The Geology of the Moon: Geochemistry and Petrology of lunar basalts

Sara Russell (sara.russell@nhm.ac.uk) and Mahesh Anand (Open University)

Project description:
This project seeks to better understand the relationship between different lunar igneous rocks. Basaltic rocks from the Moon can be broadly divided into two main types: low Ti (containing  < 5 wt % TiO2) and high Ti (containing ~9-13 % TiO2). The high Ti rocks tend to be older (3550-3850 Myr old) than the low Ti rocks (3150-3450 Myr old). Because of the geochemical differences between the two rock types, they cannot have been derived from the same initial source. This means that the geological history of the Moon has some complexity that we have yet to fully understand.

We propose to study the petrography and geochemistry of high-Ti and low-Ti basalts in some detail and using state-of-the art techniques to better understand any genetic relationship between the two. This work may also involve measuring Fe, Cu and Zn isotopes at a later stage which may give some insight into the giant impact hypothesis -the working hypothesis that the Moon formed as a result of a collision between a Mars-sized body and the Earth early in solar system history. Age dating work will also be performed on these samples, in collaboration with colleagues in the USA and Japan. The training will provide a sound background in a wide variety of modern geochemical and mineralogical techniques, that can be equally applied to terrestrial samples, and the training will also provide a background in cosmochemistry and cosmic mineralogy. The petrological and mineralogical work will be performed at the Museum, and most of the geochemical work at the Open University.