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A WANT expressed by many Geologists and A 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 same 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 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

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ists: therefore some is

T s could be well done.
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In readers that this
OS T : 25 e rezerence for surveyors

T:: __ the field. Should 127.I.Tre of rocks, they must S E D Lirirks of the different 1.

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n emay be of some small

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this Manual, the We nos consists have been conseina


55 on general subjects from wher e be procured. Dana's sugu A

c te izmirition of Rock names have been in as fess practicable, while the oder names ir rocks are generally adopted, except when the are objectionable or better names hare since been proposed. Sach local names as were known are also given, as they may assist explorers in gleaning information about a country. To varioos felow-labourers I am much indebted: to D. Forbes, F.R.S., &c., for information; also to W. King, Dep. Sapt. 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.I.A. ; besides others who have supplied me with lists of local names.

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... 106


Group N. Slate ... ... ... ... Page
Group 0. Calcareous Rocks
Group P. Pseudomorph Calcareous Rocks


Class 1. Subaqueous Rocks . ... ... ...
Group A. Rocks for the most part mechanically

formed ... ... ... ... ...
Subgroup A. Arenaceous Rocks ...
Subgroup B. Argillous Rocks ... ... ...

Subgroup C. Fault-rock ... ...
Group B. Rocks for the most part chemically formed 106
Subgroup A. Haylyte ...

Subgroup B. Gypsum ...
Subgroup C. Anhydryte ...
Subgroup D. Dolonyte ...
Subgroup E. Quartz

Subgroup F. Limonite Rock

Subgroup G. Hematite Rock ...

.. 110
Subgroup H. Spherosiderite ...

.. 110
Subgroup 1. Minerals occurring as Rock Masses 111
Group C. Rocks partly mechanically, partly chemi-

cally, and partly organically formed ...
Subgroup A. Laminated Coal
Subgroup B. Limestone ... ... ... .. 115

Subgroup C. Dolomyte ... ... ... .. 120
Class 2. Subaërial Rocks ... ... ...
Group D. Mechanically, chemically, and organically

formed ... ... ... ... ... .
Subgroup A. Coal

... ... 122
Subgroup B. Surface Deposit and Accumulations 126


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