Sahel Alma or Sahel Aalma is a Late Cretaceous paleontological site and Konservat-Lagerstätte in Keserwan-Jbeil, Lebanon. Located near the town of the same name, it documents well-preserved deepwater marine fossils dating to the late Santonian stage of the Cretaceous. It is often associated with the slightly older, similarly famous Sannine Formation sites (Haqel, Hadjula, and Nammoura), with these four sites being together referred to as the "Fish Beds" of Lebanon.[1]
It is one of the few fossiliferous units of the Chekka Formation, a wider geological formation in Lebanon deposited from the Late Cretaceous to the early Paleogene.[2]
Much like the fossil sites of the older Sannine Formation, Sahel Alma contains exquisitely preserved marine fossils from the Tethys Ocean, deposited off the northern coast of the Afro-Arabian continent. However, unlike the Sannine Formation sites, which were deposited in relatively shallow waters near the shore on the inner continental shelf, Sahel Alma was deposited in a deepwater habitat off the continental slope, at depths estimated to be greater than 150 metres (490 ft), likely at the transition between the sublittoral and bathyal zones in dysphotic or aphotic conditions. This has caused it to preserve a distinct fauna from the Sannine Formation, with a significant number of deepwater arthropods and chondrichthyans.[1][3]
As with the sites of the Sannine Formation, the fossils of Sahel Alma are very well-preserved, and include the soft body parts of cartilaginous fish and cephalopods. Palaeoctopus, the first fossil octopus discovered with preserved soft tissues, was discovered from Sahel Alma.[1]
Sahel Alma is one of the oldest-known fossil sites in Lebanon, second only to the Haqel site of the Sannine Formation. It has been known of since the Seventh Crusade in the 13th century, when bricks quarried out of it were used to build the eponymous Maronite monastery at Sahel Alma. A fossil fish presented to King Louis IX around this time may have been from the site. The site was also likely documented by C. F. Volney during the early 1780s. British adventurer Lady Hester Stanhope settled near Sahel Alma in the early 19th century, and helped to collect and circulate fossils from the site and Haqel. Paul-Émile Botta was also another prolific early researcher of the site.[4]
The site is no longer accessible for scientific research as buildings were constructed over it, due to the purchase of the site by a private company, which restored the Sahel Alma monastery as a hotel.[1][5]