218 GEOLOGY AND MINERALOGY. 



recent Report on the Geology of that State, by Dr. Dale Owen : ' In south-western 

 Kentucky, the whole of eight counties, and a part of four other counties, ar« 

 embraced in the middle coal field of the Mississippi valley, or the coal field which 

 lies partly in Illinois, partly in Indiana, and partly in Kentucky. In eastern 

 Kentucky, fifteen counties, and a large area of five more counties, are included in 

 the great Appalachian coal field, i e. in the coal region occupying the western 

 slopes of the Alleghany Mountains, and the Cumberland range, situated partly in 

 Pennsylvania, Virginia, Ohio,Tennesee, and those above-mentioned eastern counties 

 of Kentucky." . After describing the boundariea 



of the south-western coal field, the author continues as follows : " The coal bed» 

 included in these counties, (Christian county, Baker county, &c.,) naturally 

 divide themselves into Upper and Lower coal measures. These are separated from 

 each other, not only by a prominent sandstone formation, (the so-called Anvil 

 Rock,) but they have been cast off from continuity, immediately on the Ohio 

 River, by an extensive uplift and dislocation of the geological formation which 

 stretches from Gold Hill, on the Illinois side of the Ohio River, across the bed of 

 that stream at Shawneeton, to Bald Hill, in Union County. The Topographical 

 Assistant, (S. S. Lyon,) in his detailed survey of Union County, has traced a 

 continuation of this upheaval in a nearly east and west course through the entira 

 county. Beyond the Valley of Cypress, this disturbed belt has an increased 

 width to the boundary of Heuderson County. Beyond this point it has not yet 

 been systematically followed; but the occurrence of disturbances, with a reversal 

 of dip, near the confluence of Pond and Green Rivers, render it probable that it 

 can be traced completely through the coal field. In Kentucky there is no 

 evidence, whatever, that this disturbance occurred prior to the deposition of the 

 coal measures ; on the contrary, it has implicated in its movements, not only the 

 sub-carboniferous limestone, and millstone-grit, but also the entire coal formation 

 which lies in conformable dip on either side of the axis." Almost all of the coal 

 beds are stated to occur in connexion with under clays containing stigmaria. At 

 least eight workable seams occur in the Upper measures and ten in the Lower, 

 varying in thickness, from about a foot to seven feet. Beds of clay iron ore ar» 

 likewise abundant. 



ZIRCON WITH BASAL PLANES. 



The absence of the basal form, is one of the most salient characteristics of 

 zircon crystals. M. Friedel, however, has recently announced* the existence of 

 two small crystals in the collection belonging to the Ecole des Mines, in which 

 this form occurs. These crystals are said to have been brought from Serro- 

 de-Frio in Brazil. They have not been analysed, but, their identity with zircon 

 seems to be established by their physical and blow-pipe characters, and 

 by the general correspondence of their angles with the measurements of 

 that mineral. Besides the basal plane, the following forms, were also 

 recognized, viz : — the first or diaxial vertical prism, (placed, however, as a 

 monaxial prism in M. Friedel's figures, in conformity with the system of 

 the French school); the triaxial pyramids or octahedrons P, -J P (not previous- 

 ly recognized), and 3 V ; and the eight-sided pyramid 3P3. The new form 

 denoted by the symbol -J P, comes out nearest to that notation, but the agreement 

 is bv no means close. According to M. Friedel's measurements, P : P (in the 



* Annales des Mines, tome IX, p. 620, 



