545 



The Geology of Mount Remarkable. 



By Walter Howchin, F.G.S., Lecturer in Geology and 

 . Palaeontology, University of Adelaide. 



With Petrographical Notes on the Basic Igneous Rocks of the 

 Foot Hills of Mount Remarkable, by E. O. Thiele, D.Sc. 



[Read September 14, 1916.] 



Plates LIII. and LIV. 



CONTENTS. 

 I. Introduction ... ... ... ... ... ... 546 



IT. The Geological Succession ... ... ... ... 547 



a. Lower Cambrian : — 



1. Lowest (?) Beds Exposed ... ... ... 547 



2. The Main Quartzite 548 



3. The Tillite 549 



4. Ribbon Shale (Tapley Hill Series) 550 



5. The Limestones (Brighton Series) ... ... 551 



(a) The Limestones in the Western Out- 



crops ... ... ... ... ... 551 



(b) The Limestones in the Northern Out- 



crops ... ... ... ... ... 552 



(c) The Limestones in the South-eastern 



Outcrops ... .:. ... ... 554 



b. Upper Cambrian : — 



Purple-slates Series ... ... ... ... 558 



(a) The Western Outcrops ... ... 559 



(b) The Northern Outcrops 559 



(c) At the Southern end of the Mount 560 



(d) On the Eastern side of the Mount 561 



III. Igneous Intrusions ... ... ... ... ... 563 



Group (a) On Northern side of the Cathedral- 

 rock Creek 563 



,, (b) On ridge and slopes on Southern 



side of the Cathedral-rock Creek 564 



,, (c) In Creek next above Cathedral-rock 



Creek ... 567 



„ (d) On Eastern side of the Mount 



Remarkable Creek ... ... 568 



IV. Tectonic Structure ... 568 



1. The Great (?) Meridional Fault of the Range ... 569 



2. The Great Western Fault 572 



3. The Great East and West Fault at Northern end 



of the Mount 572 



4. Tectonic Features of the Eastern side of the Mount 574 



5. The Great Fault at the Southern end of the Mount 576 



V. Summary and Conclusions ... ... 578 



VI. Appendix. 



Petrographical Notes on the Igneous Rocks, by 



E. 0. Thiele, D.Sc 580 



