Answer the following question given this paragraph: 

Different seafloor magnetic stripes equal different ages. By using geologic dating techniques, scientists could figure out what these ages are. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. Scientists were surprised to find that the oldest seafloor is less than 180 million years old. This may seem old, but the oldest continental crust is around 4 billion years old.


Q: Geologists found that the youngest rocks on the seafloor were where?


A:
mid - ocean ridges