A comprehensive model of the Cambrian explosion featuring "multi-factors coupling and multi-sphere driving". Supercontinent breakup and mantle plume activity served as the initial trigger of environmental change in the Neoproterozoic, the orogenic belts and subduction zones under the modern plate tectonic regime during Gondwanan assembly served as the long-term sustained driving force, and the extreme geomagnetic field served as an important environmental stressor. The coupling of these three factors jointly provided the genetic and environmental triggers, material basis, and ecological space required for the Cambrian explosion, and together they drove the milestone evolution of Earth's habitability.
The unique characteristics of Earth include life, an oxidized atmosphere, plate tectonics, continental crust, and the hypsometry between ocean and continent. These characteristics are also fundamental elements of Earth's habitability. The evolution of Earth's habitability is largely attributed to its stable but continuously evolving oceans, continents, magnetic field, atmosphere, and surface temperature, as well as the exchange of elements and energy among Earth's different spheres. On geological timescales, tectonic movement and the supercontinent cycle have been the main drivers of continental formation and the exchange of elements and energy between oceans and continents, and between the surface spheres and the solid Earth, which has driven the evolution of Earth's surface environment. Multi-sphere driving mechanisms have triggered extreme events in the evolution of life and the environment, and ultimately shaped a habitable planet with an oxidizing ocean and atmosphere and biodiversity. Related research has become a focus of international Earth science research. These advances also have broad implications for understanding natural hazards, resource distribution, environmental change, climate evolution, and the development of planetary habitability. However, how Earth evolved from an early uninhabitable planet into a habitable planet with a multi-sphere system and flourishing life still involves major scientific debates.
To address these long-standing uncertainties, this paper systematically summarizes the patterns and characteristics of Earth's multi-sphere evolution, explores tectonically driven cross-sphere material cycling, and discusses the driving factors of the Cambrian explosion from the perspective of solid Earth science. The authors believe that the evolution of Earth's tectonic regime is a key driving force for changes in the mode and efficiency of cross-sphere material cycling. Although certain characteristics of modern plate tectonics may have appeared locally in the Archean or Paleoproterozoic, Dr. Yao argues that a global-scale modern plate tectonic regime was not finally established until the assembly of Gondwana during the Neoproterozoic–Early Paleozoic. Relevant indicators include whole-plate deep subduction and global tectonic reorganization, along with extensive metamorphic records and bimodal metamorphic T/P ratio distribution identical to that of the modern Earth.
This paper constructs a co-evolutionary mechanism of "supercontinent cycle–surface environment–life evolution," linking the breakup of Rodinia → Snowball Earth → the Neoproterozoic Oxygenation Event (NOE) → Gondwana orogens and carbon cycling → the Cambrian explosion into a complete chain of reactions. The breakup of Rodinia triggered large igneous province (LIP) eruptions and CO₂ degassing, followed by basalt weathering that consumed CO₂ and triggered Snowball Earth. The extreme greenhouse climate after the end of Snowball Earth and the oxidation event laid the ecological foundation for the Ediacaran biota radiation and the Cambrian explosion. The assembly of Gondwana formed a 9,000-km-long super-orogenic belt located at middle to low latitudes, triggering intense weathering and denudation, delivering large amounts of nutrient elements (such as phosphorus) to the ocean, enhancing marine productivity, and driving and sustaining the NOE. In addition, "orogen-driven carbon cycling" played a key role in the long-term stability of the climate. The large-scale subduction–accretionary orogens during Gondwanan assembly had dual functions as both carbon source and carbon sink. Subduction-zone metamorphic decarbonation and arc volcanism continuously degassed CO₂, preventing the Earth from falling into a permanent "icehouse" due to excessive weathering. Meanwhile, intense silicate weathering continuously consumed CO₂, forming a negative feedback cooling effect. Together, these maintained the surface temperature above the threshold suitable for life. This surface environment of "continuous oxygenation, sufficient nutrients, and relatively stable climate" provided the necessity of large-scale metazoan radiation for energy supply, biomineralization, and ecological stability. Finally, extreme geomagnetic events should also be incorporated into the triggering mechanisms of the Cambrian explosion. At the Ediacaran–Cambrian boundary, the strength of Earth's magnetic field dropped to an extremely low level, and the polarity reversal frequency reached as high as 20–25 times per million years, indicating that the geodynamo mechanism once collapsed. The initial formation of Earth's inner core may have been related to the cooling of Earth's interior caused by whole-plate deep subduction under the modern plate tectonic regime, while the enhanced penetration of high-energy particles and UV-B radiation caused by the weakened magnetic field may have exerted extinction pressure on the Ediacaran biota, while also providing selective advantages for animals with vertical burrowing, biomineralized shells, or free-swimming capabilities, thereby "accelerating" the Cambrian explosion.
Key findings include:
(1) Tectonics and supercontinent cycles serve as primary driving forces for the evolution of Earth’s habitability.
(2) Plate tectonics and mantle plume drive the exchange of elements and energy between different spheres.
(3) Coupled tectonic-environmental changes and geomagnetic field triggered the Cambrian explosion.
This paper “Material cycling across Earth’s spheres and triggers of Cambrian explosion: a tectonic perspective” was published in Continent and Life Evolution .
Yao J, Han Y, Zhang D, Liu Q, Chen L, et al. Material cycling across Earth’s spheres and triggers of Cambrian explosion: a tectonic perspective. Cont. Life Evol. 2026(2):0011, https://doi.org/10.55092/cle20260011 .
Continent & Life Evolution
Observational study
Not applicable
Material cycling across Earth’s spheres and triggers of Cambrian explosion: a tectonic perspective
16-Sep-2026