100 Dale — Ordovician Outlier at Hyde Manor in Sudbury. 



Excavation 2 (fig. 2, B). — At the northern edge and near its 

 western side schist and limestone were found in contact along a 

 steep E.-W. line, but at a depth of 5 ft. the schist was found to 

 underlie the limestone. Both rocks have a cleavage foliation 

 dipping 55° roughly E. But that of the schist dips SE. while its 

 bedding dips 75° NW. and the lower contact surface of the lime- 

 stone about 8° E. That this probably corresponds to bedding is 

 shown at a point east of one of the elms, where a small plicated 

 bed of dolomite in the limestone is about horizontal and its plica- 

 tions strike N. 15° W., which is one of the strikes typical of the 

 Ordovician in Sudbury. Near the elm this horizontal bedding 

 crosses a low easterly dipping cleavage, but on the east side of 

 the outlier the small dolomite beds dip east, about with the 

 cleavage. 



Excavation S. — Here a trench was dug 3 ft. deep through soil 

 to the schist and this was exposed by blasting to a depth of 14 

 inches. The schist foliation dips 40° eastward. 



Excavation 6 (fig. 2, C). — A trench was dug from the Cam- 

 brian schist north or northeast of the northeast corner of outlier, 

 and the contact of schist and limestone was exposed by blasting. 

 Both rocks were found to be interfolded in a direction at right 

 to the strike but their relations deeper down were not determined. 



Outcrops near elms (fig. 2, D). — These elms are on the west 

 side of the outlier. One is growing on it, and schist crops out 

 in contact with limestone and has a foliation dipping east under 

 it. South of the other elm the two rocks are within a few inches 

 of each other. 



Excavations Jf and 5 (fig. 2, E). — Here a little trenching 

 exposed a surface of schist 10 ft. long doubled on itself and 

 embracing on the south a limestone fold, 5 ft. thick at its widest 

 part. Two openings were made : one on the line of section 

 showed the limestone dipping about 45° E. betw T een two schist 

 masses to a depth of at least 5 ft. The other exposed the apex 

 of the fold with an axial plane dipping 45° E. The bed surface 

 of the apex (not its solution surface) lies in a vertical E.-W. 

 plane and the schist surrounds the apex. The strike is N.20E. 



Limestone ledge west of outlier. — This contains crinoids and. 

 has a marked foliation dipping eastward and entered on map as 

 cleavage. The course of bedding is not clear. 



Core-drill hole (fig. 2, F). — In May, 1911, one or two charges 

 of dynamite were put in at the point indicated on the map by a 

 star which is about 10 ft. NE. of the northern elm. The lime- 

 stone became exposed to a depth of 2 ft. 1 in. At this depth 

 Mr. Charles E. Connell, Supt. Brandon Marble Co., on Dec. 1, 

 1911, had a core drill put in, using crushed steel for an abrasive. 

 After penetrating 5 inches of limestone the drill crossed 9 ft. of 

 soft rock, which it ground up mostly into sand. This effervesces 

 strongly with dilute HC1 and under the microscope shows parti- 

 cles of calcite, quartz and schist. The magnet extracts consider- 

 able fine steel due to the abrasive. On Dec. 2 the drill struck 



