I. Lonne, SEDIMENTOLOGY AND DEPOSITIONAL HISTORY OF AN EARLY HOLOCENE ICE-CONTACT SUBMARINE FAN - THE EGGE-LYNGAS END-MORAINE, SOUTHERN NORWAY, Norsk geologisk tidsskrift, 77(3), 1997, pp. 137-157
The 140-m-thick 'end-moraine' ridge at Egge-Lyngas comprises a lower m
ud overlain by a 100-m-thick gravelly succession representing an ice-c
ontact submarine fan formed around 9800 years BP. Outcrop studies from
the upper 80 m thickness of the fan are discussed, focusing on the fa
n's 3-D architecture. sedimentary facies and processes. Foreset beds o
n the upper slope of the Fan dip up to 22 degrees to the south and are
dominated by ungraded to poorly graded debris-flow beds derived mainl
y from subglacial (till) debris. Few deposits of meltwater outwash ori
gin are found. The middle and lower parts of the fan slope are dominat
ed by cohesionless debris-flow deposits intercalated with turbidites a
nd debris-fall gravel. Scattered blocks of ice-rafted diamicton sugges
t a calving tidewater ice front. Five allostratigraphic units are expo
sed, inferred to have been formed by advance of the ice-front, stillst
and, retreat, followed by readvance with proglacial thrusting, final r
etreat and glacio-isostatic uplift. The initial ice-front advance and
associated fan formation were most likely caused by a climatic deterio
ration. Termination of the fan deposition was caused by retreat of the
ice-front, attributed to the regional climatic amelioration at the en
d of the Late Weichselian glaciation.