88 Mr. Weaver's Geological Remarks. [Auc. 
‘seldom forming troughs or saddles. The coal field is subject to 
faults. Z 
2. The Eastern or Petersberg tract. 
a. The Wettin Collieries (vol. iv. p. 237—260).—These collie- 
ries, which are distinguished into the lower or Wettin, and the 
upper or Schachtberg fields, are generally relieved by an. adit 
Jevel between four and five miles in length, which attains a depth 
of about 45 fathoms from the surface. The .beds of the two 
fields are very different in different places. The following is 
said to be the general arrangement in the lower field : 
. Vegetable soil and loam ; 2 fathoms 2 feet thick. 
. Sandstone, white, micaceous; 1 fathom 3 feet 6 inches. 
. Clay marly rock, brown; 7 fathoms. 
. Ditto blue; 1 fathom 6 feet thick. 
. Slaty sandstone, bluish-grey, micaceous ; | fathom 1 foot. 
. Coal, upper seam; 6 feet 2 inches. 
. Grey sandy clayey rock; 3 fathoms 3 feet. 
. Coarse sandstone ; 3 fathoms 3 feet. 
. Blue slaty rock ; 21 to 52 inches. 
10. Coal, middle seam ; 8 inches. 
11. Grey sandstone ; 3 feet 6 inches. B 
12. Sandy clay ; 1 fathom 1 foot. 
13. Blue slate clay with numerous impressions of ferns, reeds, 
&c.; 5 feet three inches. 
14. Coal, lower seam; 10 inches. 
15. Grey sandstone; 1] fathoms 4 feet. 
16. Rothe todtliegende. 
But considerable variations are to be found in several parts of 
the fields : thus, instead of the slaty sandstone, No. 5, the imme- 
diate roof of the upper coal seam consists not unfrequently of a 
bed of coarse conglomerate, 2 fathoms 2 feet thick, containing 
boulders of porphyry of the size of the head, and even larger. 
The roof of the coal seams is also often of a calcareous nature, 
consisting of sandstone combined by carbonate of lime, in which 
pure limestone occasionally appears, and generally in the form 
of geodes. The middle and lower seams, which are commonly 
between two and three fathoms asunder, sometimes approach 
within 10 inches of each other, coalesce, and bear good coal of 
considerable thickness. The coal seams are in some places 
greatly enlarged; in others closely compressed, so that they 
almost disappear. This is the case with the upper seam, which 
gradually closes and terminates both in the line of range and of 
ip. 
The coal seams of the Wettin district in general are remark- 
“able for the great variableness of position, to which they are sub- 
ject within short distances, presenting a continued succession of 
troughs, saddles, and serpentine curvatures, in which the angles 
of inclination vary from 70° or 80° to the horizontal. . 
© HAG Or da CO WD 
