Entitled "The origin and growth of a ripple mark
", it documented her work on sand ripples and vortices in water.
And, at the fossil trench at Marsh's Quarry, on Wren's Nest, you can still see the ripple marks
made by the waves on the ancient sea bed of our own Atlantis.
The sandstone is mainly composed of thin to thick bedded, gray to whitish gray to brown sandstone that is fine to medium grained and displays some laminations, ripple marks
, flat beds and cross beds at places.
, associated with the hardground in the Vasalemma quarry, were described in detail by Hints & Miidel (2008).
Above the basal conglomerate of the Tapeats, the rest of the formation is composed of sand about 200 feet thick, with bedding containing sedimentary structures typical of tidal flat, beach, and shallow-shore environments that include ripple marks
, mud cracks, and raindrop prints (Fig.
On a day the ocean was so smooth not even a ripple marked
the location of the Umpqua River bar, the Roelles boated five salmon and a mess of dungeness crab in five hours at sea.
These rocks, which contain mud cracks, ripple marks
, and terrestrial plant debris, suggest deposition in a shallow, marginal sea with alternate desiccation and stream floodwater input.
on the sandstone indicate the creature was struggling to swim against a current.
left by the sea can still be seen in the sandstone on the summit of Pen y Fan.
Most of us admit that our very best pictures of rocks were achieved by surreptitiously pointing our cameras over his shoulder when he had carefully selected the right angle to catch the shadows on a mountain range or on a row of ripple marks
. Our printed products were good but never as good as the Master's.
Fossilised ripple marks
in sand formed by water currents are preserved at Black Pastures Quarry, near Chollerford, where even the casts created by burrowing worms 325 million years ago can be seen.
At the bottom of the steps leading up to the jubilee tower at Castle Hill look for the ripple marks
still visible on the paving stones.