Petrographical,petrochemical and geochemical data show that the lavas of Byers Peninsula and Cape Shirreff and the dolerite at Siddons Point belong to calc alkaline series and with the characters of lower potassium and magnesium.

• 岩石化学和地球化学资料表明，百耳斯半岛熔岩、史莱夫角的橄榄玄武岩和西多斯角的粗玄岩等白垩纪火山岩基本属于钙碱性岩系并且具有低钾低镁的特点。