* Oceanic crust is constantly recycled. The process of plate tectonics means that older oceanic crust is constantly subducted back into the mantle at convergent plate boundaries.
* Jurassic crust is likely gone. By the time you reach the Jurassic, that crust would have been subducted long ago.
* The oldest oceanic crust is much younger. The oldest existing oceanic crust is found in the western Pacific Ocean and is about 200 million years old (early Jurassic, but not the late Jurassic).
Where to find older crust:
* Ophiolites: These are sections of oceanic crust that have been uplifted and preserved on land. They offer insights into the composition and structure of ancient ocean floors. However, even in ophiolites, finding truly Jurassic-aged crust would be extremely difficult.
* Oceanic plateaus: Some large oceanic plateaus can preserve older crust, but it's not always Jurassic-aged.
* Deep sea drilling: The International Ocean Discovery Program (IODP) has drilled into the ocean floor to retrieve cores, but the oldest samples they've recovered are still relatively young.
Key point: While it's theoretically possible that some Jurassic-aged oceanic crust might exist in very specific locations, it's highly unlikely that we would be able to drill to recover it. The vast majority of Jurassic crust has been subducted and recycled back into the Earth's mantle.
