Friday, September 27, 2019

The First Three Weeks of the 2019 Field Season at Fort Hunter

As is our tradition since 2006, The State Museum of Pennsylvania is conducting archaeology at the Fort Hunter archaeological site five miles north of the state Capitol. The focus of our research is the French and Indian War occupation (F&I - 1756-1763 aka the Seven Years War; the first global conflict as the French and English struggled for control of colonies on several continents). Beginning with the Frontier Forts and Trails initiative under the Works Projects Administration (WPA) in the 1930’s, the Museum has a long history of French and Indian War investigations including forts Augusta, LeBoeuf, Presque Isle and Loudoun.

Initially, we were interested in the soldier’s life on the frontier. However, the site turned out to be multicomponent with significant prehistoric components dating back at least 9000 years. In addition, post French and Indian War occupations representing the growth of a plantation dating between 1787 and 1860 followed by a Victorian mansion complex.

Fort Hunter was built in the fall or winter of 1756 in response to Indian raids in the region. After Braddock’s defeat near present day Pittsburgh, the British decided to establish a defensive line of forts in the Susquehanna valley with the main fort being Fort Augusta, sixty miles to the north, at present day Sunbury. Fort Hunter served as a supply fort for Fort Augusta. One of our problems since starting this investigation is the lack of historic documentation. There are general maps of its location placing it on the south side of Fishing Creek and descriptions of the fort having a commanding view of the Susquehanna river, but no details on the size or configuration of Fort Hunter. There are several references to a block house; an unfinished fort; the need to replace the stockade; the need to deepen the defensive ditch around the stockade; officer’s quarters and a hospital, but nothing on size or orientation. Based on folklore, Fort Hunter mansion was built over the block house, so in 2006 we excavated trenches around the Mansion with the goal of intercepting the surrounding stockade or the defensive ditch.

Surprisingly, those early investigations in the back yard of the Mansion encountered a high density of mid-18th century pottery (dishes), gun flints and musket balls along with a bake oven in the style typically used by the British army. We have been expanding our excavations in the back yard ever since. We also conducted extensive trenching in the front yard but, unfortunately, we have not found the stockade or defensive ditch. On the positive side, we have found a layer of soil (identified as a buried A horizon) that represents the ground surface at the time of the French and Indian War and we have continued tracing this across the site.

This year’s excavations at Fort Hunter has continued our work at the north end of the mansion. Our excavations immediately adjacent to the east side of the mansion in 2017 produced 18th century artifacts and features but the results were confusing and inconclusive. We have continued around the house opening units to the north in 2018. The buried A horizon that we have been following has become more distinct and thicker, but in 2018, a clear picture did not emerge.

A view of this year’s excavations at the north end of the mansion.

Our first few days of the 2019 season involved removing the back fill from last year’s units. We shoveled out seven 5’X 5’ units, about 6 tons of dirt, in two days of sweltering heat. We continued to follow the buried A adjacent to the north wall foundation of the mansion. This
contains prehistoric artifacts, and 18th and 19th century artifacts.  However, we have found a thickened part of the buried A that only contains mid-18th century artifacts, possibly from the French and Indian War occupation.

Artifacts from the disturbed B horizon.

Below this, what first appeared to be the undisturbed tan B horizon now seems to be disturbed based on the presence of scratch blue, delft and porcelain ceramics, iron objects, glass seed beads, brass straight pins, a musket ball and dietary bone. The unit is not finished, but these artifacts were found at a depth of over two feet into the disturbed B horizon along with a large number of flakes and projectile points never found at high frequencies at this depth. In plan view, only one side of this feature has been identified and the difference between the disturbed and undisturbed B is very clear. Our interpretation is that this soil was excavated during the mid-18th century and replaced during the same period but with other soil from the B horizon. This may represent the defensive ditch surrounding the fort or some other structure from the fort period. We were beginning to suspect that the fort never really had a stockade or defensive ditch, but this feature may be our first indication of a fortification.

A view of the thickened buried A horizon in the background and the normal thickness of the buried A in the foreground.

This season we also investigated an area across Front Street about 400 feet from the mansion. Historic references note additional structures such as officer’s quarters, a hospital and enlisted men’s quarters and we have always wondered where they are. A drone survey using infrared photography identified lineal anomalies across the road, so we decided to investigate them. We began with a 4” bucket auger but were refused by rock within a foot of the surface. We opened four units and encountered approximately three feet of cobbles and pebbles that we thought might be fill. Just to be sure, we utilized a backhoe and excavated down six feet exposing the same profile. In conclusion, we are not sure what caused the anomalies but without exposing a much larger area, we don’t think they are cultural.

Backhoe excavations east of Front street.

A second goal of the Fort Hunter project is to engage the pubic in the importance of archaeology to our understanding of both the historic and prehistoric past and its contribution to planning for the future. Over the past thirteen years we have averaged between 3000 and 6000 visitors per year. Local high school students have volunteered and college students from Franklin and Marshall, Dickinson, Shippensburg, Harrisburg Area Community College and this year Wilson College have been able to introduce their students to basic archaeological field methods. As part of our public outreach program, a new exhibit opened in early September on the second floor of The State Museum of Pennsylvania, in the Anthropology and Archaeology gallery which features our investigation of Fort Hunter and its rich cultural heritage.

The 2019 field season is coming to a close on October 4th and the work of processing and cataloging the many artifacts recovered will begin. This process allows us to further analyze the artifacts and soil layers in which they were recovered. This important analysis is valuable in documenting the activities of the former occupants of the site. Finally, none of our work could have been accomplished without the support of Fort Hunter Mansion and Park and we sincerely appreciate their cooperation.

