Guide to Landforms Seen Along SEPTA’s West Trenton Regional Rail Line

Authors

Overview: Along its 32.5-mile trip from Center City Philadelphia to West Trenton a SEPTA West Trenton train travels from the Philadelphia City Center to and then along the Coastal Plain-Piedmont boundary before moving onto the Piedmont Province to reach the Tookany Creek drainage basin. Once in the Tookany Creek valley the train travels in a north direction adjacent to south oriented Tookany Creek before turning in an east-northeast direction to follow a remarkably straight and deep through valley to reach and cross Pennypack Creek. While not perfectly straight the track continues in the through valley, which links the Poquessing and Neshaminy Creek drainage basins. As it leaves the Neshaminy Creek drainage basin the train also leaves the through valley to cross the Neshaminy Creek-Delaware River drainage divide and then to cross the Delaware River before reaching West Trenton. Along the way observant riders can see the Coastal Plain -Piedmont Province boundary, observe metamorphic rock exposures as the train travels to and through the Tookany Creek gorge, cross several drainage divides as they travel in a remarkably straight and well-defined through valley, and observe an unusual Neshaminy Creek bend and barbed tributary before ending their trip by crossing a region underlain by Triassic age shale, mudstone, and sandstone

City Center to Fern Rock Station: After leaving Jefferson Station the rail line turns in a north direction as it climbs out of the tunnel (which at Jefferson Station is approximately at sea level) and rises above street level providing good views on both sides to reach the elevated Temple University Station. From Temple University to the North Broad Station the tracks are above street level, but at the North Broad station the tracks descend to below street level and are in a trench as streets and other rail lines are located overhead. After leaving the trench the tracks are again above street level to Wayne Junction Station (elevation approximately 100 feet above sea level) and then almost all the way to the Fern Rock Station (elevation approximately 120 feet above sea level).

For the entire distance between the City Center and Fern Rock Station the track is located on the Coastal Plain Province, although from Wayne Junction Station to Fern Rock Station the track is located along the boundary between the Coastal Plain Province (to the southeast or right) and the Piedmont Province (to the northwest or left). No Coastal Plain landforms or bedrock exposures can be seen as urban development has completely altered surface features that once were present. Coastal Plain Province bedrock if it could be seen is marine or fluvial sedimentary material deposited on a basement of metamorphic rocks with the sedimentary rocks generally thickening in a seaward direction.

When the train is approaching the Wayne Junction Station a low tree-covered ridge is visible to the northwest with higher elevations along the ridge crest being 230 or more feet above sea level. This ridge marks the Piedmont Province southeast boundary. This ridge is particularly noticeable after the SEPTA rail line crosses Hunting Park Avenue and a freight rail line just before passing a large SEPTA maintenance complex. The freight rail line was built in a shallow northeast to southwest oriented valley that the railroad deepened further so as to pass under streets and the SEPTA line tracks. The shallow valley in which the freight rail line is located was eroded by southwest oriented water flowing to the Schuylkill River valley. Just before reaching the Wayne Junction station the SEPTA rail line turns in a northeast direction so as to continue along the boundary between the Piedmont and Coastal Plain Provinces to the Fern Rock Station.

Fern Rock to Melrose Park: After leaving the Fern Rock Station the track enters the Piedmont Province and while not obvious from the train it is climbing to an elevation of slightly over 200 feet above sea level as it passes through several cuts where bedrock exposures can be seen from the train window. The bedrock here is the Wissahickon Formation of probable early Paleozoic age, which is composed of metamorphic rocks that represent the roots of an ancient mountain range. Similar rocks are buried beneath the Coastal Plain Province marine and fluvial sediments, although in the Piedmont Province the metamorphic rocks stand higher in elevation and the marine and fluvial cover is not present. Reasons why the metamorphic rocks stand higher in the Piedmont Province region have been debated in the geologic literature, although many geologists consider the Coastal Plain-Piedmont Province boundary to be an erosional feature.

