Dale — Ordovician Outlier at Hyde Manor in Sudbury. 101 



solid schist and went a foot into it. At the end of another foot 

 the core barrel became clogged and was left in the hole with its 

 core. As the limestone of the outlier contains some dark sericitic 

 streaks, the calcitic, quartzose sand with schist particles, brought 

 up by the drill, is evidently finely ground weathered limestone. 

 The cores obtained consist of 4-4 inches of limestone, and 45 

 inches of schist in 9 pieces. The pieces of schist all have a 

 marked easterly dipping cleavage and one piece, an inch thick, 

 has a quartz lamina crossing the cleavage. The diameter of this 

 core along the cleavage is 2^ by 2\ in.* 



Conclusions. — The isolated mass of Ordovican limestone on 

 the old golf course of Hyde Manor in Sudbury, Yt., is sur- 

 rounded and underlain by schists of Lower Cambrian age upon 

 which it rests unconformably and with which it is interfolded in 

 synclinal attitude, and with which it is also interfolded on a part 

 of its northern side in a direction at right angles to the strike, 

 as shown in the section of fig. 1 and diagrams A-F and H 

 of fig. 2. This interfolding of the two formations reappears 

 40 ft. northwest of the outlier, where a small limestone fold 

 with an axial plane dipping 45° E. has a pitch lying in an 

 E.-W. vertical plane. 



In view of the evidence, the application of the "Fenster" 

 theory of Alpine geologists to the relations in Sudbury as 

 shown in diagram Gr of fig. 2 is quite untenable. Yaluable as 

 is the use of the imagination in geological investigations, geo- 

 logical science is still best advanced by careful observation and 

 induction. In this instance the induction has been verified by 

 physical demonstration through core-drilling. 



The main mass of Ordovician limestone west of the outlier 

 is probably continuous with that interfolded with the Cam- 

 brian schists at excavations 4 and 5, and was, of course, once 

 continuous with the outlier or the beds adjacent to it. A little 

 north of the latitude of the outlier a well marked anticline 

 appears in the Ordovician limestone and the alternation of 

 tongues (synclines) of Hudson schist and of Ordovician limestone 

 shown on the map of the original article on this locality! 

 calls for such an anticline at that point, but the outlier is so 

 near a Hudson schist tongue on the southwest that the anti- 

 cline can hardly be developed there nor is evidence of its pres- 

 ence obtainable. 



The general importance of the outlier is that it is as yet the 

 only point iu Western Yermont and Eastern New York where 

 the Ordovician can be seen unconformably on the Lower 



* As questions may arise as to this drilling the names of the workmen are 

 given : Geo. McBride of Brandon and Dennis Sullivan of Sudbury. Mr. C. E. 

 Connell of Brandon was also present when the solid slate was struck at depth 

 of 11 ft. 6 in. from surface. 



f This Journal, vol. xvii, pi. xi, 1904. 



