362 



STONY CREEK OIL FIELD TO HILLSBOROUGH GYPSUM 

 QUARRIES. 



Leaving the Stony Creek oil field, the highway 

 descends the long slope to the valley of Weldon creek, and 

 ascends and crosses the low ridge to the south, on which 

 stands Hillsborough. The strata outcropping on the 

 southern slopes of the ridge facing Weldon creek valley, 

 are red conglomerates with interbedded red shales and 

 sandstones. On the higher slopes, these measures are 

 nearly horizontal, lower down on the valley side they dip 

 both southward and westward at angles of 20° to 50°. 

 Similar measures outcrop in the valley of Weldon creek 

 dipping to the north, though where the highway crosses the 

 creek near its mouth, the strata are nearly horizontal or dip 

 at low angles to the south. Weldon creek valley apparently 

 marks a synclinal axis in the red series and confirms the 

 impression that the general structure of the Stony Creek 

 oil field is anticlinal. 



The low, broad ridge on which Hillsborough stands is 

 underlain by red conglomerates with sandstones and shales, 

 forming a general assemblage very similar to that developed 

 in Weldon creek valley. The strata are folded along east 

 and west axes, in places the angles of dip are high — 60° to 

 70° — and presumably the measures are traversed by faults. 



The ridge on which Hillsborough stands is bounded on the 

 south by the valley of Quarry creek, which heads to the 

 west in the gypsum quarries. A road leads up this valley 

 to the quarries; the main road continues southward 

 parallel with the river. Along the main or river road 

 there are a few exposures of red conglomerate and the same 

 strata, lying nearly horizontal, are exposed on the eastern 

 slopes of the ridge rising to the south. In this ridge the 

 red conglomerate is directly overlain by grey limestone 

 beds which on the summit of the ridge are capped by 

 gypsum beds. Farther south, apparently the same red 

 conglomerate beds outcrop along the river bank, dipping 

 gently to the south. These red conglomerates outcrop 

 in the steep, cliff-face of Hopewell cape and are there over- 

 lain by about 100 feet (30 m.) of red sandstones, above 

 which come 30 feet (9 m.) of red and grey shales capped by 

 heavy beds of grey quartzose conglomerate and sandstone 

 belonging to the Millstone Grit. All the strata appear 