For more information, visit PAarchaeology.state.pa.us or the Hall of Anthropology and Archaeology at The State Museum of Pennsylvania .

Friday, September 13, 2019

Experimental Archaeology with Scrapers: Scrape, Scrape, Scrape

My Name is Alaina Helm, I interned with the Section of Archaeology during the summer of 2009, and I am a Junior at Oberlin College in Ohio. You may already have seen my other posts about previous projects I have worked on: lithic analysis of Kings Quarry (36Lh2) and refitting debitage from Eelskin Rockshelter (36Bu159). This post is about another project I completed this summer doing experimental archaeology on end scrapers under the direction of Dr. Kurt Carr, Senior Curator, The Section of Archaeology at The State Museum of Pennsylvania.
                Prehistoric peoples demonstrate a preference for different lithic material types during different time periods. Paleoindians (10,000 to 12,000 years before present) preferred jasper and chert for making stone tools, despite inhabiting areas in closer proximity to alternative materials such as argillite and metarhyolite. During the transitional period (2800-4300 years before present) argillite and metarhyolite were intensively used throughout the Mid-Atlantic region.  With this knowledge in mind, we wanted to perform an experiment regarding the lithic composition of end scrapers to determine if there is a reason for biases towards certain lithic materials in the archaeological record.  Prehistoric peoples demonstrated a preference towards jasper scrapers despite being in closer proximity to other sources of useable material such as argillite. To determine if there was a functional reason for obtaining different materials from farther afield, we made scrapers of several materials and underwent experimental scraping with them. The goal of the experiment was to observe variations in wear patterns and effectiveness in scraping pieces of wood by using different materials.


Scrapers made for our experiment from various materials. Each scraper was assigned an alphanumeric designation for tracking purposes.


                Before beginning our experiments, I researched the literature to see if anyone had performed and written about a similar experiment. Although numerous articles have been published about use wear on scrapers, none of the articles compared wear between various lithic materials.  Our experiment consisted of several scrapers of varying materials created for the experiment by expert flint knapper Steve Nissley. The materials used were argillite, metarhyolite, jasper, quartzite, Normanskill chert, and Onondaga chert. All scraping was done on soft wood because it is easier to acquire than hide and would more quickly produce wear because it is a harder material.

Before being used, the scraper was hafted by channel lock pliers.

                The experiment was performed by hafting an end scraper using pliers padded with softened rawhide. The tools were then used in increments of 500 scrapes with a stroke length of thirty-two centimeters. The number of scrapes were carefully counted, and stroke length and strength was kept as uniform as possible to ensure consistency. Two sets of scrapers were used; one set was used by a variety of people including museum staff and volunteers, and the other set was used by only me. Having scrapers used by several people allowed more scraping to be performed faster without limitations caused by fatigue. Because several thousand scrapes needed to be performed for the experiment, having a separate set used by only one person allowed for a controlled comparison. The scrapers were photographed from multiple angles and at multiple magnifications using a Dino-Lite digital microscope with the highest resolution images at around 200x magnification. The scrapers were also measured using digital calipers at designated reference marks drawn on the scraper for consistency. All measurements and photographs were taken before the scrapers were used and at regular intervals of scraping to ensure a consistent record of wear on each scraper.

Alaina takes measurements and photographs of the experimental scrapers.

                The high-resolution images revealed that Argillite and Metarhyolite seemed to wear down faster with more visibly rounded edges than the Normanskill and Onondaga cherts, quartzite, and jasper. The chert scrapers showed a higher level of effectiveness than the jasper and the quartzite scrapers. Effectiveness was gauged by measuring the depth of the gouge each scraper created after the same number of scrapes. The argillite and metarhyolite scrapers shallower gouges than the jasper and chert scrapers, and the jasper scraper was slightly less effective than the chert scraper. These results suggest that the reason cherts and jaspers were the preferred materials for scrapers was due to their increased effectiveness in comparison with materials that may have been easier to obtain.

 
Argillite scraper with no wear (top) and after 500 scrapes (bottom).


This experiment was an interesting way to learn about lithic wear and get hands on experience with experimental archaeology. It allowed me to experience the nuances of designing an experiment and the difficulties in separating wear in differing lithic types. I learned a lot about aspects of experimental archaeology that are often not fully appreciated without the experience to back it up. This will help inform the way I approach any similar projects in the future. For example, on paper, scraping something 1000 times does not seem to be much until you realize that the individual scraping will need breaks. It is nice to occasionally switch up activities as well to make such experiments endurable.  I hope that my time with the Section of Archaeology at the State Museum of Pennsylvania will provide me with insight and experience during the planning and preparation of future research and will help to form a foundation on which I can further add to the results of our research.


Upcoming Pennsylvania archaeology events:

This festival features a full day of hands-on activities. Visitors will be able to work with professional archaeologists and assist with three different excavations. An archaeologist from The State Museum of Pennsylvania will be on hand to answer questions.

Archaeologists from The State Museum of Pennsylvania will be conducting excavations in the mansion’s back yard during the park’s annual fall festival celebrating the old-time ways of life. Since 2006 archaeologists have been documenting archaeological evidence from the past occupations at this site dating from approximately 9000 years ago to the present day.

Don’t miss your opportunity to learn about the prehistoric people of western Pennsylvania that we call the Monongahela Indians. This theme will be featured at the 2019 Workshops in Archaeology hosted by the Archaeology Section at The State Museum of Pennsylvania. The program will take place on Saturday, November 9, 2019 at the museum.

For more information, visit PAarchaeology.state.pa.us or the Hall of Anthropology and Archaeology at The State Museum of Pennsylvania .