INDEX.
471
| page | |
| Plastic clay, Mr. Buckland on the beds of | 277 |
| ────────, account of the beds of near Reading | 282 |
| ────────, ────────────── near London | 284 |
| ────────, ────────────── on the coast of Sussex | 294 |
| ──────────────── their connexion with those of France | 298 |
| Plumsted, account of the Plastic Clay beds near | 290 |
| Plymouth, Mr. Hannah's observations on the limestone of | 410 |
| Porphyritic veins, of St. Agnes. Rev. J. J. Conybeare on | 401 |
| ─────────────── probably contemporaneous with the schistose rocks which they traverse | 402 |
| ─────────────── appearance of the schist in contact with them | 403 |
| Porphyry of the Cheviot hills described | 93 |
| ─────── veins of, traversing the schist and granite of Cruachan | 121 |
| ──────────────── generally appear perpendicular | 121 |
| ──────── of Cruachan, its varieties described | 122 |
| ─────────────── shews a regular series of transition from porphyry to trap | 123 |
| Potter's clay, found immediately below the soil over the coal measures | 16 |
| Quartz, beds of, interstratified with the marble limestone of Sky | 167 |
| ────── Mr Phillips on the primitive crystal of | 233 |
| ────────────── on the cleavage of | 247 |
| Quartz rock and schist series of Sky, described | 161 |
| ──────────────── alternates repeatedly with red sandstone | 162 |
| ────────, Dr. Mac Culloch's supplementary observations on | 264 |
| ────────, circumstances to prove that its origin is partly mechanical | 268 |
| ────────, avanturine a variety of | 272 |
| ────────, particulars of its occurrence in Sky | 273 |
| ────────, alternations of, with red sandstone and greywacke schist | 274 |
| Quicksands, covering the coal measures | 30 |
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