National Geographic : 2009 Oct
groundwater and directed it to elds without loss to evaporation. Six hundred miles of these canals can still be detected. e system worked well for hundreds of years. And then the "fossil" water, stored up in wet times, started to give out, and the civilization collapsed. e Sahara seems like a barrier at rst glance, severing Africa into two pieces. But for the hu- mans who have lived in Libya for thousands of years, it has been a corridor. Gold and ivory and slaves came north from sub-Saharan Africa; olive oil, wine, glass, and other goods from the Mediterranean owed south. is trade creates a lasting image in our minds: the caravan wend- ing its way through huge dunes. The Saharan corridor may even have been one of the pathways our ancestors followed when they le the eastern part of the continent to populate the rest of the world. Scholars have long assumed that early humans expanded be- yond sub-Saharan Africa into Eurasia by migrat- ing either along the Nile River and across the Sinai or across the Red Sea. Now another notion is being explored: that the Fezzan may have been part of a long migratory corridor leading some modern humans to the shores of the Mediter- ranean and from there across the Sinai. Perhaps, through this sea of sand, our ancestors trekked from the Great Ri Valley and into our lives. Mattingly says he likes archaeology because "it has lessons for today." Fi een hundred years after the fall of the Garamantes, the Libyan government is now building the Great Man- Made River, a series of huge aqueducts to mine ancient underground water reserves below the Sahara and use them to make the desert bloom. e water being pumped was deposited tens of thousands of years ago, in much wetter times. Already the water table is declining because of the pumping. e project has an estimated life span of only 50 to 100 years, a blink of the eye in this region. Clearly the last chapter of the Fezzan is yet to be written. j ■ Society Grant The photographer's expedition was funded in part by your National Geographic membership.