Worlds End State Park - Geology, Fossils, and Climate

Geology, Fossils, and Climate

The land on which Worlds End State Park sits has undergone tremendous change over the last 350 million years. It was once part of the coastline of a shallow sea that covered a great portion of what is now North America. The high mountains to the east of the sea gradually eroded, causing a build up of sediment made up primarily of clay, sand and gravel. Tremendous pressure on the sediment caused the formation of the rocks that are found today in the Loyalsock Creek drainage basin: sandstone, shale, conglomerates, coal, and limestone.

Four major rock formations are present in Worlds End State Park, all at least partly from the Carboniferous period. The youngest of these, which forms the highest points in the park, is the early Pennsylvanian Pottsville Formation, a gray conglomerate that may contain sandstone, siltstone, and shale, as well as anthracite coal. The Loyalsock gorge rim and the upper part of its walls are the late Mississippian Mauch Chunk Formation, which is formed with grayish-red shale, siltstone, sandstone, and conglomerate. Below this is the Mississippian Burgoon Formation, which comprises buff-colored sandstone and conglomerate. The creek bed and base of the gorge walls are the late Devonian and early Mississippian Huntley Mountain Formation, which is made of relatively soft grayish-red shale and olive-gray sandstone.

The park is at an elevation of 1,175 feet (358 m) on the Allegheny Plateau, which formed in the Alleghenian orogeny some 300 million years ago, when Gondwana (specifically what became Africa) and what became North America collided, forming Pangaea. The local region is known as the Endless Mountains, but despite the name these are not true mountains: instead millions of years of erosion have made this a dissected plateau, causing the "mountainous" terrain seen today. The hardest of the ancient rocks are on top of the ridges, while the softer rocks eroded away forming the valleys: the Loyalsock gorge is approximately 800 feet (244 m) deep in the park. Loyalsock Creek and its tributaries have been a primary force in the creation of the valleys, as the creek makes its way across the landscape to its mouth at the West Branch Susquehanna River in Montoursville.

Fossils have been found in Worlds End State Park, as the area was once a river delta on an ancient coastline. This coast was home to an ancient ancestor of the lungfish, which would burrow in the mud to survive dry spells. Fossils of these burrows have been discovered in the red siltstone formations in and near the park.

The Allegheny Plateau has a continental climate, with occasional severe low temperatures in winter and average daily temperature ranges of 20 °F (11 °C) in winter and 26 °F (14 °C) in summer. For the region the park is in, the average minimum temperature in January is 10 °F (−12 °C), while the average maximum temperature in July is 75 °F (24 °C). The mean annual precipitation for Loyalsock Creek is 42 to 48 inches (1067 to 1219 mm). Pennsylvania receives the most acid rain of any state in the United States. Because Loyalsock Creek is in a sandstone, shale, conglomerates, coal, and limestone mountain region, it has a relatively low capacity to neutralize added acid. This makes it especially vulnerable to increased acidification from acid rain, which poses a threat to the long-term health of the plants and animals in the creek. The highest recorded temperature at the park was 104 °F (40 °C) in 1936, and the record low was −27 °F (−33 °C) in 1994. On average, July is the hottest month at Worlds End, January is the coldest, and June the wettest.