350 J. H. Coolte — Geological Notes on Oozo. 



The southern slopes are very uniform in outline ; but those on the 

 northern side are divided into a series of smaller valleys or gullies, 

 down which miniature torrents pour their waters for a few occasional 

 hours in the winter time. 



The deposits of which the valley is composed do not consist of 

 the Lower Coralline Limestone as is represented in the Geological 

 Map of the Island, which was published by Ducie, Spratt, Adams, 

 and Murray. On the contrary, the Lower Limestone is entirely 

 absent save where it is exposed along the lines of faults that bound 

 the valley ; and the deposits consist of all of the beds that are found 

 interstratified between the uppermost and the lowermost of the series. 

 The Globigerina Limestone is the predominant rock ; but the blue 

 and yellow clays, ^ and the Greensands,^ are also to be found in situ 

 along the southern slopes. 



Fringing the upper portion of the sides of the valley the Lower 

 Limestone may be seen marking the line of fault, with the Globi- 

 gerina beds of the undisturbed district above it, and those of the 

 depressed area beneath it. The. former relation that existed 

 between the depressed area and its surroundings is therefore 

 distinctly apparent. 



1 have entered thus into detail because some misapprehension 

 appears to have formerly existed with reference to the geology of 

 this part of the island. Instead of being a valley of erosion similar 

 to the Kaura, the Scini Sclendi, Asel and the Yehbug gorges, it is 

 simply a depressed area, which has been let down by the dislocation 

 of the strata on either side of it. It is also important that these 

 details should be carefully considered; as on their correct repre- 

 sentation depends the evidence that must be adduced for proving the 

 the relationship which formerly existed between the Pleistocene 

 deposits found in the valley below the line of fault, and those found 

 on the summit of the slopes above it. 



It was while engaged in noting the points of difference between ' 

 the geology of the district, as it is represented on Ducie's map, and 

 that which actually exists, that I first came across the Pleistocene 

 bed which I am about to describe. 



Starting at the head of the valley and proceeding towards its 

 mouth, the Globigerina strata will be observed sloping down the 

 valley side at angles of varying magnitude ; and breaking off 

 abruptly towards the lower part, thus forming cliffs of from 10 feet 

 to 15 feet in height. Fringing the slopes that lie beneath these 

 escarpments, there is a bed of white limestone, overlying a bed of 

 yellowish grey loam. 



The deposit maj' be traced for some distance down the valley ; 

 but in some places owing to the denuding action of several small 

 streams, that have cut their way, it will be found to occur in 

 patches only. 



It is elevated at a height of from 20 to 30 feet above the present 

 bed of the valley ; and it extends, East and West for a distance of 

 about thirty yards, and North and South for about fifteen yards. 

 1 Bed III. 2 Eed II. 



