A geological trip through Chickies Rock in Lancaster County
As you might have learned by now, I strongly encourage folks to investigate local history and geology. As I teach my students, you can read all the geology textbooks you want, but to really understand what the Earth is doing, the best teaching method is go out and look at it. If I had it my way, I would have geology students on a field trip every week for our laboratory exercises.
If you want to explore an area full of sights, go to Chickies Rock County Park on the east side of the Susquehanna River just north of Columbia.
Near the top of the hill on Route 441, turn left into the Breezyview Overlook parking area. If possible, take a second car further north on Route 441 to the base of Chickies Ridge near Chickies Creek and park a car in the pull-off area on the west side of the road. Otherwise, you will have to retrace your steps back to Breezyview after reaching the north face of Chickies Rock.
After exiting your car, walk to the wooden fence toward the river for a spectacular view of what is believed to be the second oldest-river in the United States. Depending upon the water level, you may see areas of calm water and some areas with rapids. The rapids are there because of harder, slightly more resistant rocks compared to the calm water, which are underlain with soft rocks that have been eroded over thousands or even millions of years.
Look across the river to the York County side. Starting near the west side of the Route 30 bridge and scanning to the right (north), you will notice that the topography gently increases. Again, the resistance of the rock reflects our landscape. Soft rocks erode faster, creating valleys, and the harder rocks underlie the higher elevations. In this view, limestone underlies the valley near the bridge (known as the York Valley). The first small ridge to the north is composed of sandstone; next, a wider ridge composed of the metamorphic rock phyllite; and finally, higher elevations composed of quartzite.
Okay, enough looking at landscaping. It’s time for the one-mile hike. However, before walking north on the trail, go to the fence looking up-river and just notice how high you are above the water. The large rock face stretching out toward the Susquehanna River is Chickies Rock, our destination for this adventure. Trace an imaginary line across the river from Chickies Rock and you come to the Hellam Hills at Hellam Point. Here, notice how the Susquehanna River makes a southward turn through the “Chickies Ridge” water gap. Water seeks the easiest route down a valley. It is believed there is a fault in the Earth’s crust here that was a “self-made” channel for the river, thus making the corner following the fracture.
Walk north along the tree line on the Heritage Trail and follow it into the woods and carefully down the steep hill. After about a quarter mile, you are going to descend almost 200 feet to the valley below. As you walk, examine the rock float (loose) sitting on the surface. The grayish-white massive rock is the metamorphic rock called quartzite. The other rock seen here is a “shale-looking” type of metamorphic rock known as phyllite. The phyllite is usually a light green to light tan color. Where the Heritage Trail crosses over the ravine, you also will see some white quartz boulders. Quartz is one of the most common minerals found in the Earth’s crust and formed where hot water carrying silica came up through a fracture in the Earth. As the water evaporated, ions of silica would form on the rock in the crack, eventually forming a quartz vein and filling in the entire crack.
After reaching the bottom, give yourself high-five for making it down the hill safely. Aren’t you glad we started at the south end instead of at Chickies Rock walking south? Walk north on the trail and notice the railroad ties in place. This was the location of the older railroad, used to remove a product that was manufactured just ahead. If you’re brave enough to traverse the small hill to your right to get a closer look at the rock outcrops, check the loose rocks. You might notice that there are alternating exposures of quartzite and phyllite. In fact, the higher portion of the hill is composed of quartzite with fairly large outcrops. You might have to hunt a little to find outcrops as phyllite. Remember, phyllite is softer than the quartzite and thus does not make large appearances.
As you approach what used to be Jones Creek crossing the trail, look to the right. You will see a free-standing rock wall that was the wall to the tenements house belonging to the Henry Clay furnace. (By the way, after the severe flooding in the area last September, Jones Creek was chocked by large sediments, totally eliminating the creek. How do you think I felt when I saw “my creek” was no longer visible?) If you look around in the brush on hillsides to the north and south of the abandoned streambed, you will find foundations of the casting house, engine house, furnace and other buildings.
