472 C. H. HITCHCOCK — AMMONOOSUC DISTRICT, NEW HAMPSHIRE 



cases the crevasses have been conspicuously filled, by veins of white 

 quartz. It is as easy to determine the original line in the formation as 

 to recognize the outline of a chimney that has fallen down.* 



The language descriptive of the frag mental condition of the crust of 

 the earth in the Ammonoosuc district is also applicable to the crystal- 

 line and Triassic areas of the southwest part of Connecticut,f according 

 to Professor W. H. Hobbs. He finds the fractures correspond to several 

 systems of joints. The two regions may be said to correspond in respect 

 to the origin of the mosaic structure, but the displacements have been 

 greater apparently in the more northern district. 



Other Conglomerates 



Secondly, there are other conglomerates of a very puzzling character. 

 The abrupt termination of the auriferous conglomerate at its northern 

 end south of Youngs pond has been mentioned. Its place is taken, 

 nearly along the line of strike, by a coarse mass almost suggestive of till 

 because of the miscellaneous arrangement and size of the fragments of 

 green and white schist, some attaining 2 feet in length. It may be 

 followed for 3 miles to the edge of Littleton, passing to the west of Mor- 

 mon hill, which is also full of conglomerates. Slate, conglomerate, and 

 argillitic schist are so intermingled that often any one of the three might 

 be considered as a lens imbedded in the mass of either of the two others. 

 These conglomerates dip southeasterly toward Blueberry mountain, at 

 whose base is another mass of rounded fragments called familiarly by 

 us the " egg conglomerate," some pieces attaining the size of an emu's 

 egg. The two may possibly run into each other. 



Still another conglomeratic group folio ws the course of the A mmonoosuc 

 river between the villages of Lisbon and North Lisbon for 5 miles. The 

 first one underlies the bridge at North Lisbon. The pebbles in it are 

 white and blue quartz, hydromica schist, two or three gneisses, slates, 

 calcareous bits, with an argillo-micaceous paste. The source of the 

 handsome grains of blue quartz is unknown. Some pebbles are a foot 

 long, some have been bent, flattened, and distorted. The dip is 65-70 

 degrees north 22 degrees west. A similar rock with friable cement crops 

 out opposite the mouth of Walker brook on the east side of the river 

 adjacent to a hornblendic mass. It is more strongly developed on the 

 west side of the hornblende at the W. K. Chase house of the county 

 map (or G. Conrad of D. H. Hurd and Co.'s atlas), and is continuous 

 to the school-house at the bridge over the Ammonoosuc near the rail- 

 road. In front of W. Bishop's house the pebbles have been very hand- 



*For a good map of these disturbances see Geology of New Hampshire, vol. 2, p. 296. 

 f Bull. Geol. Soc. Am., vol. 13, and also the present volume. 



