82 TRANSACTIONS OF THE 
this paper. He holds to the idea that the cracks in which 
the gilsonite is found were formed by the gentle folding 
that produced the Uinta Valley syncline. He describes the 
appearance and properties of the gilsonite coming from 
near the surface where, through atmospheric agencies, it 
has lost its luster and become “pencillated” in structure 
(columnar at right angles to the wall). Sometimes a 
cuboidal structure is developed. 
Then follow descriptions of several important veins, 
the Duchesne, Bonanza, Cowboy, Culmer and smaller ones. 
Those range in thickness from that of a knife blade to 
18 feet. From a study of conditions he concludes that the 
gilsonite found its way into the fissures as a plastic mass, 
coming from below under pressure, and though of high 
viscosity, sufficiently fluid to be pressed between the grains. 
constituting the wall rocks. He frankly confesses his lack 
of ability to suggest the condition under which the gilsonite 
existed prior to its flow into the cracks. 
Eldredge quotes from Day an analysis of gilsonite as 
follows: 
Volatile! matter: oid oe aay 56.46 per cent 
Pixed Carbom..8 0:23 pap wae 43.43 
MAES STE) SURLY oR Meee ee .10 
99.99 per cent 
Ultimate composition. 
TAP IOT Wi a Res i iwt Geese 88.30 per cent 
FLVRRGSER ue cease ee 9.96 
eo ETL OT a aR MORO ane Be Oo Bi 1.32 
PASSAIC cinta ae hake hoi) Sieh cee te Gad 10 
Oxygen and Nitrogen, un- 
determined ois fs eis oe 
100.00 per cent 
Locke’? quotes the description analysis, etc., given by 
Blake", then add further details. He notes the fact that 
it is an insulator, that it appears to be composed of two in- 
aC AST, Mi VER IViOL. 1G) pi G2) 
