l6 THE 1UII,])IN(; OK AX ISLAND. 



We mav find a prcscnt-dav illustration of this ancient process hv noting 

 what takes place in Christianstcd and the neighbourhood on the occurrence 

 of hcavv rains : the streams from the hills liring down large <|uantities of fine- 

 mud, sand, and even pebbles, and lodge them in the harbour. Even in the beds 

 of stone formed on our Long Reef, in a way to be noted later, we mav find a 

 few minute pebbles, which perhaps have been carried there attached to debris, 

 such as dried seaweed on the beach or uprooted weeds and bushes which have 

 drifted out from the land. Returning now to our search for evidence as to the 

 regular contributions to the Marl Formation, we find that somewhat similar 

 sections to that at Anna's Hope mav be seen, on a smaller or larger scale, at 

 several other points, witliout even leaving the eastern edge of the Central 

 Slope, and in some of them we shall find abundant evidence of the kind we are 

 looking for. 



The most important of these sections is at Cane Garden, wiiere the rocks 

 aie cut into bv the sea and form a low cliff for a considerable distance along the 

 shore. The lavers here are for the most part alternatelv soft and hard, the 

 soft layers often sandy and containing numerous foraminiferous shells and the 

 spines of sea-eggs, the hard lavers generallv containing the moulds of finger- 

 shaped corals, that is to say, the corals themselves have disappeared, have, in 

 fact, been dissolved out, while the sand or mud which surrounded them has 

 kept the impression of their forms. This is a remarkable change, but it is one 

 which is verv common in limestone rocks. Occasionallv, where a shell has 

 been dissolved out, a east of the interior remains; thus we may sometimes 

 meet with casts of volutes, and several kinds of bivalve shells. It seems also 

 that this dissolving out of parts of the limestone and its later solidification in 

 other spots has had a large share in tlie process of hardening, which has 

 taken place in the beds after their deposition as loose sand and mud; it has also 

 been the cause of the concretiois which will be noticed later. That the large 

 beds are sometimes broken through by a number of cross cracks, so as to re- 

 semble a building up oi separate blocks, is i)erhai)s caused bv contraction after the 

 hardening has taken place. This peculiarity is known by geologists as " jointing," 

 and is bv no means uncommon in the marl formation, though, as we shall see 

 later, it is much more marked in the blue-beach formation. Thus the section of 

 rocks at Cane Garden is a \-erv instructive one, for not onh' have we a great 

 number of beds piled one ovei- the other to a thickness, as measured bv the 

 present writer, of over 200 feet, but we learn that great changes have occurred 

 since the deposition of the material which forms these beds, changes wiiich 

 have been carried vi-rv far in the u])per ])art of the cliff, where the weather has 

 acted on the beds to an extraordinarv degree, so that all traces of the original 

 lines of stratification disappear, and the whole of the part afl'ected is converted 

 into a rather soft white marl; not only so, but this surface marl, owing, no 

 doubt, to expansion and contraction, as it becomes wet or drv. according to the 

 seasons, splits into irregular sheets roughlv parallel to the surface of the soil. 

 In this wa\ a false stratification arises, which ma\- often be seen in road-cuttings 



