Date of Award

2009

Degree Type

Thesis

Degree Name

Master of Science in Oceanography

Department

Oceanography

First Advisor

Robert Ballard

Abstract

Archaeologists have long debated the circumstances surrounding the initial peopling of North and South America. Two of the most hotly contested facets of this debate have been the timing of this event and the route that people took into the New World, whether inland or along the coast. However, without including data from parts of the continental shelf surrounding the Americas that are now submerged but were formerly a subaerially exposed coastal landscape, an important part of the equation is missing. By expanding the search for early archaeological sites onto this largely unexplored terrain, it may be possible to obtain some degree of resolution to this debate. If it is possible to locate sites on the deeper parts of the continental shelf, they could provide evidence of human occupation of the Americas before the Clovis period, which began approximately 13,250 years ago. Radiocarbon dates from sites on land that predate this horizon have been vehemently challenged by "Clovis-first" proponents. If it is possible to locate sites on a landscape that would have already been submerged by the beginning of the Clovis period, they would be very difficult to Refute.

The landscape surrounding Norfolk Canyon, a submarine feature on the continental shelf off the coast of Virginia, has great potential to be a site of early human habitation. Norfolk Canyon is one of a series of submarine canyons that line the edge of the continental shelf of the eastern United States. Importantly, it may have represented the point at which the Susquehanna River, which today terminates at the head of Chesapeake Bay, would have intersected the Atlantic Ocean during the low stand in sea level associated with the Last Glacial Maximum (LGM). Today, Chesapeake Bay is a very productive estuary that is an important resource for the occupants of the surrounding region. Certainly, if similar conditions existed in parts of Norfolk Canyon during a period of lower sea level, they would have been of similar importance for any human populations that lived nearby. On top of that, they would almost certainly have attracted people to the surrounding landscape. Therefore, if humans were in the New World at the time that the head of Norfolk Canyon was subaerially exposed, it is extremely likely that they would have included these resources within their subsistence strategies and it is quite possible that evidence of such activities could remain on the landscape.

However, whether the Americas had been colonized before the outermost parts of the continental shelf, including the head of Norfolk Canyon, were submerged by rising water levels is a subject of intense debate. One of the eventual goals of the search for submerged sites on the continental shelf is to test this question. In order to justify this project, I argue only that humans could possibly have entered the New World and reached the mid-Atlantic region of the United States by the LGM. This is supported by three past discoveries. The first is Meadowcroft Rockshelter, a site in western Pennsylvania that has yielded several radiocarbon dates predating the Clovis period. This site has been the subject of intense debate for more than three decades. The second is Cactus Hill, a site in southeastern Virginia that has yielded radiocarbon and sediment luminescence dates predating Clovis from a stratigraphic layer below Clovis. And the third is a projectile point that was previously recovered by a scallop dredge from the continental shelf near Norfolk Canyon but was only recently rediscovered in a local museum collection. This point, which appears to bear some resemblance to those of the Solutrean tradition of southwestern Europe, was recovered from the same dredge material as megafaunal remains and other organic material dating to 22,000 years ago.

As a first step to potentially locate evidence of human occupation within our study area on the continental shelf near the head of Norfolk Canyon , we conducted an acoustic survey using side scan, multibeam , and single beam sonars. This survey was part of a larger underwater archaeological project called the Virginia Capes Archaeology Project that was comprised of a series of four oceanographic cruises that took place during the summers of 2006, 2007, and 2008. Other objectives of this project included a general survey for historic shipwrecks as well as a more specific search for an individual sixteenth century wreck that is believed to be in the area. In order to accomplish the other goals, a magnetometer survey and video ground truthing with remotely operated vehicles were also performed. Specific survey areas within the overall study area were chosen with all three objectives in mind.

Based on the acoustic data, I argue that there is strong evidence to suggest that had humans been living in the New World at the time that the landscape surrounding the head of Norfolk Canyon was subaerially exposed , there are several areas within the study area that represent excellent places to look for submerged sites. In particular , there are three features that are especially promising and demand further investigation. The first is a relatively steep portion of a possible shoreline feature that is evident in the single beam and multibeam data. The shoreline would have remained in the same place for a relatively long period of time, allowing people to occupy the same location on the landscape for an extended time, potentially increasing the size and archaeological visibility of any nearby sites. The second feature is a terrace immediately adjacent to a topographic valley that may represent a segment of a submerged river, possibly the ancestral Susquehanna River. Such features are commonly the location of known terrestrial Paleoindian sites in the mid-Atlantic United States. Finally, the third is a series of potential river mouths and shallow estuaries surrounding the head of Norfolk Canyon. These undoubtedly would have been attractive to human populations due to the abundant resources they would have provided. Although these results are promising, they are useful only upon completion of further research, including the collection of core, rock, and organic samples and more extensive acoustic surveys, including with sub-bottom sonars. However, the outcome of this thesis and the Virginia Capes Archaeology Project represent an important step in the quest to locate submerged archaeological sites on the continental shelf off the coast of Virginia and throughout the Americas as a whole.

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