What people are saying - Write a review
We haven't found any reviews in the usual places.
10th Census 20 feet abandoned analyses Andover Annual Report apatite associated Authority beds belt bodies Byram calcite cent Chester contained crystalline deposit depth distance east Farm explorations fault feet deep feet long feet thick feet wide feldspar folded Franklin limestone Furnace gabbros garnet geology gneisses graphite hematite Hibernia Highlands hornblende Hunterdon County igneous iron Jersey Kittatinny known later layers lean limestone limonite magma magnetic magnetite masses mile northeast minerals mines Morris County Mountain northwest occur opened operated origin Oxford Oxford Furnace Oxford Township oxide Passaic County pegmatite phosphorus pinches pitch pits Pochuck gneiss Pond portion probably produced pyrite quartz quartzite Randolph Township References reopened Report State Geologist ridges River road rock Rockaway Township sample shaft Shipment shipped shoots side silicates slope southeast southwest sunk surface Sussex County tion valley vein wall Warren County width yielded
Page 18 - Sei., 2d series, vol. 32, pp. 208-209, 1861. The annual report of the State geologist [of New Jersey] for the year 1864, 24 pages, Trenton, 1865. Third annual report on the geological survey of the State of New Jersey for the year 1866, 27 pages, Trenton, 1867. Geology of New Jersey, 900 pages, 7 plates, 13 maps in portfolio, imp. 8°, Newark, 1868. [Appendix, pp. 721-870, by other authors.] Annual report of the...
Page 137 - Laurentian gneiss. Messrs. Miller and Knight, however, have recently subdivided the Grenville series of Eastern Ontario into an older and a younger series which are described as being separated by an erosion unconformity. The younger series is correlated with the Huronian of the Lake Superior region and the older, for which the name Grenville is retained, is correlated with the sedimentary portion of the Keewatin series in the Lake region. The igneous portion of the Keewatin is represented by a spheroidal...
Page 167 - All these rocks were referred to as exhibiting "violent dislocations, being displaced vertically, laterally, contorted, folded, etc. Their general strike is northeast and southwest, and their dip southeast. They are traversed by joints • • • and in addition to their distinct stratification • * • they exhibit planes of cleavage frequently at right angles to the plane of stratification.
Page 133 - Graphitic varieties are also occasionally found that are very rich in this constituent. In a few places these varieties have been mined as a source of plumbago. The question as to the origin of the magnetite and graphite has not yet been completely solved. In some specimens these minerals are embedded in feldspar and hornblende and thus appear to be original. In other specimens, however, magnetite occurs in the interstices between the feldspars and the graphite, in plates wrapping around quartz grains....
Page 129 - Quartz 32.85 Orthoclase, 7.23 Oligoclase (albite, 56.07 : anorthite, 3.43), 59.50 Other components 1.22 100.80 The Byram Gneiss. — The Byram gneiss is a medium to coarsegrained gray rock in its most characteristic outcrops. Its essential components are microcline, a microperthite, orthoclase, quartz, brown and green hornblende, and sometimes green pyroxene. The accessories are sphene, apatite, and magnetite, and sometimes biotite. In some varieties quartz predominates over the feldspars. In some...
Page 169 - ... true veins of igneous origin, which implies that they extend to an indefinite length and breadth, that they differ in character from the rock in which they are situated, and have been formed subsequent to it. Such deposits do not usually coincide with the strike and dip of the strata in which they are...
Page 136 - Ontario there is in addition a series of amphibolites which have a three-fold origin. Certain ones are considered to represent limestones that have been altered by invading granites. Others have been produced by the dynamic alteration of basic igneous intrusions; while still others have in all probability resulted from the recrystallization of basic, fragmental, volcanic material. All three processes have produced amphibolites that cannot be distinguished from one another either by appearance or...
Page 132 - ... They are strongly schistose and in many places they exhibit every evidence of having been crushed. The coarser varieties grade into garnetiferous pegmatites, though it is probable that some of them are crushed sedimentary rocks. The quartz-graphite schists are fine grained, very schistose, dark-gray, friable rocks composed of quartz, biotite, muscovite, occasionally a garnet, and a considerable quantity of graphite, in some cases reaching' 3% to 4% of the rock's mass. The graphite is usually...
Page 165 - ... of the hornblende or red felspar. " The first theoretical inference naturally suggested by the remarkable manner in which all the veins without exception occur, is that the strata of the formation were, in all probability, at a pretty steep inclination previous to their appearance between the rock ; for it is inconceivable how a forcible injection of fluid ore could enter a series of beds, lying in a nearly horizontal position, without in one case causing and occupying fissures transverse to...