Plate tectonic processes in the Pacific and Atlantic during the
Cretaceous period have shaped the Caribbean region to this day

Date:
April 19, 2023
Source:
Johannes Gutenberg Universitaet Mainz
Summary:
Earthquakes and volcanism occur as a result of plate tectonics. The
movement of tectonic plates themselves is largely driven by the
process known as subduction. The question of how new active
subduction zones come into being, however, is still under
debate. An example of this is the volcanic Lesser Antilles arc
in the Caribbean. A research team recently developed models that
simulated the occurrences in the Caribbean region during the
Cretaceous, when a subduction event in the Eastern Pacific led
to the formation of a new subduction zone in the Atlantic. The
computer simulations show how the collision of the old Caribbean
plateau with the Greater Antilles arc contributed to the creation
of this new Atlantic subduction zone. Some 86 million years ago,
the triggered processes subsequently resulted in a major mantle flow
and thus to the development of the Caribbean large igneous province.


Facebook Twitter Pinterest LinkedIN Email
FULL STORY ========================================================================== Earthquakes and volcanism occur as a result of plate tectonics. The
movement of tectonic plates themselves is largely driven by the process
known as subduction. The question of how new active subduction zones
come into being, however, is still under debate. An example of this
is the volcanic Lesser Antilles arc in the Caribbean. A research team
including geophysicists Dr.

Nicolas Riel and Professor Boris Kaus of Johannes Gutenberg University
Mainz (JGU) as well as researchers from Universidade de Lisboa
(ULisboa) recently developed models that simulated the occurrences in
the Caribbean region during the Cretaceous, when a subduction event in
the Eastern Pacific led to the formation of a new subduction zone in
the Atlantic. The computer simulations show how the collision of the
old Caribbean plateau with the Greater Antilles arc contributed to the
creation of this new Atlantic subduction zone. Some 86 million years
ago, the triggered processes subsequently resulted in a major mantle
flow and thus to the development of the Caribbean large igneous province.


========================================================================== Subduction as a driving force of plate tectonics Subduction is a
geological process in which the cold oceanic lithosphere, which is part
of the rocky and about 100 kilometer thick outermost layer of the planet,
runs into the edge of a continental plate and slides beneath it to be
recycled back into the Earth's mantle. Together with the release of
hot mantle material in the form of mantle plumes and new oceanic floor generation at mid- ocean ridges, subduction events form the backbone of
plate tectonics. However, it is largely unknown how active subduction
zones form mainly because there are very few examples of ongoing
subduction initiation currently here on Earth.

With this in view, Dr. Nicolas Riel and Professor Boris Kaus of the
JGU Institute of Geosciences decided to investigate the geodynamic
conditions that would have predominated in the Caribbean region in the
late Cretaceous period.

"In terms of its plate tectonics, the Caribbean is a particularly
interesting location," said Professor Boris Kaus, head of the Geodynamics
& Geophysics group at Mainz University. The Caribbean region can be seen
as a kind of natural laboratory in which, over millions of years, plate tectonics resulted in the transfer of a subduction zone from the Pacific
to the Atlantic. This was associated with very extensive magmatic activity
that accounted for the origin of the Caribbean large igneous province
(or CLIP for short). This structure of magmatic rock is now the center
of the Caribbean plate.

For their computer simulations, the researchers selected a point in time
140 million years ago when the so-called Farallon plate, an ancient major
plate in the Eastern Pacific, began to move east and subduct beneath the
South American margin, thus shifting the old Caribbean plateau in the
direction of the Farallon trench. About 135 million years ago, the old Caribbean plateau came into collision with the proto-Caribbean plate. As
the simulations showed, the subduction of the Farallon plate was then temporarily interrupted while the subduction of the proto-Caribbean
plate was initiated. Several subsequent phases follow over a period of
some 50 million years, including the renewed subduction of the Farallon
plate at the western end of the old plateau, the formation of a mantle
plume, and the transfer of the Greater Antilles arc onto the retreating proto-Caribbean plate.

Simultaneous subduction of two plates forced part of the mantle upwards
"With the help of our computer simulations, we can better understand
the physical process," added Dr. Nicolas Riel, the lead author of the corresponding article recently published in Nature Communications. "We
were all surprised by the results showing that 90 to 86 million years
ago the renewal of the Farallon plate subduction led to a major mantle
flow, triggering the formation of a plume. This produced a huge amount
of magma." This molten rock material added to the thickness of the crust
of the Caribbean plate, making it up to 22 kilometers in depth, thus
8 to 10 kilometers thicker than the standard for the oceanic crust. It
was previously assumed that the mantle plume induced the renewal of the Farallon plate subduction.

"We are in the unique situation of being able to carry out very realistic simulations," said Boris Kaus. His team is one of the few groups worldwide
that can use supercomputer modeling to test to the plausibility of their physical assumptions and thus to analyze what plate tectonic events
actually occurred in the Caribbean. For their complex calculations,
the researchers had access to the MOGON II supercomputer operated by
Johannes Gutenberg University Mainz and the Helmholtz Institute Mainz
(HIM), one of the fastest high-performance computers in the world.

Research under the aegis of TeMaS The geophysical research was undertaken
under the aegis of the Terrestrial Magmatic Systems (TeMaS) research
platform, a joint project of the universities of Mainz, Frankfurt, and Heidelberg. TeMaS coordinates interdisciplinary research on magmatic
processes in the broadest sense, from the generation of magma in the
Earth's mantle through to its eruption in volcanoes and how this impacts
the atmosphere and climate. TeMaS is a High-potential Research Area at
JGU, funded by the Ministry of Science and Health of Rhineland-Palatinate.

Boris Kaus is Head of the Geodynamics & Geophysics group at the JGU
Institute of Geosciences. In 2018, he was granted an ERC Consolidator
Grant, one of the most richly endowed EU funding awards, to support
his research into magmatic processes. As part of the ERC project MAGMA,
short for "Melting And Geodynamic Models of Ascent," Kaus and his team developed numerical models that enabled them to simulate magmatic
events. The geophysicist is also a Fellow of the Gutenberg Research
College (GRC) of JGU.

* RELATED_TOPICS
o Earth_&_Climate
# Earthquakes # Geology # Natural_Disasters # Tsunamis
o Fossils_&_Ruins
# Fossils # Origin_of_Life # Early_Climate # Evolution
* RELATED_TERMS
o Mid-ocean_ridge o Earthquake o Great_Hurricane_of_1780
o Volcano o Oceanic_trench o Plate_tectonics o Ocean o
Geologic_fault

========================================================================== Story Source: Materials provided by
Johannes_Gutenberg_Universitaet_Mainz. Note: Content may be edited for
style and length.


========================================================================== Journal Reference:
1. Nicolas Riel, Joa~o C. Duarte, Jaime Almeida, Boris J. P. Kaus,
Filipe
Rosas, Yamirka Rojas-Agramonte, Anton Popov. Subduction
initiation triggered the Caribbean large igneous province. Nature
Communications, 2023; 14 (1) DOI: 10.1038/s41467-023-36419-x ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/04/230419125108.htm

--- up 1 year, 7 weeks, 2 days, 10 hours, 52 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)