GEOLOGY OF THE GLOUCESTER DISTRICT, N.S.W. 



261 



Table of Analyse* 





T. 



II. 



III. 



IV. 



V. 



VI. 



Si0 2 



69-82 



74-56 



77-76 



77-82 



75-06 



55-64 



A1 2 3 . 





12-41 



12-87 



9-94 



11-46 



14-21 



17-70 



Fe 2 3 . 





1-10 



1-80 



1-15 



0-30 



1-3-1 



7-85 



FeO 





054 



0-36 



0-59 



0-09 



0-27 



1-75 



MgO 





0-29 



0-29 



0-18 



0-23 



0-09 



1-46 



OaO 





1-86 



0-28 



0-24 



0-22 



0-42 



1-31 



Na 2 . 





4-63 



4-91 



0-86 



0-86 



6-88 



8-51 



K 2 . 





1-67 



3-43 



7-75 



7-19 



0-58 



1-20 



H 2 O(100°C.) ... 



1-05 



0-35 



0-38 



0'36 



0-56 



0-72 



H 9 O(100°C. + )... 



6-55 



0-91 



1-00 



1-40 



0-62 



2-24 



C0 2 



0-03 



0-01 



003 



0-03 



— 



0-04 



Ti0 2 



0-25 



0-40 



0-15 



0-02 



absent 



1-45 



ZrO 



— 



absent 



absent 



— 



— 



— 



P 2 0, 



0-05 



0-04 



003 



0-04 



0-03 



0-11 



so 3 



absent 



absent 



absent 



0-07 



o-u 



trace 



CI 



trace* 



trace* 



trace* 



— 



— 



trace 



S(FeS 2 ) 



absent 



absent 



absent 



— 



— 



absent 



Cr 2 3 



absent 



absent 



absent 



— 



— 



o-oi 



NaOandCoO .. 



trace* 



absent 



absent 



— 



— 



absent 



MnO 



0-03 



03 



0-02 



trace 



0-04 



0-25 



BaO 



0-02 



0-04 



002 



0-02 



— 



0-01 



SrO 



tracef 



tracef 



tracef 



— 



— 



tracef 



Li0 2 



absent 



absent 



absent 



trace 



absent 



absent 



v 3 o 5 



absent 



absent 



absent 



— 



absent 



trace 



Total 



100-30 



100-28 



100-10 



100-11 



100-18 



100-25 

 2-721 



Specific gravity ... 



2-266 



2-622 



2-582 



— 



2-604 



* Less than - 01% f Spectroscopic reaction only. 



Summary. 

 The Devonian strata which occur in the Gloucester 

 District are similar to those already described from other 

 parts of north-eastern New South Wales by Prof. W. N. 

 Benson, they indicate the deposition of very fine sediments, 

 together with enormous numbers of silicious radiolarian 

 skeletons upon asea bottom, which may have been fairly deep 

 and was far removed from any shoreline; sub-marine vol- 

 canic activity was a pronounced feature during this period. 

 Important crustal movement took place throughout the 

 greater part of New South Wales at the close of the 



