Previous investigations. In many Arctic regions there is a very striking abundance of fossil wood, usually silicified and of Tertiary age. We still lack a critical summary on the subject, in connection with a detailed examination of all the collections available; but quite a number of contributions have already been published in the course of time, dealing with the occurrences in various parts.
One may mention:
From Spitsbergen (Tertiary and older) : Cramer 1868 p. 175, Schroeter 1880, Schenk 1890, Gothan 1910, Walton 1927.
From King Charles Land (Upper jurassic): Schroeter 1880 p. 3, Nathorst 1901, Gothan 1907, Edwards 1925.
From Franz Josef Land (Upper jurassic): Newton & Teall 1897 p. 508, Koettlitz 1898 p. 636, Horn 1930 p. 10.
From New Sibirian Islands (Tertiary): Schmalhausen 1890. From Iceland (Tertiary): Windisch 1886.
From Greenland: Cramer 1868, Beust 1884, Nathorst 1885 p. 279, Schenk 1888 p. 19 (a short note), Newton & Teall 1897 p. 510 (the same), Walton 1927, Mathiesen (in Koch 1929).
From the Arctic Canada (Tertiary), at Mackenzie River: Schroeter 1880 p. 16 and 1881, and on Banks Land: Cramer 1868 p. 170.
It is very probable that the fossilization of all this wood has some causal connection with the eruptions of basalt, at least in many cases; this possibility has been mentioned by various authors previously. It is not, however, of the same age in all places. As will be seen from the short indications of the list above, most of the occurrences date from the Tertiary or from the end of the Cretaceous; but some of them probably even go back to the upper part of the jurassic.