462 THE PEXOKEE lEON-BEARING SERIES. 



various sizets is toiiiul about each tost pit, althuuyh parts ot tlie rock hold 

 togethei' with sufficient linnness to yiehl large specimens of the conglomer- 

 ate. The pebljles and bowlders are well rounded. The character of the 

 pebbles indicates that thev liave been derived from the Southern Com- 

 plex, the Penokee and the Keweenaw series. ?'rom the last are coarse red 

 indurated sandstones, amygdaloids, coarse grained basic eruptives, quartz- 

 porphyries, and other varieties of rock. From the Penokee series the pebbles 

 are moj-e numerous than from either of the otliers, as would be naturally the 

 case since the exposed conglomerate is in contact with these rocks. The 

 pebbles belonging here are lean ore, banded jasper, magnetitic schist, chert, 

 chert-breccia, recomposed granite, and quartzite, the induration of which is 

 due to the enlargement of ([uartz-grains. From the Basement Complex 

 pebbles and bowlders are also very numerous, comprising white vein quartz, 

 gneiss, granite, and many varieties of crystalline schist. The pebbles from 

 all of these sources are charactei'istic of the series from wiiich they are 

 derived. Fo describe them in detail here would be but to repeat the litho- 

 logical descrijjtions given of them in the treatment of the formations of the 

 district. It is, however, to be remembered that in this area no crystalline 

 schist, gneiss, or granite has been found anywhere except in the vSouthern 

 Complex; no jasper, magnetitic schist, cliert-l)reccia, lean ore, or recom- 

 posed granite has been found in other than the Penokee series, while quartz- 

 porphyry and certain phases of the basic eruptives have been found nowhere 

 but in the Keweenaw series; so the evidence is as clear as any lithological 

 evidence can be that the various pebbles have been derived from the sources 

 assigned them. The test pits show, so far as the rock has any stratifica- 

 tion, that it lies in a horizontal position, and the character of the basal con- 

 glomerate alone wt»uld l)e sufficient to ))r()ve that we have to deal witli the 

 Eastern sandstone. P^ii'ther, the relation of the underlying rock to tlie 

 sandstone is shown in one test pit. After jtassing through a thickness of 24 

 feet of the conglomerate just described, the shaft penetrated the chert-brec- 

 cia of the Penokee series (p. 4()(i) clearl}' i)roving that this rock is earlier 

 than the conglomerate. Again, a, short distance northeast of these test pits 

 are others in sjindstone which in every respect is like the ordinary red 

 Eastern sandstone, and which show, so far as it is possible in test pits, the 



