Page:The South Staffordshire Coalfield - Joseph Beete Jukes - 1859.djvu/30

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14
SOUTH STAFFORDSHIRE.

banded felspathic ash, quartz rock, variegated marl, quartz pebbles, altered slate, ribboned slate, and blocks of a coarse conglomerate.

"The igneous rocks of Staffordshire are very different from those in the breccia; and none of the other kinds quoted occur in that district, with the exception, perhaps, of the quartz rock, which might be compared to that of the Lickey."

Professor Ramsay then goes on to show reasons why even the quartz rock fragments are not derived from the Lickey, but as the facts mentioned by him will, in my opinion, admit of a rather different interpretation to that which he gives them. I proceed to his description of the breccia near Northfield.

"The summit of the hill, called Frankley Beeches, is crowned by an outlier of the breccia; and it also forms a piece of ground about a mile and a half long, a little to the north-west of Northfield, a good section[1] of which occurs in the lane leading from Northfield to Bangham pit. The larger stones lie mostly at the top. Many of them consist of Caradoc limestone (Upper Caradoc[2] of some geologists), and calcareous sandstone and conglomerate, some of them attaining a diameter of about two feet. I submitted a collection of the fossiliferous pieces to Mr. Salter, who determined the following species:—

  • "Strophomena compressa.
  • Orthis calligramma.
  • Atrypa reticularis (very common).
  • Spirifera trapezoidalis.
  • Leptena (Strophomena) depressa.
  • L. transversalis.
  • Rhynchonella semisulcata.
  • Pentamerus oblongus (rare and small).
  • P. undatus.
  • P. lens.
  • Mytilus mytilimeris.
  • Encrinurus punctatus.
  • Favosites alveolaris.
  • Petraia bina.
  • P. subduplicata.
  • Heliolites interstinctus.
  • Scalites (Raphistoma) lenticularis.
  • Euomphalus funatus (var. sculptus).
  • Goniophora cymbeformis.
  • Serpulites.

"Besides the blocks containing these fossils, the breccia includes fragments of other calcareous sandstone, ribboned slate like that near Shelve, quartz rock, porphyritic felspathic ash, felstone and greenstone like that of the Lower Silurian rocks, purple conglomerates similar to those of the Longmynd, and yellow sandstone and black chert, the latter like that of the Carboniferous limestone.

"The Upper Caradoc (Llandovery) limestone and fragments of calcareous sandstone and conglomerate are peculiar. They do not resemble the Caradoc beds of Walsall, Builth, Malvern, Mayhill, or the Lickey; but both lithologically and zoologically they are like the equivalent strata that rest unconformably on and once formed the


  1. This is the section drawn in Figure No. 3.
  2. Now called Llandovery sandstone.