Mr. Crean in the report of his explorations in 1909 states:—“The outcrop of tar-sand commences about thirty miles south of McMurray on Athabaska river. It continues to about forty miles below McMurray on the river. It extends to the east and west for at least thirty miles, and varies in thickness from twenty to two hundred and twenty-five feet, with probably an average of one hundred and fifty feet thickness. . . . . The value of this immense deposit on the Athabaska is not known. . . . . During the past season representatives of interests in England and France have made examinations of it on the ground. Should it be found to be capable of being converted to any commercial use, the enormous extent of it would ensure that industries of considerable public importance would be established in connection with it as soon as railway communication is provided. Since Mr. McConnell’s report was published, several other outcrops of the mineral have been reported. A. W. Ponton, D.L.S., reports an outcrop near the fifth meridian, which is about ninety miles west of McMurray. I reported an outcrop of tar-sand in my report of last season on Buffalo lake which is one hundred and twenty miles southeast and in the province of Saskatchewan. That these outcrops are part of the same field is probable.” INDICATIONS OF PETROLEUM. Apart altogether from the commercial value of the tar sands themselves, they are regarded by many geologists and practical operators as chiefly important as indicating the existence of deposits of petroleum. For instance, as long ago as 1888, Doctor G. M. Dawson of the Geological Survey stated before the Senate committee:—“The pitch found along the Athabaska may probably be of considerable value in the future; but in the meantime was most important as giving reason to believe that extensive deposits of petroleum existed in the country in which it occurred. The quantity appeared to be practically inexhaustible.”