1854.] WILSON CALIFORNIA GOLD-FIELDS. 315 



which seem to have fallen into the rent, previously to or during the 

 formation of the quartz-vein. 



It was in the highest part of this vein, and on its lower side 

 (fig. 4), that the gold was first discovered, and it was certainly the 

 richest portion of the rock ; for, having been tried at diiferent eleva- 

 tions, it is found to lose all traces of gold as it descends. At the top 

 of the hill the quartz-vein was in a state of decomposition, and of a 

 reddish colour ; and, besides gold, it here contained a large amount 

 of iron and slight traces of copper ; but the lower part of the vein 

 becomes white, glassy, and hard, and void of all traces of metal. 



Looking from the top of this hill, in a north-westerly direction, the 

 same quartz-vein can be seen cropping out in several other hills. 



The line which I subsequently travelled being parallel to the range, 

 there was little variety to notice ; surface-diggings only occasionally 

 occurred, which were similar to such as I had frequently seen. 



Greenstone Vein near Sulivan's Camp. — ilfter a few days I left 

 San Francisco and returned to the mines, intending to continue my 

 researches, commencing vsith a hill one mile to the eastward of Suli- 

 van's Camp. It was altogether of granite, with the exception of a 

 large vein of greenstone, passing through and dividing the hill into 

 equal parts. 



I traced the vein to the base of the hill, where it entered the gneiss 

 and passed on through the crystalline limestone and mica-slate. Its 

 section is wedge-shaped ; and so regularly did it decrease in thick- 

 ness, in descending towards the base of this hill, and again increased 

 in thickness in ascending the next hill, which was of slate, that an 

 approximative calculation of its depth (which cannot be very con- 

 siderable) might readily be made. It was evident that this vein was 

 of a much more recent date than the vertical metamorphic rocks 

 through which it passed in a well-defined course. It also crosses a 

 large quartz-vein in the slate. The crystalline limestone, a rock 

 without any particular line of cleavage, was greatly fractured, and the 

 crevices were penetrated by small lateral veins of the greenstone, 

 some of which are not more than half an inch in thickness, are ex- 

 cessively hard, and produce a metallic sound when struck against 

 another hard substance. It seemed evident with regard to this vein, 

 that there had been no great amount of disturbance since it was 

 formed, as is indicated by its close contact with the rocks through 

 which it passed. 



Toulumne River Diggings. — The Toulumne is a considerable 

 stream, nearly equal in its volume of water to the Stanislaus. Gold 

 is pretty equally distributed along its banks, and the workings paid 

 a good average to the miners. In passing from Jacksonville on the 

 Toulumne to Curtisville, I traversed a granitic district strewed with 

 fragments of the slate-rocks, which are no longer seen there in situ. 



Curtis Creek Diggings. — The diggings in Curtis Creek were tole- 

 rably rich, but not extensive ; and the gold found there was com- 

 monly coated with quicksilver ; indicating the existence of a vein of 

 that mineral in the vicinity. This is not peculiar to Curtis Creek, 



