Is the lithosphere a closed system?

The lithosphere is generally considered a closed system in terms of matter exchange because it does not readily exchange material with its surroundings, such as the atmosphere or hydrosphere. However, it can exchange energy, particularly through processes like geothermal heat flow and tectonic activity. In some contexts, such as localized ecosystems or during specific geological events, the lithosphere may exhibit open system characteristics. Overall, while it behaves predominantly like a closed system, interactions do occur with other Earth systems.