First of all...BE CAREFUL. This is very uneven ground, and it's slippy when wet.
So, what are we here to look at? Well, up here on Smearsett, we are amongst a limestone pavement. What is a limestone pavement I hear you ask?
Well, the geology of the stone that you see here, is limestone. This was laid down during the Carboniferous period, when a shallow tropical sea existed here. Over time, layers of lime mud and the remains of ancient creatures accumulated as sediment. This sediment over time, was compacted and eventually formed limestone. This limestone was in layers known as strata.
In the below image you can see layers of limestone. The location is Kinsey Cave which is in the local area.
Over millenia, further layers were laid down. Now the land here has been affected by fault action, in that it has been risen up in places, and in other places sunken down. Hence why you can see the scenery that you can see. Then came the ice age, and thick layers of ice known as glaciers moved over the land. As the glaciers moved they stripped away layers of rock, and when the glaciers eventually retreated they left a barren expanse of limestone rock, known as limestone pavement. But that is not the end of the story. Over time, factors such as water and ice eroded the limestone pavement where there were weaknesses in the limestone. This meant that the limestone pavement was now criss crossed with what is known as clints and grykes. Clints are individual blocks of limestone, whilst grykes are fissures going downwards in the limestone. The Craven Dales are renowned for their limestone pavements, and there great examples below Ingleborough near Great Douk Cave, at Thieves Moss near Crummack, and above the Dry Valley near Malham.
Limestone pavement at Scar Close, near Ingleton.
Limestone pavement near Feizor.
In the below image, the grykes are the fissures going downwards, and the clints are the individual blocks of limestone.
Now, not all limestone pavements are alike. Some have expansive clints some which are metres apart, whilst others are like a shattered landscape, with thinner clints. The reason for this is fault action.
So what is a fault?
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement as a result of rock-mass movement. Large faults within the Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes.
Now, here we are in a locality known as the Craven Fault Zone. To the north you will see a low hill, this is where the North Craven fault is. Here we are very near to the Feizor Fault, whilst near the A65 at Buckhow Brow is the South Craven Fault.
We are in what is known as a shatter zone. The fault lines put a lot of stress on the limestone strata here, meaning that the rock in simple terms had a lot of weaknesses and cracks. Also the fault action in places moved the horizontal limestone strata in places, so it was tilted upwards.
Due to this, the water and ice eroded the limestone pavements more in this locality , giving rise to a much more chaotic and shattered looking limestone pavement.
This being an EarthCache, in order to log it, I ask that you answer some questions. Please send them to me, and do not include them in your log. You can send them to me by using the message facility or email, both of which can be found by looking at my profile.
1. Please measure the width of the widest and thinnest clint here.
2. Please tell me what direction that the clints are aligned.
3. What has caused the limestone pavement here to appear as it does?