Birker Fell facts for kids
Birker Fell, also known as Birker Moor, is a wild, open area in the western part of the Lake District National Park in Cumbria, England. It's not just one tall mountain. Instead, it's a wide, wavy landscape about 6 kilometers (about 3.7 miles) across. You'll find many rocky cliffs and hills scattered all over. The highest point is Green Crag, which is 489 meters (about 1,604 feet) high.
The fell is surrounded by other interesting places. To the south-east is the Duddon Valley. To the south-west is Ulpha Fell. Harter Fell is to the north-east, and Eskdale is to the north-west.
Only one tiny village, Birkerthwaite, sits in a shallow valley near the middle of the fell. Other than that, you'll only see a few scattered farms. A road crosses Birker Fell, connecting Eskdale Green and Ulpha in the Duddon Valley.
Exploring Birker Fell's Landscape
Besides Green Crag, Birker Fell has many other interesting high points. These include Crook Crag (469m), White How (444m), and Great Worm Crag (427m). There are also Iron Crag (408m), Kepple Crag (328m), and Great Crag (323m). Other notable spots are Rough Crag (319m), Water Crag (305m), and Brantrake Crags (259m).
Between these higher points, you'll find lots of smaller rocky outcrops and little hills. These are separated by shallow valleys and wet, boggy areas. This makes the high parts of the fell look very uneven and wild.
Water is a very important part of Birker Fell's look and feel. Many small streams flow between the rocky areas. These streams are called becks or gills by local people. Many of these streams start in one of the many boggy areas. The biggest bogs include White Moss, Sike Moss, Tewitt Moss, and Foxbield Moss.
At the western edge of the fell is Devoke Water. This is the largest tarn in the Lake District. A tarn is a small mountain lake. Devoke Water sits 235 meters (about 770 feet) above sea level. It is about 1 kilometer (0.6 miles) long and 0.4 kilometers (0.25 miles) wide.
The southern border of Birker Fell follows a line from Devoke Water to the valley of Crosby Gill. Crosby Gill is a large stream that flows down the southern side of the fell. It eventually reaches the village of Ulpha in the Duddon Valley. The northern edge of the fell has steep cliffs that drop sharply into Eskdale. These cliffs are home to the beautiful waterfalls of Stanley Force and Birker Force. These are two of the most amazing waterfalls in the Lake District.
The Amazing Geology of Birker Fell
Birker Fell is very important for understanding the Earth's history. It is the main place where scientists study the Birker Fell Formation (BFF). This formation is part of the Borrowdale Volcanic Group (BVG). The BFF is the oldest part of these famous volcanic rocks.
The Birker Fell Andesite is a type of volcanic rock found all over the western Lake District. Scientists believe the BVG rocks formed a very long time ago, during the early Ordovician period. This was when volcanoes erupted on an "island arc." An island arc is a chain of volcanoes that forms above a subduction zone. This happens when one of the Earth's tectonic plates slides under another. This process was happening as the ancient Iapetus Ocean was closing.
The central and northern parts of Birker Fell are mostly made of layers of andesite lava. Within these lava layers, there's a special layer called the Great Whinscale Dacite lava flow. Below it is the Little Stand Tuff. Tuff is a rock made from volcanic ash. These layers form a marker band that crosses the fell from northeast to southwest. You can see them best at Silver How and Great Whinscale.
About 1 kilometer (0.6 miles) north of Birkerthwaite, you can find a small area of basalt rock. Basalt is another type of volcanic rock. This area is made of different kinds of andesite-basalt lavas and tuffs. The main area for some of these rocks is actually to the south-west of Devoke Water, on Ulpha Fell.
The southern and south-eastern parts of the fell are made of layers of tuff. These tuffs have many different compositions, from rhyolitic (light-colored, silica-rich) to basaltic. These layers sit on top of the Birker Fell Formation. They form the next part of the Borrowdale Volcanic Group.
In the north-western corner of Birker Fell, there are many faults. Faults are cracks in the Earth's crust where rocks have moved. These faults have pushed the volcanic rocks of the BVG next to the granite rocks. These granite rocks formed from the Eskdale Intrusion in the late Ordovician period.
