Wednesday, July 15, 2009

One Final Discovery

Last Friday, we completed our field season at the Heckleman site and closed our excavations. Our landowner was kind enough to backfill most of our units with his tractor and blade as shown below.

During this last week, we did make one interesting discovery. We excavated a portion of a pit feature in one of the 3 x 3 meter units opened a few days earlier. I was hoping that this pit feature was like several of the others we had encountered nearby which were rather shallow. We did not want to get bogged down in a deep feature that would require us to complete the work in the following week.

Luckily this pit (Feature 09-31) was also rather shallow, but unlike its neighbors, it contained a lot of cultural material that included much FCR, a large slate core, burned bone, and abundant charcoal. Most surprising though was the discovery of a siltstone gorget (ornament?) that was broken into three pieces. As shown below, the gorget fragments were easily reassembled.

It is made from a reddish siltstone with two small holes that were drilled from both faces. The maker of this artifact may have cracked it during the drilling of these holes, or the gorget could have been deliberately broken prior to being deposited in the pit feature. In any case, these enigmatic artifacts are typical of the Early to Late Woodland periods in northern Ohio; however the asymmetrical form of this piece is unusual. Perhaps it was meant to resemble or symbolize the triangular preforms or 'cache blades' found in Woodland burial features or ceremonial deposits.

The following image compares the Heckleman gorget with a cache blade from the Middle Woodland Pumpkin site on Sandusky Bay. Hopewell societies occasionally produced effigies of bear canines and other artifacts out of stone or bone, so perhaps my explanation is possible.

See the Plain Dealer article and video report on our project!

Saturday, July 11, 2009

Moving Inside the Enclosure

Early in Week Five we were fortunate to have the assistance of the Museum's Future Scientists under the direction of Dr. Jeff Day and supervisors Lin and Frank. Not one to miss such an opportunity, I set them to work excavating two three by three meter units to the east of the enclosure trench. These young men and women did an excellent job removing 30 cm of plow zone soils using rounded shovel, flat shovels, hoes, and finally trowels. On the way down they discovered lots of stone tool debris, fire-cracked rock, and a few artifacts such as a Late Prehistoric period triangular (Madison type) arrow point and a corner-notched (Middle Woodland) dart tip. Here they are in their freshly-dug units.

As a result of their efforts, we were able to examine an 18-square meter area of the enclosure interior. This was our first foray 'inside', and we did not know what we would find. When we did the final troweling and sweeping of the unit floors the next day, we identified several dark feature stains and numerous post molds. In the western unit (shown below) we defined a large oval stain that appears to have been the source of yet another magnetic anomaly.

Upon excavation of this feature (09-26), we found a shallow pit containing a large quantity of charcoal and FCR, just the stuff to produce a strong magnetic signal. Unfortunately, no diagnostic pottery or stone tools were found, but this feature still provides important 'ground-truth' data on the magnetic signatures of prehistoric features at the site.

Intrusive Features and the Enclosure

During weeks four and five, another two meter-long section of the enclosure trench (Fea. 09-10) was completely excavated. This section is located just northwest of the first trench section that produced the distinctive Leimbach series ceramics. This neighboring bit of trench turned out to be very similar in terms of its contents and stratigraphy, with one important exception. As shown in the section view below, the trench contained alternating layers or light and dark soil which represent episodes of filling.

The large hole in this profile was made by an intrusive pit feature that contained thin, finely cordmarked pottery of the Esch Cordmarked variety. We believe these ceramics are associated with the Middle Woodland occupation of the site due to their resemblance to pottery from the Esch Mounds, formerly located about four miles downriver. We found similar sherds during weeks one and two associated with bladelets, our best Middle Woodland diagnostic.

At the bottom of the trench, we found a cluster of thick, cordmarked sherds of the Leimbach series. As seen in the following image, they represent a large section of a vessel. One base sherd was rounded, unlike the flat-bottomed base sherd found next door.

Thus, the 'superpositioning' of these ceramic wares (i.e., Leimbach in the earlier trench and Esch in the later pit feature) nicely illustrates the succession of Woodland period occupations at the site. It also tells us that the enclosure trench was deliberately filled during the Early Woodland time period and not by later Middle Woodland arrivals, as is apparently the case with the large parallel ditches to the west. What this says about the function of the enclosure is still not clear.

Sunday, July 5, 2009

Early Woodland Pottery from the Enclosure

By the close of week four, we had excavated a total of six meters of the enclosure trench. In each section, ceramics similar to Early Woodland Leimbach Cordmarked forms were found. These relatively thick, grit-tempered sherds with somewhat coarse cordmarking were found at all levels of the feature. The sherd shown below illustrates the flat-bottomed, "flower pot" shape typical of many Leimbach vessels.

