This Earthcache was once part of a series, but is now the lone survivor. There is plenty of parking nearby, and picnic tables at this location. Although the rest of the series of physical caches is gone, we hope you still enjoy the wee walk around the bay and the gorgeous views of Strangford Lough. In order to log this cache, you must answer the questions found at the bottom of this listing. Have fun, and many thanks for taking part. Go ahead and log your find, and we will contact you if there are any problems with your answers.
At GZ you are standing on the shore of the southern part of Strangford Lough.
Strangford Lough is a large sea loch or inlet. (the largest in the British Isles) It is almost totally enclosed by the Ards Peninsula and is linked to the Irish Sea by a long narrow channel that runs between the towns of Strangford and Portaferry. It is well worth taking a trip across the channel on the car ferry that runs regularly between the towns.
The main body of the Lough has at least 70 islands and many islets, known as pladdies, and bays, inlets, coves and headlands, spread over its 58 square miles (150sqkm)
The area is in County Down, a county that is covered in evidence of glacial activity, including many Drumlins and Moraines.
Drumlins
A Drumlin (from the Irish word droimnín) is an elongated hill in the shape of an inverted spoon or half buried egg, formed by glacial ice acting on underlying unconsolidated till or ground moraine. Because of the nature of Drumlins, the appearance of much of County Down can be described as ‘Basket of Eggs Topography’. Sometimes over geological time, as sea levels rise, areas get flooded and Drumlins can survive as small islands or islets. Drumlins tend to be bullet shaped, with the long axis indicating the direction of the ice flow, and the highest part of the drumlin being 'upstream' and the lower, tapered end being 'downstream'.
Moraines
A moraine is a mass of rocks and sediment carried down and deposited by a glacier, typically as ridges at its edges or extremity. These are typically harder to spot than the distinctively shaped Drumlin. To get an idea of how and why moraines are formed, think of yourself with a toy bulldozer on a lawn covered in dry leaves. When the bulldozer goes through the leaves, some get pushed aside, some get pushed forward, and when the bulldozer stops, you are left with long lines of leaves in the direction the bulldozer travelled, and a line of leaves the width of the bulldozer at 90deg to the bulldozer’s direction. Now think of the bulldozer as a glacier and the leaves as soil and rock. You can now think of these lines as moraines (lateral and terminal) stretching for miles across the countryside.
Q1. Look at the information board in front of you, and identify the feature described as Town Rock Light. To the south east, and shown on a photograph on the information board, is Jackdaw Island. Is this island a Drumlin or a Moraine?
Q2. In what direction was the ice flow when the material was deposited to form the island?
Q3. What material is the island made of?
Q4. To the north east of GZ, you can see Dunnyneill Island - it is actually two islets joined by a causeway, but this can't be seen from GZ. Excavations on the island have shown that it was used in the 7th Century as a major trading centre. The island is roughly opposite #1 in this series Run Every Day in May. Make a rough calculation of the distance between the Town Rock Light in front of you and Dunnyneill Island.
Q5. (Optional task) Take a photograph of your party or your GPS with Jackdaw Island in the background.