(96) 



Geology. — "Sonic obserrdtions on the (jeohhjlcal dructare <ind or'ujin 

 of the Hondsrug'\ By Dr. H. G. Jonker. (Communicated by 

 Prof. K. Martin). 



For some years already I have been occupied in making obser- 

 vations on the sti-ucture of the Hondsrug. Tiiese are far from being 

 complete yet and also for other I'easons it will be impossible for me 

 to examine that material with proper care for some time to come. 

 Indeed, I should have had no reason for writing about it so soon, 

 had it not been for an essay on this subject by Prof. E. Dubois at 

 Haarlem published some years ago, in which a view is taken alto- 

 gether ditfering from the opinion generally adopted till now. As his 

 opinions seem to me to be wrong and yet have been propagated to 

 an undue extent by their insertion into a little book for the use of 

 schools ^) — I have to thank Dr. J. Lorie for this infoi-mation — 

 I consider it my duty at once to de\'elop in a somewhat detailed 

 criticism, why I do not agree with him in his opinions. 



EuG. Dubois: "TJie geohijical structure of the HondsriKj in Drenthe 

 and the oritjin of that ridcje. {JJe (/eohtgische samen- 

 stelUny en de n^ijze van ontstaan van den Nondsrin/ 

 in Drenthe)." 



Roy. Acad, of Sc, Proceed, of the Sect, of Sc, Meeting of June 28, 1902; 

 Vol. V, p. 03—103. (Veisl. v. d. gew. Verg. d. Wis- en Nal. Afd. van 31 

 Mei en 28 Jimi lOOS; Dl. XI, J, p. 43-50, 150-152.) 



EuG. Dubois: "La structure c/eologicpte et V origine dn //ondsjng (/ans 

 hl /n-orince de Drentlie.'" 

 Arch, néerl. d. Sc. exact, et nalur., Sér. 2, T. VII, p. 484— 40G; 1002. 



Further see : 

 J. LoRiÉ: "Beschrijrint/ ran eenige nienn-e (/rondhoringen, V," p. 20 — 21. 

 Mcded. omlr. d. geol. v. Nederland, veiz. d. d. conini. v. h. geol. onder- 

 zoek, n". 33. 



Verh. d. Kon. Ak. v. Wet., 2e Sectie, dl. X, n'\ 5; 1004. 



EuG. Dubois: "On the direction and the starting point of the diluvial 

 ice motion over the Xetherlinds. {Richting en uitgangs- 

 punt der dihiviale ijsheineging over ons land)." 

 Roy. Acad, of Sc, Proceed, of tlie Sect, of Sc, Meeting of May 28, 1004; 

 Vol. VII, p. 40—41. (Vers), v. d. gew. Verg. d. Wis- en Nat. Afd. v. 28 Mei 

 1904; dl. XIII, 1, p. 44—45). 



1) Overzicht van de geologie van Nederland ('•Outlines of the geology of the 

 Netherlands"'), written hy a teacher for his pupils. 



