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Part III Options: Petrology

PA: Volcanology

Andy Woods

8 lectures and practicals

This course will cover the causes, mechanisms and nature of volcanic eruptions in a range of settings on Earth and other planets. The course will cover the thermal, thermodynamical and fluid mechanical aspects of magma transport and storage in the crust. We will discuss the nature of volcanism in different tectonic settings, how volcanic eruptions are triggered and the factors that control the style of eruption. Mechanisms of magma fragmentation and the development of eruption columns and plumes will be discussed with reference to the textural and petrological features of the deposits they produce. We will focus on the role and behaviour of volatiles in magmas and their effects on volcanic processes. The role of volcanism in global geochemical element cycling and on modulating climate over geological and more recent timescales will be discussed. Practical sessions will include demonstration of laboratory experiments of volcanic phenomena, both in the magma chamber and above the surface, together with exercises working through real data to interpret the possible style of and controls on the associated eruption processes.

Examinations: There will be a 90-minute theory paper.


PB: Evolution and Composition of the Earth's mantle

Sally Gibson

8 lectures and practicals

This Part III course on the Evolution and Composition of the Earth’s mantle uses and expands on the fundamental concepts of petrology and geochemistry to examine how our planet’s lithospheric and convecting mantle have evolved over the past 3.5 billion years. The course draws on direct observations from diamonds, fragments of mantle material (many are 3 billion years old) and indirect evidence derived from the study of mantle melts (including those rich in volatiles), experimental petrology and geophysics to explore the nature and composition of the Earth’s deep interior. These findings are placed in the context of current paradigms related to: (i) the physical and compositional structure of the Earth’s rigid and convecting mantle and (ii) deep volatile (CO2 and halogen) cycles.

The relationship between micro-scale observations and macro-scale processes is key to understanding how the deep interior of our planet works and the course has a strong practical component, involving spectacular hand specimens and thin sections of mantle lithologies (peridotites, pyroxenites) and melts (kimberlites, carbonatites etc) together with the application of numerical models. Case studies include: the Galápagos, East African Rift, Kaapvaal Craton of southern Africa and the Paraná-Etendeka Large Igneous Province of South America and southwest Africa.

Course requirements: Recommended: 1B Geological Sciences B
Advantageous: Part II Core Geophysics, Petrology or Mineralogy

Examinations: Theory paper: 90 minutes, answer two questions from a choice of three.
Practical paper (Easter Term): 90 minutes, answer all questions.
Marks split 60% to theory paper and 40% to practical paper.


PC: Planetary Chemistry and Evolution

Helen Williams and Oli Shorttle

8 lectures and seminars

This Part III course on Planetary Chemistry and Evolution builds on fundamental topics in petrology and geochemistry and applies these to a range of current research topics in planetary chemistry and cosmochemistry.  Specific topics that will be covered will include (i) nucleosynthesis and compositional heterogeneity of the solar nebula; (ii) nebular condensation and the formation of chondrite meteorites; (iii) evidence for early planetesimal formation and the formation and crystallization of planetary cores; (iv) accretion, core formation on Earth, the Moon-forming giant impact and the lunar magma ocean; (v) the formation and chemical evolution of Mars, the Moon and Venus; (vi) volatiles, water and the late veneer on Earth and other terrestrial planets; (vii) the oxidation state of planetary mantles; (viii) prospects for habitability among exoplanetary systems.  This option will begin with an extended refresher/synthesis lecture and will subsequently run as a seminar course and discussion group, where students will take it turns to work in small groups and prepare seminars based on a series of pre-defined topics and suggested reading materials.  Question sheets containing both essay-type and more quantitative exercises based on the seminar topics will also be made available during this course.

Course requirements: Recommended: 1B Geological Sciences B, Part II Petrology
Advantageous: Part II Mineralogy

Examinations: there will be a 90 minute theory paper answer two essay-style questions from a choice of three in the main examination period.


Past Tripos papers