Melrose Park to Elkins Park: The Melrose Park Station has an elevation of approximately 200 feet above sea level with a hill to the northwest rising to approximately 250 feet while a Tookany Creek tributary valley can be seen to the northeast. The Piedmont Province surface in this region has been eroded by east and northeast oriented Tookany Creek tributaries and after leaving the Melrose Park Station the train passes through a cut as it crosses the ridge between two such tributary valleys before reaching the Elkins Park Station. The rail line between Melrose Park and Elkins Park maintains its elevation at close to 200 feet above sea level.

Elkins Park to Jenkintown: After leaving the Elkins Park Station the train passes over Old York Road (Route 611) and then closely follows Tookany Creek, with the creek being first located to the east (right) and then switching to the west (left). The rail line elevation at Elkins Park is slightly below 200 feet above sea level, but rises to slightly more than 200 feet at Jenkintown. South-flowing Tookany Creek crosses the 200-foot contour line a short distance south of the Jenkintown Station. While not easy to visualize the trip between Elkins Park and Jenkintown is made at the bottom of a V-shaped valley with elevations to the east at Jenkintown rising to more than 340 feet and elevations to the west rising to more than 400 feet. The water-eroded valley is carved in the Wissahickon Formation metamorphic rock complex, which underlies the entire region. Bedrock exposures are visible along both the rail line and the stream channel. This rock cut valley or gorge was eroded by large quantities of water, probably much more water than the present day Tookany Creek drainage basin could possibly produce. Evidence that water once flowed from other drainage basins into the Tookany Creek drainage basin is seen as the train travels beyond Jenkintown Station.

Jenkintown to Noble: The Jenkintown Station is located in the deepest section of the Tookany Creek gorge with elevations in Jenkintown to the east rising to approximately 340 feet and elevations along the Tookany Creek-Wissahickon Creek drainage divide to the west rising to more than 400 feet. Yet immediately after leaving Jenkintown Station there is a major rail junction with the SEPTA West Trenton Rail Line turning to the northeast while the Warminster and Lansdale Rail Lines turn to the northwest and the West Trenton Line for a short distance is parallels southwest oriented Baederwood Creek, which is flowing in a deep and easy to see southwest oriented valley that is much larger and deeper than the present day Baederwood Creek could possibly erode. Today Baederwood Creek originates in the hills north of the tracks and flows in a narrow south oriented valley to reach the broad southwest oriented valley in which the rail line is located and then to flow to join south oriented Tookany Creek near the Jenkintown rail junction.

After traveling in a northeast direction for a short distance the train turns again to travel in an east-northeast direction as the rail line and the well-defined valley in which it is located cross the Tookany Creek-Pennypack Creek drainage divide and continue in a remarkably straight line for the next 5.5 miles. The through valley in which the West Trenton Rail Line is located is remarkably straight and is the boundary between the Wissahickon Formation metamorphic rocks of probable lower Paleozoic age to the south and somewhat different and older metamorphic rocks of probable Precambrian age to the north. Both rock units represent the roots of one or more ancient mountain ranges. The remarkably straight boundary between the two different metamorphic rock types, along which the valley in which the West Trenton Rail Line is located, has been interpreted to be an ancient fault line. If correctly interpreted the valley was not formed by fault movements, but was instead eroded by massive and prolonged west-southwest oriented flood flow eroding a west-southwest oriented valley headward along the fault zone. The west-southwest oriented flood flow was captured from west to east by headward erosion of the south oriented Tookany, Pennypack, Poquessing, and Neshaminy Creek valleys and headward erosion of the south oriented Delaware River valley in that sequence.

