REPORT OP THE DIRECTOR AND STATE GEOLOGIST 1900 v97 



is occupied by anortliosite, the contact between the anortbosite 

 and the gneiss being found just south of Aideni Lair. Anjorthosite 

 occurs on. the hill in the extreme southeastern corner of Minerva, 

 a mile and a half from Pat pond. Excavation on McKee's farm 

 at the foot of the hill exposed the contact between anorthosite 

 and gneiss, and showed small amounts of pyrite and other 

 sulfids. A few small outliers of gabbro are to be mentioned, but 

 the present paper has to do principally with the relations between 

 the gneiss and the limestone, with a view to the recording of 

 such facte as bear on the question of the sedimentary, or non- 

 sedimentary origin of the gneiss and associated schists. 



It will be seen by an inspection of the map that the forms of 

 high relief are of gneiss, while the limestone is found occupying 

 the valleys. The largest area of limestone extends from Trout 

 brook, east of Olmstedville, to a point 3 miles northwest of the 

 town of Minerva. An outlier runs up the valley a mile beyond 

 Irishtown, and a second reaches over toward Dutton mountain. 

 Smaller areas occur east of Huntley pond, south of Black moun- 

 tain and along the Hudson, which is rapidly cutting its bed on 

 limeistone from the mouth of Cedar river to Blue Ledge. 



The crystalline limestone preserves the character which is 

 common to it in many other parts of the Adirondack area. It is 

 uniformly coarse grained and when much decomposed by weather- 

 ing it gives a coarse gi^avel-like soil. In the met amorphic proc- 

 esses to which the region has been subjected the limestone has 

 been very sensitive to pressure. It yielded most often along 

 certain planes where the dark silicates appear drawn out in flow 

 lines. Bands of dark silicates much squeezed and contorted, 

 several inches in width, result in this way, as well as rounded 

 masses, often several feet across. Many of these are well ex- 

 posed in the ledge near Mr Owen's house south of Dutton moun- 

 tain. Hornblende in large crystals is found associated with lime- 

 stone on the Minerva road just west of Olmstedville. Flecks of 

 graphite in the limestone are very generally conspicuous. The 

 graphite is commercially important however in but one locality 

 near the boundary line of Essex and Warren counties at the base 



