Thursday, October 25, 2012

Guest Blog #3: From the Field to the Lab: Artifacts and “Microfacts” from the McMaster Archaeological Field School

Our third guest blog features the Centre for Sustainable Archaeology at McMaster University in Hamilton, ON. This post was written by Jennifer Walton, a third year anthropology student at McMaster, and Research Assistant at Sustainable Archaeology. The blog features her experience using the Centre's materials analysis equipment to examine "microfacts" recovered from the McMaster field school at the Nursery Site (AhGx-8) this past spring.

From the Field to the Lab: Artifacts and “Microfacts” from the McMaster Archaeological Field School
 By:  Jennifer Walton, Honours Anthropology (III), Research Assistant, Centre for Sustainable Archaeology at McMaster Innovation Park

This spring I had the opportunity to attend the McMaster University archaeological field school held at the Nursery Site (AhGx-8) in Cootes Paradise within the Royal Botanical Gardens. The site dates from approximately 3000 years ago and was also used as a farmstead during the historic era.  During the course of the excavation, we were responsible for conducting two different types of sub-surface surveys to find the boundaries of the site and to evaluate the differences between traditional test-pitting used in cultural resource management, and a finer resolution method.  Each student took standard test-pit samples using a shovel alongside bucket-auger samples to analyze the variability in field survey methods.  Understanding the variability in the recovery of artifacts using different techniques is important because of the history of plowing at the site, and the fragmented nature of the artifacts we recovered.  Test-pit sediment was screened in the field, following the guidelines set by the Ministry of Culture. The auger samples were later wet-screened at the Centre for Sustainable Archaeology at McMaster Innovation Park.
Using the auger at the 2012 field school

Auger sampling has been used at the Nursery Site since the 2010 field school. Since the site has been a plough zone for over 50 years, the Nursery Site had experienced heavy disturbances, resulting in the fragmentation of many of the artifacts. Auger sampling is useful in this context because it retains the entire sediment sample and the finer screening method allows for the collection of smaller artifacts, often resulting in more artifacts per litre of soil compared to traditional test pitting.  The boundaries of a site should show a decrease in artifact density as one moves away from the central area of the site, therefore augering is potentially a more effective way of finding the outer limits of the activity area, especially in highly disturbed areas. 

The bucket-auger sampling method uses a hand held device (7.5cm bucket-auger) that is twisted into the ground below the sub-soil to extract an intact sediment sample. All of the sediment is retained, and once in the Sustainable Archaeology lab, each auger sample is washed through 2mm mesh, dried, and the sediment fraction >2mm is examined beneath a stereomicroscope. The sediment from the test pits, in contrast, is screened in the field through 1/8 inch mesh and artifacts are picked in the field. It is the difference in these screening methods, in association with the methods used to identify artifacts that accounts for the variance in artifact recovery.

In the lab the auger samples were wet-screened, and the remaining fraction was viewed under a Zeiss V8 microscope at 10 X magnification to distinguish if the materials were, in fact “micro” artifacts.  Many research questions can be answered from the analysis of these samples, such as artifact densities and types of artifacts found in specific areas of the site or throughout the site as a whole.  Site boundaries may also be estimated and further insight into disturbance levels may be gained. The results from the auger samples have shown new insights into the artifact densities as well as the extreme fragmentation of the artifacts, especially calcined bone, ceramics and tertiary debitage.  Using this survey method and the resources at the Centre for Sustainable Archaeology has allowed us to identify new areas of the site which can be excavated in future field seasons.

Examples of the "microartifacts" found in the auger samples, using a Zeiss V.16 axiozoom telecentric microscope at 20 X magnification. From left to right: historic era ceramic; tertiary debitage; calcined bone; pre-contact ceramic)



  1. How did the results of the auger tests compare to the results of the test pitting? Were there locations where the auger tests identified site components that were not apparent in the test pits?

    Also, it would be interesting to know how much more efficient, if at all, the auger is compared to traditional test pitting methods.


    Scott Neilsen
    Labrador Institute Research Station

  2. Hi, posted this once, but it didn't seem to work. Try again I guess.

    I was wondering if the auger testing identified site components that were not identified in the shovel tests?

    Also, is the auger testing more efficient than the shovel testing? Can you test a larger area faster? What about when you factor in the wet screening time back in the lab?

    And, how long a core does the auger take?


    Scott Neilsen
    Labrador Institute Research Station

  3. Hi Scott,

    We've notified McMaster that you've left some comments here for them so they can weigh in here as well.

    I've used core samples for survey in Iceland with great results. It took about the same amount of time as test pitting. The core itself takes less time than shoveling, but instead of screening we photographed and recorded the stratigraphic results from each core as we did them. I recommend working in a team though - 1 person to core and photograph, the other to record details. We were just looking for feature boundaries, so we didn't screen any material.

    Note, however, there is a difference between coring and auguring. Cores will maintain a (compressed) subsurface stratigraphic profile. Whereas bucket augers are designed to take a 'scoop' or multiple scoops of subsurface material. If you're less concerned about stratigraphy and more concerned with artifact distribution (i.e. single context), then a bucket auger is your better strategy. If you're concerned with stratigraphy as well as distribution - you could employ both methods.

    The following reference might be of interest:

    Cannon, Aubrey 2000. Assessing Variability in Northwest Coast Salmon and Herring Fisheries: Bucket-Auger Sampling of Shell Midden Sites on the Central Coast of British Columbia. Journal of Archaeological Science 27(8): 725-737.

    Best regards,

    Dr. Rhonda Bathurst
    Sustainable Archaeology Operations

  4. Hi Scott,

    The director of the McMaster field course, Meghan Burchell ( has suggested an email conversation if you'd like additional information on the field course.

  5. Thanks a bunch, folks.