Monday, November 3, 2008

West Point on the Eno (Durham, NC)

Overview: On Sunday, November 2, my husband and I took a long walk at West Point on the Eno, a 388-acre park bordering the Eno River in Durham, NC. Our walk emphasized local geology and was taken from an excellent publication produced by the North Carolina Geologic Survey (see pages 49-56 for the guide to West Point on the Eno):

Bradley, P. J. 2007. A Geologic Adventure Along the Eno River, Information Circular 35. North Carolina Geologic Survey: Raleigh, North Carolina. 65 p

During our hike, we used three trails: the South River trail (0.52 miles), Sennett Hole trail (0.15 miles one way) and the Buffalo Trail (0.40 miles) (see trail map). These trails not only revealed fascinating rocks and minerals, but also yielded beautiful trees ablaze with fall color and interesting animal sightings.

Directions: West Point on the Eno is located at 5101 N. Roxboro Road in north Durham. The geology hike described by Bradley (2007) begins at the West Point Mill, an obvious landmark located to the north of the parking areas.

Observations - Geology Hike: The geology hike begins at the West Point Mill, a once thriving center for Durham that was in operation from 1778 until 1942. Here, one is struck by Durham's fascinating history, as well as the impact of people on the environment. Careful observers are likely to find water snakes (Nerodia spp.) and queen snakes (Regina septemvittata) swimming and basking in the rocky area next to the large mill wheel.

The next stop (stop 2) is at Turtle Rock. Turtle Rock overlooks the Eno River and from here visitors can almost always find turtles basking on fallen logs in the water. Turtle Rock itself is an outcropping of felsic tuff, composed of 600 million year old volcanic ash that has been folded and refolded over time.

Felsic tuff at Turtle Rock (Stop 2)

Felsic tuff at Turtle Rock (Stop 2)

Stop 3 on the geology hike highlights floodplain cobbles and gravel along the South River trail, while stop 4 impresses with deep red quartz cobbles.

Quartz cobble (stop 4)

Stop 5 displays a line of rounded diabase boulders. Diabase intruded along the Eno River during the Triassic period, as Pangea split apart (Bradley, 2007). This same diabase is responsible for the interesting geology and ecology of Penny's Bend, east of West Point on the Eno. The prairie that grows there thrives in the basic soil formed from the diabase sill.

Diabase boulders (stop 5)

After passing the diabase boulders, the geology hike continues along beautiful Warren Creek and points out floodplain deposits of boulders, cobbles, sand and silt (stops 6a & 6b). The hike then continues across the creek, onto the Sennett hole trail and brings you to Sennett hole (see previous posting), a lovely place to sit with a picnic lunch.

Warren Creek (stop 6a)

After a brief respite at Sennett Hole, the hike heads back to Warren Creek, where you join the Buffalo Trail. Stops 8 and 9 highlight deposits of tuff and granodiorite, an igneous rock similar to granite. Stop 10 is delightful, allowing you to ponder the beauty of more hydrothermal quartz tinted red and pink by iron.

Granodiorite (stop 9)

Hydrothermal quartz with iron impurities (stop 10)
The final stop on the geology hike (stop 11) explains the origins of several large diabase boulders near Meadow Branch creek. These boulders were actually brought to West Point on the Eno from a nearby quarry.
Observations - Trees & Other Sightings: Besides enjoying the fascinating geologic story of West Point on the Eno, our hike also afforded us the opportunity to enjoy the fall colors of the over 35 species of trees and large shrubs that we identified. An alphabetical list (by scientific name) of those trees and large shrubs is provided:
box elder (Acer negundo)
black maple (Acer nigrum)
red maple (Acer rubrum)
river birch (Betula nigra)
musclewood (Carpinus caroliniana)
mockernut hickory (Carya alba)
ironwood (Carya virginiana)
sugarberry (Celtis laevigata)
eastern redbud (Cercis canadensis)
dogwood (Cornus florida)
persimmon (Diospyros virginiana)
American beech (Fagus grandifolia)
green ash (Fraxinus pennsylvanica)
witch hazel (Hamamelis virginiana)
American holly (Ilex opaca)
black walnut (Juglans nigra)
red cedar (Juniperus virginiana)
sweet gum (Liquidambar styraciflua)
tuliptree (Liriodendron tulipifera)
red mulberry (Morus rubra)
sourwood (Oxydendrum arboreum)
shortleaf pine (Pinus echinata)
loblolly pine (Pinus taega)
American sycamore (Platanus occidentalis)
black cherry (Prunus serotina)
white oak (Quercus alba)
southern red oak (Quercus falcata)
swamp chestnut oak (Quercus michauxii)
water oak (Quercus nigra)
willow oak (Quercus phellos)
northern red oak (Quercus rubra)
post oak (Quercus stellata)
sassafras (Sassafras albidum)
winged elm (Ulmus alata)
mapleleaf viburnum (Viburnum acerifolium)
arrowwood viburnum (Viburnum dentatum)
American holly (Ilex opaca) with berries

Swamp chestnut (Quercus michauxii)
Mark and I were also fortunate to find a late-season queen snake (Regina septemvittata) near the old mill, which we happily shared with a boy and his father, as well as a wheel bug. Wheel bugs are named because of their wheel-like armour. They feed on caterpillars and japanese beetles (by piercing them with their beak, paralyzing them and then slurping up their dissolved insides!), making them a beneficial insect for gardens, but BE CAREFUL, they can deliver a relatively painful bite if handled.

Queen snake (Regina septemvittata)

Wheel bug (Arilus cristatus)

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