6 THE GEOLOGY OP TYTHERINGTON AND GEOVESEND. 



Stone" there are black bands of limestone giving a bitumi- 

 nous odour when freshly broken. 



It is difficult to assign with any degree of certainty the 

 position of the "Tire-stone" beds in the Limestone series, 

 owing to the reversed fault which breaks the continuity 

 of the strata. The same beds appear, however, on Tyther- 

 ington Hill, so that their strike can be laid down on the 

 map, while the point where they cross the line can be 

 readily determined. In the field near the Station beds of 

 somewhat silicious limestone occur ; they probably belong 

 to the Upper Limestone Shales, for in the barton of Mill 

 Farm (see map), beds of grit are exposed, overlain by Base- 

 ment Beds of the Trias. The distance from the strike of the 

 " Fire-stone " beds to the uppermost Limestone bed visible 

 in this field, measured across the dip, is 750 feet. The dip 

 of the beds is 34°. Calculating on this basis, I find the bed 

 in the Station field to have a position of about 420 feet 

 (vertically) higher in the series than the " Fire-stone." 



Sub-section 2. — A very interesting feature of the section 

 is the reversed fault. It is unfortunate that no sketch- 

 section of the beds here shown was published at the time 

 when the line was formed. I give one (Fig. 1) as it now 

 appears. The beds of Mountain Limestone have been 

 thrust up along their dip faces over Basement Beds of the 

 Trias. The line of fault, as seen, makes with the horizontal 

 an angle of 20°. The irregular nodules at a consist of 

 marly limestone. They protrude from yellowish-white 

 calcareous marl. It is strange to see Mountain Limestone 

 overlying, apparently un conformably, beds of a far more 

 recent age. The existence of the fault, however, at once 

 explains matters. There are no data for estimating the 

 throw of the fault, but I do not suppose it is of any con- 

 siderable magnitude. 



