Resumen de Datos bioestratigráficos de los materiales silúricos del Sinclinal de Herrera del Duque (Badajoz)

Agustín Pieren Pidal, Juan Carlos Gutiérrez Marco

• The Silurian sequence in the Herrera de/ Duque syncline (Southern Centra/ Iberian zone) starts with 20 m. of black shales (Guadarranquejo Formation) which lay disconformably upon the Hirnantian diamictites (Gualija Formation). Within the black shales, eight graptolite horizons have been recorded (A-H) and two (1-1) at the base of the overlying sandy alternances. A Telychian (post-Turriculatus Zone) age for the Guadarranquejo Formation has been suggested, the Llandovery/Wen/ock boundary lying probably near its top