Why do we survey gravel pits?

Aggregate pit applications, even renewals, are regularly triggered for Historic Resources Impact Assessments in Alberta.  This is mostly due to two factors: their location, and their impact levels.  Good sand and gravel deposits are often located near watercourses, especially major rivers, and the presence of coarse parent sediment usually gives them better drainage than surrounding terrain. High, dry ground next to water is exactly the kind of place people have been camping for thousands of years.

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Reid taking notes after testing a high potential landform in a planned gravel pit.

The second factor is the expected impact.  Other development types, like forestry or seismic, may disturb sites, but will leave some or most of them intact.  By their nature, aggregate pits will result in complete destruction of any archaeological sites that may be in their footprint.  Once an archaeological site is destroyed, it’s gone forever.  This means the province only gets one chance to find, understand and protect sites if they’re in a planned gravel pit.  The survey intensity and mitigation standards are therefore more stringent.
Gravel pits also have a high potential to contain quaternary (ice age) mammal fossils.  Bones and tusks from ice age animals like mammoths, extinct bison and sabre toothed cats were often deposited in gravel bars along ice-age rivers.  These gravel bars are the gravel seams that the modern aggregate industry targets.
Alberta Culture released new guidelines for gravel pit Historical Resources Act compliance two years ago.  In short, pits under 5 ha require an HRIA if there’s a known site in the immediate area.  Pits over 5 ha require an HRIA if there’s a known site, or if the land is deemed to have high archaeological or palaeontological potential.
The 2004 Code of Practice for sand and gravel pits says that gravel pits “may be required to shut down if artefacts are discovered during operation of the pit” (section 8.3.6).  This is very rare. Usually if an archaeological site is found during the HRIA, it can be avoided or archaeological digs (mitigative excavation) can be done to salvage a sample of the site before development.  If archaeological or palaeontological resources (for example arrowheads, stone tools, ice age mammal or dinosaur bone) are found during operation, the pit operator is required to report it (this post explains how), and some salvage may be done, but it’s unlikely the pit will be shut down.  Alberta Culture and historic resource management professionals like us work to balance economic development for Alberta’s future with preservation of it’s past.

To keep up to date on Historic Resource regulations and processes, you can subscribe to our quarterly Regulatory Update email.

 

The King of Spades vs. the Grizzly

Over the years archaeologists have adopted technological advances from other disciplines. In the office, using programs such as QGIS along with LIDAR and other data sets we can create models to predict sites. In the field, we use a GPS for navigation and iPads to take our notes. Artifact processing has also seen many advances helping us to date and source artifacts.

For all of these advances that have been made in the field, certain tools remain the same. One of the most essential tools that we use in the field is a shovel. I know many people associate trowels and fedoras with archaeologists, however these are most commonly used in academic excavations. While in the world of CRM the trowel will be used for certain situations, the shovel reigns, specifically at Tree Time it is the King of Spades.

The reigning king

The advantages to the King of Spades are its durability and its ability to cut through roots. The all metal shovel has never been broken by a staff member at Tree Time. Maybe lost forever in a deep stream when accidentally dropped… but never broken. In addition, the sheer weight of the shovel can help pound through roots. Other shovels are not as durable, the blades may warp, and they are more prone to breaking at the shaft break. Not the king though.20160519_153950

The Grizzly Challenger

Most shovels are not made of all metal but incorporate bits of wood. There can be a wide variety in quality so we highly recommend the Grizzly. These shovels are much lighter and easier to sharpen. The durability of the King of Spades comes at a cost, it is by far the heaviest and the most difficult to sharpen due to its thick blade. The ability to sharpen the Grizzly easily due to the thinner blade helps us maintain a sharp edge in the field to cut through roots. The light weight also makes them a lot easier to hike a long distance with, making for a much more pleasant hike.20160519_153703

In the end the durability of the King of Spades wins the favor of most of us at Tree Time. In fact five out of seven archaeologists, well at least at Tree Time, agree that the King of Spades shovel is the preferred tool. Long live the king.

This would not have happened if Madeline had the King of Spades!

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Asymmetrical Knife

This week we feature a picture of an asymmetrical knife found north of Lac La Biche at a site called Buffalo Beach. The knife has one rounded retouched cutting edge and the other edge is straight. The notched knob at the bottom of the artifact is where the knife would have been attached to a handle. The handle was likely made from an organic material that does not preserve as well as stone (for example bone, antler, wood, etc.). The style of this knife does not match any previously recorded artifacts found in Alberta.

Bone Needle

This week we showcase a very unique artifact, a bone needle.  This tool is very long and thick compared to the modern steel needles that we are more familiar with, but it still very sharp at the tip. The eye of the needle is diamond-shaped and tapered, which shows us that the eye was made by gouging the bone with a stone flake, rather than using a bow drill. A bow drill would have left a round hole rather than a diamond-shaped one. This type of artifact is extremely rare in North America, especially one that is complete. Most of the time when they are found, bone needles like these are broken around the eye, or you just find the tip of the needle.

This artifact was found in a dry cave in Utah, which is filled with artifacts left behind from thousands of years of indigenous people living in the cave.  These repeated occupations left behind countless layers of juniper bark, which was laid down as a floor matting. The bone needle was found three meters below the modern surface. Talk about finding a needle in a haystack!

End Scraper

This week we feature a stone tool found upstream on Fall Creek, about 55 km west of the community of Caroline, AB. We were undertaking an assessment for Sundre Forest Products and testing a flat area overlooking the creek (shown below) when Ryan found the end scraper shown above.

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A “scraper” is a type of tool that is usually unifacial, meaning the stone was worked on one of its sides (or faces) only. Compare the two sides shown in the image above and you’ll see the one shown on the left is much smoother, except for a small piece that may have been broken off when digging the shovel test. The face of the scraper that is worked typically has pieces chipped off on the side or end in order to make a thick and strong edge. This is the scraping edge that could be used to prepare hides.

Unifacial working and a thick edge are the two main criteria used when identifying an artifact as a scraper, so as you can imagine there are a lot of different styles of scrapers found at archaeological sites. Just take a look at the beautiful example Reid describes in this blog post.

Regardless of what style of scraper you’ve found, a close look at the edge of these artifacts can reveal some “use wear,” when the edges become chipped, polished or worn down through the process of scraping hides, bone, wood or other softer materials. As a result of this wear, scrapers would occasionally need to be resharpened and the tools would become smaller and smaller through the resharpening process. It’s possible this scraper was considered too small to be of any more use and so was thrown away only to be found by us, perhaps thousands of years later.

Biface Preform

This week we feature an artifact found recently while conducting a survey for an Associated Aggregates gravel pit along the Nordegg River. The artifact is an irregular biface that is likely a preform. A preform is often an ovate or triangular shaped rock that has been flaked on both sides using percussion and pressure flaking techniques. This artifact was likely in the early stages of becoming some form of tool (e.g. knife or projectile point) before it was discarded by the flintknapper.

It is not clear why the flintknapper quit working on the artifact, the knapper may have made a mistake or did not like the stone material. The artifact is made from a unique red speckled chert with some fossilized plant remains embedded on the dorsal side of the artifact. We asked the consulting community if they knew what kind of chert the artifact was made from and Jason Roe, Lifeways Canada, identified the material as Paskapoo chert.

The artifact was found at a site identified by our clients, Dan Hill and Jodie Bauman, who were interested in the process of historical resource impact assessments (HRIA). While screening a shovel test, under the supervision of our archaeologists, Jodie found a large utilized quartzite flake. Further testing, revealed the site was over 200 m long and had evidence of fire (fire cracked rock) and tool making (biface).

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