The Garamantes, referred to by Herodotus, are generally considered to have been the first Libyan empire. However, attempts to link them to the Atlantis story would appear to be undermined by the fact that they flourished around the middle of the first millennium BC, which would appear to be far too recent to fit any interpretation of Plato’s 9,000 ‘years’, be they solar, lunar or seasonal.
Frank Joseph identifies the Garamantes with the Sea Peoples whom he considers to have been Atlantean refugees. However, the Garamantes are generally accepted as having developed urban centres in what is now southern Libya(a)(b), which is not what you might expect from a maritime culture. Recent satellite images(c) offer new information on the extent of the Garamantes domain.
Further information is available on the Temehu.com website(d), but perhaps the most intriguing theory is that the Garamantes originally came from the Carpatho–Danubian region of eastern Europe sometimes referred to as Dacia. It is suggested that the fair-skinned Berbers of North Africa are the descendants of those European invaders!
Bob Idjennaden, a Belgian living in Ireland, has published a short Kindle book(f) on the Garamantes. He has also authored a series of Kindle books on various aspects of ancient African history, including one about the Sea Peoples, co-authored with Taklit Mebarek.
(f) https://www.amazon.co.uk/Buried-Kingdoms-Garamantes-Forgotten-Civilisations-ebook/sim/B007Q239OE/2 (link broken Sept. 2020)<