Near the bottom of the trench we found a large body sherd (shown below) with a distinctive knob handle, also typical of Leimbach wares.

At the nearby Seaman's Fort site, similar sherds have been found in pit features dated between 500 and 100 B.C. Like the Heckleman site, Seaman's Fort was enclosed by two large ditch features but lacked the interior oval enclosure that we are now investigating.

Monday, June 29, 2009

Rare Artifacts From the Pit House

As work continued last week on the excavation of the pit structure (Fea. 09-04), some very interesting artifacts turned up. Near the floor level an area of carbonized plant material resembling bark was exposed. We were even more surprised when some of the fragments were removed to reveal two interesting objects laying side by side. One artifact is a well-made awl or perforating tool made from the scapula (shoulder blade) of a deer. As the image below shows, this tool is drilled at one end, possibly for the attachment of a cord. The other specimen is a piece of shell that has been fashioned to look like a bear claw. This artifact was decorated with three tiny punctates on both sides and perforated, most likely for attachment to clothing or to be worn as a pendant.

The discovery of these objects on the floor of the pit structure may indicate that they were lost by the inhabitants; however this seems unlikely. Instead, I think that they may have been deliberately left behind when the house was abandoned, perhaps as a spirit offering. Whatever the explanation, it is very exciting to discover artifacts that may very well have belonged to the people who lived in this pit house at least 600 years ago.

Sunday, June 28, 2009

Digging the Enclosure Trench

In week three, we succeeded in exposing a small section of the trench that makes up the oval enclosure. This enclosure was identified in the magnetic survey and is tucked up into the northeastern corner of the site. The trench (Fea. 09-10) is about one meter wide, a little less than one meter deep, and is bordered by lines of post molds. The fill is clearly stratified with light and dark soil horizons as shown below.

In earlier posts, I explained our (mostly my) assumption that this enclosure represents the stockade line of a Late Prehistoric period village site. This was based on the oval shape which resembles a number of village sites in this region. So early this past week, we began to carefully cross-section Fea. 09-10 and recover its contents, all the while assuming that we would find late pottery types such as Parker Festooned, the type of pottery found in Feature 09-04, the pit house described in my last post. Of course, things don't always work out that nicely in archaeology.

As Mary Lou's fine crew carefully removed layer after layer of the ditch fill, they uncovered numerous rather thick, grit-tempered, cordmarked pot sherds which did not resemble the much thinner and well-made pottery of the Late Prehistoric period. The pottery they were finding more closely resembles Leimbach Cordmarked ceramics of the Early Woodland period. One large body sherd (shown below) has the distinctive flat bottom and curvilinear application of cordmarks that is typical of the Leimbach series. So far, we have found no Late Prehistoric

period ceramics or triangular points. We have exposed two other sections of this trench and will excavate their contents to see if this feature is truly older than we think. If so, then this enclosure is something much different than anything we have encountered before. But I won't get ahead of myself; we will wait to see what turns up this week. So stay tuned.

Sunday, June 21, 2009

From Trash Pit to Pit House

In my last post, I described the discovery of Feature 09-04, a large concentration of charcoal and ash that produced a distinct magnetic signature. Upon excavation, this feature produced rather large quantities of artifacts and food remains such as animal bones. But late this past week, we realized that this feature is not just an over-sized garbage dump, but something else entirely. As we quarter-sectioned this big stain, we identified a concentration of ash deposits and burned soil near the center, a classic hearth feature. Then, at the outside edge of the feature stain, we discovered a ring of regularly-spaced post molds which most likely represent a superstructure of some kind.

Now, why would the prehistoric inhabitants of this site construct a roof over their trash pit? Of course they would not, but they would build a roof over a dwelling. Based on these clues, we concluded that Feature 09-04 is a pit house, a small structure used by just a few people.

Similar pit houses have been found at Late Woodland sites in Illinois and Pennsylvania. Our own excavations at the White Fort site in 2002, exposed six such structures. All have the distinctive "key-hole" plan form which consists of a round to oval basin with an elongated entryway. The image of Feature 09-04 below shows this characteristic form.

The quarter section profiles reveal a rather complex stratigraphy in the fill of this pit. As shown in the image below, most of the fill consists of lenses of trash deposits and sandy soil which were dumped into the pit after the dwelling was abandoned. Beneath this fill are several thin strata of carbon-rich soil which represent the successive floor levels of the dwelling. A distinct floor layer is indicated by the red arrow in the image below.

