Good luck.
Here the soil is alkaline clay, Extremely fertile, but not worth much if left untilled. Adding copious amounts of organic matter to the top two feet is one great solution for bringing the PH closer to neutral, however the composting products only last a couple of years. It is a constant chore to replenish and maintain the tilth of the soil.
I grew up along the Rio Grande river delta/valley/flood plain area. Very fertile, but alkaline as well. People often make fun of that river's name, because it is not really so Grande these days, but there is a very real geological reason that there is about one hundred miles of laser-flat land on each side of it. It is the ancient river bed and it is VERY FERTILE, SUPER-FINE GRAINED SILT, washed downstream from the continental divide.
Again, it just needs organic matter added to make the soil near perfect.
It takes some effort, but you should have similar results adding organic matter to Your soil, regardless of the shells.
The "so called" peat I mentioned is a waste product, in the way of a future quarry. They used to just dump it out of the way somewhere, but they now have become smart enough to sell it to local farmers, nurseries and landscaping companies.
They will also bring a truckload to a residence, but that means I have to be ready to deal with a dumptruck worth all at once. I am prepared!