108 J. Starhie Gardner ^ Q. F. Harris — The Gelinden Beds. 



am personally unacquainted with the district, I have induced my 

 friend Mr. Gr. F. Harris, F.G.S., to send the following notes upon it. 

 The importance of a true appreciation of the evidence upon which the 

 age of the plants is based is apparent, when it is considered that 

 at the present moment the relative ages of the whole of the immense 

 Tertiary formations of Ireland, Scotland, and Greenland rest almost 

 solely upon it. This fact is brought into strong relief in my paper 

 on the beds of Ardtan Head, Mull, read before the Geological Society 

 on the 12th January, and further insistance upon it here is therefore 

 unnecessary. 



On the Gelinden Beds, etc. 



By Geo. F. Harris, F.G.S. 



Gelinden is a village about a mile and a half N.W, of Hears in 

 Limbourg. The formation in which the flora occurs is called by 

 the Belgian geologists Heersien superieur ; and the pit whence the 

 great majority of the plants came from is very close to Overbroeck, 

 about three-quarters of a mile due south of Gelinden. 



On the opposite page is a geological map of the district, scale 

 "aTToo-o- (about 3^ inches to the mile). 



It will be observed that the section near Overbroeck is just off an 

 outlier. The main mass, however, is close by, and the section in 

 the " Heersien " is in fact in the valley of the Molen Beck, which 

 cuts the outlier from the main mass. The Landenien beds thus thin 

 out on the outlier, and their greatest thickness on it is probably not 

 more than 3ra. 40. I am nearly certain that no fossils have been 

 found in the Lower Landenien beds on this outlier, but on the main 

 mass, just a little N.W. of Gelinden, fossils occur in them, and the 

 beds are thus easily identified. The base of the Landenien beds here 

 is a more or less hard greenish sand. 



The Heersien beds in the pit at Overbroeck are a pure whitish 

 grey " marne," lOm.^ thick, fossiliferous (especially towards the 

 base). The base presents rather larger " bancs" than the other parts, 

 but it is very much cracked up. The " bancs " towards the top are 

 hard. The following fossils ^ have been found in the marne : — 



Cycloides indsns. 

 Osmeroides belgicus, 

 Smerdis Seersensis. 



Lamna elegans, sp ? 

 Callorhynchus, sp. ? 

 Natica Deshayesiana ? 



^ The following analysis is by M. Laminne, of Tongres. Analyse de la marne 

 de Gelinden, 100 parties de marne de Gelinden renferraent : — 



Carb. de chaux melange d'un peu de carb. de magnesie 71"290 



Phosphate de chaux 0-141 



Sulfate de sonde ; sulfate de chaux ; chlorure de sodium 0-155 



Silice soluble 0-170 



Sable, argile et oxyde de fer 26-612 



Matiere organique 1-380 



Ammoniaque traces 



(Extracted from " Explication de la feuille de Heers," by Rutot and Van den Broeck 

 (1884), p. 125.) Marne of exactly similar appearance is found in many Belgian 

 Eocene beds, even up to the Bruxellien. It usually occurs in bands more or less divided 

 by sands (often false-bedded). 



2 Eutot and Van den Broeck, op, cit. p. 21. 



