In an appendix to the foregoing paper, the examination of two other crystals is detailed; the results afforded were very different from those of the preceding ones, but not less favourable to the theory of igneous origin.
The native metal and the sulphide are believed to be formed mainly as primary minerals of igneous origin.
They show a complete gradation from dikes of definitely igneous characteristics to veins consisting largely of quartz in which evidence of igneous originis not so clear.
The copper-bearing beds have been much silicified, and it has been suggested that mineralization was accomplished by hot-spring waters, probably of igneous origin.
There are also other rocks in England, Scotland, Ireland, and almost every country in Europe, which we infer to be of igneous origin, although they do not form hills with cones and craters.
All these and other varieties of granite pass into certain kinds of trap-- a circumstance which affords one of many arguments in favour of what is now the prevailing opinion, that the granites are also of igneous origin.
We have already assumed that one principal division of rocks--the unstratified--is of igneous origin.
So early as 1768, before Werner had commenced his mineralogical studies, Raspe had truly characterized the basalts of Hesse as of igneous origin.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "igneous origin" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
