Facebook Twitter LinkedIn Email The story behind the discovery of Grosbeak is told in in GEO 08/2018. The map below illustrates the stuctural location of the Grosbeak discovery (red area) on the Ryggsteinen Ridge on the Horda Plattform. Structural map at the Volgian unconformity. The Grosbeak structural high can be seen dipping into the deep Sogn Graben. © CGG The full line is available in GEO 08/2018.© CGG