| Resumo: |
In 1944 Miss Dr. A. Schreuder sent me for identification a fossil horncore, which according to the accompanying letter came from a well-boring near Grubbenvorst (province of Limburg). It was found in a coarse sandy layer with gravel at a depth of 61.50 m below the surface; the topographic height of the latter is given as 24.53 m + N.A.P. (N.A.P. = sea-level at Amsterdam). Dr. J. F. Steenhuis, geologist to the Government Geological Foundation, informed me that deep borings for the water-supply of Central-Limburg have been made in the years 1918, 1919, and 1922 S. and S.E. of Grubbenvorst. Evidently we have to do with boring no. I of October 1918, which reached a depth of 83 m, the top being at 24.50 m + N.A.P. (Geological Foundation Index no. 695/4). The section is as follows (the denotations of the strata are those used by Tesch (1930)) : Laagterras II 8 from 24.50 m + to 15.50 m + N.A.P. Middenterras (?) II 6 and Hoogterras II 1 from 15.50 m + to 4.— m + N.A.P. Zone of the Teglian Clay, "Onderste Fijn" II o from 4.— m + to 2.50 m — N.A.P. More or less coarse, mostly mudfree sand with gravel, alternating with rather fine sand with a variable mud and gravel content from 2.50 m — to 45.50 m — N.A.P. Below 45.50 m — N.A.P. very fine micaceous sand containing much mud. The percentage of mud and mica increases with depth. The boring was finished at a depth of 58.50 m — N.A.P.
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