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Photos from Pinhay Bay, Dorset

These are a few photos from a visit in Winter 2006

Looking East towards Seven Rock Point. The Blue Lias Formation can be seen in the cliffs extending from left to right. At the base of the cliff to the left can just be seen the Langport Member of the Lilstock Formation which appears lighter in colour. The Triassic/ Jurassic boundary is generally taken as being a few metres above the Lilstock Formation. Further East is Lyme Regis.

Looking East towards Seven Rock Point.

The next photo shows the Langport member of the Lilstock Formation. The darker shales and bands of limestone above are the Pre-Planorbis beds of the Lias. For scale, the thickest bed near the base of the cliff is just over a metre deep. On this part of the coast the Langport member is a lot more well developed than in the Somerset and Gloucestershire coastal outcrops. The bed forming the top of the Langport member is called the Sun Bed, due to apparent dessication cracking. This has been used, along with other evidence, to suggest a fall in relative sea level prior to onset of the fully marine conditions.

The Langport Member at Beach level.

This one is a closer view of that thicker bed refered to above. The Langport Member contains a number of features that suggest disturbance of the sediments, including the break up of lithified material to be reincorporated in newly deposited beds as the small pebbles are in this photo. I've read that this could indicate debris flows induced by tectonic activity.

The thicker bed.

Beach level, and the lower portion of the Langport member which is around 8m thick at this location. Deformation of the once soft sediments can be seen.

The lower part of the Langport Member.

2006