2026 Internship Opportunities

Understanding the long-term evolution of seawater chemistry is central to reconstructing Earth’s climate, tectonic, and carbon-cycle history. Lithium (Li) isotopes are a powerful tracer of silicate weathering, hydrothermal alteration of oceanic crust, and global silicon and carbon cycling, yet direct records of ancient seawater lithium isotope composition remain sparse, particularly prior to the Phanerozoic.

This project focuses on reconstructing the lithium isotope composition of seawater over the past ~3 billion years using chemical sedimentary archives, specifically marine dolostones and fluid inclusions preserved in marine halite. These archives uniquely preserve primary seawater chemistry and provide a direct window into ancient oceans across Earth’s deep-time history

The summer intern will work on the preparation and geochemical analysis of halite and dolostone samples for lithium isotope (δ7Li) measurements. This work contributes to an ongoing research program aimed at generating a continuous, multi-billion-year record of seawater lithium isotope evolution and linking these changes to tectonic cycles, climate transitions, and Earth- system feedbacks.
The student will be trained in laboratory-based preparation and analysis of geological materials used for lithium isotope geochemistry. Specific responsibilities include:

• Preparing halite samples for fluid inclusion analysis, including razor-blade cutting, ethanol cleaning, and identification of inclusion-rich zones using a petrographic microscope
• Selecting representative dolostone samples from core cuttings and preparing powders by micro-drilling rock chips
• Learning clean-lab procedures for sample handling
• Dissolving halite samples in Milli-Q water and digesting dolostones using weak acids, with subsequent cation-exchange chromatography to isolate and purify Li from matrix elements
• Supporting lithium isotope measurements using triple quadrupole inductively coupled plasma mass spectrometry (QQQ-ICP-MS)

The intern will work closely with the project supervisor throughout the internship and will contribute to data that form part of a larger, publishable research effort. The project may develop into a Junior Paper (JP), Senior Thesis (ST), or future independent research project, depending on student interest.

Prior to the internship, basic familiarity with Microsoft Excel (including formulas and plotting) is required.

GEO 203 is a significant advantage, or other GEO courses; though not required.

Previous experience with rock preparation tools or geochemical laboratories is helpful but not required, as all necessary training will be provided.

Wearing a tyvek "bunny suit" in a clean laboratory; episodic sitting and standing

A laptop is required.

• By the end of the internship, the student will understand how chemical sediments (halite and dolostone) record ancient seawater chemistry.
• Students will meet with internship mentors in the spring, prior to the internship start date. Reading materials may also be provided.
• Students are responsible for securing accommodations for the duration of their internship. On-campus summer housing is typically available the first week of June until the first week of August (details to become available in Spring 2026). If the internship falls outside of on-campus housing availability, students will need to secure alternate housing.