Ancient Civilization - Gonur

Link above is to a government site describing some of the historical signifigance of the site I describe below - beware of strange English. Wiki link here has more and better general information, on what is better known as the Bactrian-Margiana Archaeological Complex.

Read an interesting article this weekend about a Bronze Age civlization in Discover, centered on what is today Turkmenistan. Unfortunately, Discover requires a subscription to access web content. Russian archaelogist Victor Sarianidi has been working the site off and on, depending on the political situation, since the 1970's. Harvard and Italy also have teams working in the area, where the delta of the Mugrab River was 4000+ years ago, one which traded extensively with Mesopotamia and the Harappa civilization of the Indus River valley, and perhaps as far as China and Egypt as well.

"Sarianidi has turned up the remnants of a wealthy town protected by high walls and battlements. This barren place, a site called Gonur, was once the heart of a vast archipelago of settlements that stretched across 1,000 square miles of Central Asian plains. Although unknown to most Western scholars, this ancient civilization dates back 4,000 years—to the time when the first great societies along the Nile, Tigris-Euphrates, Indus, and Yellow rivers were flourishing.

Thousands of people lived in towns like Gonur with carefully designed streets, drains, temples, and homes. To water their orchards and fields, they dug lengthy canals to channel glacier-fed rivers that were impervious to drought. They traded with distant cities for ivory, gold, and silver, creating what may have been the first commercial link between the East and the West. They buried their dead in elaborate graves filled with fine jewelry, wheeled carts, and animal sacrifices. Then, within a few centuries, they vanished."

The theory is that climate change negatively impacted the civilization, along with its trading network partners, resulting in the Bronze "Dark Age". Its people apparently migrated with the river as it changed course, and/or south into Persia.
The government website linked above makes claims that the culture may have spawned the beginnings of the Zoroastrian religion, the state religion of the ancient Persian empire.