The central hearth feature also exhibits distinct layering of ash and burned sand which indicates that successive fires were constructed during each occupation. The distinctive entryway points to the southeast and may have been constructed to prevent large quantities of warm air from escaping the interior. This would have been an important consideration if the dwelling was inhabited during the winter months, a likely conclusion. The few decorated rim sherds recovered from the pit house indicate that it was inhabited during the fourteenth or fifteenth centuries A.D.

Saturday, June 13, 2009

Finding the First Features

As I mentioned in my last post, our shovel-test survey discovered several prehistoric features. Interestingly, two of these features were not identified by the geophysical surveys conducted by Jarrod Burks. That does not mean that Jarrod did a poor survey, it just indicates that not all the features at the site contain material that is sufficiently magnetic to be detected by his instruments.

One of our previously unknown pits is Feature 09-02 which was excavated by Glen Boatman's crew. The cross-section of this feature (shown below) revealed it to be a rather deep pit with several layers of fill. It contained a nice sample of grit-tempered pottery with rather fine cordmarking. Such pottery is called Esch Cordmarked and appears to be the typical ceramic made by the Middle Woodland inhabitants of the site. In some respects, this pottery resembles McGraw Cordmarked which is the most common type of ceramic found on Ohio Hopewell sites in southern Ohio.

In my last post, I mentioned the shovel-test with a projectile point in the wall. Beneath the point, Jim Bower's crew found another apparent Middle Woodland feature (Fea. 09-03). They have just begun the profile of this feature but already have found one complete Flint Ridge bladelet and several sherds of Esch Cordmarked pottery. Once Jim's crew troweled the floor, we noticed a distinct line of post molds running across the feature and into the southeast corner of the unit. This line extended across the dark fill of the feature and showed up clearly in cross-section as shown in the image below. The observation that these post molds penetrate Fea. 09-03 demonstrates that the posts were set sometime after Feature 09-03 was filled. We will try to trace this post line to see if it is part of a structural outline (house?) or perhaps part of a stockade barrier.

In order to test the accuracy of the magnetic survey, we placed a 3m by 3m unit over Anomaly 100 identified by Jarrod Burks. Once the plow zone was removed, a very large pit feature was revealed, as shown below.

We have just begun the cross-sectioning of this pit, called Fea. 09-04, but have already exposed distinct lenses of ash and charcoal as well as bits of fish and mammal bone, flint debitage, and fire-cracked rock. One small pottery rim sherd bears an incised decoration typical of Late Prehistoric period pottery made by the Sandusky Tradition inhabitants of the region. Thus, it seems that this feature relates to the late period village occupation of the site, even though this feature lies outside (to the south) of the oval-shaped enclosure detected in the magnetic survey. We are quite excited about the subsistence evidence and other information that will come from this apparent trash pit.

So, all-in-all, this was a very productive week thanks to the hard work of our field staff and first-week field school crew.

Field School Begins at Heckleman site

This past Friday, we completed our first week of field school excavations at the Heckleman site. On Monday we began a shovel-test survey of the eastern end of the site within the large enclosure. This type of survey involves the excavation of 50 cm by 50 cm squares along east-west transects. The goal is to sample the contents of the plow zone in order to identify the spatial distribution of artifacts such as pottery, flint debitage, animal bone, fire-cracked rock, and more recent historic material. By end of the day on Tuesday our crew had excavated 16 shovel-tests and recovered good samples of artifacts. The counts of artifacts derived from this survey will be used to construct maps of artifact densities across the site. We are looking for patterns in these distributions which may help identify what activities were carried out by the prehistoric inhabitants and where these took place. In the image below, you can see small groups of students working on shovel-tests along the 490N line.

Below is a close-up view of a shovel-test in progress.

Our testing paid some immediate benefits when we uncovered several possible pit features and post molds. The small shovel-test units at these locations were expanded into larger units to exposed the suspected features and permit their excavation. I will discuss some of these discoveries in subsequent posts. In one excavation we uncovered the base of a Middle Woodland (Lowe cluster) projectile point at the base of the plow zone and just above a feature. The point can be seen in the lower right corner of the profile wall shown below.

