Pangaea supercontinent integration during Permian and mass extinctions

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com

A recent paper that may be of interest:



YIN HongFu & SONG HaiJun (2013)
Mass extinction and Pangea integration during the Paleozoic-Mesozoic transition.
SCIENCE CHINA Earth Sciences 56 (11): 1791-1803
DOI: 10.1007/s11430-013-4624-3
http://earth.scichina.com:8080/sciDe/EN/abstract/abstract511745.shtml

Note: pdf can be downloaded for free from abstract link.




The greatest Phanerozoic mass extinction happened at the end-Permian
to earliest Triassic. About 95% species, 82% genera, and more than
half families became extinct, constituting the sole macro-mass
extinction in geological history. This event not only caused the great
extinction but also destroyed the 200 Myr-long Paleozoic marine
ecosystem, prompted its transition to Mesozoic ecosystem, and induced
coal gap on land as well as reef gap and chert gap in ocean. The
biotic crisis during the Paleozoic-Mesozoic transition was a long
process of co-evolution between geospheres and biosphere. The event
sequence at the Permian-Triassic boundary (PTB) reveals two-episodic
pattern of rapidly deteriorating global changes and biotic mass
extinction and the intimate relationship between them. The severe
global changes coupling multiple geospheres may have affected the
Pangea integration on the Earth's surface spheres, which include: the
Pangea integration→enhanced mountain height and basin depth, changes
of wind and ocean current systems; enhanced ocean basin depth→the
greatest Phanerozoic regression at PTB, disappearance of epeiric seas
and subsequent rapid transgression; the Pangea integration→thermal
isolation effect of continental lithosphere and decrease of mid-ocean
ridges→development of continental volcanism; two-episode volcanism
causing LIPs of the Emeishan Basalt and the Siberian Trap (259-251
Ma)→global warming and mass extinction; continental aridification and
replacement of monsoon system by latitudinal wind system→destruction
of vegetation; enhanced weathering and CH4 emission→negative excursion
of delta13C; mantle plume→crust doming→regression; possible relation
between the Illawarra magnetic reversal and the PTB extinction, and so
on. Mantle plume produced the Late Permian LIPs and mantle convection
may have caused the process of the Pangea integration. Subduction,
delamination, and accumulation of the earth's cool lithospheric
material at the "D" layer of CMB started mantle plume by heat
compensation and disturbed the outer core thermo-convection, and the
latter in turn would generate the mid-Permian geomagnetic reversal.
These core and mantle perturbations may have caused the Pangea
integration and two successive LIPs in the Permian, and probably
finally the mass extinction at the PTB.

News release:

http://phys.org/news/2013-11-biggest-mass-extinction-pangea.html