﻿248 NEW YORK STATE MUSEUM 



Material : 



0-55 feet=el.+8 feet=modified drift (fine silts) 



55—155 feet— to-108 feet=micaceous soft material with 

 broken sand=decayed micaceous rock 



155-215 feet=to-i52 feet=reddish mud of similar constitu- 

 ents. Is decayed rock colored by iron 



215-240 feet— to-i "J7 feet=transition to more grayish and 

 greenish soft matter 



240-245 feet— to-182 feet=greenish mica rock=a decayed 

 chlorite, mica quartz, schist layer 



248.33-254.25 feet=from el.-185.35 to-191.25 feet=:chloritic 



Inwood limestone 



A summary of these data gives : 



0-55 feet=drift 



55-245 feet=decayed rock ledge 



248-254 feet=solid rock ledge (limestone) 

 / Hole no. 2 at 123d street, 100 feet east of Morningside Park East 



Surface elevation+30 feet 



Rock floor at depth of 220 feet=el.-i90 feet 

 Material : 



0—13 feet=to eL+17 feet=soil and mixed drift 



13-220 feet=to el-190 feet=modified drift=mostly assorted 

 sands and silts 



220-245 feet=to el-215 feet^soft decayed schist 



245-355 feet=to el-325 feet= Manhattan schist much broken 

 — poor core recovery — worst material at about 225-240 feet 

 and again near bottom. Formation evidently much shattered 

 and considerably decayed 

 g Hole no. 33 on 121st street, 300 feet east of Morningside Park 

 East 



Surface elevation+31 feet 



Rock floor at depth of 195 feet— el- 164 feet 

 Material : 



0-25 feet — soil and mixed drift 



25-195 feet=to el-164 feet— drift, mostly modified drift= 

 assorted sands and fine silts 



190-195 feet coarser material — pebbles 



195-200 feet=to el-169 feet=Inwood limestone, coarser lime- 

 stone of usual type 



200-237 feet=to el-206 feet=Manhattan schist 



Ordinary type and in good condition [for interpretation see 

 later comments] 



