48 NEW YORK STATE MUSEUM 



and in about a mile again joins the main fault. A well-defined 

 block of Black River-Trenton limestone is included between the 

 main fault and this branch and where the branch crosses the road 

 near the four corners the fault plane is exposed showing Trenton 

 in contact with dolomite. On the downthrow side of the main fault 

 here Utica black shale comes against the Black River-Trenton and 

 the shale dips 25 degrees away from the line of fracture due to 

 updrag during the faulting [see fig. 8] . 



GAL^^'AY FAULT NO. 2 



This is another branch of the Hoffman's Ferry fault which enters 

 the sheet one and one-third miles south-southwest of Galway ; 

 passes through the eastern edge of the village of Galway ; and 

 leaves the map two-thirds of a mile east-southeast of Parks Mill. 

 About a mile still farther eastward it seems to join Galway fault 

 no. I. The upthrow side is on the west and from Galway south- 

 ward a large w^edge of Black River-Trenton limestone is faulted 

 against the dolomite. The amount of throw^ is not definitely known 

 but at Galway it is quite certainly under one hundred feet. The 

 relations are well shown near the schoolhouse in Galway village. 

 Where the fault leaves the map the Little Falls dolomite comes 

 against the Theresa formation and the throw has increased to over 

 one hundred feet. 



About a mile northeast of Galway a small branch fracture strikes 

 north-northeast through Parks Mill and then dies out rapidly. The 

 fault plane is exposed in the bed of Glowegee creek where the 

 lower dolomite beds (with chert) are in contact with the passage 

 beds of the Theresa formation. 



BROAD ALB IN FAULT 



The Broadalbin fault strikes northeast-southwest along a very 

 straight line past the northern edge of the village of Broadalbin, 

 and is one of the few Mohawk valley faults with upthrow on the 

 east side. The fault plane is nowhere visible but the outcrops are 

 so distributed as to permit fairly accurate mapping. The down- 

 throw side is entirely of Canajoharie shale which outcrops near 

 the fault one and one-half miles west, and in the creek three-fourths 

 of a mile north, of Vail Mills ; and one mile south of North Broad- 

 albin. In large outcrops w^est and northwest of Broadalbin the 

 shale beds are considerably tilted. On the upthrow side the Little 

 Falls dolomite is exposed at only one place, three-fourths of a 



