Zheng-Xiang Li talks with
ScienceWatch.com and answers a few questions about
this month's New Hot Paper in the field of Geosciences. The
author has also sent along images of his
Article Title: Assembly, configuration, and
break-up history of Rodinia: A synthesis
ZX;Bogdanova, SV;Collins, AS;Davidson, A;De Waele,
B;Ernst, RE;Fitzsimons, ICW;Fuck, RA;Gladkochub, DP;Jacobs,
J;Karlstrom, KE;Lu, S;Natapov, LM;Pease, V;Pisarevsky,
SA;Thrane, K;Vernikovsky, V
Journal: PRECAMBRIAN RES, Volume: 160, Issue: 1-2, Page:
179-210, Year: JAN 5 2008
* Curtin Univ Technol, Dept Appl Geol, Tecton Special Res
Ctr, GPO Box U1987, Perth, WA 6845, Australia.
* Univ Western Australia, Sch Earth & Geog Sci, Tecton
Special Res Ctr, Crawley, WA 6009, Australia.
* Lund Univ, Dept Geol, S-22362 Lund, Sweden.
(addresses have been truncated)
Why do you think your paper is highly
This paper represents the final outcome of the UNESCO/IUGS-sponsored
IGCP-project 440 "Rodinia Assembly and Break-up." It summarizes 17 years of
concerted global efforts in testing the validity of the supercontinent
Rodinia. It provides a self-consistent geodynamic model for the assembly,
configuration, and breakup history of Rodinia in the lead-up to a period of
rapid changes in global climate and atmospheric composition, and the
explosion of multicellular life on Earth.
The relevance of this synthesis, co-authored with 16 eminent geoscientists
from around the world, to the broader geosciences community is nicely put
by Professor Emeritus Eldridge M. Moores (ex-President of the Geological
Society of America and ex-Vice President of IUGS) in his generous review of
the work: "This is a very exciting, even historic, comprehensive synthesis
of the work of many people on the assembly and breakup of Rodinia. This
paper will be a major contribution to all of geology. It breaks
revolutionary new ground. It will quickly find its way into the general
textbooks and be quoted for years."
Does it describe a new discovery, methodology, or
synthesis of knowledge?
Simplified Geodynamic Map of Rodinia
An animated history of the assembly and breakup of
Rodinia, and the formation of Gondwanaland
(PPT file is zipped)
Cartoon showing the formation of bipolar
superplumes due to circum-supercontinent mantle
In writing this paper, we took a holistic approach in synthesizing all
available data from various disciplines—including geology,
geochronology, and paleomagnetism, and utilizing our knowledge of how
tectonic plates interact in the process of supercontinent assembly and
breakup, and how plate dynamics might interact with mantle dynamics. We
were able to develop a feasible global paleogeographic history for the time
interval of 1,100 million years to 530 million years ago (Ma). This covers
major global geodynamic events such as the formation and breakup of
Rodinia, possible superplume activity and true polar wander (whole-Earth
meridional motion relative to its rotation axis), possible snowball-Earth
events, and the final formation of the well-known supercontinent
Would you summarize the significance of your paper
in layman's terms?
The global configuration of continents and oceans changes all the time in
Earth's history. In particular, continents sometimes collide together to
form a single continent—a supercontinent—and breakup later due
to the Earth's internal forces and energy. This evolving continental
configuration, along with the formation of mountain belts during
supercontinent assembly and global volcanic events during supercontinent
breakup, not only impacts on the formation of mineral and energy resources
that we utilize today, they also impact on the atmospheric composition, the
global climatic conditions, and the evolution of life.
For some time, geoscientists postulated the existence of a supercontinent
that pre-dated Pangaea and Gondwanaland, but it was only in 1991 that
convincing evidence was advanced for the existence of the supercontinent
"Rodinia." This event revolutionized the geoscientific world, extending
understanding of the evolution of supercontinents from around 540 million
years to beyond 1,000 million years. Of particular importance, the
hypothesis suggested that the breakup of this earlier supercontinent with
its resultant continent–ocean configuration and climatic changes,
created conditions that led to the explosion of life on Earth.
Although few now doubt the existence of Rodinia, there is still no
consensus regarding the number of participating cratons, their relative
configuration within the supercontinent and the chronology and mode of
assembly and breakup of the supercontinent. In our paper we provide an
overview of evidence for and against major Rodinian reconstructions,
including the preferred model that we used for constructing the first
Geodynamic Map of Rodinia (Fig. 1), and also an animated history of the
formation and breakup of Rodinia and the subsequent birth of Gondwanaland
(Fig. 2, a PowerPoint animation). The global paleogeographic configurations
presented in this animation provide a set of more robust base maps for
paleoclimatic modellers to simulate the causes for extreme global climate
(a snowball Earth?) during Neoproterozoic time.
