MEASUREMENT OF CHALK DISCONTINUITY IN PEACEHAVEN CLIFF
In Peacehaven the Chalk discontinuities are really of import in drop and foreshore stableness, ( Lord et al, 2002 ) . Discontinuities and breaks are favorable for accretion of H2O though they appear in different format sometimes creates assorted technology uncertainnesss. This study high spots on the stone stableness and possible failure of Peacehaven Friars Bay, ( from appendix 1 ) outlines the measurings of different discontinuities across the perpendicular scan line with the usage of normal clinometers to buttress this fact.
Geology of Peacehaven Cliff ( Friars Bay )
Most of the down land countries of Sothern England comprises of Chalks ( Lord et al, 2002 ) , these Chalks are made up of series of cocolith ( planktonic algae ) and biomicrities micro-porous Limestone of approximately 425 m in thickness ( Young and Lake, 1988 ) . Friars Bay drop of Peacehaven consists of an outcrop of Chalk between 80 million old ages during cretaceous era of campanians era ( Brenchley and Rawson, 2006 ) .
The Different Types of Discontinuities in the chalk
Discontinuities in Chalks are of major importance in the technology field ; manner of discontinuities, frequence, and aperture and weathering ( Lord et al, 2002 ) .
Types of discontinuities in Friars Bay drop ( Ref: Appendix 1 ) ;
1 Fracture caused by enduring
At the top bed below the top dirt is a 10m of tremendous fractured Chalk which decreases and reduced the characteristics of the Chalk. Such fractured characteristics are fundamentally from mechanical weathering ; hoar and roots from workss, ( Lord et al, 2002 ) .
2 Marl seams and Bedding planes
Bedding planes are of horizontal or inclined characteristics within 5 grades in way of the North in this subdivision. Nodular flints are more condensed around the confines of the bedclothes plane which are of pebble and cobble dimensions. Marl seams of different thickness of about 20 centimeters are present in topographic points of really tight aperture, though some marl seams have gaps and are called griotte.
3 Inclined articulation
Inclined articulations are located within the bedding planes of about 40-50 centimeter tight in aperture ; its disposition is about 40-65 grade.
4 Conjugate articulation
Conjugate solution articulations are tremendous around this drop ; it has more than 500 cm cutting in the bedclothes planes. These articulations are 65 degree with different waies, due to formation of conjugate articulation. These articulations have gaps with unsmooth surface that has spots of clay and Chalk grain Brescia.
The way of the drop face is in a location of 098 to the way of E with a dip scope of about 5 grade. The bedding planes of the dip way are in opposite way to the drop face, the dip way are with low grades of approximately 4 to 5 demoing that there are no failure possibilities caused by bedding planes. The griotte Marl and joint shows that slope way are in same way of dip to the drop face with less grade due to skid in the Chalk in the way of the drop face, though this phenomenon which is the intersection of joint plane organizing conjugate cuneus failures to the way of cliff face, can make an abnormalcy in the graduated table due to the little distance of griotte Marl and joint that reaches up to about 50cm.
From the information collected, it is clear to demo the different discontinuities in the Chalk some of which culminate to failure in different graduated tables. The conjugate cuneus failure is the highest possible to happen, besides the slickenside highlights the same chance in the drop face. There will be jobs in the hereafter particularly for the dwellers near to the top drop of the extremely weather-beaten Chalk ; marks of top dirt have oning out. Measures should be taken to turn to the dangers it posses.
BRENCHLEY, P. J. , P. F. RAWSON. ( 2006 ) The Geology of England and Wales.
The Geological Society, London.
LORD, A. J. , MORTIMORE, R. N. ( 2002 ) Engineering in Chalk, London, CIRIA.
YOUNG, B. , LAKE, R. D. ( 1988 ) Geology of the Country around Brighton and
Worthing. British Geological Survey London, Crown.