Why not take a sample and send it in to your local ag center for testing. That would be a start. You could also do a test area to see how well it does.

deep_south_gardener is right about getting a sample to your ag rep. But aside from being on the acid side, the soil ought to be fine. In Florida and parts of Louisiana, vegetables are grown on this type of soil commercially, called muck farming.

There is one quick way of finding out if it is muck as it will not be thick but like shredded fiber and fall apart easily. It will also burn well when dried out. I Michigan we knew that if it caught fire the only way to stop the burn was to plow down below the muck. So if this is what it is then you have great soil to use in your garden and should get a great garden out of what you have there.