1869.] JOASS SUTHERLAT!^D GOLB-EIELD. 321 



intervals up stream, alternating with softer gneissose rocks and 

 micaceous schists, with an occasional thin bed of white felspathic 

 rock, c. Here gold is found in small scales by washing the over- 

 lying drift, which consists of a dark blue clay, containing rolled frag- 

 ments of red granite and quartz, and is overlain by yellowish clays, 

 gravel, and sand, all apparently arranged by running water. The 

 lower part of this stream runs through shingle, and finally between 

 steep banks of black alluvium, till it enters Loch Brora. Falling 

 into this loch from the north-east, AUt-Smeorail, or the Gordon-bush 

 burn, emerges near the road from a deep ravine, where the rocks are 

 well displayed. These dip E. and S.E. at a high angle, and consist 

 of flaggy quartzites and micaceous beds, with associated granitiform 

 rocks, red and pink, among which are h and c, and a few quartz -veins. 

 The granites never flex the neighbouring strata ; the quartz-veins 

 occasionally do. The gritty drift, or gold- wash, is here overlain by 

 reddish-clay and sand, derived apparently from the detritus of 

 Beinn-Smeorail, a conglomerate mountain capping unconformably 

 flaggy quartzose and gneissose beds. Old-town and Clais-mor burns, 

 both tributaries of the Brora from the east, run through red boiilder- 

 clay and over Old E,ed Sandstone, which is the underlying rock, to 

 the junction with the Clyne Oolite. No gold was found in either of 

 these two streams. 



The Coast, 



A very small quantity of gold was found at the head of the Clyne- 

 Millton burn to the eastward, where flaggy quartzites occur. Kin- 

 tradwell burn runs in a deep ravine cut through yellowish boulder- 

 clay. The channel is almost covered by boulders of granite and 

 sandstone ; but a small section of a rock in situ shows flaggy gneiss 

 dipping E.S.E. AUt-Choille is a deep and rugged ravine, the lower 

 part of which is cut through boulder-clay and soft oolitic sandstone. 

 Near the bridge the rocks are highly indurated and quartzose, con- 

 taining carbonate of iron in thin seams and drusy cavities. No gold 

 has been found either in Kintradwell or Allt-Choille. 



Glen Loth. 



The Loth-beg "Water runs its lower course over a red porphyritic 

 granite, resembling that of the Ord. In Sletdale burn, a tributary 

 from the west, a few flaggy gneissose rocks are seen above the bridge 

 dipping E.S.E. The course of this stream, in its upper reaches, is 

 over gravel and through peat moss, concealing the junction which 

 here takes place between the Lower Silurian and Old E-ed Sandstone. 



On the shoulder of the hill which bounds the opening of Glen 

 Loth to the east, large-grained porphyritic granite crops out, in 

 many places highly ferruginous. This rock is believed to persist 

 to the Ord of Caithness, as it is visible at intervals along the hill- 

 side, and forms the bed of the Culgower burn and the mountains 

 that overhang the opening of Strath TJUie or the Helmsdale valley. 



Pursuing the course of the Glen-Loth stream upwards, the rocks, 

 where visible in the escarpments of the lofty mountains to the left, 



