Lecture 3.  Beyond the Plate Tectonics: Plumes, Large Ign. Provinces and Mass Extinctions
Download
1 / 64

Lecture 3. Beyond the Plate Tectonics: Plumes, Large Ign. Provinces and Mass Extinctions - PowerPoint PPT Presentation


  • 133 Views
  • Uploaded on

Lecture 3. Beyond the Plate Tectonics: Plumes, Large Ign. Provinces and Mass Extinctions. Plumes and LIPs general features Siberian Traps Major open questions Model Relation to mass extinction. Outline. Plates. Hot Spots. Hot Spot Track. Willson, 1963; Morgan, 1971.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Lecture 3. Beyond the Plate Tectonics: Plumes, Large Ign. Provinces and Mass Extinctions' - qamra


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Outline

Outline


Plates Provinces and Mass Extinctions


Hot Spots Provinces and Mass Extinctions


Hot Spot Track Provinces and Mass Extinctions

Willson, 1963; Morgan, 1971


Hot Spot= Mantle Plume- Provinces and Mass Extinctions

Classical feature beyond plate tectonics

Currently, existence of plumes is under debate: anti-plume site– www.mantleplumes.org

Main anti-plume argument—no predicted uplift before eruption of Large Igneous Province


Large igneous provinces lips
Large Igneous Provinces (LIPs) Provinces and Mass Extinctions

After Saunders et al. (1992)


Large igneous provinces lips1
Large Igneous Provinces (LIPs) Provinces and Mass Extinctions

After Saunders et al. (1992)


Large magma volume
Large Magma Volume Provinces and Mass Extinctions

  • Siberian Flood Basalts- over 4 mln. km3

  • Deccan Traps- 2 mln. km3

  • North Atlantic Province- over 2-4mln.km3

  • Columbia River Province- 0.3 mln. km3

  • Plato Onthong-Java-over 40mln. km3


Short time scales of major magmatic phases
Short Time Scales of Major Magmatic Phases Provinces and Mass Extinctions

  • The most precise dating gives age ranges for the main magmatic phase within method accuracy ±1 mln.y.

  • The full range of magmatic activity may exceed 10 mln.y.


Ar ar age of siberian flood basalts 250 1 1 ma
Ar-Ar age of Siberian Flood Basalts 250±1.1 Ma Provinces and Mass Extinctions

Reichow et al, 2009


Lips often predate continental break up
LIPs often predate continental break-up Provinces and Mass Extinctions


Continental break-up Provinces and Mass Extinctions


Continental break-up Provinces and Mass Extinctions


Continental break-up Provinces and Mass Extinctions


Continental break-up Provinces and Mass Extinctions


Lips are related to hot spots deccan traps reunion hs
LIPS are related to hot spots Provinces and Mass ExtinctionsDeccan Traps—Reunion HS


Parana etendeka tristan hs
Parana-Etendeka—Tristan HS Provinces and Mass Extinctions


Lips source has high temperature
LIPs source has high temperature Provinces and Mass Extinctions

Herzberg & Gazel, 2009


LIPs sources are in the Lower Mantle ? Provinces and Mass Extinctions

Torsvik et al., 2007, 2008


Campbell griffiths 1990

Plume Provinces and Mass Extinctionshead model of LIPs

Campbell & Griffiths, 1990

Plume

An experimental starting plume (in glucose syrup)


Plume head model of lips
Plume head model of LIPs Provinces and Mass Extinctions

White and McKenzie, 1989; Richards et al.,1989, Campbell and Griffiths, 1990

Uplift of >1 km must be common for LIPs but it is not!

Surface uplift = 0.7-1.0 km/100°, i.e. 1.4-3 km for DT= 200-300°


Lips correlate with mass extinction events
LIPs correlate with mass extinction events Provinces and Mass Extinctions

Ridgwell, 2005

White and Saunders (2005)


Ocean acidification as a kill mechanism Provinces and Mass Extinctions

Payne et al, PNAS, 2010


No correlation with lips volume
No correlation with LIPs volume Provinces and Mass Extinctions

Ganino & Arndt, 2009, Svensen et al., 2009


Elegant explanation Provinces and Mass Extinctions

Ganino & Arndt, 2009, Svensen et al., 2009


Siberian LIP Provinces and Mass Extinctions

  • Over 4 mln. km3 of magmas produced in less than 1 ma

  • The age of province is about 252ma and coincides with P-T mass extinction

  • No uplift before magmatism


Siberian traps

Reichow et al, 2009 Provinces and Mass Extinctions

Siberian Traps


Siberian traps1
Siberian Traps Provinces and Mass Extinctions


Questions
Questions Provinces and Mass Extinctions

  • Why no pre-magmatic uplift?

