. Annual report . ion. Ripple or wave marks are frequently seen on the surfaceof its beds, in the cliff at the Little Silver mine on the Nipissing property. Mudcracks are occasionally present. While usually showing little evidence of disturbance,the greywacke is quite compact and does not split readily along the junction of manyof the beds. Normally, the greywacke passes upwards into quartzite, more or less impure, andthe latter into conglomerate, but at times the quartzite is lacking and the greywackgis succeeded by conglomerate. Where the members of the series are complete, as atsome p
. Annual report . ion. Ripple or wave marks are frequently seen on the surfaceof its beds, in the cliff at the Little Silver mine on the Nipissing property. Mudcracks are occasionally present. While usually showing little evidence of disturbance,the greywacke is quite compact and does not split readily along the junction of manyof the beds. Normally, the greywacke passes upwards into quartzite, more or less impure, andthe latter into conglomerate, but at times the quartzite is lacking and the greywackgis succeeded by conglomerate. Where the members of the series are complete, as atsome points along the eastern shores of lake Temiskaming, the conglomerate appearsto be succeeded without unconformity by what has been called the Lorrain arkose andquartzite, the latter of which is frequently interbanded with pebbly material. At two or three places, however, where the upper members of the series, con-glomerate or arkose, lie directly on the greywacke without the quartzite or other Bureau of Mines No. 4. 1913 Cobalt-Nickel Arsenides and Silver 83 intermediate member being present, the greywacke appears to have been eroded beforethe deposition of the overlying rock. On lot 4, in the twelfth concession of Lorraintownship, a striking contact, and unconformity, between the lower slate-like greywackeand overlying arkose is to be seen. The surface of the dark colored greywacke hasbeen broken into angular fragments, the spaces between which are filled in andcemented by the light colored arkose (Fig. 38). The feldspar grains in the arkoseare remarkably fresh, some of them retaining the pink color characteristic of ortho-clase or microcline.* This unconformity, between the greywacke and arkose, should in all probabilitynot be considered to represent a great time interval or period of erosion. To use aterm that has been employed in other regions, it may be called an interformationalunconformity. The unconformity is the only one that has been observed between members of theCoba
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectminesandmineralresou
