Jonathan Tucker

Research

vesicular MORB

Vesicular mid-ocean ridge basalt glass from Axial Seamount, Juan de Fuca Ridge

Mantle geochemistry

Mantle geochemistry is the study of chemical composition of the Earth's mantle, its largest and most massive layer, often through its volcanic products mid-ocean ridge basalts and ocean island basalts. I use chemical measurements and modeling to study the interior chemical structure of the Earth, its origin, and evolution.

I use the noble gases and other geochemical tracers to examine the distributions of primitive and recycled material in the mantle. I also use joint geochemical-geodynamic models to simulate and study the history of crust-mantle evolution.

Hawaiian olivine-hosted melt inclusions

Olivine-hosted melt inclusions from a Hawaiian picrite

Deep Earth volatile cycles

Volatiles elements and compounds like water and carbon are critical for maintaining our habitable surface and are building blocks of life. Nonreactive elements like the noble gases are passive tracers of planetary-scale Earth processes. By studying the cycling of these elements and compounds between the Earth's major reservoirs, the mantle, crust, ocean, and atmosphere, I seek to understand the origin, history, and interaction of these reservoirs over geologic time.

I am study the natural carbon dioxide output from oceanic volcanoes, as well as the mechanisms and expressions of volatile element cycling through the Earth's mantle.

giant impact illustration

Illustration of a giant impact onto the primordial Earth

Earth's accretion and early history

Because no rock record survives from the first days of our planet, studying Earth's origins is a difficult endeavor. This period saw giant impacts, magma oceans, and the formation of our atmosphere and core.

To glimpse the ancient past, I study chemical elements and isotopes, such as those of the noble gases, which retain memories of Earth's earliest history. These systems include stable isotopes which are susceptible to accretionary processes but unmodified since, and the daughters of short-lived radioactive elements alive only during and shortly after accretion.

Jasper Knob banded iron formation

Jasper Knob banded iron formation, Michigan

Planetary habitability

Was habitability the inevitable outcome of 4.5 billion years of Earth history, or is our comfortable, clement surface a coincidence? I study the major planetary processes and events operating during Earth's formation and subsequent evolution through the lens of surface habitability.

The question of habitability informs many of my large research questions including natural volcanic carbon dioxide emissions, the origin and evolution of Earth's atmosphere and oceans, and the events during Earth's earliest history.