Base of the Toarcian Stage of the Lower Jurassic defined by the Global Boundary Stratotype Section and Point (GSSP) at the Peniche section (Portugal)

• 来源期刊: 幕-国际地学杂志（英文版）
• 关键词: Early Jurassic
• 年，卷（期）: 2016,（3）
• 页码范围: 1-22
• 页数: 22页
• 语种: 英文
• DOI: 10.18814/epiiugs/2016/v39i3/99741

摘要

Introduction The Toarcian is the highest stage in the Early Jurassic. D’Orbigny in 1852 designated “étage Toarcien”, from the town of Thouars (Toarcium) (Deux-Sèvres, France), but the boundary Pliensbachian - Toarcian is marked by an important unconformity in this locality, and a big question stands: what is missing at the base of the Toarcian (or at the top of the Pliensbachian)? This well-known problem has prevented easy correlations since the beginning of the use of the Toarcian stage. The lower limit of the stage has to be selected elsewhere.