The geology of the Dun Mountain subdivision, Nelson . d have an important, contact effect on the surrounding sedimentary rocks. It isfound, however, that this is not the case. The Maitai limestone, which is in manyplaces the nearest member of the sedimentary series to the peridotites, is but littlechanged—a finely crystalline structure being the main result. In the Serpentine Valley,where red argillites are in contact with the peridotite, the change has been far moremarked. Not only have the stratification-planes become obscured and the lock far moresolid and resistant, but a new set of minera
The geology of the Dun Mountain subdivision, Nelson . d have an important, contact effect on the surrounding sedimentary rocks. It isfound, however, that this is not the case. The Maitai limestone, which is in manyplaces the nearest member of the sedimentary series to the peridotites, is but littlechanged—a finely crystalline structure being the main result. In the Serpentine Valley,where red argillites are in contact with the peridotite, the change has been far moremarked. Not only have the stratification-planes become obscured and the lock far moresolid and resistant, but a new set of minerals has been formed. The crystals of theseare very small, but are believed to be andalusite and feldspar. The grauwackes are much less altered than the argillites; in fact, there are prac-tically no mineral changes to be seen with the microscope. However, the stratificationis, as was noticed by Hochstetter, completely lost. The comparative absence of mineralchange is very striking when it is remembered that several patches of grauwacke not PLATE VI. Dyke of Worn Rodingite 10 in. thick in Serpentine belowLower Adit of Champion Mine, Champion Creek.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectgeology, bookyear1911
