may the force be with ryan

Sad but true: our Lone Male Excavator has left us for more exotic locales (grad school in plant and soil sciences on OAHU) and we miss him already. Ryan has been a careful and conscientious excavator, a funny dude, a good friend, and last but not least, an incredibly snazzy dresser (plaid + camo = AWESOME).

Yes, we will miss his hard work, his dedication to replacing shoring boards in the heat of summer, and his enviable ability to reach things on tall shelves, but we will also miss his encyclopedic knowledge of all things Star Wars, his willingness to talk in funny voices for our amusement, and perhaps most of all...

his unparalleled ability to re-purpose old broken office furniture during his lunch break. The above photo may appear to be an ordinary office chair, but look closer! It is actually an office chair attached to another chair because it broke off its original base. The wooden legs of the base chair have been careful sawed at an angle for maximum comfort.

And what became of the base of the chair, you ask? BEHOLD:

This is quite possibly my favorite piece of furniture ever. It's an end table! On WHEELS! This handcrafted beauty is made of another chair (with the back sawed off) screwed onto the base of the broken office chair, with a piece of laminate for a top. And it's the perfect height for chips and salsa!

Finally, Ryan's coup de grace:

A genuinely well-made desk for volunteer Christina, made out of the side of box 10B (I think it's 10B).

In conclusion: Ryan is awesome! We totally miss him! He is funny and us taught about plants and how to sharpen tools and such! However, on the bright side: we now have a couch to sleep on when we go to Oahu...

Godspeed, Ryan, and may the force be with you.

Final Note From the Lone Male Excavator

Shore, -ing. (Verb):

the process of replacing old side-wall boards in large dug-out spaces (e.g., Pit 91).

This post will serve as both an introduction to some of the "other work" that excavators (and excavatrices) perform at Rancho La Brea and a documentation of the particular method of shoring board replacement that the Lone Male Excavator has developed.

So as the thick boards holding up the side walls of Pit 91 grow old, they often bow out, rot out, or both. Up above the pit, 14ft x 11 3/4" x 2 3/4" boards are stored ready to be cut to an average of about 75" long for use as a shoring board.

After a board is slated for replacement, of course it must be extracted. This is commonly far more difficult than it sounds. If the board is rotted to extremes on the ends locked in by the I-beams, then it is not too tough for a hatchet to cut through one end and pry the board out with a crowbar. If the board is not rotted away much at the ends, however, (as the boards pictured here) it can be quite difficult.

Initially, a cut with a circular saw is made through the board(s) being replaced. This is very dangerous and every safety precaution must be taken at this point (e.g., clean goggles, steady hands, hard hat). It is also messy and anything, including one self, which should not get covered in sawdust should be protected. If two parallel cuts, about 2" apart are made, extraction will be easier. Our cordless circular saw, however, does not cut deep enough to go through to the back of the boards.
So I have added to this method inspired by the wisdom of William A. Akersten's thought on sabertooth cat incisor (front teeth) functional morphology.

The points on large, cone-shaped incisors of Smilodon fatalis are separated to the extent that when they pinch together top to bottom and pierce into the skin of prey, they are thought to create a perforated line which allows for easy tearing off of chunks of flesh. When we are unable to pry/break out a board along the saw cuts, holes can be drilled along the cuts to create such perforated lines which can then be hacked trough easily or broken out through prying.Once a board is out, the wall of earth, often asphalt saturated, must be shaved a little with hand tools or, in dire need, a pneumatic chipper. Occasionally fossils are found in the side walls, so these must be watched for and documented when discovered.

Depending on the thickness of the new board and the bowing out of the old board shaving the walls may take up to a couple hours. Once this is done a measurement for the new board's length is taken, giving about an inch and a half behind the lip of each I-beam. (Often, when you think you've shaved enough and try to get the new board in, you find that a few spots need more shaving. The first of these two pictured here took me 3 attempts. I also found that I had cut it too long and had to take an inch off one end.)

