A Field Trip to an Ocean Two Million Years Past

Geology DigOff a small dirt road in Hallsboro, N.C., nearly 45 minutes away from Wilmington and the coast, there is a large quarry filled entirely of shells. The shells are fossils from an ocean that stretched across the land two million years ago. Formed when the world was a different place, the quarry makes up part of the Waccamaw Formation, a specimen rich site for geologists of Southeastern North Carolina and Northeastern South Carolina.

On November 1st, Dr. Patricia Kelley, her Geology 132 students and three graduate students traveled to the quarry in Hallsboro. Armed with large plastic bags and digging tools, the students were there to collect samples of bivalves and other marine life left behind over the two million years since the ocean withdrew.

Though they are from the Late Pliocene and Early Pleistocene time periods, these samples are all recognizable since they are organisms that are still around in modern North Carolina waters. The class's main focus was that of mollusc specimens, but they were encouraged to note any other taxa found at the quarry. Once the finds are documented, the students will write a five-page paper cataloguing their findings and extrapolating paleoecological findings about the area and time period.

Graduate student Samantha Stanford will use the findings from the dig as evidence her thesis, "Relationship of prey escalation to frequency of drilling predation in Cenozoic molluscs of the US Coastal Plain." While the undergraduates handpicked samples they could identify or made for interesting finds, Stanford was busy collecting what is called a "large sample." By pushing large chunks of specimen and dirt into a bag with a shovel, Stanford will get an unbiased representation of the fauna at the formation in order to study and catalogue in the lab.

Some things the students are looking for are bivalves and gastropods. They will also look for certain characteristics that will help them learn about the time periods and geological phenomena of the area. Along with these things, the students are searching for evidence of animal interaction, such as predation holes. These will provide clues the the habits and diets these animals may have had and how that would differ from other locations and ages.

Geology 132, The Earth Through Time is a course where geology students learn about the Earth's formations and history. At the time of the dig, Kelley's students were transitioning from studying Paleozoic (ancient life) to Mesozoic and Cenozoic (middle and modern life). Kelley said the dig was perfect for them since it allowed them to study more modern creatures. This hands-on experience is vital to the students' careers as geologists.

The Waccamaw Formation is not a new site to visit for students at UNCW. Previous paleontology classes of Dr, Kelley's that visited the site published two papers and presented them at the 2011 Geological Society of America (GSA) Annual Meeting in Minneapolis (9-12 October 2011). Samantha Stanford presented one paper entitled "Effect of Pleistocene Extinctions on Paleoecology of Lower and Upper Waccamaw Formation Mullucsan Assemblages in Southeastern North Carolina and Northeastern South Carolina." And Anna Zappulla presented another entitled "Molluscan Diversity Patterns in the Lower and Upper Waccamaw Formation (Pleistocene) of Southeastern North Carolina and Northeastern South Carolina."

By Sally J. Johnson '14 MFA