85 



APPENDIX. 



No. I. 



It remains to offer a few remarks on an interesting feature of our marls ; I al- 

 lude to the abundance of Lignite and Amber, (Succinite,) contained in some of 

 them, especially in the lower mass of strata traversed by the Chesapeake and De- 

 laware canal. 



Lignite was at one period considered to be indicative of Tertiary formations, 

 but it is now frequently recognized in the green sand of Europe : and as analogies 

 in geological arrangement in remote parts of the world, are both interesting and 

 instructive, a few instances may be adduced to illustrate the point in question. 

 M. Boue informs us that the marls which alternate with the ferruginous and 

 green sandstones, (gres ferrugineux et vert,) below the chalk in the south west of 

 France, contain beds of Lignite.* M. Boiie further remarks that Lignite and re- 

 tinasphalt characterize the green sand formation (craie chloritee) at Obora, in 

 Moravia. In allusion to these Lignites he says : — " Ces bois montrent qui'ls ont 

 ete longtemps sur la rivage de la mer, puis qu'ils sont couverts d'huitres et de ser- 

 pules, et qu'ils sont perces de trous de Tarets (Teredo) qu'ont remplis posterieure- 

 ment par de la pyrite." The last two circumstances are common to our own 

 Lignites. 



Humboldt, in his " Tableau des Formations Geologiques," gives as a synonym 

 of the Ferruginous sand series, gres secondaire a lignites, in contradistinction 

 to his gres tertiare a lignite, or Plastic clay formation. 



Cuvierf describes the green sand of France as containing both Lignite and 

 Amber, the former being abundant in the strata between Dives and Fecamp, 

 Another remarkable instance occurs in the green sand of the Isle d'Aix, near La 

 Rochelle. At this place is a submarine forest of dicotyledonous trees, sometimes 

 bituminous and brittle, and again having the texture of jet. These Lignites are 

 perforated by the Teredo, and accompanied by Amber.t 



The lower divisions of the Green sand of England contain considerable quanti- 

 ties of fossil wood, and even regular beds of wood coal.§ 



* Ann. des Sciences Nat. torn. iii. p. 309. t Discours sur les Revolutions &c. p. 294. 



t Humboldt, Gissement des Roches, p. 294 and 297. § Conyb. and Phil. Geol. p. 137. 



