AGE OF THE COALS AT TIPTON, PENNSYLVANIA 477 



readily followed in a direction nearly south 10 degrees east to a point on the west 

 side of Loop run about 200 yards southwest of the Loop Run slope, where coal in 

 bad condition was shafted ahiiost directly against the lower Pocono red shales. 

 The southeast boundary of the fault appears to coincide with the transverse valley 

 in which Loop and Tipton runs converge and unite. 



The sequence of the formations is well shown in the south point of the low spur- 

 ridge between these runs. At the extreme southeast, above the valley bottom, the 

 green and red shales and sandstones of the Mauch Chunk appear, while in passing 

 along the track of the old railway up Tipton run the Carboniferous limestone in 

 the upper part of the Mauch Clmnk presents itself. Above this are characteristic 

 Mauch Chunk beds up to the massive lower conglomerate (Olean) of the Pottsville 

 formation. The ledges of the Pottsville diagonal through the steep southeast slope 

 of the spur, and form the rugged crest point of the latter. The lower conglomerates 

 cross Tipton run near the old commissary site, but the upper part of the formation 

 does not reach the valley level until near the tunnel. It se6nis probable that 

 the lower prospect drift a short distance south of the tunnel is in this formation, 

 and it is possible that some of the fruits collected by Koch were obtained at this 

 point. 



No attempt was made by the writer to trace the eastern border of the coalfield* 

 The strike of the Pottsville near the point of the knob is nearly north 10 degreeg 

 east, the dip, as determined by d'Invilliers, being 12 degrees west. On crossing to 

 the east of the run the Pottsville sandstones appear to swing still farther to the 

 north, while flattening somewhat so as to form the long gradual rise to the east- 

 ward. Such a swing appears to be indicated not only by the topography, but by 

 the attitude of the coal at the head of the Gates drift, whose local dip is south 

 60 degrees west. The series of several coal provings ranging from this drift to a 

 point about 2,700 feet north of the Tipton tunnel are probably near the line of 

 general strike, and may all lie within the Allegheny series. The line where the 

 gentle grade of the Coal Measures abuts against the somewhat abrupt escarpment 

 of westward dipping sandstones of the upper ("gray ") Pocono is not far from the 

 farthest of these provings. The Pocono escarpment is bold and strong, extending 

 along the northwest side of the coalfield depression and meeting the Pocono spur, 

 first mentioned, on the west of the coalfield. 



Although the eastern boundary has not yet been located, it is probable that, as 

 might be expected from the attitude and age of the beds, the Tipton Run coal- 

 field consists of a faulted block M^hich includes at least a portion of the Mauch 

 Chunk shales and sandstones with the Carboniferous liuiestone, the Pottsville and 

 the Allegheny series, if not higher terranes of the Coal Measures. The block is 

 somewhat warped, as well as slightly shattered, so that toward the east the strike 

 of the Coal Measures is at a wide angle to that of the adjacent Pocono. The minor 

 northwest-southeast faults, described by the state geologists as occurring in the 

 mines and compared by Lesley with the transverse faults at Orbisonia and Three 

 Springs, in Huntington county, or in the Houtzdale-Osceola district of Clearfield 

 county, presumably belong to the same system as the great transverse faulting of 

 the coalfield itself. The stratigraphic displacement of the coal at the Loop Run 

 slope, which, according to Franklin Piatt, should be within 200 feet of the base of 

 the Pocono, is probably about 1,550 feet. 



LXVIII— Bum,. Geol. Soc. Am.. Vol. 12, 1900 



