[Journal entry for August 16, 2017]. Flat Rock Brook Nature Center is a tract of wooded land on the west flank of the ridge of the Hudson Palisades that includes Flat Rock Brook and a small disused traprock quarry. I parked at the entrance of Jones Road, on the west side of the Center, by the picnic area. The afternoon was sunny and very humid. Steeply eroded banks suggest that the brook roars in heavy rain, but today it was just a trickle and I was able to walk along the streambed, stepping from stone to stone. Newark Basin sedimentary rocks are exposed in the bed. The strata tilt slightly to the west, creating broad plates whose edges impound small pools and over which pours small cascades of water. Small fish and frogs inhabit the pools. I walked upstream to just below Mystery Bridge, build over a dam that impounds a small reservoir, which is now silted up. It hosts a small wetland of cattails and Phragmites.

I took the red trail west, through woods with exceptionally tall hardwood trees, such as oaks and Tulip trees. An overpopulation of White Tail Deer has substantially reduced the lushness of the undergrowth. The staff is in the process of building a tall deer fence, but it is as yet incomplete. Ironically, I spotted a doe and her fawn grazing in the fence’s corridor. I switched to an informal trail when I neared the quarry. It led to a small overlook above the quarry with a rock ledge with exceptionally well-reserved glacial striae. I rejoined the main path and went down into the quarry, which hosts the Nature Center building, a small pond and a wetland. I followed a boardwalk around the interior of the quarry, past exposures of Palisades diabase (the traprock that was quarried). A few wildflowers bloomed in the wetland, including Cardinal flower (Lobelia Cardinalis), with its brilliantly red flower stalks. I stood by Quarry Pond for a few minutes, whose still and dark waters reflected the clouds and sky above.

I then took the red trail back past Mystery Bridge and continued on it until I was back at the picnic area. About 1:30.