Tidally Laminated Sediments

Preston martin 1 miguel a.

Tidally laminated sediments.

Lamina that occurs in sedimentary rocks laminae are normally smaller and less pronounced than bedding lamination is often regarded as planar structures one centimetre or less in thickness whereas bedding layers are greater than one centimetre. Laminated glacimarine sediments form by a variety of processes including suspension settling from turbid overflow plumes turbidity current deposition and contour current activity. Published 31 january 2008. At d2 non cohesive sediment and b4 d1 cohesive sediment the critical shear stresses for seabed erosion or resuspension were estimated to be 0 11 and 0 07 0 09 n m 2 respectively.

In general the glen eyrie tidalite is similar to other carboniferous tidalites because the laminated sequence directly overlies a coal is well laminated directly above the coal and becomes more bioturbated and possesses more fine scale erosional features beginning several meters above the coal. Gon i 2 and john s. Although this result is reasonable when only the three sites are compared both values are lower than predicted by existing threshold models with a. Subglacial deformation of pre existing sediments may also produce laminated deposits in the form of glacitectonite and deformation till.

A tidally averaged sediment transport model of san francisco bay was incorporated into a tidally averaged salinity box model previously developed and calibrated using salinity a conservative tracer uncles and peterson 1995. Tk s rs sediments from the kap stewart formation in scoresby land are described and interpreted as tidally in d j fluenced detaic deposits. A horizontally laminated black mudstone followed by flaser or lenticularly bedded sandy mudstone and erosively overlain by cross bedded channel sandstone. Revised 3 march 2007.

Sediment delivery from the fly river tidally dominated delta to the nearshore marine environment and the impact of el nin o andrea s. However structures from several millimetres to many centimetres. Two major types of sequences can by destinguished. The bay is represented in the model by 50 segments composed of two layers.

Accepted 25 may 2007.