Issaouane Erg with foreign assistance, including from Korea and Spain (Repsol signed an agreement to invest and explore in 1990). The oilfield has been in production since late 1998. Issaouane Erg The Issaouane Erg (also called Issaouane-N-Irrararene) is an approximately 38,000 km erg (sand sea) in Algeria's portion of the Sahara desert, located at . The Issaouane Erg is located near the Ahaggar Mountains. It is part of a major dune field that extends from Issaouane Erg in the north to the Sudanese Erg in the south, flanked by the Libyan erg of Murzuq. In the north, the Issaouane Erg ends at
What Love Is Made Of extremely positive about "What Love Is Made Of", describing it as "darker than anything" from "On a Mission", while calling it "slinky". The reviewer went on to commend the "irresistibly pouty" chorus. Pitchfork Media's Katherine St. Asaph commented that, in the song, the singer "sound[ed] completely enthralled, by either her lover or the music" and complimented her voice, noting that it seemed "ten times bigger than before". Jordan Sargent of "Spin" magazine called the track "exuberant" and highlighted Katy's vocal performance, which he deemed "typically fantastic", while the team from pop music website Popjustice gave "What Love Is Made Of"