Room: 407 Tel: Patrice Rey

Lecturers are guides, they open doors and show paths to knowledge... Become an independent learner. There is no bad students, only bad learning habits. …but it’s up to you to do the journey. 1 hour of lecture should be followed by 2 hours of work involving reading and synthesizing information gathered from textbooks and other resources. Use the web and make the library your second home! Do not work alone. Consider lectures and practical classes for what they really are: introductions to knowledge. Most importantly: Get organized, work steadily, and have fun!

Lecture 1: Lithosphere, asthenosphere, and Archimedes ( BC) Aims: A brief reminder about the earth and lithospheric plates

Structural geology deals with deformation of earth materials: From minerals to tectonic plates ~15 plates travel at the surface of the a speed of a few cm/y Plates travel at various speed and in various direction...=> …seismicity and deformation at plates boundaries

Plate boundaries features Topography

Plate boundaries features Seismicity

Plate boundaries features Volcanism

Australian plate

Plate tectonics and things that plate boundaries

Divergent plate boundaries

Convergent plate boundaries

Transform fault, and strike slip fault boundaries

Earth’s structure

Continental lithosphere: Some physical characteristics Radiogenic upper crust Radiogenic elements U, Th, K Temperature

Continental lithosphere: Some physical characteristics (z c /z l )*  c +(z lm /z l )*  lm Density lithosphere ? Density

Isostasy and surface topography

Isostasy: A surface exists at a certain depth where the pressure, from the column of earth material above, is the same across and underneath the surface.

Continental lithosphere: Some physical characteristics Strong upper crust Weak upper crust Strong upper mantle Weak lower lithospheric mantle Very weak asthenosphere Strength

Lecture 1 at a glance ~15 plates move at the surface of the earth. Plate boundaries: locus of seismicity +/- magmatic activities, and high topography. Divergent, convergent, and transform plate boundaries. Lithospheric plates: oceanic lithosphere only, or both oceanic and continental lithosphere, they float on the asthenosphere. Strength of continental lithosphere Strong upper crust, weak lower crust, strong upper mantle, weak lower lithospheric mantle, very weak asthenosphere. Thickness Continental lithosphere: 180 +/- 100 km thick; Oceanic lithosphere: km Continental crust: 35+/-10 km; Oceanic crust: 5-7 km Temperature Temperature at continental Moho: 500+/-150ºC Temperature at base of lithosphere: /-100ºC Density Density continental crust: /-100 kg.m -3 Density lithospheric mantle: /-100 kg.m -3 Density asthenosphere: /-100 kg.m -3