The River Wharfe is a dominant feature in the local area, and rises and lowers depending on the amount of rain that there is. When it is in spate, it can be an sight that is an awe to watch. The while of the valley has been shaped by the action of the river. If you take time to look at the valley bottom, it tends to be flat with level fields, or a gentle incline down to the river. Once at the river, there is a steep bank on either side which contains the river. The geomorphology that can be seen today was shaped at the end of the last ice age, known an the Quartenary Period. The area was at first covered by a thick ice sheet, which gradually retrated northwards. As the ice sheet melted, a glacial river flowed down the valley. This river was much wider and deeper than the river we see today, a thundering torrent of ice cold water carrying with it a vast amount of sediment. As time progressed, the river level dropped, sediment was laid down into what is known as a fluvial landscape.
if you look at the valley, there is evidence of that time.
So what is there here? You are stood on a footpath looking over to Ilkley Moor. Immediatley behind you there is a bank, this is what is known as a fluvial terrace.
Fluvial terraces are past evidence of a floodplain. During the end of the Quartenary period, the river channel cut into the landscape and caused lateral erosion of the landscape, this formed a bank, like what can be seen today next to the river. As the river level dropped, the sediment was deposited, and that is why you can see a gently slopping field which leads down to the current course of the river. Fluvial terraces tend to have a steep terrace, which is bordered by a flattened area. if we stripped back the flora and fauna of the valley we may notice a stepped appearance of fluvial terraces as water levels dropped.
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. It is not meant to be difficult to do.
1. How high is the fluvial terrace?
2. What is its angle of slope?
3. What direction is the fluvial terrance alligned along (i.e north, south, east or west)?