- you have the same composition as the uppermost, the rigid part of the mantle, but the temperatures have now gone up enough that it now turns it now into not quite a liquid, we won't call it a liquid, it still transmits a certain type of waves that liquids wouldn't transmit. it's more of like a putty-like texture, it has fluid-like properties, it can float, it's way more viscous than what we'd associate with most fluids, so it's not rigid and solid, it can have convection going on in it, but it's not a liquid 