112 BULLETIN OF THE 



upper contact. Sand grains fill vesicles and irregularities of surface, 

 conforming closely to their shape ; intermixture of sand and numerous 

 large and small trap fragments along line of junction ; occasional 

 rounded (water-worn) fragments of amygdaloidal trap even five feet 

 above trap sheet. 



Locality 18. Section numbers, 132-134. Lamentation Mountain. Percival's Report, 

 pp. 351, 352. Percival's notation, E. IIL (5). 



A road passes the north end of Lamentation Mountain and bridges 

 Spruce Creek, that flows northward from the back of the mountain. 

 Exposures of sandstone on the trap are found up and down stream from 

 the bridge ; the best locality is about an eighth of a mile up stream, 

 south (Fig. 10), where the exposure is of much interest. 



Trap porphyritic and glassy, particularly at upper surface ; upper 

 contact not locally of close texture ; upper portion of irregular texture, 

 highly vesicular, with uneven, rolling surface ; sand grains fill fissures 

 and vesicles near surface of trap ; narrow necks filled with the same 

 clastic material connect these vesicles with the sandstone above ; inti- 

 mate and complicated mixture of sand and trap over the upper surface 

 (Fig. 15) ; stratification of sand in vesicles and above sheet conformable 

 to surface, and generally parallel. 



Water-worn fragments of vesicular trap occur in sandstone for two 

 or three feet above surface of sheet. The vesicles in these fragments 

 often contain small particles of trap mixed with quartz and muscovite 

 grains. 



Locality 19. Section numbers, 136-150. Meriden City Quarry. Percival's RepoH, 

 pp. 370, 371. Percival's notation, E. IV. 1 (1). 



The small easternmost ridge of the Hanging Hills group (Fig. 5 

 or 6) has been deeply quarried for railroad ballast and road metal at 

 its southern end, and now presents an excellent dissection of a complex 

 trap sheet, — the most instructive quarry in the region. It is about 

 a mile north from the centre of Meriden. The trap of the quarry con- 

 sists of a lower and an upper portion, separated by a well defined surface, 

 inclined to the eastward with the general dip of the Triassic monocline. 

 The lower sheet is exposed for about ten feet below the surface of sepa- 

 ration ; the upper, for sixty or eighty feet above it. Lower sheet ex- 

 tremely porphyritic, vesicular, and glassy ; upper part scoriaceous, of 

 rolling, ropy surfiice, showing evidence of normal weathering previous 

 to quarrying. A small amount of foreign clastic material occurs mixed 



