Projects — Mebrahtu Weldeghebriel

Developing an ⁸⁷Sr/⁸⁶Sr chronometer of sea‑salt inclusions to date >1 Ma blue‑ice stratigraphy via LA‑ICP‑MS imaging.

LA‑ICP‑MS Sr isotopes Blue‑ice areas

Figure 1. Blue‑ice stratigraphy sampled by LA‑ICP‑MS for 87Sr/86Sr geochronology.

Documenting the major, minor, trace element, and isotopic composition of ancient seawater using direct measurements of halite fluid inclusions.

Fluid inclusions Halite Trace elements

Figure 2. Halite crystal with trapped brine inclusions; in‑situ spot analyses characterize ancient seawater.

Understanding long‑term controls on elemental and isotopic seawater composition using forward/inverse mass‑balance models.

Mass balance Modeling Isotopes

Figure 3. Reservoirs and fluxes linking sources/sinks to ocean composition.

Linking changes in ancient seawater chemistry to climate, atmospheric CO₂, and the evolution of shell‑building organisms.

Climate CO₂ Biomineralization

Figure 4. Ocean chemistry coupled to CO₂ and biomineralization.