PREFACE. WANT expressed by many Geologists and often felt by the Author, is a classified HANDY-BOOK OF ROCK NAMES. It is hoped that, until a better appears, this Manual may be useful to the Public. To write such a work satisfactorily is no easy task. In other branches of Natural Science, such as Botany, Zoology, and the like, some systematic nomenclature has been followed, but in Geology no one system has been used, or all system has been ignored. It is not uncommon to find eminent Petrologists calling the rock by several names, or, what is more perplexing, using for a rock a name already given to a totally different one. At the present time Rock names same are in such confusion that if an observer names a rock, without at the same time mentioning his authority, he may be supposed to be referring to a rock, or even rocks, totally different to that which he intended to illustrate. This irregularity has caused many names to be used, not only unscientifically but also absurdly, as the original name may refer to a mineral or character not possessed by the rock or rocks to which it is now applied. From the above it is evident that a compiler of such a book as this Manual must run contrary to the opinions and Damng the camlade is Manual, the sts have been con sulted and acce cooted: also also works in general subjects from which information could be procured. Dana's suggestions as to the termination of Rock names have been adopted as far as practicable, while the older names for rocks are generally adopted, except when they are objectionable or better names have since been proposed. Such local names as were known are also given, as they may assist explorers in gleaning information about a country. To various fellow-labourers I am much indebted to D. Forbes, F.R.S., &c., for information; also to W. King, Dep. Supt. Geol. Surv., India, and for his valuable assistance while arranging and classifying the rocks. I should also mention the names of the Rev. M. H. Close, M.R.I.A., &c.; Stackpoole Westropp, M.D., M.R.I.A., &c.; and H. Leonard, M.R.Í.Ä.; besides others who have supplied me with lists of local names. G. H. K. Group N. Slate Group O. Calcareous Rocks Group P. Pseudomorph Calcareous Rocks PART III.-Order II. DERIVATE ROCKS ... ... ... Page 88 89 ... Group A. Rocks for the most part mechanically Group B. Rocks for the most part chemically formed 106 110 110 Subgroup F. Limonite Rock Subgroup G. Hematite Rock Subgroup H. Spherosiderite Subgroup 1. Minerals occurring as Rock Masses 111 Subgroup B. Limestone Subgroup C. Dolomyte Class 2. Subaërial Rocks ... ... 112 ... ... 112 Group D. Mechanically, chemically, and organically formed ... Subgroup A. Coal 115 122 122 122 Subgroup B. Surface Deposit and Accumulations 126 |