Hi! Thanks so much for participating in the webinar! The scientists
really enjoyed all of your questions. I asked Julian to help me with your
question. Here is his response-

Unfortunately, they are only found in the deep oceans. They need quiet
conditions on the ocean floor with little sedimentation over millions of
years. You do find them in US waters near some of their tropical islands
but you would need a submarine to see them. When continents collide, they
can get uplifted onto land but they then get mangled by the collision. So
if you go to San Francisco, where there are deformed deep ocean sediments
exposed on land, you will see a lot of manganese but no nice
burnt-baked-potato shaped nodules with concentric rings and a nucleus.

Thanks!
Mrs. Pena