Battling the Water Table

Perhaps we can go into building underground houses after this project

I mentioned previously the surprise occupation located 185cm below the surface, it turned out to be a rather good occupation level with ample bones and artifacts. Our problems arose as we got a bit deeper into it and encountered the water table – unlucky for us there happens to be a high water table in the area. So, now we not only had to worry about creating shoring that would prevent us from being covered in sand at any given moment but also how to draw the water away from our active units.

It’s just a bit of water, no big deal.

In the end, our solution was sump pumps. We had four pumps running around the clock to keep the water low enough that we could excavate through the occupation level; we started this area at the end of winter and as spring thaw hit us we had to try and dig the pumps even deeper to keep on top of the water situation (we had to quickly, but still properly, excavate sump pump holes in areas of low artifact returns). We also discovered that water-logged sand is also rather prone to giving out suddenly – quite aggravating when you’re trying to keep the walls looking good for photographs, profile drawing and site visitors (no one wants to be accused of having sloppy walls, no one).

We only recovered 5 projectile points from this occupation level – not great but not terrible. They’re a bit mysterious though, they don’t really fit with the type of points we were expecting to find at that depth. We were expecting thicker, chunkier points, but these ones are relatively thin and well-made. They look like they should be Late Period points but that doesn’t fit with the order of the occupations we have represented on our site. So, at the moment our best guess is that they are intermediate points from the transition of Early to Middle Prehistoric – which is exciting because that means they’re quite old indeed (7 – 9,000 years old).

Normally, we do radiocardon dating of the bone to back-up our estimation of the date based on the projectile points. Our sneaky low occupation had plenty of bone but the water table got one up on us this time. The bone looked fantastic as you exposed it from the damp, organic-rich sediment but as soon as you tried to remove it from the ground it would crumble into a pile of tiny fragments. Through much painstakingly slow work we managed to get some of the bone out in relatively one piece and sent it off to the labs in Florida.

It looked so good until we tried to take it out.

Sadly, all our efforts were in vain. The constant movement of water in the area had leached all of the collagen out of the bones, leaving nothing for the lab to extract and test for us. We sent them almost 10 samples and each one came back with the same disappointing outcome. Not to be discouraged, we were set upon the idea of doing OSL (optically stimulated luminescence) dating. This method of dating involves taking samples of sand from deep within our profiles and using science-magic (ok it’s real science I just don’t know all the specifics of how it works) they analyze the last time the sand was exposed to sunlight.

Lining up the OSL samples.

Taking the samples took an afternoon, waiting for the lab in Scotland to get us some dates took about 5 months longer. Our preliminary look at the dates supports our Early to Middle transition deduction with the date range being 6780 – 8700 years BP. We still need to do some further analysis and make sure everything matches up like it should between all the records, but we’re excited and this is definitely the oldest Alberta site I’ve worked on thus far.

Sailing the Prairies

My return to fieldwork has been greatly anticipated by…well, me. It has only been a couple of days so far, but things look like they should be picking up after this. I’ve been assisting another archaeologist with some small, one-day projects in various places around southern Alberta. It’s been some good learning, and they’re the size of projects I hope to start with when I finally get permit-holding capabilities (some day Alberta Culture you’ll let me out on my own, some day!).

The first place we headed to was Carstairs – not glamorous, and still kinda frozen. We rented a small jackhammer but in the end we were able to get through the partially frozen ground with a bit of sweat and jumping energetically on our shovels. Sadly all our hard work resulted in lots of test pits and nothing awesome to show for it. Our endeavors were probably hindered by the 3 pre-existing pipelines already cutting through the area – oh well, was a good day to get my first sunburn of the season.

The second job involved assessing a wellpad, access road and pipeline near Cochrane. We dug fewer holes but we had to traverse through a minefield of cattle droppings to get there, so it kind of evened out. The area was largely broken by cultivation, so anything that might have been there would likely have been destroyed years ago.

I’m starting to feel better about my ability to do a job this size, my experience last summer with the giant oil sands projects had me a bit intimidated. But, something like this seems like a good start – if I don’t get lost getting through all the fields and back roads…

Our last job was near Suffield, where they have a military training area; thus, we were hoping to catch a glimpse of rugged young men running drills but alas, we were disappointed. To make up for that we had ourselves a little adventure by driving through a lake. It looked quite dry and it was, until we got about half way through it, then it got soupy and we may have panicked a bit. But never fear, we escaped with our lives.   

It’s a good thing too because we finally managed to find something! It was a small cairn of about 6 rocks, but to their credit they are the only rocks we came across in the section and there are a couple recorded stone features in the neighboring sections. Woohoo!

Tomorrow’s adventure: gravel pits!

The Return to the North

They promised me the bugs would be gone by now. They lied. Granted it is much better than it was last time I was up here but I am still fighting off mosquitos that I wish would hurry up and freeze.

We did another couple of days in the Birch Mountains as an extension of the project we were working on before. We did a fair amount of walking through the forest which was rough going with all of the deadfall – my shins are delightfully black and blue from that. the next day we attempted to use the argo more; however, this time our argo did not fair quite so well either – I suppose that’s what we get for letting my boss drive. He pointed the argo at the forest and decided to drive over everything between us and the well pad site – this generally consisted of trees, a lot of trees, big trees. Not surprisingly we got the argo stuck very deep in the middle of a heavily wooded area with no hope of getting it moving again on our own.  In the end we had to hike the 2km back to the helicopter, holding our helmets in shame.

We had to hike in the next day with saws and clear an area around the argo large enough that the helicopter could lift it out for us. Thankfully we were able to get a replacement argo in rather quickly.

We’ve begun a new project up here now, it is south of the Birch Mountains and is much more low-lying – this means that it is obscenely wet everywhere on the lease area. I’m pretty sure the entire area is straight muskeg. We surveyed 35 well pad sites and only 2 of them look like they will have enough dry ground for us to actually do shovel tests on.

This area has a lot more wildlife though which is a nice change, we’ve seen a lot more birds in the area, as well as small things like mice, squirrels, rabbits and a coyote. There is definitely a bear or two in the area but they have been steering clear of us which is just fine by me.

I’ve been working on my navigation skills the last couple of days. Generally I get lost going everywhere, apparently this is not a desirable trait when in the forest. I seem to be doing better with a gps and a map now, just needed to get the hang of it. No one will give me a straight answer though on how many days of good navigation will earn me my orienteering badge.

We’ve gotten the argo stuck in the muskeg/lakes twice now and had to use the winch to pull ourselves out – this is a tricky feat when all the trees in the area are brittle and dead. The muskeg creates this floating mass of moss and roots over the standing water and you never quite know how deep the smelly black water will be. In some areas the muskeg covers over entire lakes – cool. The first time we got stuck it was very deep and lake-like indeed. We ended up sitting so low in the water that the treads couldn’t grip onto the muskeg enough to get back up onto it. The second time we got stuck we were attempting to cross what turned out to be a bit of a lake when we became hung up on some deadfall hiding under the surface. Thank goodness for winches and tall gum boots.

What’s getting a bit high…

Trust me, it’s deeper than it looks

 

 

 

 

 

 

 

He gets to hook up the winch because he’s got the waders

 

The black smelly water