Noun. 1. heat sink-a metal conductor specially designed to conduct (and radiate) heat. conductor-a device designed to transmit electricity, heat, etc. sink - (technology) a process that acts to absorb or remove energy or a substance from a system; the ocean is a sink for carbon dioxide.
The crust is composed of many different types of rocks that fall within three main categories: igneous, metamorphic and sedimentary. However, most of those rocks originated as either granite or basalt. The mantle beneath is made of peridotite. Bridgmanite, the most common mineral on Earth, is found in the deep mantle. How We Know the Earth Has a Crust
Most of the continental crust is made up of igneous rocks. However,  there are metamorphic and sedimentary rocks that make up the  continental crust as well. Contributions. Mainly boulder clay (Soft rock) and chalk (Hard rock) these are what also form headlands and bays due to the difference in their resistance to weathering.