A STUDY OF THE IMPACTS OF FREEZE-THAW ON CLIFF RECESSION AT THE CALVERT CLIFFS IN CALVERT COUNTY, MARYLAND

The Calvert Cliffs, which form much of the western coastline of the Chesapeake Bay in Calvert County, Maryland, are actively eroding and destabilizing, resulting in a critical situation for many homes in close proximity to the slope's crest. Past studies have identified that where waves directly interact with the toe of the slope, wave action controls cliff recession; however, where waves do not regularly interact with the slope toe, the past work identified that freeze-thaw controls recession. This study investigated the validity of this second claim by analyzing the recession rate and freeze-thaw behavior of six study sites along the Calvert Cliffs that are not directly affected by waves. While waves do remove failed material from the toe, in these regions freeze-thaw is believed to be the dominant factor driving recession at the Calvert Cliffs. Past recession rates were calculated using historical aerial photographs and were analyzed together with a number of other variables selected to represent the freeze-thaw behavior of the Calvert Cliffs. The investigation studied sixteen independent variables and found that over 65% of recession at these study sites can be represented by the following five variables: (1) cliff face direction, (2 and 3) the percent of total cliff height composed of soil with freeze-thaw susceptibility F4 and F2, (4) the number of freeze-thaw cycles, and (5) the weighted shear strength. Future mitigation techniques at these sites should focus on addressing these variables and might include vegetation or addressing the presence of water along the face of the slope. Unmitigated, the Calvert Cliffs will continue to recede until a stable slope angle is reached and maintained.

More favorable combination of circumstances could hardly have been desired : a bottom to top examination of the Pittsburgh and Boston Mining Company's Cliff Mine

The Cliff Mine, an archaeological site situated on the Keweenaw Peninsula of Michigan, is the location of the first successful attempt to mine native copper in North America. Under the management of the Pittsburgh & Boston Mining Company from 1845-1879, two-third of the Cliff’s mineral output was in the form of mass copper, some pieces of which weighed over 5 tons when removed from the ground. The unique nature of mass copper and the Cliff Mine’s handling of it make it one of the best examples of early mining processes in the Keweenaw District. Mass copper only constituted 2% of the entire product of the Lake Superior copper districts, and the story of early mining on the Peninsula is generally overshadowed by later, longer running mines such as the Calumet & Helca and Quincy Mining Companies. Operating into the mid-twentieth century, the size and duration of these later mines would come to define the region, though they would not have been possible without the Cliff’s early success. Research on the Cliff Mine has previously focused on social and popular history, neglecting the structural remains. However, these remains are physical clues to the technical processes that defined early mining on the Keweenaw. Through archaeological investigations, these processes and their associated networks were documented as part of the 2010 Michigan Technological Archaeology Field School’s curriculum. The project will create a visual representation of these processes utilizing Geographic Information Systems software. This map will be a useful aid in future research, community engagement and possible future interpretive planning.

Public values and perceptions of industrial heritage in the Keweenaw Peninsula, Michigan

The purpose of this research is to assess public values and perceptions concerning industrial heritage in the Keweenaw by studying visitors at an endangered mining site tour. This research presents and analyzes feedback collected directly from participants in the Cliff Mine (Michigan) archaeological field school public tour surveys in June 2011, gathers semi-structured interview data from survey participants and local experts, and synthesizes and collates both survey and interview data. As those who study heritage site visitors have found, in all outreach there is a necessity for deeper understanding of visitors for the outreach to be effective. An appropriate metric for collecting public values and opinions was created and used at the Cliff Mine archaeological field school public tours. To accomplish research goals, an opinion survey was created to collect demographic information and qualitative feedback from visitors at the Cliff Mine field school. The survey, a pre-tour and post-tour question list, found that all visitors who filled out a survey supported preservation and most were adults over 46 years of age. Most visitors were white-collar professionals, identified as local residents, and found out about the tour through the newspaper. Interview questions were constructed to supplement and expand on the visitor survey results. In addition, local experts involved in Keweenaw heritage were interviewed. All interviewees supported heritage preservation but often had conflicting views when activities such as mineral collecting were factored into the preservation question. By analyzing responses to the survey and interviews, improvements to outreach efforts at the Cliff Mine are recommended. Future research should further explore perceptions of social class and identity, and should seek out stakeholders not contacted through this research, in order to improve outreach and include all community groups.