Mantles

Mantle is a term used in several scientific and everyday contexts. In geology, the Earth's mantle is the large, mostly solid layer between the crust and the core, extending from about 35 km below continents to around 2,900 km beneath the oceans. It accounts for about 84% of Earth's volume and is divided into the upper mantle (including the asthenosphere) and the lower mantle, with a transition zone around 410–660 km. The mantle’s rocks are silicate minerals rich in magnesium and iron, such as olivine and pyroxene. Heat from radioactive decay and residual heat drives slow convective flow, which powers plate tectonics and volcanism. Seismic data show increasing velocities with depth, and the mantle behaves as a mostly solid region that can flow very slowly over geological timescales.

In biology, the mantle is a key anatomical feature of mollusks. It is a significant dorsal tissue that encloses the visceral mass and, in many species, secretes the shell. In cephalopods the mantle also plays a role in locomotion through jet propulsion and may form various recognizable structures.

In clothing, a mantle refers to a loose, sleeveless outer garment worn over other clothes for warmth or ceremonial purposes. Mantles vary widely in style and length across cultures and historical periods.

Other uses include planetary and stellar contexts, where mantles describe radial layers surrounding a core or nucleus. These senses share the underlying idea of a distinct, substantial layer enveloping a central region, though they are specialized terms within their respective fields.