BULL. GEOL. SOC. AM. 



VOL. 25, 1913, PL. 17 



Figure 1. — Pillow Basalt 



Showing radial jointing (in the two upper masses), flattened pipe-like vacuoles (in the 

 lower ellipsoid), and interstitial tachylite breccia, cemented by zeolites, etcetera. Secondary 

 minerals are also developed in the pipe-like cavities. The hammer is one foot long. The locality 

 is the quarry of Francisco Bros., at Great Notch, New Jersey. 



Figure, 2. — Glaciated Surface of Ely Greenstones, sih)wing 



ELLIPSOIDAL PARTING" 



Photo- 



The locality is one mile east of Soudan, Vermilion iron-bearing district. Minnesota, 

 graph by the U. S. Geological Survey. Monograph xlv, plate iv-A 



PILLOW BASALT AND GLACIATED SURFACE OF ELY GREENSTONE 



