

E. Suess — Paleogeography of North America. 101 



Art. XIII. — Synthesis of the Paleogeography of North 

 America; by Edward Suess.* 



It is only now, after more than four months of fatigue, that 

 I can sit down to answer your kind letter of April 20 and 

 thank you for the transmittal of your great paleogeographic 

 memoir [The Paleogeography of North America] and the 

 honour of having my name on the title page beside that of 

 your illustrious Dana. I believe I cannot express my deep 

 feeling of gratitude better, than by trying to enter into a can- 

 did comparison of the existing differences of views as they 

 result on both sides of the Atlantic from differences of per- 

 sonal experience, and differences in nature ; further, from those 

 variances that are caused by different systems of classification 

 or nomenclature, and which, as results from your memoir, are 

 all governed by the indisputable fact, that great eustatic move- 

 ments of the strand-line have taken place. 



I intend first to write of tectonic influences on the distribu- 

 tion of seas, second to compare several great eustatic phenom- 

 ena, and third to discuss the difficulties in finding an explain- 

 ing hypothesis. 



1. Tectonic movements influencing the distribution of seas. 



First, I must confess myself a heretic in all regarding isos- 

 tasy. I have in my last volume given the facts [IV, 1909 : 

 608-] which cause me to doubt anything like a deficit in grav- 

 ity beneath the mountains. Faye has always doubted it and, 

 if I am not wrong, Professor Gilbert seems also to partake of 

 this view. There is not sufficient space here to enter into this 

 question and I only permit myself to doubt likewise whether 

 any sinking can be caused by loading. All these loads seem 

 trifles in comparison to the magnitude of the planet. 



The ideas of Dana on mountain-making were the concep- 

 tion of a great genius. Experience tells us now, that caution 

 is necessary in the use of terms like syncline, synclinorium, etc. 

 I formerly used these terms for structures that are produced 



* This very valuable contribution came in the form of a letter dated Marz 

 (Marczfalva), Hungary, September 2, 1910, and addressed to the undersigned. 

 The subject matter is of so much importance to geologists that it should 

 have wider circulation than that of a personal letter, and it is here published 

 with the author's consent. It will be seen that as yet geologists cannot 

 explain several of the more fundamental characteristics on The Face of the 

 Earth but that we are approaching a determined synthesis. This desidera- 

 tum will come all the sooner through the life work of Professor Suess in 

 making accessible the garnered geologic knowledge of all lands, printed in a 

 multitude of languages, in his " Antlitz der Erde, " or in the English transla- 

 tion by Sollas and Sollas, " The Face of the Earth." — Charles Schuchebt. 



Am. Jour. Sci. — Fourth Series, Vol. XXXI, No. 182. — February, 1911. 



