Book on man's earliest religions

A book in the Schattenjäger library, set in the section on religion.

Excerpt
The African sun god was violent and terrible, and so became his worshipers. They practiced a particularly bloody form of ritual sacrifice, much as the sun-worshiping Aztecs did centuries later and thousands of miles away. The most brutal and grisly tribes in African history descended from this sun-worshiping cult, though the cult itself expanded to include many other deities, merging with other African religions to become Voudoun.

The most fascinating archaeological site related to sun worshipers is in this region. It's the snake mound in the Republic of Benin, located fifty miles south of the border to Burkina Faso. Thirty miles northeast of Natitingou. Unlike the snake mounds of North America, the Benin example is a double snake mound.