Stable Isotope Geochemistry
Gypsum Hydration Water
Water is fundamental to life as we know it, and the current strategy for the search of life on Mars is to “follow the water”. Much of the water on Mars exists today in the form of hydrated minerals that incorporate molecular water or hydroxyl into their crystalline structure. Studying these hydrated minerals can provide a crucial insight into the past climate of Mars. Equally, they also give us important information that can be used to decode the history of some of Earth's most extreme environments. Oxygen and hydrogen isotopes of hydration water in minerals record information about the conditions under which the minerals form and subsequently interact with fluids after deposition. My research is focused on the isotopic study of the hydration water in these minerals and mineraloids; this has wide ranging application for addressing fundamental problems across many disciplines in Earth and Planetary sciences.
This color view of a mineral vein called "Homestake" comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity. The vein is about the width of a thumb and about 18 inches (45 centimeters) long. Opportunity examined it in November 2011 and found it to be rich in calcium and sulfur, possibly the hydrated calcium-sulfate mineral gypsum.
Image Credit: NASA/JPL-Caltech/Cornell/ASU
I work in the Godwin Laboratory to study the nature of water isotopes in hydrated minerals in order to understand: (1) how many different types of hydration states of water are present and how they are fixed into the mineral structure; (2) how the isotopic composition of the hydration water varies in different environments; and (3) whether or not any of the hydration water has retained its isotopic composition from the time of formation. Using this information, I reconstruct past environments during some of the most climatically unstable periods of earth's history, from the "Messinian Salinity Crisis" to the collapse of the Mayan civilisation.
Large to giant gypsum crystals of the Pulpi Geode, Mina Rica near Pilar de Jaravia in Southeastern Spain.
- Was the Mediterranean a desert? Understanding the Messinian Salinity Crisis
- Human-climate-environment interactions - the collapse of the Classic Maya civilization
- Cryogenic mineral formation
Geochemistry ; Stable isotopes