- Travel and Places
Delaware Water Gap
New, Green Pennsylvania Welcome Center at Delaware Water Gap
The new, state-of-the-art Interstate 80 Pennsylvania Welcome Center in the Delaware Water Gap now provides a grand first impression to the Commonwealth of Pennsylvania. The facility's environment-friendly green design brings unique features to the structure and will also save energy and cut operating costs, part of the Commonwealth's goal to reduce energy costs by 15 percent in 2007.
From the welcoming courtyard to the impressive granite surfaces, geothermal heating and cooling to a roof-top gardens and picnic areas, and even a fenced in pet walk area, this new 12, 721 square-foot Welcome Center designed by Maria C. Romanach Architects of Philadelphia, is unlike any other in Pennsylvania or in the nation.
The only fault I found with the Center is it's location which does not provide a view of the scenic and historic Delaware Water Gap on the Delaware River.
How the Delaware Water Gap Formed
WHAT IS A WATER GAP?
Several words in English denote a "break" or "cleft" in the mountains. Chasm and notch are popular in New England; pass and gorge in the South and west of the United States. Gap is especially common in this part of the country.
A gap or wind gap is a break or pass through the mountains, in this case the Appalachian Mountains. a water gap is a pass that a river runs through.
The Delaware water gap is justly famous for its depth, width and scenic beauty. The Gap is a mile wide from New Jersey's Mount Tammany (1527 feet) to Pennsylvania's Mount Minsi (1463 feet). The Gap is about 1,200 feet deep from the tops of these mountains to the surface of the river, which at this point is 290 feet above sea level. The maximum depth of the river at the Gap is about 55 feet.
HOW DOES A GAP FORM?
Geology is the study of the earth's formation. Though the geologist's time frame may seem vast and remove, the results of geological processes are the mountains we hike on, the river we swim in, and the scenery we admire.
Starting with the Native American legend, there have been many ideas about how the Delaware Water Gap formed. One current theory explains the Gap through a series of processes: continental shift (involving plate tectonics), mountain building (orogeny), erosion, and the "capturing " of rivers and streams. This last process of "capturing" is further explained below.
The capturing story begins 420 million years ago when the ancestral continents of North America and Africa collided. The impact caused the earth's crust to rise and mountains to form, including the ancestral Appalachian range, tens of miles east of today's Gap. Streams flowing westward off these mountains eroded their slopes, carrying sand and pebbles west and depositing them in layers. These layers later compacted into erosion-reisitant gray sandstone and "conglomerate" rock called the Shawangunk Formation. This rock is the dominant feature of the ridges on either side of the Delaware River today.
Over millions of years, many different kinds of rock were laid down on top of the Shawangunk Formation. About 290 million years ago, in an era of mountain building, further pressures crumpled and folded the layers of rock in the area of today's Gap. These layers eroded at different rates: softer limestones and shales eroded more quickly into valleys, while harder sandstone and conglomerate rock remained as mountains like Kittatinny Ridge. Now the "mountain" part of today's gap was essentially in place.
THE GEOLOGY OF THE DELAWARE WATER GAP
A FEW MILLION YEARS AGO (a geological yesterday!) there was a river whose headwaters were around present-day Trenton, and which flowed from there south to the sea. North of Kittantinny Ridge, near today's Water Gap, streams flowed into a second river, which flowed southwest.
Over time, the headwaters of the first river eroded their way north to the area of the Gap. Finding a fault in the rock--probably only a small cleft or fracture--the headwaters worked their way through to the north side. There they "captured the flow of the streams and river on the north side of the ridge, making their water flow through the Gap.
Cherry Creek may represent the abandoned bed of the "captured" river. However, at the time the creek "turned around" to flow into the river, the surface of the Delaware River was hundreds of feet higher than it is today. Over time, the cleft in the ridge eroded further from wind, rain and the constant scraping of sand and rock carried by the river. A water gap was taking shape.
Near the recreation area are several other gaps whose formation is related to that of Delaware Water Gap. At one time, rivers may have run through these gaps also, and it is possible that the Delaware River has "captured" the rivers in these other gaps as well. When these gaps "dried," the erosive action of the river stopped, and most of these gaps are jmuch higher (less eroded) than the Water g"ap. At the Water Gap the Delaware River continues to cut into the mountains to the present day. So, when you stop to admire the scenery at the Delaware Water Gap, you are also watching the Water Gap continue to form.
While in the area, look on maps and signs for other gaps. Culver's Gaps near Newton NJ, and Totts Gap and Foxtown Gap PA at the south end of the recreation area are three gaps nearby. To the southwest, along other ridges of the Appalachian Range are the towns of Wind Gap and Little Gap PA, and west of Philadelphia near Rt. 30 is a town named simply Gap.
[From National Park Service Pamphlet on the Delaware Water Gap National Recreation Area.]