DISTRIBUTION GERMANY 597 



of the spheroids led Dalmer^ to the conclusion that the remarkable sphe- 

 roidal structure that is so abundant about Neumark and Planitz must be 

 original and not the result of weathering. 



Hanover. — Nearly fifty years ago Creel ner^*^ described spheroidal and 

 ellipsoidal structure in the mining district of Saint Andreasberg, in the 

 Harz Mountains. The masses range from one-fourth of a foot to 2 feet 

 in diameter and lie loosely on one another without filling the interstitial 

 spaces. Each mass is coated with a vesicular crust one-fourth to one- 

 half inch in thickness containing abundant chlorite. 



Bavaria. — The altered aphanitic diabase of the Fichtelgebirge was de- 

 scribed by Gregory^^ as "jointed" into spheroids from 80 millimeters to 

 more than 1 meter in diameter. The masses are compact, but at a little 

 distance from the surface and parallel to it is a band of variolite with 

 varioles from 2 to 3 millimeters in diameter, decreasing in number and 

 size on either side and passing into normal diabase. Some of the smallest 

 masses are variolitic throughout. The origin of the spheroids is attrib- 

 uted to contraction during solidification, while still semiviscid on the 

 exterior but fluid within. Presumably this is conceived as a subterranean 

 process, for the author adds : "Under the pressure of the forces that 

 drove them upward these rolled over one another and were drawn out 

 into oval masses." 



From the country north of the Ficlitelgebirge Hoffmann^^ has described 

 excellent examples of pillow structure in the dense greenstones at Wiedes- 

 griiner Miihle, near Schauenstein. The masses are finely vesicular to 

 slaggy, of rounded, elongated, or oval shape, and have their greatest diam- 

 eters (6 to 8 feet) lying parallel. Psj\ elevation or depression in the sur- 

 face of one is matched by a conformable irregularity in its neighbor, and 

 from this it is concluded that they must have been formed contempora- 

 neously from the fluid mass. 



Hesse. — Ludwig^^ has described spheroidal and ellipsoidal constituents 

 of the Upper Devonian "Deckdiabas" as flow-surface phenomena : 



"Man findet . . . im Schelder Walde mid im Dilltale ofter Wechsel von 

 in Schollen abgesonderten Massen, der Art mit kugelformig abgesonderten 



» K. Dalmei- : Erlaut, zur geol. Specialkarte d. Konigr. Sachsens, Sec. Planitz-Ebers- 

 brun. 1885 ; Sec. Rbsswein-Nossen. 1887. See also Sec. Plauen-olsnitz. 1887, by E. Weise. 



1" H. Credner : Geognotlsche Beschreibung des Bergwerkdistriktes von St. Andreasberg. 

 Zeitschr. d. deutschen geol. Gesell., vol. xvii. 1865, pp. 11-231. 



11 .T. W. Gregory : The variolitic diabase of the Fichtelgebirge. Quar. Jour. Geol. Soc. 

 London, vol. 47, 1891, pp. 45-62. 



12 F. Hoffmann : Uebersicht der orographischen und geognotischen Verhiiltnisse vom 

 nordwestlichen Deutschland, vol. ii, p. 429. 



^^ R. Ludwig : Geol. Specialkarte des Grosshertzogtums Hessen, Sec. Gladenbach. 

 Darmstadt, 1870, pp. 34, 93, 96, 103, 106. 



