SURVEY OF BUILDING STRUCTURES OF THE SIERRAN GOLD BELT, 1848-70 HEIZER AND FENENGA 



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adobe, sun-dried mud blocks several times larger than conventional 

 bricks. These were laid flat, usually without mortar. Adobe buildings are 

 seen most frequently in the centers of Mexican activity (Hornitos and 

 Sonora) but this material was adopted by others. The frugal Chinese, 

 who gleaned from the abandoned workings of other peoples, especially 

 appreciated this most economical building material. Brick was the 

 favored building medium of the Americans. It symbolized for them sub- 

 stance and permanence and its prestige is reflected in the widespread use 

 of brick facades for stone buildings. Some stone structures were also built 

 by Americans for New Englanders. Middlewesterners were accustomed 

 to building dry rock walls with stone cleared from fields; to building 

 frame structures on stone foundations; and to lining cellar walls with 

 mortar-laid stone. The stone masons par excellence were the Italians who 

 came to the gold fields. In the central and southern section of the Mother 

 Lode region a large proportion of the good stone buildings, especially 

 those of rhyolite tuff, bear Italian names. 



FIG. 1. Wall of old print shop at Mokelumne Hill showing details of 

 hand-chipped blocks of rhyolite tuff. 



The large number of ruins of stone, brick and adobe buildings may 

 be partly accounted for by the fact that the Sierra lies outside the earth- 

 quake region. If this area were subject to earth tremors the number of 

 standing walls would surely be much reduced. 



Rhyolite tuff, known locally as ' ' lava ' ' is one of the few stone mate- 

 rials which was quarried and transported beyond its local occurrence for 

 use as a building material. The reasons for its popularity can easily be 

 recognized. It is as durable as any material which was available in the 

 Gold Rush days but more important, is soft enough that it can easily be 

 dressed with the stone mason's adze. This workability permits the cutting 

 of long narrow blocks to serve as lintels over doors and windows ; the 

 dressing of all six faces of a block so that it can be squarely fitted with a 

 minimum of mortar ; the dressing of thin blocks for facing over a rubble 

 core ; and the use of the keystone. There are old rhyolite tuff quarries near 

 Fiddletown, Altaville and Mokelumne Hill and the high knoll which pro- 

 vided Altaville with its first building stone is still being quarried. 



Wherever it is immediately available, rhyolite tuff is used in the con- 

 struction of all four walls of buildings and occasionally for such ordinary 

 purposes as stone retaining-walls and fences. Beyond the limits of its 

 natural occurrence, it has been transported to such towns as Murphys, 

 San Andreas, Placerville, and Coloma, where it is employed to construct 

 decorative facades for buildings the other walls of which are made of 

 various local field rocks. 



A very similar stone as far as gross appearance and quality of work- 

 ability are concerned is tuffaceous sandstone derived from the Valley 

 Springs formation. There is an old quarry of tuffaceous sandstone at 

 Littlehales and buildings made from it are there and at Jenny Lind. 

 Several buildings in Campo Seco utilize tuffaceous sandstone for an 

 ornamental facade. 



Meta-andesite agglomerates, commonly called greenstones, occur in 

 a band of varying width along the entire western border of the Mother 

 Lode. In the immediate locale of its occurrence meta-andesite is employed 

 for most building purposes. Unlike the schists, it has no well defined 

 planes of cleavage, and unlike rhyolite tuff and sandstone, it is too hard to 

 be easily squared and dressed. In consequence these irregular blocks can- 

 not be set in a wall without the use of heavy mortar, such as mud, which 

 was occasionally used, or lime, which was commonly used. Greenstone 

 was seldom obtained from special quarries and it appears that surface 

 fieldstone (float) was the usual source. When it is used as a structural 



