Paleontology and geology

The southern part of Alabama has some of the best sections of Tertiary marine fossils found anywhere in the world. Evidence of near-tropical, coastal forests of the Early Tertiary is preserved in layers of lignite (brown coal) that surface in curving bands across the southern counties. Studies of pollen grains preserved in the lignite and in other sediments show that during the middle part of the Tertiary, Alabama’s forests were more like those of today. This change from near-tropical to temperate forests was probably a response to a cooling climate.