Hidden away between Nuttal Park and Gollinrod Gorge is a hidden waterfall, though to get to it you have to follow a narrow stream bed, which can be slippy and wet. You are rewarded with a gem of a spot, where the stream tumbles down in a waterfall over rocks which have a linear strata.
DIFFERENT TYPES OF WATERFALLS
One of the most popular, if least scientific, ways to classify waterfalls is by type. A waterfall's type is simply the way the descends. Most waterfalls fit more than one category.
A block waterfall descends from a wide stream.
A cascade is a waterfall that descends over a series of rock steps.
A cataract is a powerful, even dangerous, waterfall.
A chute is a waterfall in which the stream passage is very narrow, forcing water through at unusually high pressure.
Fan waterfalls are named for their shape. Water spreads out horizontally as it descends.
Frozen waterfalls are just what they sound like. For at least part of the year, the waterfall freezes.
Horsetail waterfalls maintain contact with the hard rock that underlies them.
Multi-step waterfalls are a series of connected waterfalls, each with their own plunge pool.
Plunge waterfalls, unlike horsetail falls, lose contact with the hard rock.
The water flowing over segmented waterfalls separate as distinct streams.
EROSION
Erosion plays an important part in the formation of waterfalls. As a stream flows, it carries sediment that can erode the soft bed rock (limestone and sandstone) underneath. Eventually this cuts deep enough so that only harder rock, such as granite, remains. Waterfalls develop as the granite forms cliffs and ledges.
Waterfalls themselves also contribute to erosion. Stream velocity increases as it nears a waterfall, increasing the amount of erosion. The movement of water at the top of a waterfall can flatten rocks at the edge. The plunge pool at the base gets bigger as rushing water and sediment erodes it and the area behind the waterfall is worn away, creating cave-like shelters.
THE GEOLOGY
The rocks that lie underneath the valleys and hills around Ramsbottom were formed millions of years ago at a time when the whole of what is now the North of England was covered by huge river deltas and lagoons.
We believe that sediments, mainly sands, silts and muds, were eroded from hills in an area that now includes Scandinavia and Greenland and were swept into vast river deltas and lagoons in a central basin in a position now occupied by the Pennines. The sediment settled to the bottom as the water slowed down in the deltas and lagoons. The nearest equivalent sediments of today are forming in huge river deltas such as the Mississippi delta. This sediment built up until it was hundreds of metres thick and was gradually compacted and cemented into the “sedimentary” rocks we know today.
All Ramsbottom's rocks are layered or “stratified”. This is because over the years conditions changed leaving different layers in the sediment. Sometimes the sediment would be mud, whilst at other times it would be sand. There were even times when pebbles were washed down to form a layer of pebbles mixed with sand. The different layers eventually turned into rocks with different properties. Coarse grained sedimentary rocks, perhaps containing pebbles, are known as gritstones, but in the past have been called ‘grits’ leading to the name Millstone Grit; medium grains equal ‘sandstone’; finer grains give rise to ‘siltstones’. The finest grained sedimentary rocks were once mud and are often dark coloured. Formerly known as ‘shale’ they are now referred to as ‘clayrock’. Typically the rock sequence is alternating layers of strong brown sandstones, softer dark shales (clayrock) and occasional gritstones.
Now in order to log this earthcache I ask you to answer some questions, please do not include them in your log:
(1) What type of waterfall do you think this is?
(2) Can you see any erosion, and if so what evidence do you have for this?
(3) What type of stone do you think the face of the waterfall composes of?
(4) What does the stone feel like?
(5) How thick are the layers of strata?