Dale — Ordovician Outlier at Hyde Manor in Sudbury. 97 



Art. XII. — The Ordovician Outlier at Hyde Manor in 

 Sudbury, Vermont ; by T. Nelson Dale.* 



In a paper on the geology of the north end of the Taconie 

 Rangef the writer called attention to the generally divergent 

 strikes of the Lower Cambrian and Ordovician in the town of 

 Sudbury, Yt., as a key to the perplexing geology of the western 

 side of the Taconie Range. These were regarded as pointing 

 to a crustal movement at the close of Lower Cambrian time 

 which raised the Cambrian beds, west of the later formed axis 

 of the range, above water, and to their submergence in Ordo- 

 vician time, which was followed, at the close of Ordovician 

 time, by another movement which refolded the Cambrian beds 

 with the Ordovician, in places producing a folded overlap pos- 

 sibly accompanied by minor faulting. One of the pieces of 

 evidence offered was a small outlier of Ordovician limestone 

 in what was then the golf course of Hyde Manor, about 1^ 

 miles SSE. of Sudbury village and 5-J- miles about WSW. of 

 Brandon, in Rutland County, Yt.J 



Dr. Rudolph Ruedemann, Assistant Paleontologist of New 

 York State, in a recent paper§ reproduced a part of the 

 writer's plate from this Journal and referred to the outlier in 

 these words: 



" It is there quite probable that the whole folded plate of 

 Cambric rocks has been pushed along a slightly inclined fault 

 plane from the east over the Lower Siluric rocks, and that the 

 outlier of Stockbridge limestone does not rest in a small syn- 

 cline of the Cambric, as it would seem, but protrudes from 

 below the Cambric or is a " Fenster," as the European geolo- 

 gists term it (an outlier of younger rock protruding through 

 older rock in consequence of extensive overthrust and partial 

 weathering away of the overthrusted mass)." 



In July and August, 1910, the writer spent a few days at 

 Hyde Manor in order to determine the real relations of the 

 outlier and with the aid of two men and dynamite four exca- 

 vations were made. The distances between outcrops and 

 excavations were measured with a steel tape. Thin sections 

 of the schist underlying the outlier on the north side and 

 overlying it on the east were examined microscopically to fix 

 the directions of bedding and cleavage. In May, 191 L, the 



* Published by permission of the Director of the U. S. Geol. Survey. 



f This Journal, Ser. 4, vol. xvii, pp. 185-190, pi. xi, 1904. 



jlbid., p. 187, footnote, also p. 189, middle, pi. xi, black dot on section. 



§ Rudolph Ruedemann: Types of inliers observed in New York, N. Y. 

 State Museum Bull. No. 133, 5th Rept. of the Director, 1908, Albany, 1909, 

 pp. 190, 191, fig. 33. 