Noble to Rydal: Noble Station is located where Old York Road (Route 611) crosses the West Trenton Rail Line. Old York Road was originally established as a stage route in the early 1700s and crossed the through valley near the point where the through valley was shallowest, which is at the Pennypack Creek-Tookany Creek drainage divide. East of the drainage divide the through valley is drained in an east-northeast direction to Pennypack Creek by Meadow Brook. However, urban development has buried Meadow Brook under streets on the through valley floor, which is seen on the north (or left) side of an out bound train. The through valley valley walls are easily seen from the train and rise more than 100-feet deep on either side. The valley is carved in the hard to eroded metamorphic rocks and is much too large to have been eroded by a stream the size of present day Meadow Brook. The through valley floor on which the West Trenton Rail Line has an elevation of approximately 220 feet at the Tookany-Pennypack Creek drainage divide (near Noble Station). South of Noble Station Old York Road climbs to elevation greater than 320 feet in Jenkintown before descending into the Tookany Creek valley to reach Elkins Park. North of Noble Station Old York Road climbs to an elevation of almost 400 feet before descending to reach Willow Grove. There is a small decrease in elevation as the train approaches Rydal Station, which has an elevation of approximately 190 feet.

Rydal to Meadow Brook: Once leaving Rydal Station east-northeast oriented Meadow Brook is to the north of the remarkably straight tracks although is hidden in the trees. While Meadow Brook flows in an east-northeast direction the valley was originally carved by west-southwest oriented flood flow moving to the Tookany Creek valley, but the flow direction was reversed when the deeper Pennypack Creek valley eroded headward and captured the west-southwest oriented flood flow. At that time valleys to the north had not been eroded and floodwaters moving across uplands to the north flowed in south directions to reach the much deeper through valley and it was that flood flow from the north that eroded the east-northeast oriented slope seen today. Meadow Brook is what might be called an underfit stream as it drains a valley much larger than it could possibly have eroded and has a much lower gradient than its headwaters and tributaries, which flow down the valley walls to reach the very low gradient through valley floor. Note how the pronounced valley walls on both sides of the through valley.

Meadow Brook to Bethayres: The straight track continues from Meadow Brook Station to Bethayres Station on the floor of the remarkably straight through valley. Again the valley floor descends gradually to reach the south oriented Pennypack Creek valley, which has an elevation of approximately 110 feet near the Bethayres Station. Meadow Brook can be seen from the train flowing in an east-northeast direction in the golf course north of the tracks until it turns in a southeast direction to flow under the tracks and to join Pennypack Creek at a point just south of the tracks. At the point where Meadow Brook joins it south oriented Pennypack Creek is turning from flowing in a west-southwest direction to flow in a southeast direction before resuming its south oriented course. The west-southwest oriented Pennypack Creek segment is located on the south side of the track before the train crosses the Pennypack Creek bridge just before going under the Huntingdon Pike overpass and reaching the Bethayres Station. Upstream from where Pennypack Creek flows under the railroad tracks the creek has a south oriented valley and the short west-southwest oriented Pennypack Creek segment is where Pennypack Creek crosses the straight west-southwest oriented through valley.

Bethayres to Philmont: After leaving Bethayres Station the train continues along the straight east-northeast oriented track, which is located on the floor of the straight west-southwest oriented Huntingdon Valley. North of the tracks is west-southwest oriented Huntingdon Valley Creek, which also is an underfit stream. Huntingdon Valley Creek originates in the hills north of the tracks and flows in a south-southwest direction to enter the very low gradient through valley floor and then flows in a west-southwest direction to reach Pennypack Creek. The outbound train gradually gains elevation as it approaches Philmont Station, which has an elevation of approximately 140 feet.

