TRAP, ALTERED ROCKS AND BITUMEN OF HAUGHMOND HILL. 265 



Longmynd, of conglomerate, slaty sandstone and schist. It is cut through on its south- 

 eastern side (the Warren) by syenitic trap and greenstone, composed principally of flesh- 

 coloured felspar with some hornblende and quartz. The schist and sandstone near the 

 flanks of the trap are in vertical beds, striking due north-east and south-west. 



At Ebury Wood, the northern termination of this elevation, another boss of trap has been laid 

 bare by clearing away the surrounding strata of altered and indurated strata. It appears that the 

 trap at this spot, protruding in a dome-like or sub-conical form, has thrown off the slate and purple 

 sandstone on all sides. These strata are very brittle, and break into prismatic fragments. Their 

 faces are sometimes coated with serpentine and films of anthracite. The trap is grey, granular 

 felspar, with very fine acicular crystals of common felspar and a little disseminated carbonate of lime, 

 It passes into a sandy-looking granular rock with small crystals of felspar and grains of quartz. 



In ascending the hill from Downton and proceeding to the north-east we find the 

 slaty rocks in nearly vertical positions, and on reaching the summit of the " Warren " 

 they give way to and are entirely cut out by a large mass of trap, which there protrudes 

 in rugged lumps from ten to twelve feet above the turf. This mass is composed of 

 syenite and syenitic greenstone, as above mentioned, and is about a quarter of a mile 

 wide. To the north-east it sinks beneath indurated siliceous sandstones, passing 

 into quartz rock, in the same manner as on the sides of the Wrekin and Caradoc. 

 This line of eruption is parallel to that of Ebury, and although the trap is not visible 

 upon the surface beyond the Warren, the linear direction of the outburst is marked for 

 a mile to the north-east by a zone of dislocated and altered rocks, the last of which is 

 seen near the four cross roads between Haughmond and Ercal. The highly indurated 

 and apparently altered strata which appear in various parts of Haughmond Hill, whether 

 at the ascent near the Abbey or at the Criftin, are all indicative of changes similar to 

 those described in chapter 18. at the Wrekin, Charlton, &c. 



The most remarkable appearance connected with the trap of Haughmond Hill is at 

 Downton, its south-eastern extremity. At a small knoll near the farm-house, the beds 

 of slaty sandstone are thrown off in opposite directions, as at Ebury, from an under- 

 lying irregular protuberance of felspathic trap, which has been .quarried down below 

 the ordinary surface of the adjacent ground, as rudely expressed in this wood-cut. 



38. 



a. Slaty schist and flagstone (Cambrian) forming the mass of Haughmond Hill. a*. The same resting upon trap, has 

 been cleared away from the underlying trap on the sides, b. Trap rising in irregiilar bosses, the schist in contact highly 

 altered, c. Vein proceeding from the floor of trap, filled with bitumen and fragments of schist, &c. 



