The deep mantle is primarily composed of silicates, compounds of silicon and oxygen, and likely also contains iron, magnesium, and calcium.
The Earth's mantle, a massive layer of mostly solid rock beneath the crust, accounts for roughly 84% of our planet's volume. While the provided reference focuses on the mantle in general, understanding the composition of the deep mantle requires further consideration.
Here's a breakdown:
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Silicates: These are fundamental components. The most abundant silicates in the mantle are thought to be in the form of high-pressure minerals such as bridgmanite and ferropericlase.
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Bridgmanite (Magnesium Iron Silicate Perovskite): Believed to be the most abundant mineral in the Earth, and the dominant constituent of the lower mantle (deep mantle).
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Ferropericlase (Magnesium Iron Oxide): This is another major component, coexisting with bridgmanite.
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Calcium Silicate Perovskite: Although less abundant than bridgmanite and ferropericlase, calcium silicate perovskite is also a significant component of the deep mantle due to the high pressures and temperatures.
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Other Elements: Iron, magnesium, and calcium are essential building blocks within these silicate structures. Other trace elements likely exist, but their precise nature and abundance are still subjects of research.
The extreme pressures and temperatures in the deep mantle cause the minerals to exist in different crystal structures (phases) compared to those found closer to the surface. Research continues to refine our understanding of the deep mantle composition through seismic studies, laboratory experiments simulating deep mantle conditions, and analysis of mantle-derived rocks brought to the surface.
