258 TUE MARQUETTE IRON-BEAEING DISTRICT. 



forms a great westward-plunging syncline, with the eastern termination in 

 sees. 5, 6, 7, and 8, T. 47 N., R. 26 W. 



However, the folding in the two areas east and west of Goose Lake is 

 interesting and j^eculiar. In sees. 13 and 24, T. 47 N., R. 26 W., and sees. 

 18 and li), T. 47 N., R. 25 W., the slate has been affected by both an east- 

 west and a north-south folding. The north-south pressure has folded the 

 slates into a series of minor rolls, and the same layer is repeated many 

 times. Tlic east-west pressure has bowed the slates into anticlines and 

 synclines. The character of this folding is particularly well shown by the 

 almost continuous sections which are observable along the east jjarts of 

 sees. 13 and 24 and along the west side of the southeast arm of Goose 

 Lake (Atlas Sheets XXXIV and XXXV). A major anticline causes the 

 little east-west folds to plunge to the eastward on the east side of the area, 

 and to the westward on the west side. The slate originally arose above 

 the Kona dolomite of Kona Hills, but has been removed from it by erosion. 



West of Goose Lake (Atlas Sheet XXXV) it has been said that the 

 slate covers a belt of greatly varying width, in which are Archean islands. 

 The largest of these areas covers a considerable part of the central por- 

 tion of sec. 23. Another area is southwest of this, in sees. 22 and 23, 

 and two other areas occur in sec. 22, one at the center of the section and 

 the other in the center of the southwest quarter. The conglomerates, 

 slates, and quartzites in sec. 23 and in part of sec. 24 have a quaquaversal 

 aiTangement around the oblong" Archean area of sec. 23. In other ^\-ords, 

 the slates and quartzites constitute a part of a northwest-southeast anticline 

 which plunges both to the east and to the west from the center of sec. 23. 

 The strikes about this and the other areas are northwest-southeast except 

 at the ends of the areas; the dips are all to tlie northeast, showing that the 

 folds have been pushed over from the northeast or pushed under from 

 the southwest. The dispersed distribution of the small Archean patches 

 and the fact that basal conglomerates cover a considerable area are taken to 

 indicate that there are several subordinate folds in this part of the district. 



PETROGRAPHICAL CHARACTER. 



Macroscopicai. — For tlic arcas north and east of Goose Lake the rocks of 

 the formation are slates and graywackes. Southwest of Goose Lake the 



