Question: Adolf Overweg died in what geological area?

Knowledge 1: Adolf Overweg
In 1849, he joined a 3-man expedition under the command of James Richardson and Heinrich Barth (who later took command after Richardson's death). They set to leave Tripoli in the Spring of 1850 in order to help the British government forge relations with central African kingdoms and explore unknown territory there. They crossed the Sahara carrying a boat on the backs of camels, splitting up in 1851 with Overweg trekking by route of Zinder to Kukawa, rejoining expedition scientist (now leader) Heinrich Barth. After 18 months of exploring the Adamawa Emirate, Benue River, and finally completing his most notable feat of circumnavigating Lake Chad, he died of an unknown illness in Maduari, Chad after swimming in cold waters. [SEP] Knowledge 2: Ngadda River
The Ngadda River is a river in Nigeria that flows into Lake Chad and the Chad Basin. The Alau dam built on the river has interfered with fertile seasonal floodplains in the region of Maiduguri.
Knowledge 1: Adolf Overweg
In 1849, he joined a 3-man expedition under the command of James Richardson and Heinrich Barth (who later took command after Richardson's death). They set to leave Tripoli in the Spring of 1850 in order to help the British government forge relations with central African kingdoms and explore unknown territory there. They crossed the Sahara carrying a boat on the backs of camels, splitting up in 1851 with Overweg trekking by route of Zinder to Kukawa, rejoining expedition scientist (now leader) Heinrich Barth. After 18 months of exploring the Adamawa Emirate, Benue River, and finally completing his most notable feat of circumnavigating Lake Chad, he died of an unknown illness in Maduari, Chad after swimming in cold waters. [SEP] Knowledge 2: Reinhold Hanisch
Reinhold Hanisch (27 January 1884, Grünwald an der Neiße near Gablonz/Neiße, northern Bohemia, Imperial & Royal Austria 2? February (death date controversial) 1937, in Vienna, aged 53) was an Austrian migrant worker and sometime business partner of the young Adolf Hitler. Hanisch, who published articles on Hitler, with whom he had lived in 1910, is, next to August Kubizek, one of the few witnesses to Hitler's Vienna years.
Knowledge 1: Adolf Overweg
In 1849, he joined a 3-man expedition under the command of James Richardson and Heinrich Barth (who later took command after Richardson's death). They set to leave Tripoli in the Spring of 1850 in order to help the British government forge relations with central African kingdoms and explore unknown territory there. They crossed the Sahara carrying a boat on the backs of camels, splitting up in 1851 with Overweg trekking by route of Zinder to Kukawa, rejoining expedition scientist (now leader) Heinrich Barth. After 18 months of exploring the Adamawa Emirate, Benue River, and finally completing his most notable feat of circumnavigating Lake Chad, he died of an unknown illness in Maduari, Chad after swimming in cold waters. [SEP] Knowledge 2: East Prussia
In 1938 the Nazis altered about one-third of the toponyms of the area, eliminating, Germanizing, or simplifying a number of Old Prussian names, as well as those Polish or Lithuanian names originating from colonists and refugees to Prussia during and after the Protestant Reformation. More than 1,500 places were ordered to be renamed by 16 July 1938 following a decree issued by Gauleiter and Oberpräsident Erich Koch and initiated by Adolf Hitler. Many who would not cooperate with the rulers of Nazi Germany were sent to concentration camps and held prisoner there until their death or liberation.

Answer: Chad Basin