  • Why enormous volume of magmas erupted at thick cratonic lithosphere without extreme extension?

  • How lithosphere was thinned by >50 km during only few 100 thousand years?

  • What was the source of large volumes of CO2 and other gases that triggered P-T mass extinction? Heating of coal?


Sobolev et al, Provinces and Mass ExtinctionsScience, 2007


Sobolev et al, Provinces and Mass ExtinctionsScience, 2007


Crustal recycling hofmann and white 1980 1982
Crustal recycling Provinces and Mass ExtinctionsHofmann and White, 1980-1982

Kellogg et al., 1999


Eclogite clinopyroxene garnet sio 2 phase
Eclogite: clinopyroxene ≥ Provinces and Mass Extinctionsgarnet ± SiO2 phase

1 см

Photo and sample of I. Aschepkov


T C Provinces and Mass Extinctions

Pyroxenite -Sobolev et al, 2007;

peridotite- Walter, 1998

Sobolev, et al, 2005


Pyroxenite derived melt compared with peridotite derived melt
Pyroxenite-derived melt compared with peridotite-derived melt

  • High Ni and Si and low Mn/Fe, Ca and Mg: because pyroxene and garnet buffers Ni, Si, Mn, Fe, Ca and Mg instead of olivine (Kelemen et al 1998, Humayun et al, 2004, Sobolev et al, 2005, Herzberg, 2006, Sobolev et al, 2007);


Thermomechanical model of siberian lip constrained by petrological data based on 2011 paper
Thermomechanical model of Siberian LIP constrained by petrological data based on 2011 paper


Petrological constraints
Petrological constraints petrological data based on 2011 paper

  • Plume potential temperature Tp=1600°C

  • Eclogite content in plume 10-20wt% (15wt%)

  • Initial lithospheric thickness >130 km


Melt sources composition
Melt sources composition petrological data based on 2011 paper


Improvements of tne thermomechanical modeling technique petrological data based on 2011 paper

Melting of peridotite (Katz et al, 2003), of eclogite and pyroxenite (based on experiments of Yaxley, and Hirschmann group, Sobolev et al, 2007

Melt transport procedure (fast compaction porous-flow-like in the melting region and intrusion in the lithosphere)


Model setup
Model setup petrological data based on 2011 paper


Thermal plume tp 1650 c no melting
Thermal plume petrological data based on 2011 paper(Tp=1650°C)no melting

0 Myr


Thermal plume no melting
Thermal plume petrological data based on 2011 paper no melting

0.25 Myr


Thermal plume no melting1
Thermal plume petrological data based on 2011 paper no melting

0.5 Myr


Thermo chemical plume tp 1650 c 18 eclogite no melting
Thermo-chemical plume petrological data based on 2011 paper(Tp=1650°C,18% eclogite) no melting

0 Myr


Thermo chemical plume no melting
Thermo-chemical plume petrological data based on 2011 paper no melting

0.5 Myr


Thermo chemical plume no melting1
Thermo-chemical plume petrological data based on 2011 paper no melting

1.5 Myr


Thermal plume
Thermal plume petrological data based on 2011 paper

0.5 Myr

Thermo-chemicalplume


Elevation
Elevation petrological data based on 2011 paper


Temperature petrological data based on 2011 paper


Composition petrological data based on 2011 paper

0.5 Mln years


Numerical model
Numerical model petrological data based on 2011 paper

Sobolev et al. submitted


Effect of lithosphere petrological data based on 2011 paper

Different lithospheric thickness

Different lithospheric depletion


Effect of plume petrological data based on 2011 paper


Effect of plume petrological data based on 2011 paper

Different plume composition


Melt production and composition petrological data based on 2011 paper


Plume degassing petrological data based on 2011 paper


Plume degassing petrological data based on 2011 paper


But we lose elegant explanation! petrological data based on 2011 paper

Ganino & Arndt, 2009, Svensen et al., 2009


But we have another! petrological data based on 2011 paper


Conclusions petrological data based on 2011 paper

Such a plume is able to thin dramatically cratonic lithosphere without extension and to generate several mln km3 of melt in few 100 thousand years

  • Thermochemical plume rich in recycled crust does not generate significant pre-magmatic uplift of the lithosphere

  • Massive CO2 and HCl degassing from the plume could alone trigger the Permian-Triassic mass extinction and before the main volcanic phase


Conclusions petrological data based on 2011 paper

  • Plumes do exist, but they are not purely thermal but thermochemical


Model of the petrological data based on 2011 paperOntong Java Plateau

Sobolev et al. in prep.


ad