GEOLOGICAL SECTIONS. 53 



means of observing the strata ; although perhaps not 

 of great depth, their length is sufficient to bring on, 

 it may be, several beds that are slightly out of hori- 

 zontal position, and to show them in their actual 

 superposition. 



The points of which special notes have to be made 

 are, the kind of rock of which the bed or series of beds 

 consists ; the number, thickness, and sequence of those 

 beds, their apparent dip and its .bearing ; also the true 

 dip if it can be obtained. All peculiarities must be 

 sought out and noted, such as false- or current-bedding, 

 cleavage, concretions, signs of fracture, slickensides, and 

 so on the lines of bedding and jointing observed, and, 

 in short, anything and everything that can be detected 

 and described. (The modes of determining the nature of 

 the rocks are described in Part III. ; and of finding, col- 

 lecting, and preserving the included fossils, in Part IV.) 

 Notes. As illustrations of the manner in which pit 

 sections are observed and noted, we may select those that 

 occur in the area supposed to have been surveyed, and 

 which is represented in figs. 5, 6, 7, and 8. In the first 

 slip, fig. 5, soon after starting, we came upon an old pit, 

 nearly overgrown, but of which some notes must be taken, 

 (a.) In the lowest part of this pit we find, after re- 

 moval of the fallen soil, a fair section of fine light sand, 

 with many green-looking grains scattered amongst its 

 other component particles. Some lines of bedding can 

 just be made out, and these appear to be horizcfntal or 

 nearly so, but they are not defined sufficiently for a dip 

 to be taken from them, and in one place a thin broken- 

 up seam of harder sand, almost a stone, occurs. Some 

 elongated lumps of whitish material are imbedded in the 



