Stop 4, Stockton Formation, Raven Rock, NJ

Stop 1 Watchung Reservation above Seeley's Pond and across New Providence road
from the Weldon quarry, Berkeley Heights, NJ. This is Kari's Thesis area in the
Orange Mountain Basalt, about 201 my.
Strike of Joint measured ~ N30E
Position N40 40.1', W74 24.1'
Specimen 29-III-08-01
Between Stops 1 and 2 we visited two localities briefly
The Preakness Basalt, along the service road north of where Rt 78 crosses Diamond
Hill Road at N40 40.5' W74 29.5', we looked at the large scale columnar jointing and
noted that it was larger than jointing to the northwest where McMane Avenue
crosses 78.
At this point I turned up the resolution on the GPS
The Orange Mountain Basalt at the Donald R. Scotti Public Works, 880 Somerset
Road, Watchung, NJ. N40 38.089' W74 26.833'. Permission and Hard Hats required.
Contact Mr. Charles Gunther, Site Supervisor, in person. We saw two lava flows
here. The lower basalt had a normal dark, high strength traprock appearance with
~8 cm circular vugs that mostly contained calcite. The upper flow had a green
appearance with irregularly shaped mineralizations and numerous 1 mm vesicles; it
appeared weathered and was softer. Specimen 29-III-08-02
Stop 2. Orange Mountain Basalt, Chimney Rock Road, Bound Brook, NJ, along Middle
Brook. We looked at the hornfels on the contact of the
Passaic Formation (+ "Brunswick Formation") and Orange Mountain Basalt, then
along the stream
N40 35.105' W 74 33.403 at four lava flows. Specimen 29-III-08- 03.
We spoke of research projects investigating the upper contact for inclusions and
glassy chill zones, and we exited along the contact between the first (lowest) and
second flow. Back at the truck, I showed you a shattered basalt with calcite from the
quarry, and we discussed the origins of explosion breccias. I promised we would see
these in situ at the last stop.
Stop 3. Round Valley Reservoir, Lebanon, NJ. Early Jurassic Diabase, Cherry St.
N40 37.952' W 74 50.089. Diabases have the same composition as basalt and
gabbro, but have Ophitic texture. We discussed the shallow depths of Diabase dikes
and sills and their roles as feeders to surface lavas. We looked at the NJ Geologic
Map and noted the ring shape of this one. We talked about Olivine gravity settling in
the Palisades Sill Diabase exposed along the Hudson River, and the fractionation of
the remaining magma that results. We searched for and collected fresh and
weathered specimens.
Stop 4, Stockton Formation, Raven Rock, NJ
N40 24.781' W75 02.265'
Surfaces in the Stockton were too irregular for a strike and dip.
Specimens 29-III-08-05
Stop 5 Locatong Formation
N40 26.850' W75 03.900
Specimens 29-III-08-06
Stop 6 Perkasie Member of the Passaic Formation
Red conglomerate and sandstone
N40 34.546 W75 07.796
Specimens 29-III-08-07
As we traveled along these outcrops we noticed an increase in maximum particle
size, from sands near Milford, to cobbles here, then to boulders closer to the border
Stop 7. Holland, NJ, near the border fault
Carbonate Breccia
N40 34.453' W75 11.172'
Specimens 29-III-08-08
No definite strike and dip here
Stop 8. Flemington, Route 12, hill above Old Croton road.
Lockatong Formation gray argillites w mudcracks and burrows ~ .8m. Alternating
with gray mudstones ~.35m w small scale (3 cm) rippled shales
N40 30.387' W74 52.903'
no samples
Stop 9 Flemington NJ,Dolores Morales Nature Trails, near Mine Brook Park, Capner
Lockatong Fm. and Orange Mtn. Basalt.
We examined the contact metamorphism of the local red Lockatong into gray
hornfels, caused by the heat of the basalt that flowed over it. We also collected
basalts that showed explosion breccia features and discussed possible causes.
Finally, we collected copper mineralization in the red/hornfels boundary within the
Lockatong, and a mudcrack specimen from the river bed.
N40 30.773' W74 52.452
Specimens 29-III-08-09
N50E32S Hornfels
Prof. Smart