REPOET ON MATERIALS FROM THE BORINGS AT FUNAFUTI ATOLL. 



803 



(5) Notes on the Cores from the Second Boring "D" (Sollas, 72 Feet). 



The second boring (D), undertaken by Professor Sollas in 1896, was situated 

 further to the south of the Mission Church than the first, and on the ocean side of 

 the reef'"' 'Jlie bore-hole was carried down to a depth of 72 feet from the surface, 

 when it became choked with debris and had to be abandoned. No samples of thef 

 rock between the surface and 12 feet below appear to have been brought to England ; 

 between 12 feet and the bottom of the boring, 72 feet, the length of the solid cores 

 obtained was 12 feet 5 inches, which would average a little over 1 foot of solid core 

 in each 5 feet of the actual boring. The distribution of the cores in various parts of 

 the boring is shown in the following table : — 



Depth from 

 surface in feet. 



Distance laored 

 in feet. 



Length of cores. 



Numbers of 

 cores. 



0-12 

 12-20 

 20-30 

 30-40 

 40-50 

 50-60 

 60-72 



12 

 8 

 10 

 10 

 10 

 10 

 12 



ft. in. 



1 4 



10 



1 2 

 3 

 3 7 



2 6 



D. 1-D. 4 

 D. 5-D. 10 

 D. 11-D. 17 

 D. 18-D. 35 

 D. 36-D. 57 

 D. 58-D. 74 



72 



12 5 



Some of the cores are cylindrical with the same maximum diameter as those of the 

 First Boring (C), viz., 3^ inches (80 millims.), but the larger number are fragments 

 of cores, often rounded into nodules by the drill, or irregular in shape. The cores 

 further resemble those of the First Boring in having their surfaces covered in places 

 with small shallow pits, probably the work of boring organisms, and in these pits 

 colonies of a small species of Spirorbis have become attached. 



The character of the rock forming the cores is very uniform throughout the 

 boring. It is a cream-coloured or greyish-white hard limestone, generally compact, 

 but occasionally porous where the interstices of corals have remained empty. 



To a very large extent the solid cores are composed of corals which retain their 

 form and structure throughout, but their characters are often very much obscured 

 by the way in which the interseptal and intercostal spaces, and the pores in the 

 perforate forms, are now solidly infilled with sclerenchyma or with crystalline fibrous 

 material, so similar to that of the coral tissues, that these latter can hardly be 

 distinguished unless in microscopic sections. The prevailing coral which forms the larger 

 part of nearly every core is Madrepora, and probably it is represented by the single 



* See Section I, supra. 



t Professor Sollas states that a pit was sunk from the surface to a depth of 1 1 feet through fragments 

 of coral, crystalline coral limestone, and partly consolidated sand (see p. 4, ^^irp'm). 