Philmont to Forest Hills to Somerton: After leaving Philmont Station the train continues in a straight line until curving slightly about midway between Philmont Station and Forest Hills Station. The track here is not located in the deepest section of the through valley floor but is located along the south valley wall as the track gradually rises from an elevation of approximately 120 feet in the Pennypack Creek valley to reach an elevation of almost 200 feet at the Pennypack-Poquessing Creek drainage divide before reaching the Forest Hills Station. After crossing the Pennypack-Poquessing Creek drainage divide the train begins to descend very gradually and after the Forest Hills Station the track is located on the north side of a small drainage ditch or stream draining in an east-northeast direction to the south oriented Poquessing Creek. This minor east-northeast oriented stream also is an underfit stream as it drains the floor of a valley much larger than it could have eroded and is flowing at a much lower gradient than its tributaries, which flow from the hills to the north into the low gradient through valley. 

Somerton to Trevose: After leaving Somerton Station the train continues its gradual and hardly noticeable descent into the Poquessing Creek valley and crosses Poquessing Creek at an elevation of approximately 150 feet just before traveling under the Pennsylvania Turnpike overpass. Poquessing Creek is a very small stream and is easily missed and is today probably too small to be considered a major drainage route, yet at one time it did erode a shallow south oriented valley to and across the west-southwest oriented through valley in which the West Trenton Rail Line is located. After crossing Poquessing Creek (and going under the Pennsylvania Turnpike) the track makes another curve and very gradually rises to an elevation of about 175 feet at the Poquessing-Neshaminy Creek drainage divide and then begins to gradually descend into the Neshaminy Creek valley as it approaches the Trevose Station, which has an elevation of approximately 120 feet.   

Trevose to Neshaminy Falls: After leaving Trevose Station the valley of a northeast oriented Neshaminy Creek tributary is located south of the West Trenton Rail Line. The tributary joins Neshaminy Creek just south of the Neshaminy Falls Station at the point where Neshaminy Creek turns from flowing in a south direction to flow in a northeast direction along the floor of the east-northeast oriented through valley. The Neshaminy Falls Station elevation is approximately 80 feet and Neshaminy Creek, which is crossed after leaving the Neshaminy Falls Station, is flowing at an even lower elevation.

Neshaminy Falls to Langhorne: Almost immediately after leaving the Neshaminy Falls Station the outbound train crosses over south oriented Neshaminy Creek. Good views of the south oriented Neshaminy Creek valley to the north of the bridge can be obtained as the train crosses the bridge. While not as easily seen a short distance south of the bridge Neshaminy Creek makes an abrupt turn to flow for approximately one mile in an east-northeast direction along the west-southwest oriented through valley floor before turning to flow in a southeast and then south direction to join the southwest oriented Delaware River. Trees beyond the adjacent highway (Business Route 1) prevent good views of the east-northeast oriented Neshaminy Creek segment. The highway veers away from the tracks near the point where Neshaminy Creek turns to flow in a southeast direction and the rail line then is located on the north side of a west-southwest oriented Neshaminy Creek tributary valley. After crossing the tributary’s south oriented headwaters the rail line continues in an east-northeast direction to Langhorne Station, which has an elevation of about 100 feet. From Noble Station to Langhorne Station the rail line has been located on the floor of the west-southwest oriented through valley and has followed east-northeast and west-southwest oriented Pennypack Creek, Poquessing Creek, and Neshaminy Creek tributaries as it gradually descended and then gradually ascended to cross drainage divides separating the major south oriented drainage basins.

Langhorne to Woodbourne: After leaving Langhorne Station the out bound train leaves the west-southwest oriented through valley it has been following and curves so as to travel in a north-northeast direction and then crosses and follows south oriented Mill Creek before reaching Woodbourne Station. Mill Creek is a Neshaminy Creek tributary and is only visible from the train at the point where it flows under the tracks and is easily missed. The through valley in which the train had been traveling does continue in an east-northeast direction from where the rail line leaves it and is known as Oxford Valley, although it is much less pronounced then it was further to the west. East of the Delaware River several through valleys cross the Delaware River-Raritan River drainage divide and provide northeast to southwest oriented routes used by the Delaware and Raritan Canal, the former Reading Railroad line to Bound Brook, and the present day Amtrak Northeast Corridor rail line. These New Jersey through valleys suggest that large volumes of southwest oriented water once flowed in a southwest direction from the present day New York City region to and across southeast Pennsylvania and which was probably responsible for eroding the west-southwest oriented through valley now used by the West Trenton Rail Line from west of Noble Station to east of Langhorne Station. Headward erosion of the south oriented Delaware River valley in the Trenton, New Jersey region captured the southwest oriented flood flow and ended all flood flow in the through valley in which the West Trenton Rail Line between Jenkintown and Langhorne is located. The Woodbourne Station has an elevation of approximately 160 feet.

