA/HRIM requirements have been satisfied.
Have you been required to obtain a permit-status archaeologist to undertake an HRIA/HRIM? We’d be happy to discuss how Tree Time Services can best help you through the approvals process so you can focus on your core business. Call Kurt at 780-472-8878 or email[email protected]
1 Archaeological Heritage Policy Framework, Department of Canadian Heritage, Ottawa, 1990.
2 “We value the natural heritage and human history of Alberta because they help us understand and value the past on which our present is built, and give us a deepened awareness of our common roots and shared identity.” The Spirit of Alberta: Alberta’s Cultural Policy, 2009:3
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.