Endogenous petrology

In the first part of this course, we will discuss the genesis and evolution of magmas from a petrological (microscopic observations of rocks and minerals, phase equilibrium) and geochemical (major and trace elements and isotopic composition of minerals and rocks) point of view in different geodynamic contexts: oceanic rifts, hotspots and subduction zones.

In the second part of this course, we will introduce the main variables and the different geodynamic contexts of metamorphism. You will learn to recognize mineral reactions and to interpret them with geometrical rules of chemiography. We will discuss the notion of metastability and the influence of rock chemistry on metamorphic evolution.

Hourly volumes:

CM : 9

TP: 18

Know how to identify the structures and textures of magmatic and metamorphic rocks under the microscope and know the conditions of their genesis in different geodynamic contexts.

Basic notions of mineralogy and crystallography: definition of a mineral, what is it made of, what are the properties allowing to identify them, recognition of common minerals (macroscopy and microscopy).

Geochemical knowledge: concept of incompatible/compatible elements, partition coefficient, stable and radioactive isotope, partial fusion/fractional crystallization equation.

Recommended prerequisites:

The content of the UEs " Earth and its resources " of the L1, " Rocks and minerals " and " Geochemistry " of the L2 Earth-Water-Environment constitutes an ideal pre-requisite to approach this UE.

Control of knowledge: Continuous control. The students will be evaluated during the semester on 3 tests allowing the evaluation of the practical and theoretical knowledge seen in courses and TP.

• Synthetic description of the concepts covered in CM:

CM1 1.5 h: Textures of magmatic and metamorphic rocks.

CM2 1.5 h: Genesis of magmatic rocks in the context of oceanic ripples and hot spots.

CM3 1.5 h: - Genesis of magmatic rocks in the context of subduction and collision zones.

CM4 1.5 h: Metamorphism and geodynamics: recent mountain ranges

CM5 1.5h: Metamorphism and geodynamics: ancient mountain ranges

CM6 1.5h: Texture of metamorphic rocks and introduction to the chemical representation of metamorphic reactions

• Synthetic description of the practical sessions and number of hours associated with each session

TP1 : Optical microscopy - Recognition of minerals in polarized/analyzed light.

TP2 : Optical microscopy - Recognition of minerals in polarized/analyzed light.

TP3: Optical microscopy observations of magmatic rocks in the context of oceanic ripples and hot spots.

TP4 : Optical microscopy observations of magmatic rocks in the context of subduction and collision zones

TP5: Optical microscopy observations of metamorphic rocks

TP6: Observations of thin sections reflecting hot barrovian and abukuma metamorphic gradients (MP/HT and LP/HT)

Competences targeted by the EU:

• Know how to recognize at the microscopic scale the main minerals of magmatic and metamorphic rocks, the texture and structure of rocks, and know how to deduce their formation condition.
• Know how to relate the mineralogy, petrology and geochemistry of rocks and discuss their genesis in their geodynamic context.
• Know how to work independently, describe, write and synthesize.