De Lautour. — On a Diatomaccous Deposit. • 293 



which is from forty to fifty miles south-west of the position of 

 the epicentrum. 



Certainly, Professor De Eossi has stated that in the neigh- 

 bourhood of Rome the rock-fissures form axes of propagation 

 of the earth-wave, the movement being at first parallel with 

 and then at right angles to the axis of the fissure ; but the 

 even outward spread of our earthquake shows no such connec- 

 tion, and we do not yet know the geology of the district suffi- 

 ciently well to say where the fissures are. In our case time- 

 observations point to the conclusion that the locus of the 

 centrum w^as small and without any well-marked seismic 

 radiant like those so often found in other earthquakes, and I 

 should therefore conclude that our earthquake was not due to 

 splitting, or movement along a fissure, but to the crushing of a 

 compact mass of rock. 



Art. XXXIII. — On the Fossil Marine Diatomaceous Deposit 



near Oamarii. 



By Harry A. de Lautour, M.E.C.S.E. 



IBcad before the Otago Institute 12th June, 1SS8.] 



Plates XVIII-XXIII. 



Considerable interest has been excited in scientific circles 

 throughout the world by the reports of Messrs. E. Grove 

 and G. Sturt on the deposit of diatomaceous earth found at 

 Cormack's siding, near Oamaru, which were published in 

 the " Journal of the Quekett Microscopical Club.'"'- 



The attention of these gentlemen was drawn by Mr. H. 

 Morland to a specimen sent home to the Colonial Exhibition 

 in 1886, and further specimens were given them by the late 

 Sir Julius von Haast. 



It is not quite clear who sent the original specimen to the 

 Colonial Exhibition, neither does it matter very much. Cer- 

 tainly, early in 1886 the late Resident Magistrate here, Mr. 

 H. "W. Robinson (now Resident Magistrate at Wellington), 

 received a circular letter from Dr. Hector (now Sir James 

 Hector) asking for specimens of various kinds from this dis- 

 trict. Mr. Robinson consulted me on the matter, and I sug- 

 gested that amongst other things he should send some peculiar 

 earth, which I then thought was a form of kaolin, from Cor- 

 mack's siding. Cave Valley. My attention had been drawn 

 to this deposit by Mr. A. McKay, of the Geological Depart- 



* " Journ. Quekett Micr. Club," IGth September, 1886; 17th January, 

 1887 ; 18th May, 1887 ; and 19th August, 1887. 



