2025 Internship Project Overview

Our research focused on gaining a better understanding of how certain biominerals, specifically eggshells, record environmental signals and the information about the organism that produced them. There exist processes that overwrite the original geochemical signatures after deposition, making it difficult to distinguish primary signals from secondary modifications. To address this problem, we examined the rates of diffusion of elements and isotopes in these materials, with an emphasis on identifying eggshells suitable for uranium-thorium dating—a technique used to determine the age of material by analyzing the uranium and thorium concentrations.

We began our research by cataloging the eggshells and preparing our samples by cutting them with a wet saw, sanding them down, and then mounting them in epoxy to polish the surface and produce a smooth finish.

We then brought our samples into a clean lab, where we were able to use laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to measure trace element concentrations. We placed ablation lines onto our samples using iolite software and recorded elemental data that we later reduced to evaluate their uranium-thorium ratios.

This project enabled us to gain experience in sample preparation, clean lab techniques and the use of LA-ICP-MS in the context of our Earth’s geological archive.

ORGANIZATION/RESEARCH GROUP

Niespolo Research Group, Department of Geosciences, Princeton University

LOCATION

Princeton, New Jersey

 

Interns

Kelsey Campbell ’27
Major: Civil and Environmental Engineering
Minor(s): Climate Science
"My laboratory skills increased tenfold, my insight into research and academia skyrocketed, and I learned interesting geochronological and archeological knowledge. I found the inferences we can make based on trace evidence mindblowing—like human migration based on burnt eggshells. I absolutely loved every step—from reading papers to reducing data. Everything came together in the end, concluding that one eggshell was viable for Uranium-Thorium dating. I am considering incorporating similar methods into my senior thesis, and am now thinking about graduate school."
Adriana Gaitan ’27
Major: Civil and Environmental Engineering
Minor(s): Planets and Life
"“I was able to gain experience in sample preparation. Working in a clean lab environment exposed me to handling large data sets, and taught me how to troubleshoot large instruments when running long experiments. As someone greatly interested in planetary/earth science, I plan on applying the knowledge and skills developed through this internship to the classes and lab work I will be involved in this school year."

Click to view the end-of-project presentation

 

Elizabeth Niespolo
Assistant Professor of Geosciences

Mentors

  • Alliya Akhtar, Postdoctoral Research Associate, Geosciences
  • Noe-Heon Kim, Ph.D. Candidate, Geosciences