GEO-4840 TECTONICS-s06. PART 1: Lectures [ Mondays 8-12 ] 23/1 - 06/3. PART 2: Student projects [ Essay and presentation ] Weeks 16-17. PART 3: Field teaching [ Western Norway ] Weeks 18-19. PART 4: Field reports [ Hand in ] Friday 2/6.
PART 1: Lectures [Mondays 8-12] 23/1 - 06/3
PART 2: Student projects [Essay and presentation] Weeks 16-17
PART 3: Field teaching [Western Norway] Weeks 18-19
PART 4: Field reports [Hand in] Friday 2/6
PART 5: Evaluation [projects, reports, examination] 14/6
Introduction and course content;
Tectonic processes and anatomy of mountain belts.
1) Material balance and properties
Uplift and subsidence.
Topography, crustal and lithospheric thicknesses/structure
2) Wilson cycle tectonics,
Oceanic complexes, exotic terranes.
Ophiolite obduction, (Oman, Caledonian and Appalachian).
Incipient continental collision, Australia - Banda Arc collision.
3) Examples of Continental collision zones:
The Himalayan-Tibetan region
The Caledonides, with emphasis on Scandinavia
4) From collision to extension,
Dynamics of orogenic wedges,
All projects are related to the field-course/work/excursions.
The student seminar day will be Mon 24. and Wed 26. April
Extensional detachments in Norway ()
Main tectonic units in the Scandinavian Caledonides ()
Main tectonic units in east Greenland Caledonides ()
Ophiolites in the Scandinavian Caledonides ()
5) Lower Palaeozoic rocks in the foreland Scandinavia ()
PT-time history of eclogites in Western Gneiss Complex()
Melanges and Olistostromes ()
Ultramafic rocks in the Western Gneiss Complex ()
The mineralogy of Ultra-high-pressure rocks ()
PT-time history of eclogites in the Caledonian nappes
VISIBLE TOPOGRAPHIC FEATURES ON THE
The product of complex interactions of thrusting and extension
accompanied by pro- and retrograde metamorphic reactions and
space and time)
Hinterland orogenic plateau
5) Remnant stage
Continental collision, suture zones, deform-
ation and metamorphism, mountain building
Extensional collapse, faulting and collapse
4) Terminal stage
Near closure of ocean, mature arcs and
back-arc, accreationary wedges, HP-LT
(Mediterranean See area)
3) Vaning stage: Intra-oceanic subduction
and island arcs transition to Andean margins.
(SE Asia and Western Passific)
2) Mature stage Passive margins with large
shelf-areas (Atlantic Ocean)
1) Embryonic to Young stage.
Rifts to small ocean basin with sea-floor
spreading. (East African rift and Red Sea)
Le Pichon et al., 1993
Topography and erosional levels are taken into consideration:
Dewey et al. (1986) ca 1,2 x 104 km2
Le Pichon et al (1993)
Linear shortening between 1850 - 2600 km
Surface loss during the past 45 myr from 57 to 62 x 105 km2
Rate of surface loss: ≈ 1,1 x 10 km2 x 10-6yr
Arial deficit in sections ≈ 33 - 52 x 105 km2 (max)
18 - 30 x 105 km2 (min)
(Depends on estimates of original surface elevation)
WHAT IS THE EXPLANATIONS FOR THE DEFICIT?
For SE Asia
Tapponnier et al., 1982, 1986
Jolivet et al.
(SUBDUCTION / EDUCTION)