74 HORN EXPEDITION — GENERAL GEOLOnv. 



EXPLANATION OF PLATES. 



Index to Signs on the Sections. 



Pre-Camhrian — 



a. gneiss. 



yS. mica-scliists. 



y. quartzite. 



Eruptive Dykes (granite, etc), .r. 



Ordovician — 



a. quartzite. 

 /'. Sandstone. 



c. Dolomite. 



d. Fossiliferous Limestone. 



e. clay slate. 



/ Micaceous Slates. 



g. Mudstone with culies. 



Post-Ordovician Conglouierates. o. 

 Recent alluvinm. V 



(Figures 3, 8, 9 and 10 drawn })y R. Tate; Figures 1, 2, 4, .5, 6 and 7 drawn by 



J. A. Watt). 



Plate I. 



Fig. ]. — Section across McDonnell Ranges in the meridian of Ellery Creek. 



Vertical scale - - - - 2000 feet to 1 inch. 

 Horizontal scale ... 2 miles to 1 inch. 



„ 2. — Section across Soutli McDonnell Range, near Heavitree Gap. 



Vertical scale - - - - 1000 feet to 1 inch. 

 Horizontal scale - - - 800 yards to 1 inch. 



,, 3. — Belt Range seen from the south, showing Ordovician sandstone and 

 quartzite resting unconformably on Pre-Canibrian gneiss and mica- 

 schist. 



,, 4. — Section of Ordovician Strata north of George Gill Range. 



Horizontal scale - - - 1 mile to the inch. 



Vertical scale - - - 500 feet to the inch. 



