ABSTRACTS OF PAPERS 89 



fanglomerate I have seen outside of the Great Basin. The materials came 

 from the east, evidently from very steep topography, and the presence of 

 vesicular basalt boulders indicates that one of the lava sheets extended east 

 of the fault zone. The upper (posterior) sheet was poured out while the 

 fanglomerate was accumulating, for the sheet thins and apparently wedges 

 out in the coarse deposits. Recurrence of faulting is suggested by the pres- 

 ence of coarse fan deposits at several horizons, and by the presence in the 

 fanglomerate of distinctive material from quartz veins that parallel the fault 

 zone. Very possibly these veins mark the location of earlier faults, and, dur- 

 ing later movements the veins themselves have been faulted and shattered. 



Dr. Kummel: The Triassic trough in New Jersey is in many fundamental 

 respects like that of Connecticut and Massachusetts. Since the dip is to the 

 west and not to the east, the eastern margin in New Jersey corresponds to 

 the western in Connecticut. In New Jersey, as in Connecticut, arkose beds 

 occur along the margin from which the beds dip, while coarse conglomerates 

 characterize the other margin. These conglomerates were found by streams 

 capable of transporting boulders upward of a foot in diameter. The western 

 margin of the trough in New Jersey is a fault border, the faulting probably 

 having been progressive during the Trias and at its close. 



Professor Rice: I can well believe that no one of the three hypothetical 

 sections of the Connecticut Trias exactly represents the actual history. I can 

 well believe that, as has been already suggested in this discussion, there may 

 be an element of truth in each of the three hypotheses. There is no absolute 

 distinction between a fault and a flexure, between a graben and a geosyncline, 

 since a breaking is apt to begin with a binding. Nevertheless, I am inclined 

 to believe that the Barrell-Foye hypothetical section is nearer to the exact 

 truth than either of the two sections suggested by Davis. On the graben hy- 

 pothesis — the hypothesis that the depression in which the sedimentation took 

 place was due to faults of approximately equal tbrow on the two margins of 

 the formation — all the strata should have been approximately horizontal at 

 the time when the present monoclinal dip was developed by movement follow- 

 ing the close of the deposition. On this hypothesis, therefore, the present dips 

 should be equal on the two sides of the area. On the Barrell-Foye hypothesis, 

 at the close of the period of deposition the older beds on the west side of the 

 valley should have had a dip to the east, while the newer beds on the east 

 side should have been nearly horizontal. On this hypothesis, therefore, the 

 western side of the formation should now have a slightly steeper dip than the 

 eastern. On the geosynclinal hypothesis, the beds on the east side of the 

 formation should have had a westerly dip at the close of the period of deposi- 

 tion. On this hypothesis, therefore, the dips at present should be decidedly 

 steeper on the west side than on the east side. The actual dips on the east 

 side range in general from 15 to 20 degrees ; those on the west side from 20 

 to 25 or 30 degrees. While these facts do not afford a basis for a positive 

 conclusion, they seem rather favorable to the Barrell-Foye hypothesis. On 

 the geosynclinal hypothesis, apparently, the difference of dip should be greater. 

 On the graben hypothesis, there should be no difference. 



Professor Westgate: If the Newark beds are largely subaerial, can we as- 

 sume that the beds were originally horizontal, or must we not assume an 

 initial dip from each side toward the axis of the basin which may be in part 

 at least responsible for the present difference in dips on the opposite sides? 