After you've seen that the board will fit the space you've shaved out of the earth-wall, you must get it equally situated behind the lip of each I-beam... not so hard when you've got two-three boards out and you are doing the bottom board, but if you are trying to slide a single board over in a single space (like w/ the second board pictured) it can sometimes involve a long trial messing with crowbars. I have no solution, except putting in the lag screws early and trying to use them to slide the board. This does not often work.

If gaps are left, they are reduced by placing thin pieces of wood at the bottom of boards.

The boards are locked in between (and behind the lip of) I-beams which run about 40 ft under ground. As much of the board as possible is slid behind the inside of the I-beam before 5/16" holes are drilled beside the lip of the I-beam for 9/16" x 3 3/4" lag screws. The lag screws go through, what I'm gonna call, giant square washers which tighten the board flush to the I-beam. A thin, small piece of plywood is often needed between the shoring board and the giant square washer.

There you have it; Shoring 101. The final exam is getting a board replaced and not injuring yourself in the process.

So the Lone Male Excavator is off to grad school. This is my last day as an excavator at the Page Museum at Rancho La Brea, but I will still be around in spirit. (In fact don't be too surprised to see posts in the future by The Ghost of the Lone Male Excavator.)

attack of the 3' x 4' blob

In addition to our 23 fossils boxes (and 327 buckets, 20 plaster jackets, assorted ziploc baggies, etc etc) we've acquired a number of what we've been affectionately referring to as fossil blobs.

Several of the deposits were too large to place into buckets, but too small to box up. Consequently, they were carefully chipped out the ground, lifted onto wooden palates, and brought over to the Pit 91 compound. The asphaltic matrix (the dirt and "tar" between the bones) has melted and softened in the sun since the blocks' removal, giving some of them a distinctly melty appearance. Hence: fossil blobs! The 3' x 4' x 2' blob pictured above is the largest of them all, and we originally thought that the dire wolf skull (lower right hand corner) was the most interesting thing about it. However, as we reached the end of the blob, we uncovered the following melange:

left/front

I know it doesn't look like much, but fossil Number 1 is actually one side of a bison jaw, Number 2 is the back half of a sabertoothed cat skull, and Number 3 is the horn core of a bison skull!

Paleontology -- especially paleontology at Rancho La Brea -- is occasionally more about nimble fingers and well-trained eyes than it is about the science of evolutionary biology. With these three specimens, that has definitely been the case. There was so much matrix surrounding the fossils, and so few immediately identifiable features that it took us about four days to fully realize what, exactly, we were digging up. The bison jaw was the first thing we were able to identify --

bottom

the teeth are kind of a dead give away (the jaw is upside-down, mind you)-- and after that the sabertoothed cat skull quickly came into view:

back

In the above photo, we're looking at the back of the roof of the cat's mouth. This skull in particular was encased in extremely hard, dry, brittle clay. It took an entire day to gently chisel away the matrix without damaging the paper-thin bone underneath.

top

And finally, the horn core. Now. I desperately wish I could take credit for identifying this rare and unusual specimen, but, in actuality, I stared at the dang thing for two days straight without realizing what I was looking at.

I lose five paleontology points.

i still think we should try stilts

So we have all these boxes of fossils, right? And we have all these excavatrices (and Ryan) to dig the fossils out. No problem, yeah?

look! look how happy we are! how happy, and... how short.

Problem, yeah: At least four of the tree boxes (forgive me, fossil boxes) are well over 10 feet tall, and therefore well out of the reach of even our tallest paleontologists. Consequently, the past week has been spent figuring out how to essentially turn our Pit 91 excavation methods upside down. We gathered, we discussed, we brainstormed, and we eventually decided on...

A jungle gym! Yes! And the teeter totter will be installed next week.

Clearly, reader, I am joshing you. However, suggested (and summarily rejected) ideas for excavational elevation included stilts, a trampoline, moon shoes, and hovercraft technology. We settled on scaffolding (kindly donated by a certain excavatrix's father) and old reliable:

An extendable ladder. Genius, I know.

But wait, there's more! Look:



we built a RAILING! Gravity, your charms will ensnare us no longer! We are safe as houses. And check out the view -- we've got box seats for LACMA's Saturday evening latin jazz.



Life is good. Even without stilts.