28 April 2009

update: the demise of deposit 10a, the flattening of deposit 1

top of deposit 1, as of 29 apr 09

After about 8 months of digging, Deposit 1 is finally starting to look markedly different than it did when we first unveiled it -- well, to us, at least. Yes, it's still a dusty hunk of rock, but now it's a dusty hunk of rock that's around half a meter shorter than when we first got it.

As I've hopefully mentioned before, we work in 1m x 1m grids, and dig down 25 cm at a time. You've seen this before:

Main fossil deposit as of 7 Apr 09

...the large, convoluted bone mass that was keeping us from "closing" grids B-1 and B-2 and moving on to other portions of the box. In both grids, we're working on level 3, which is the section of dirt 50-75 cm below the original ground level of the deposit. Does that make sense? Those large saber-toothed cat scapulae and innominates were sticking out above floor (the bottom of each 25 cm deep level) and needed to be removed before moving on.

Now the grids look like this:

main bone deposit

Yes, there are still bones, but if you look carefully, you'll note a wonderful lack of scapulae...

tara and shoulderblade

...because Tara got the last one out! Everything left in place is too far below floor to excavate at this time. The grids surrounding the bone mass are still at level 2, so we have to get those down to level 3 before we can open up grids b-1 and b-2 at level 4. Did that all make sense? Excavational peccadilloes are difficult to describe via the interwebs. To sum up: if we keep excavating just the main bone deposit, we'll wind up with a giant hole in the ground (in the box) which will be too deep to keep digging at. So: sterile grids for us, for a while.

In non deposit 1 news: as Ryan and I have both mentioned, 10A is no more! We time lapsed it's final moments:

I have to say, I like the soundtrack to this one better than last week's, but I don't think anything will match excavation to the tune of "I Am the Walrus." Ah well.

Next week: we just laid grid lines out for 5 new deposits -- 7A-E! We're very excited to start work in new, softer dirt. Pictures soon to follow. OH! And click through to flickr to check out the giant freaky black (and brown) widows Laura and Michelle found under 10A.

23 April 2009

more fun with time lapse

We've been having a lot of fun with the built-in intervalometer on our new camera:

expect more videos like this in weeks to come! To our email subscribers -- the blank space you see above (and in my last post) is actually a youtube video embedded in the blogpost, which unfortunately doesn't seem to translate to email. Go to excavatrix.blogspot.com to view.

16 April 2009

Note from the Lone Male Excavator:

Y'all need to chime in and tell Andrea what a good job she is doing on this here blog a'ight!

We've got a lot done since my last post. Finished another box, matter-O'-fact (10A)! We've busted out them there scapulae from box 1 and got loads more dirt out to, eh.

Keep yer eyes open for a new "what is it" post coming soon!


14 April 2009

8ish hours in 80ish seconds

07 April 2009

weekly update: all in a day's work.

Yes indeedy, as Ryan pointed out last week, we have finished excavating our very first deposit from Project 23:

Where 10B isn't!

10B is no more! And its big sister 10A is soon to follow:

10A as of 7 Apr 09

We're down to Project 21-and-a-half. The small patch of fossils from this deposit seems to have petered out. We can't be sure, but we're thinking the remaining few feet of dirt are largely -- if not entirely sterile. The boundaries between grids are left in place until they're completely exposed, and then mapped and photographed. This way, we can reconstruct the deposit's geology long after the deposit has been excavated.

And 5B looks much the same is it did last time I posted, only sans a level of plywood around the sides.

Deposit 5B as of 7 Apr 09

We're waiting to speak to one of the geologists who originally supervised the salvage before we begin digging.

Meanwhile, in Deposit 1....

Main fossil deposit as of 7 Apr 09

We're still plugging away at the main bone jumble in Box 1. We've measured out at least another 100 fossils from this area. Right now, however, we're at a bit of a standstill, stuck between a rock and a hard place so to speak. Or rather, a scapula (shoulder blade) and an innominate (one half of a pelvis):

Close up of fossil deposit

Pleistocene pick-up sticks once again! From left to right: we can't get the first innominate out without removing the scapula immediately above it, but we can't get that scapula out because of the saber cat vertebra immediately above it. THAT's stuck under the middle scapula, which is in turn pinned in place by next-to-last scapula, which is, of course, covered by both a cat humerus (lion or saber cat, not sure though) and yet another scapula.

This is all very detailed, very slow work. However, on the other side of Box 1, we get the other end of the paleo-work perspective:

This is Grid D-3/Level 2 at 9am. Mouse over to see it at 5. Or, just scroll down:

All in a day's work: Grid D-3 at 5pm

D-3 is largely sterile, except for the occasional articulated millipede or bit of plant matter. This means we can power through it as quickly as our muscles allow. Spencer and I worked on D-3 all day, and chiseled out about 5 full buckets of matrix! Hard, hard work, as evidenced below:


6 blisters on my right hand! Badges of honor, all.