Lithostratigraphy and sedimentology across the Cretaceous/Tertiary boundary in the Flyschgosau (Eastern Alps, Austria)

Detailed lithological profiles across the CretaceouslTertiary boundary (KIT) in the tlyschoid Gosau Formation at Gosau (Elendgraben) and Gams (Knappengraben) are presented. The revised low sediment accumulation rates in the lowermost Danian correspond to those calculated by Smit & Hertogen (1980) for the Caravaca section. The estimated longer time-span for the deposition of the KIT boundary layers of 6-11 ka seems to be more realistic. The sediment at the KIT in the Gosau area was deposited under reducing conditions (Reissner el al. 1985). Peak levels of the siderophile elements do not coincide at Gosau and Gams. A diachronism of events is therefore assumed. The gradual decline of CaCO 3 and sorne majar element oxides beginning 4 cm below the K/T boundary and also a 1 mm thin yellow clay !ayer 10 mm underneath the boundary clay at Gams suggest multiple events and could be the result of a period of increased volcanism. el al., 1985). Los niveles de anomalías de los elementos siderófilos no coinciden en Gosau y Gams, por lo que se asume un diacronisrno entre los acontecimientos respectivos. El declive gradual del CaCO 3 y de algunos óxidos principales 4 cm bajo el límite KIT, así corno la presencia de un nivel de arcilla amarilla oscura, de 1 mm de grosor, a 10 mm bajo las arcillas del límite KIT en Garns, podrían ser el resultado de un período de mayor volcanisrno. Palabras clave: Límite Cretácico-Tertiario, Formación Gosau, Alpes Calcáreos del Norte, sucesiones turbidíticas.