A Spring Walk at Yesnaby
submitted by Ian Thain
submitted by Ian Thain
This is a tour rather than a walk. The distance travelled is around 6 kilometres. If you get a reasonable day, this walk is as good as it gets. The ideal time for this walk is from late April onwards when there is a chance of the first flush of Primula Scoticae.
Allow two and a half to three and a half hours depending on the interest and the weather. For the purist, one and a half hours without any long stops is the calculation.
At this time of year I would recommend that boots should be worn. As far as early walks are concerned, this is about as dry as it gets in Orkney.
There is much of interest to the geologist in this walk, and the details are given as notes at each point.
As you can see from the map, this walk starts at HY 221161 at the Yesnaby Car Park. See Note 1
Move in a southerly direction down the track until you come to GR HY221157.
HY221157 The Noust of Bigging - this is also a wonderful area of seabird activity, especially Eider Ducks and their habitats. It is also dramatic in westerly gales and good for a photoshoot. Continue roughly south and cross a burn that flows into the noust by a bridge (New). See Note 2
Turn right and follow the fence line until you get to HY220153. The path is now much improved.
HY220153 Boulder Field and extreme surface erosion - due to severe gales, rocks are thrown for more than a hundred feet in the air and impact on the top destroying the cohesion of the surface and accelerating erosion. In this same area near the fence there appears to be a millstone or half a millstone. Its purpose is not obvious but I have seen similar in Europe for oil extraction from various plants and olives. This is also an area of fine clay in varying colours, near the Burn of Langadee.
Continue south although slightly uphill towards the gate at HY221152.
HY221152 Gate to the West Maritime Heath and the Yesnaby Granitic Uplift - the approach to the gate is a fine grassy area where you have a good view of the Stack of Yesnaby from quite close and in the same area a large piece of rock that appears to have no visible means of support. The stack from time to time is climbed by enthusiasts who often leave their ropes on the stack. See Note 3
In the breeding season, I am normally met by my friends the Arctic Skuas just clear of this area, therefore it never comes as a surprise.
Continue southwest for a little until GR HY220151
HY220151 Viewpoint looking northwards and southwards - from this position you can see fine views of the west maritime heath north and south. The Orkney northern headland is majestic, and from this point it is a matter of wonder that the Yesnaby Stack is still standing, and the false bedding of the sandstone layers is most evident. At this point I must mention that there are many paths, and care must be exercised, because some are made by sheep, and go perilously close to the cliff edge which is often difficult to define.
We will continue roughly southwest to HY 198148 to an unusual area visited by many Geologists.
HY198148 Harra Ebb - Geologists favourite area. Some care has to be taken when you visit this area. It is not terribly dangerous but some time must be spent on finding the best path to suit your requirement. If in doubt, avoid it and carry on down the heath following a south easterly direction until you reach the large Geo that points westward at HY220143. See Note 4
HY220143 Geo of Inganess - this is a magnificent geo of considerable size. It is dark because it is north facing, and higher at the south side. There are several large caves here, and at times they can be difficult to see. At nesting time there is a wonderful cacophony of sounds that seem to be amplified by the geo itself. In springtime proper, there is a multitude of lovely small flowers in the short grass. This is a lovely place to waste time but we must continue southwards to HY221141.
HY221141 Burn of Uppadee North Bank - when you approach this area from the geo, a fence and a gate is visible to the front, but before that is the Burn of Uppadee. Do not cross the burn but turn left and stay on the upper bank (Roughly Southeast) keep moving along the bank of the burn uphill until you reach HY224140.
HY224140 Burn of Uppadee Bridge and deep area - this deepening of the burn is not natural and is man made. I have observed this pool sometime in the past, and I saw some strange aquatic forms I had never seen before in Orkney. In particular, there was a flat white wormlike object. Its appearance is hard to define since it was easily disturbed but was five to six inches long and moved very slowly. This is a point where the fence intersects the burn.
Keep moving in a north easterly direction and cross a stile at HY225139 and continue roughly northeast. Follow the fence line and a few hundred metres from the stile you can pick up an old track that goes parallel with the Burn of Sowadee, but do not cross the burn until you see a small hut with a chimney at HY231145. Cross at the hut.
HY231145 The Sauna - at first glance it is difficult to imagine what it is. On closer inspection the Sauna is well designed, and well sited. It is very difficult to see, and the burn adjacent to it would make an excellent plunging pool. It was built by an Orkney resident and at one time had a Bible in it, and religious German inscriptions on the wall. It appeared to be much used. It is not only a good site for a Sauna, but a good site for a picnic and I would recommend it for a break if you are having one. Recently it has fallen into neglect but some restoration work has been done.
HY231145 Leaving the Sauna Site - cross the burn to the other side where you entered, and move in a westerly direction but maintain your height. Do not go into the valley as it can be very wet. You will enter what appears to be a green meadow just below The Stany Knowe. Carry on and you will see a fence with a gate. Sometimes you have to climb it at the hinged side. It is better to try and get through the gate. Follow the fence line roughly westward until you come to the gate into the maritime heath that you went through earlier at HY221152.
HY221152 Maritime Heath Gate - continue northwards back to the car park by retracing your former route. The car park and vehicles can be easily seen from this point to the Yesnaby brick buildingsat the car park at HY221161.
Note 1 The Yesnaby Car Park - this is the start point of the walk, but since you are at Yesnaby, the area at the car park going towards the edge is fascinating. Geology and Yesnaby are synonymous. Where else can you find the evidence that this area was once near the equator over 300 Million Years ago? Among the sandstone breakup in this area you can easily find Sand Cracking, Sand Rippling and Pseudomorphs. A geologic dyke is obvious about forty metres to the North with a great deal of evidence of metamorphosis. In this area exists what I believe to be the rarest sight of all - a Stromatolite. These are extremely rare on earth. The Orkney type appears to be advanced algae like tangle roots. The action of trapping sedimentary grains by micro-organisms caused the sediment to have similar shape and dimensions to the algae host. In time the organism disappeared and only the sediment remained and fossilised in the shape of the host. This was much earlier than the Devonian period. Greater than 600 Million years ago.
Note 2 HY221157 - The Noust of Bigging - this is a small bay with a rocky outcrop. Nothing unusual about it, except that the rock is metamorphic in the middle of sedimentary sandstone. No theories have been accepted so far for this occurrence. This Yesnaby area was an area of intense volcanic activity.
Note 3 HY221152 - Gate to the West Maritime Heath and the Yesnaby Granitic Uplift - like everything in this area, the sandstone is different. It is called false or cross bedding, and is abnormal. Most sandstone layers are parallel to each other both above and below. In false bedding, the layers are not parallel, either above or below a given layer and this was caused by the formation of sand dunes in the Devonian period. When you cross through the gate and turn right along the shore (Southwest) the grassland is replaced by a granitic area measuring just over 200 metres in a rough circle. The other two areas are Brinkies Brae in Stromness and a tinyl granitic area in Graemsey.
Note 4 HY198148 Harra Ebb – the geologists favourite area - this is an area with a strange mixture of volcanic activity, where sandstone and a rough granite blend together, and at low tide many beautiful rock pools. It is an intensely complicated rock structure that pokes into the sea.