The Cordova daily times., 1920-11-20
NLCKLE MINES LOWER COPPER
 RIVER VALLEY
Continued from page 6.)

comparison Wltn pOllSneu SuTldCeS OI known pyrrhotite show there is a de- cided difference in coler. The most abundant mineral, next to pyrrhotite, in most of the specimens is light colored and has roughly equidimen- sional surfaces that show cubic cleavage. The mineral occurs also in slender stringers cutting through the pyrrhotite. The pyrrhotite is very. strongly magnetic; the un- known mineral is nonmagnetic.
 The sulphides are so brittle and so badly weathered that a good pol ished section on which the relations of the opaque minerals can be seen is difficult to get. Stringers of a bluish mineral that seems in part to be hematite are abundant in the section. These stringers are later than the other minerals in the sec tion. Marked cleavage occurs in the pyrrhotite, and in places the bluish mineral follows these cleavage lines. With high powers of the microscope minute parallel cleavage lines can be seen starting out on either side of the cracks that cut the polished sur face, Chalcopyrite is scattered through the slide and varies in amount in different specimens. The order of deposition of the three min erals can not be told from the high ly polished specimens. The unknown mineral seems to be present both as crystals and as stringers.
 An attempt was made to determine the two principal minerals that were observed on a polished surface of the ore. In order to get material, l if possible, that would be homo | ganeous 3 piece of the ore was cut l into many thin slices. The slices were polished on both sides so that the minerals could be recognized and picked out. After the material was selected in this way it was ground very fine, and further separation was made with a magnet
 The iron-stained outcrops on the east side of the creek reach 100 feet in width, but their outline is ir- regular. They occur in a country rock. Some stringers of pyrrhotite Such outcrops can be traced inter- mittently up the hillside and over the ridge, and they may have at one time belonged to a single body that has since been broken by fault ing. At several places in these croppings shots have been put in, but there are no satisfactory eX possures of the fresh underlying rock. Some stringers of pyrhotite were found at places, but analysis of this pyrrhotite showed only a trace of nickel.
 It is reported that the best assay
 returns obtained from the Canyon creek claims showed about II per cent of nickel and about 2 ounces of silver to the ton. A selected speci- mon of the sulphide ore was ana lyzed in the laboratory of the survey and reported to contain 723 per cent of nickel and trace of cobalt. One mined about the deposit is whether the nickel is a surface concentration or whether the tenor holds or in creases with depth. To determine this point further development work and additional assays are necessary. All the specimens that are now avail able show the effects of extensive surface alteration.
 The amount of development work done on the claims is so small that assay returns as to the amount of nickel in the ores may be mislead- ing. Weathering, for example, may have leached and calried away much of the nickel, or it may have concentrated the nickel under the leached surface cropping. Most very basic dikes, such as peridotite dikes, carry small percentage of nickel, | and surface teaching and reconcen- tration of this nickel may cause an | enrichment near the surface that would give an erroneous idea of the tr1Jn ~e l., pyrrhotite taken from one of these dikes was tested for nickel and showed only the most minute trace The deposits in New Caledonia rep resent the type of nickel deposit which is formed from the surface enrichment of basic igneous rocks. Such deposits, to have economic value, must be rather large and so