‘New Continent and Ocean’: Earth’s mantle is splitting apart faster than we thought

Produced by Tarun Mishra

Pacific Ring of Fire

New research reveals that Earth's mantle is divided by the Pacific Ring of Fire, a geological boundary reflecting the formation and breakup of the supercontinent Pangaea.

African and Pacific Domains

The mantle beneath the African domain, which spans continents including Africa, Europe, Asia, and the Americas, shows a greater diversity of elements and isotopes compared to the Pacific domain, which primarily lies beneath the Pacific Ocean.

Supercontinent Cycles

The distribution of elements in the mantle reflects two supercontinent cycles. Rodinia formed around 1.2 billion years ago and broke apart 750 million years ago, while Pangaea emerged 335 million years ago and began to split 200 million years ago.

African Continent Splitting

Due to this phenomenon, tectonic plates of African continent are splitting apart. This process is happening on East African Rift System (EARS). The EARS is a large fault line that goes through Ethiopia, Kenya Uganda and Tanzania. This split will form a totally new land mass and another water body.

Shallow Mantle Analysis

Building on earlier studies, researchers analysed nearly 4,000 samples of volcanic rock from mid-ocean ridges. These samples provided data on the chemistry of shallow mantle magma and its connection to surface processes. According to the samples, the process could now happen in 5 million years instead of 50 million years, which was previously estimated.

The Process

Supercontinent cycles concentrate elements beneath the landmasses through subduction, where oceanic crust sink beneath continental plates. This process transports elements from the crust into the mantle, leaving long-lasting geochemical signatures.

Why it happens?

The rise of hot mantle material from large low-shear velocity provinces (LLSVPs), or mantle "blobs," is believed to drive supercontinent breakup. These blobs exist beneath both the African and Pacific domains.

Significance for Geoscience

The study highlights how mantle processes influence surface activity, such as the cycling of essential elements for life and the concentration of rare earth materials critical for technology. Researchers aim to deepen understanding of Earth's unique tectonic system and its role in sustaining life.