Wave-dominated shelf deposits in the Anchorage Formation (late Jurassic), Byers Peninsula, Livingston Island

Abstract:

The oldest rocks cropping out in Byers Peninsula are found along coastal cliffs and surrounding hills, 1.5 km NW of Ocoa Point, and were defined as Anchorage Formation, Byers Group, by CRAME et al (1993). Its age is well constrained (Kimmeridgian-Tithonian, Late Jurassic). The section is incomplete, bounded by faults, and from base to top, it consists of grey siltstones with millimetric-centimetric graded ash and volcanic fragments beds, alternations of greywackes with parallel lamination and Hummocky Cross-Stratification (HCS) and grey, bioturbated siltstones, amalgamated beds of sandstones with HCS, and massive or tabular sandstone beds with Inoceramus, fish-markings, pyritized wood remains and bioturbated levels. PIRRIE and CRAME (1995) interpreted these deposits as deep marine sediments, deposited at 1000 or more meters below sea-level, but the internal sedimentary structures and vertical succession of beds indicate sedimentation in a wave-dominated outer shelf evolving towards an inner shelf with shoreface bars.

Año de publicación:

1997

Keywords:

Fuente:

scopus