Final answer:
The oceanic crust in the Mediterranean is considered geologically young, with a continuous renewal cycle occurring every 100 million years driven by seafloor spreading at an average rate of 5 centimeters per year.
Step-by-step explanation:
Considering the age, the oceanic crust in the Mediterranean is relatively young when viewed on a geological timescale. From analyses of the seafloor spreading process, we know that the Earth's oceanic crust is fully renewed about every 100 million years due to the continuous creation of new crust at mid-ocean ridges and the subduction of older crust at tectonic plate boundaries. The Mediterranean oceanic crust's age, like other oceanic regions, is determined by the spreading rates, which average about 5 centimeters per year, as identified by about 60,000 kilometers of active rifts.
The oceanic crust is predominately mafic in composition, consisting of basalt from erupted magma on the seafloor and gabbro from magma cooling deeper within. This crust forms the basins that, when filled with water, become our planet's oceans. Due to tectonic activity and seafloor spreading, the new crust is added to Earth each year, covering an area of approximately 2 square kilometers. Therefore, the Mediterranean, like other ocean basins, is among the youngest features on our planet.
Overall, the ratio of the created area of ocean crust to its total area reveals that the average age of oceanic crust is less than 3% of the Earth's total age, making these ocean basins relatively youthful in comparison to other geological features.