In the paper we also proposed a mechanism that links the formation of the
supercontinent to the subsequent formation of a mantle superplume beneath
it (Fig. 3), which in turn caused the breakup of the supercontinent. We
argued that, like the supercontinent Pangaea, Rodinia only lasted about 150
million years after final assembly. Mantle avalanches, caused by the
sinking of stagnated oceanic slabs accumulated at the mantle transition
zone surrounding the supercontinent, plus thermal insulation by the
supercontinent, led to the formation of a mantle superplume beneath Rodinia
40-60 million years after its final assembly (Figs. 2 & 3). As a
result, widespread continental rifting occurred between ca. 825 Ma and 740
Ma, with episodic plume events at ca. 825 Ma, ca. 780 Ma, and ca. 750 Ma.
We argued in our paper that Rodinia assembled through worldwide orogenic
events between 1,300 and 900 Ma. Likewise, the breakup of Rodinia was also
a protracted and diachronous process. The first major break-up event
occurred along the western margin of Laurentia (North America and
Greenland), possibly as early as 750 Ma. Rifting between the Amazonia
craton and the southeastern margin of Laurentia started at approximately
the same time, but only led to break-up after ca. 600 Ma. By this time most
of the western Gondwanan continents had joined together, although the
formation of Gondwanaland was not complete until ca. 530 Ma.
How did you become involved in this research, and
were there any problems along the way?
My involvement in Rodinia-related research started from the "Gondwana
Eight" conference held in Hobart, Australia, in 1991. I presented a paper
there with a co-worker, the late Professor Chris Powell, on the assembly of
Gondwanaland, and we were excited to hear Professor Ian Dalziel's talk on
the new hypothesis of a supercontinent called Rodinia, the predecessor of
Gondwanaland and all later continents. We immediately started testing the
hypothesis using both paleomagnetic and geological observations, leading to
the establishment of the Australian Research Council-funded Tectonics
Special Research Centre (1997-2006).
Expanding global-scale international collaborations further led to the
establishment of the IGCP 440 project (1999-2004) with the late Professors
Rafael Unrug and Chris Powell being the co-leaders and me as the project
secretary. With the untimely passing away of both founding leaders, the
leadership team later included Professor Svetlana Bogdanova (co-leader),
Dr. Sergei Pisarevsky (project secretary), me (co-leader), and the late
Professor Henri Kampunzu (co-leader). The project involved over 300
scientists from around the world, and it has been regarded as one of the
most successful IGCP projects.
Where do you see your research leading in the
My continued research in this field may lead in two related directions. One
is further examination of the nature and evolutionary history of Rodinia
and older supercontinents in Earth's history. The other is to examine the
Earth's record of superplume events and their relationships to
supercontinent events. Both will involve extensive international
collaborations and, through working with mantle dynamists, we hope to
achieve a better understanding of how the Earth works.
Do you foresee any social or political implications
for your research?
Apart from helping people to understand how the Earth evolved and how the
Earth's deep mantle interacts with the tectonic plates, my research also
helps in understanding the processes controlling the formation and location
of mineral and energy resources, and how geological processes impact on our
climate and environment.
For instance, the identification of the timing, extent, and geographic
location of past mountain ranges, major volcanic provinces, and
continent-ocean configurations during Earth's history helps us to
understand what caused the occasional catastrophic climatic events like
icehouse (even snowball Earth) conditions. The extensive international
collaborations that my research involves also bring scientists from all
cultural background to work together toward common goals.
Professor Zheng-Xiang Li The Institute for Geoscience Research (TIGeR) Department of Applied Geology Curtin University of Technology Perth, Australia Web | Web
KEYWORDS: DRONNING-MAUD-LAND; TRUE POLAR WANDER;
SIBERIA-LAURENTIA CONNECTION; PB ZIRCON GEOCHRONOLOGY; LARGE IGNEOUS
PROVINCE; ARABIAN-NUBIAN SHIELD; WESTERN NORTH-AMERICA; NEOPROTEROZOIC
TECTONIC EVOLUTION; GRANULITE-FACIES METAMORPHISM; LATE PROTEROZOIC
Images used in this feature in ScienceWatch.com
are reprinted from PRECAMBRIAN RESEARCH, Vol. 160,
Li ZX, et al., "Assembly, configuration, and
break-up history of Rodinia: A synthesis," Pages: 179-210,
Copyright JAN 5 2008, with permission from