The Henry Clay furnace was one of eight anthracite-burning iron furnaces between Columbia and Marietta. This was one of the first such operations in this industrial district, built in 1845 by Peter Haldeman, a prominent Columbia merchant. The property changed hands a number of times after 1855. In 1875 Clement Brooke Grubb purchased the furnace and renamed it St. Charles Furnace No. 2. The furnace was finally abandoned in 1889.
It’s interesting to note that after the furnace was shut down, the tenement house was used in the early 1900s by railroad workers and employees at the stone crusher just north of here. My dear friend June Evans, now retired from Millersville University, conducted archaeological excavations at the tenement house during three seasons of field school.
There is a small outcrop of phyllite behind the tenement house wall and depression that was once the office.
Continue walking north. A short distance up the trail, you will see a man-made stone wall against the bank to the right. This is the location of the stone crusher. Originally, limestone was brought in and crushed to be used in the construction of the Pennsylvania Railroad’s Atglen and Susquehanna line from Columbia to Marietta. The crusher was used later in the quarrying of quartzite in the hillside. The crushed rock was transported to Pittsburgh where it was used to make refractory linings in furnaces.
The crusher belonged to the Chickies Silica Sales Company, which operated from around 1915 to 1920.
Now you’ve arrived at the south face of the “kings of rocks” in southeastern Pennsylvania, Chickies Rock — one of the most outstanding outcrops in the Mid-Atlantic states. Before looking at the big rock, look at the isolated quartzite exposure just south of Chickies Rock. Notice how the rock has been contorted and twisted by pressures within the Earth that are hard to imagine.
In the large opening between Chickies Rock and the railroad, look at the outline of the cliff. Notice how it appears as an arch shape. This massive exposure of quartzite has been pushed into this shape and is known to geologists as an anticline. This is one of the finest examples of an anticline in this portion of the country. The cracks running up the face are faults, fractures that occurred during the folding of the rock. You can see the same principle if you take a block of Play-Doh, place your hand on either end of the block and push your ends downward as if trying to tear the block in half. You will fold the Play-Doh but cracks (stress fractures) also will appear across the top of the block.
Chickies Rock is used by novice and expert rock climbers. It is amazing to watch these brave people traverse the 220-foot high rock and take a break on one of the horizontal ledges available unless one of the many resident snakes already claimed the shelf for a sun bath.
As you walk north on the abandoned railroad bed, you will spot a small anticlinal fold that appears to be a rock shelter. Indeed, this was used by the early Indians to get out of the weather when needed. Supposedly, an Indian canoe was discovered here and became the first recorded archaeological site in Lancaster County. The site is known as 36 LA01. The “36″ stands for Pennsylvania, the “KA” stands for Lancaster County, and the “01″ is the number of the site as recorded in the Pennsylvania Historical Commission’s database.
If you walk down to visit the rock shelter, examine the roof of the overhang. You will see several rounded tubes in the rocks. These are some of the state’s oldest fossils, known as Scolithus linerais — 600-million-year-old borings of a marine worm. Matter of fact, this worm tube, known around the world, is named from here. As the story goes, local naturalist Samuel Haldeman, who lived in a mansion at the north end of Chickies Rock, found these fossils but did not know what they were. Samuel sent a specimen to Charles Darwin, who identified and dated the worm tube. Because these sea creatures lived a very short time in geologic terms, any rock containing these fossils is 600 million years old.
One more stop is at the northern edge of Chickies Rock. Look at the near vertical face and you will notice ripple marks. These features were formed when the area was under the ancient ocean known as the Iapteus. By visiting the seashore today, we can see where and how ripple marks are formed. As your feet are getting used to the water, look at the sandy bottom. It appears to be rippled. Imagine that — you can touch ripple marks that formed at the beach 600 million years ago!! We can’t get you any closer to geology than that!!
As you make your way around the northern face of the “rock,” you’ll walk through an area containing some stone steps and undefined walls. This was the location of the Samuel Haldeman mansion. This house was designed by Samuel and built in 1833 on lands owned by his father, Henry. Samuel and his new bride, Mary Hough, moved into the house in 1835. Samuel lived here until his death at age 68 in 1880. Among many of his accomplishments, Samuel published numerous treatises on the subjects of philology, phonography, ethnology, natural history and archaeology. He also was the first president of the American Philological Association and corresponded with Noah Webster in the compilation of his dictionary.