PCAS General Meetings
Monthly lecture meetings feature noted archaeologists and anthropologists who provide insight into a variety of topics. Lecture meetings are held via Zoom at 7:30 pm on the second Thursday of each month. Meetings are free and open to the public.
Many past PCAS lectures are available on the PCAS YouTube channel.
PCAS Zoom Meetings
- Email a registration request to membership@pcas.org by noon on the day of the meeting.
- You will receive an email shortly with a link to the Zoom meeting.
- Guests (non-PCAS members) are welcome with registration.
- When the presentation starts, please mute your microphone and turn off your webcam.
April 10, 2025
Zoom Meeting
Dr. Marilynn Johnson
What is Philosophy of Archaeology?
Philosophy of archaeology is a relatively nascent area of inquiry—which means that theorists working in this area are in a position to shape how it is understood and where it goes in the future. In this presentation Dr. Johnson will attempt to provide a summary of the history of philosophy of archaeology and philosophical thinking within archaeology that can prove useful both to philosophers and archaeologists who are unfamiliar with the area of study. She will approach this talk as an opportunity to brainstorm about how to best characterize this subfield and what future directions we should all aim toward.
In considering the history of the intersection between these disciplines, theories from philosophy of language have been explicitly used by archaeologists throughout the twentieth century and this continues today. Structuralism allows archaeologists theoretical frameworks with which to go beyond the empirical data themselves and posit meanings. With this history we see an opportunity for clarity about ways that philosophy has already directly contributed to archaeology. At the same time, certain sites and artifacts, such as some caves and bodily adornment, are likely of the sort best understood within aesthetic theories about beauty rather than the symbolism that is the focus of language. Thus, theories from aesthetics are also needed for a robust understanding of interpretation and meaning in archaeology. And philosophical questions of ethics should never be lost when considering archaeological research. Dr. Johnson will argue that there are many fruitful areas of intersection between the theory of philosophy and the practice of archaeology.
Dr. Marilynn Johnson is Associate Professor of Philosophy at the University of San Diego. Prior to her time at USD, she completed a post-doctoral fellowship in Miami focused on the topic of philosophy of archaeology. She completed her PhD in 2017 at CUNY, supervised by renowned philosopher of art Dr. Noel Carroll. Her first book, Adorning Bodies: Meaning, Evolution, and Beauty in Humans and Animals, was published by Bloomsbury in 2022. She is in the early stages of a second book on the topic of philosophy of archaeology. Her scholarly work has been published in the journals Biological Theory, the Journal of Aesthetics and Art Criticism, Frontiers in Psychology, the Croatian Journal of Philosophy, and in an edited volume entitled Explorations in Philosophy and Archaeology. She has published pieces written for a general audience at Aesthetics for Birds, Psyche, and The Philosophers’ Magazine. You can learn more about Dr. Johnson on her website.
May 8, 2025
Michael Tucker
Unraveling the Mystery: Triangular Geoglyphs near Afton Canyon—A Multidisciplinary Investigation
This presentation outlines Michael Tucker's upcoming thesis which investigates triangular geoglyphs near Afton Canyon, California. He seeks to determine the purpose of these distinctive 1 × 2 meter formations that point in different directions on Bureau of Land Management land overlooking the Mojave River. The talk will covers several key research areas including worldwide geoglyph traditions and significance, Mojave Desert historical climate patterns, regional rock art traditions and cultural practices, ancient desert food production techniques across global cultures, and Desert Serrano indigenous culture and practices. The methodology combines rigorous quantitative approaches (soil chemistry analysis, directional measurements, and water percolation testing) with qualitative literature review of prehistoric Mojave Desert cultural practices. This multidisciplinary approach aims to identify the most probable explanation for these geoglyphs, examining potential connections to landscape features, astronomical events, cultural practices, or food production systems. While acknowledging that the original creators' intent cannot be known with absolute certainty, this research will provide valuable insight into an extinct culture while raising awareness about these vulnerable archaeological features.
Michael Tucker is pursuing a master's degree in anthropology through the Harvard Extension School with planned thesis completion and graduation in summer 2026. His strong academic background includes an MS in Geological Engineering from Missouri University of Science & Technology, an MA in Strategic Studies from the Army War College, an MA in Science in Biology from CSU San Marcos, and a BS in Environmental Science from UC Davis. Following a military parachute accident in September 2022, Mr. Tucker retired as Chief Game Warden at Camp Pendleton and as a Colonel in the Army Reserves. His distinguished military service includes two Bronze Star medals and a Combat Action Badge earned during deployments to Iraq and Afghanistan. He currently serves as an assistant director at VCS Environmental.
June 12, 2025
Zoom Meeting
Dr. Robert Dello-Russo
Context is Everything: Ruppia cirrhosa and Dating the White Sands Footprints
There is a fascinating scientific controversy surrounding the radiocarbon dating of the footprints left by early humans at White Sands National Park. Accurate ages of the footprints are important to our understanding of the Peopling of the Americas so, in this presentation, Dr. Dello-Russo will focus on several factors critical to this debate, including 1) Geological aspects of the Paleolake Otero Basin and the trackway site; 2) How the Ruppia cirrhosa seeds came to be found at the site; 3) The impact of the hard water effect on the radiocarbon ages attributed to the tracks; and 4) The role of stable carbon isotopes in evaluating the accuracy of Ruppia radiocarbon dates. Our research demonstrates that these contextual factors have largely been ignored by the NPS researchers, to the point that their Last Glacial Maximum (LGM) claims for the ages of the human footprints are likely erroneous.
Dr. Robert Dello-Russo is the retired Director of the Office of Contract Archeology at the University of New Mexico. Prior to that, he was the Deputy Director at the NM Office of Archaeological Studies and the Compliance Archaeologist for the NM Department of Game & Fish—both in Santa Fe—and the owner and principal of Escondida Research Group, a private archaeological consulting firm. He has almost 40 years of archaeological experience, including field work in the Rocky Mountains, the Pacific Northwest, the Intermountain West, and the Southwest, where he served as Principal Investigator for dozens of grants funded and large scale CRM projects (including at White Sands National Park). In addition, he was the Principal Investigator for 20 years at the Water Canyon Paleoindian site in west-central New Mexico. His fields of research include hunter-gatherer prehistory in western North America, paleoclimate and paleoenvironmental studies, geomorphological processes, and the XRF sourcing of silicified rhyolites and dacites. Dr. Dello-Russo has a PhD in Anthropology/Archaeology from the University of New Mexico.