Friday, February 13, 2009

Summer Field School at the Heckleman Site

In the summer of 2009, we will carry out test excavations at the Heckleman site, a prehistoric Native American settlement located on the Huron River near Milan, Ohio. The Heckleman site (33Er14) was first investigated in 1968 by Dr. Orrin Shane of Kent State University. These and subsequent excavations discovered a large prehistoric ditch feature that enclosed a large settlement thought to date to the Early Woodland period (ca. 500 to 100 BC). Shane's crews also found numerous Middle Woodland period (ca. 100 BC to AD 400) stone tools and pottery sherds resembling Ohio Hopewell culture artifacts from southern Ohio.

In 2008, we commissioned a series of geophysical surveys by Dr. Jarrod Burks of Ohio Valley Archaeology, Inc. Jarrod conducted an extensive magnetic survey of the site area using a gradiometer. This device is able to pick up magnetic 'anomalies' in the subsoil, some of which can be prehistoric features. We were delighted when his resulting maps revealed not one but two parallel ditch features extended north to south across the promontory.

Dr. Jarrod Burks conducts the magnetic survey, Brian Scanlan assists in the background.

The magnet survey also identified an oval enclosure to the east of the ditch features which may represent a Late Prehistoric period (ca. A.D. 1200-1600) village site. Additional surveys, which measured subsurface electrical resistivity and magnetic susceptibility (too technical to explain here), were carried out over more limited areas of the site. The resistance readings revealed additional possible prehistoric features and some areas of recent disturbance which may be the traces of Shane's earlier excavations. The magnetic susceptibility survey identified a large area of midden soils which covers most of the area to the east of the parallel ditch features. This tells us that most of the prehistoric activities took place within this large enclosed area.

In the fall of 2008, 'ground-truthing' of the innermost ditch anomaly was conducted by archaeologists from the Firelands Archaeological Research Center in Amherst, Ohio. Excavations revealed a substantial prehistoric ditch that measured nearly two meters wide and a meter deep.

Vertical section of the ditch feature showing light and dark fill layers.

Crew members Michael Niece (left) and Glen Boatman remove samples of the ditch fill for flotation processing.

The team recovered Hopewellian bladelets and projectile points made of Flint Ridge chert as well as Middle Woodland (Esch phase) pottery, butchered animal bones, and charred plant remains. It now appears that the Heckleman site was the location of three large prehistoric occupations which spanned a period of as much as 2000 years.

Expanded-stem Middle Woodland point made of Flint Ridge chert from ditch fill (image by Brian Mickey).

In the summer of 2009, CMNH archaeologists will return to the Heckleman site to systematically test selected areas to identify the various prehistoric occupations and to continue to ground-truth many of the subsurface anomalies and oval enclosure located by the geophysical surveys. For additional information about this summer's project see the Museum's website.

New Botanical Data from Burrell Orchard

Back in November, I sent eight samples of carbonized plant remains from the summer 2008 excavation out for analysis. These samples were derived from the light fraction residue of flotation processing. Two samples came from the lower (dark) midden stratum (see image below), one from a smudge pit, and five from pit features. The botanical remains were analyzed by Dr. Leslie Bush, an ethnopaleobotanist in Manchaca, Texas.

The results are not very spectacular but informative. As expected, a large proportion of the plant remains (14 g) were fragments of wood charcoal, primarily from white oak, red oak, ash, and hickory. Interestingly, carbonized nutshell was even more common (19 g) than charcoal. The vast majority was hickory, followed by black walnut, and one fragment of acorn. The result was a nutshell to wood (charcoal) ratio of 1.36 which indicates a strong preference for nut resources by the site inhabitants. Early survey records from the French Creek area of Lorain County report that the ridgtops supported forests dominated by oaks and hickories. Thus, it looks like the Late Archaic residents were maximizing their use of these local plant resources.

One surprise was the identification of four carbonized bulb fragments from the wild hyacinth, also known as Atlantic camus (Camassia scilloides). This native plant produces an edible bulb that was harvested by Native Americans in historic times and roasted in earth ovens. All four bulb fragments from Burrell Orchard were found in Feature 08-26, a medium-sized cooking pit in unit 500N 514E. Since this plant most commonly grows on the same kinds of moist, wooded slopes bordering streams like French Creek, the site inhabitants probably did not have to go far to collect these bulbs.

The relatively large quantity of hickory nutshell at the Burrell Orchard site most likely points to a fall occupation when these nuts would have been most abundant. In additon, the best time to collect camus bulbs would have been the late fall to winter months when these parts of the plant would have reached their maximum size. When we add this information to the prevalence of deer bones and antler (another fall-harvested food source), it becomes very likely that the Late Archaic residents of Burrell Orchard were present during at least some of the colder months of the year, perhaps from October to December.