Thanks to Thalia for sending in these photos of the September excavation. Lots more in Flickr.
Category Archives: Excavation
Preliminary stratigraphic report
Joe Artz sent us the following report concerning the clay layers we observed Saturday. A 10,000 B.C . or early 20th century flood shortly after the stream was straightened (ca. 1917-1923) would explain why we didn’t find any bones in what appeared to be such promising ground.
We encountered three stratigraphic units (SU’s)–for convenience I’ll call these SU’s 1 through 3, in order of ascending age. All three are channel facies, meaning that they have sedimentary characteristics of having been deposited by swifter currents of water than were encountered in the blue clay where the sloth remains were found.
No bones but important new information
Site prep a success
Everything is going according to plan. The water level is about as low as we’ve ever seen it. Will cleared a lens shaped island in the middle of the creek Friday–approximately 30 ft. long and 15 ft. wide. Work went fast, we’re out from behind the sand bags and didn’t have the usual 15 inches of muck to tend with. We’ve dug up part of this area before but sections were covered by the berm and look promising. Bob Athen is optimistic. 30% chance of rain later today. Photos next week. . . . Dave
digging this weekend
We have the crawler reserved for this Friday to prepare the Tarkio Valley site for a dig on Saturday. This could last into Sunday (but not likely). We will meet at the Days Inn parking lot at 7:30 on Saturday September 12 and caravan to the site. We will provide water, sunscreen and Deet. You should bring your own light tools (trowel, etc.). Dave, Will and I believe that we have dug up to the north bank excavation cleared a few years ago but that bone may still lie below one of our old levees. This area will be the target this trip. Will should have the overburden cleaned down to this level by Friday afternoon. Sloth on. Holmes
more dig photos
More photos from August dig
Another successful dig
A foray to the site August 14-15 netted 16 more segments of bone through the heroic efforts of 20 volunteers. Most of the elements appear to be portions of juvenile ribs. Positive assignment to the “toddler” or “baby” awaits cleaning and a closer look. A couple of unidentified pieces are intriguing, but time for cleaning and study was curtailed by the storms that moved through the region all day.
Holmes and I were accompanied on the trip out by Meghann Mahoney, UI Museum of Natural History and Jan Ailes, Education Facilitator, Indian Creek Nature Center, Cedar Rapids. We were joined in preparing the site for Saturday’s dig by our long-time Bobcat operator Will Mott, Council Bluffs, Bill Wiechman from the Greater Shenadoah Historical Society, and Mary Brenzel the co-PI’s sister, who drove up from Fayetteville, Arkansas to help.
Photos preparing the site last week
The week of July 6 was predicted to be sunny and apparently an ideal time for a two day excavation to recover additional remains of the baby and toddler discovered at the end of the May dig. As in the past, Evans Rental hauled the rented crawler to the site a day in advance. Will Mott arrived mid-morning with a large gas-powered pump which rapidly pumped the accumulated water from inside the levee. He estimated the capacity at about 100 gallons/minute. After the pit was ‘dry,’ Will relocated the levee protecting the previous dig north about 12 feet and then removed the muck resulting from two floods from off the floor of the excavation area. This was accomplished by 7:00 PM. Unfortunately, overnight thunderstorms produced heavy rains which lasted into the following day. While the creek did not overtop the levee, the rain was sufficient to flood the excavation and render the area inaccessible for the pump, crawler and people. More storms were predicted later in the day. The volunteers vowed to return as soon as possible after the area dried. Participants were William Mott, Lee McNair, Bill Wiechman, Aaron Last, David Brenzel and Holmes Semken.
Holmes Semken and David Brenzel, July 9, 2009.
It was susposed to be clear this afternoon but a big thunderstorm around 10:30 made the locality unworkable. We will start again as soon as it looks like we have a dry period. Sloth on, Holmes
getting a late start today
Currently raining. 1/2″ last night shouldn’t pose a problem for the berm we built yesterday but it would be nice to have the ground dry out a little bit for walking around. Scattered lightning around us now too that has to move off before we go out. The forecast says all of this should be gone in a couple of hours and we can look forward to nice steamy afternoon of excavating. Will cleared a large area for us yesterday–hate to see all of his work wasted. Dave
the dig is on
Holmes and I are here in Shenandoah. We drove over last night from Iowa City with long-time MNH volunteer Aaron Last. Will be joined by dig-veterans Will Mott, Rob MacAfee and Lee McNair this AM. Despite an inch of rain on Saturday, the creek is still down and the forecast is good (chance of scattered showers tomorrow). Tuesday is scheduled to be an equipment day with most of the morning and early afternoon being spent by Will clearing the muck and moving the berm. Most of the volunteers are coming in Wednesday to excavate . . . . Dave