A Phase I Remote-Sensing Archaeological Survey Near the Location of a Proposed Groin at Ocean Isle Beach, Brunswick County, North Carolina
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A Phase I Remote-Sensing Archaeological Survey Near the Location of a Proposed Groin at Ocean Isle Beach, Brunswick County, North Carolina Submitted to: Coastal Planning & Engineering of North Carolina 4038 Masonboro Loop Road Wilmington, North Carolina 28409 Submitted by: Gordon P. Watts, Jr. Principal Investigator Tidewater Atlantic Research, Inc. P. O. Box 2494 Washington, North Carolina 27889 7 March 2015 i Abstract Coastal Planning and Engineering of North Carolina (CPE-NC) is the project engineer representing Ocean Isle Beach, North Carolina in its efforts to control erosion at the eastern end of Ocean Isle Beach immediately west of Shallotte Inlet. In order to determine the effects of proposed terminal groin construction activities on potentially significant submerged cultural resources, CPE-NC contracted with Tidewater Atlantic Research, Inc. of Washington, North Carolina to conduct a marine and terrestrial remote-sensing survey of the proposed construction area. Field research for the project was conducted on 12 through 14 December 2014. Analysis of the remote-sensing data generated during the Ocean Isle Beach survey identified a total of 22 magnetic anomalies in the offshore project environment and 4 anomalies in the terrestrial project environment. Sonar identified 16 targets in the marine environment. All of the anomalies and all of the sonar images are associated with previous groin structures or small objects that represent debris associated with those groins or perhaps residential material deposited by storms. None of the anomalies and sonar images appears to represent more complex signatures associated with historic vessel remains. No additional investigation is recommended in conjunction with the proposed groin construction. ii Table of Contents Abstract .................................................................................................................................................... i List of Figures ........................................................................................................................................ iii Introduction ............................................................................................................................................ 1 Project Location ...................................................................................................................................... 1 Research Methodology ........................................................................................................................... 3 Literature and Historical Research ..................................................................................................... 3 Remote-Sensing Survey ..................................................................................................................... 3 Remote-Sensing Data Analysis .......................................................................................................... 7 Historical Background ............................................................................................................................ 8 Description of Findings ........................................................................................................................ 15 Conclusions and Recommendations ..................................................................................................... 19 References ............................................................................................................................................ 20 Appendix A .......................................................................................................................................... 22 Appendix B ........................................................................................................................................... 24 Appendix C ........................................................................................................................................... 26 Appendix D .......................................................................................................................................... 28 Appendix E ........................................................................................................................................... 30 iii List of Figures Figure 1. Project Location Map (USGS "Cape Fear, North Carolina" 1:24,000). ................................ 2 Figure 2. Survey map coordinate locations. .......................................................................................... 4 Figure 3. The EG&G GEOMETRICS G-881 cesium vapor magnetometer. ............................................ 5 Figure 4. The KLEIN SYSTEM 3900 digital sidescan sonar. ................................................................... 6 Figure 5. Computer navigation system located on the research vessel helm. ....................................... 6 Figure 6. The Geometrics G-856 magnetometer and Trimble DGPS terrestrial survey. ....................... 7 Figure 7. Magnetic anomalies and contoured magnetic data. ............................................................. 16 Figure 8. Previous groins and dredge spoil pumped on beach in project area ca. 1993. ..................... 17 Figure 9. Sonar coverage mosaic with target locations. ...................................................................... 18 1 Introduction Coastal Planning and Engineering of North Carolina (CPE-NC) is the project engineer representing Ocean Isle Beach, North Carolina in its efforts to control erosion at the eastern end of Ocean Isle Beach immediately west of Shallotte Inlet. In order to determine the effects of proposed terminal groin construction activities on potentially significant submerged cultural resources, CPE-NC contracted with Tidewater Atlantic Research, Inc. (TAR) of Washington, North Carolina to conduct a marine and terrestrial remote-sensing survey of the proposed construction area. As a consequence of that agreement, CPE-NC contracted with TAR to conduct a magnetometer and sidescan sonar survey of the offshore construction site and a magnetometer survey of the terrestrial construction area. The marine and terrestrial remote-sensing investigations conducted by TAR archaeologists were designed to provide accurate and reliable identification, assessment and documentation of submerged cultural resources in the study area. The assessment methodology was developed to comply with the criteria of the National Historic Preservation Act of 1966 (Public Law 89-665), the National Environmental Policy Act of 1969 (Public Law 11-190), Executive Order 11593, the Advisory Council on Historic Preservation Procedures for the protection of historic and cultural properties (36 CFR Part 800) and the updated guidelines described in 36 CFR 64 and 36 CFR 66. The results of the investigation were designed to furnish CPE-NC with the archaeological data required to comply with submerged cultural resource legislation and regulations. Field research for the project was conducted on 12 through 14 December 2014. Analysis of the remote-sensing data generated during the Ocean Isle Beach survey identified a total of 22 magnetic anomalies in the off shore project environment and 4 anomalies in the terrestrial project environment. Sonar identified 16 targets in the marine environment. All of the anomalies and all of the sonar images are associated with previous groin structures or small objects that represent debris associated with those groins or perhaps residential material deposited by storms. None of the anomalies and sonar images appears to represent more complex signatures associated with historic vessel remains. No additional investigation is recommended in conjunction with the proposed groin construction. Project field personnel consisted of Gordon P. Watts, Jr., principal investigator and Ralph Wilbanks remote-sensing operator. John W. Morris from the Underwater Archaeology Branch (UAB) of North Carolina Department of Cultural Resources (NCDCR) was aboard the survey vessel for the marine investigation. Dr. Watts and Morgan V. Arnold conducted the terrestrial survey. Senior Historian Robin Arnold carried out the historical and literature research. Dr. Watts and Ms. Arnold prepared this report. Project Location The remote-sensing project area is situated at the east end of Ocean Isle Beach immediately west of Shallotte Inlet (Figure 1). The terrestrial survey area is rectangular in shape measuring 450 feet in width and 800 feet in length and equals 8.26 acres. The marine survey area is approximately square measuring 750 feet in length and 800 feet in width and equals 13.77 acres. Data was collected on 50- foot survey lines in the marine environment. That same line spacing was carried out as vegetation permitted in the terrestrial environment. 2 Figure 1. Project Location Map (USGS "Cape Fear, North Carolina" 1:24,000). 3 The survey boundaries (Figure 2) defined in North Carolina State Plane Coordinates, based on NAD 83, U.S. Survey Foot are shown in the following table. Table 1. Survey boundaries defined in North Carolina State Plane coordinates, NAD 83, U.S. Survey Foot. Research Methodology Literature and Historical Research TAR historians conducted a literature search of primary and secondary sources to assess the potential to find significant historic and/or cultural resources within the proposed dredge site. A general background history of Ocean Isle Beach and the lower Cape Fear region was prepared from source material in