Woodburne to Yardley: After leaving Woodbourne Station the outbound train turns slightly so as to be traveling in a northeast direction to Yardley Station and for much of the distance is following the valley of northeast oriented Brock Creek. Brock Creek originates on the northwest side of tracks and then passes under the tracks to flow on the southeast side of the tracks before turning in a north direction to pass under the tracks again and to join Buck Creek, which flows to the Delaware River. Other than where it is crosses Brock Creek is not easily seen from the train and it is also a small stream and is easily missed. After crossing Brock Creek for the second time the rail line ascends to an elevation of almost 140 feet before gradually descending as the Yardley Station and the Delaware River are approached. Bedrock under the region between Woodbourne Station and Yardley Station is primarily Triassic age shale, mudstone, and sandstone and has a much different composition and history than the Precambrian and lower Paleozoic rocks underlying the region between Fern Rock Station and Woodbourne Station, although the region between Woodbourne Station and Yardley Station was scoured by immense floods, which first moved in a southwest direction across southeast Pennsylvania and later were captured and diverted in a south direction when the present day Delaware River valley eroded headward into and across the region.

Yardley to West Trenton: Yardley Station has an elevation of approximately 80 feet. Almost immediately after leaving Yardley Station the outbound train begins to cross the Delaware River valley and the first bridge crosses the Delaware Canal, which is now maintained as a Pennsylvania State Park. Next the train travels on a viaduct across a Delaware River flood plain segment where elevations are less than 40 feet and then crosses the Delaware River itself. The Delaware River at this location is flowing in a southeast direction, although further to the south it flows in a south direction and then turns to flow in a southwest direction to reach Philadelphia and the north end of Delaware Bay. Normally the river surface elevation at this location is less than 20 here, although during major floods the water level can be much higher.

After crossing the Delaware River the outbound train crosses the Delaware and Raritan feeder canal, which has an elevation of approximately 50 feet and is located along the Delaware River valley southwest wall. The feeder canal was built to supply water to the Delaware and Raritan Canal, which once provided a water-level transportation route from the Delaware River to the Raritan River in northeast New Jersey. The feeder canal was designed so as to permit Delaware River water (obtained from upstream on the Delaware River) to flow across the Delaware River-Raritan River drainage divide into the Millstone River drainage basin and the elevation of that drainage divide is slightly lower than the feeder canal elevation. The Delaware and Raritan Canal was built along one of the routes used by southwest oriented flood flow that was captured as the Delaware River valley seen from the train eroded headward across the region to capture the flood flow. Once captured the southwest oriented flood flow eroded deeper southwest oriented valleys across New Jersey before being captured by headward erosion of the deeper Hudson River valley. After climbing out of the Delaware River valley the outbound train reaches the West Trenton Station, which has an elevation of approximately 120 feet.

The SEPTA train does not go beyond West Trenton, but the tracks continue as a CSX freight rail line in a northeast direction across New Jersey to the New York City area and cross the Delaware River-Raritan River drainage divide at an elevation of slightly more than 200 feet. The route used by this CSX Rail freight line, while not as deep as the Delaware and Raritan Canal route, was also carved by southwest oriented flood flow moving from the New York City area to and across southeast Pennsylvania before being captured by Delaware River valley headward erosion and subsequently being captured by Hudson River valley headward erosion to end flow across New Jersey.

 

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