Heavy Mineral Associations Research Articles

Preliminary Note on the Heavy-mineral Association of the Ishikari Series (Eocene-Oligocene) in the Ishikari, Kabato and Rumoi Coal Fields in Hokkaido, Japan

Preliminary Note on the Heavy-mineral Association of the Ishikari Series (Eocene-Oligocene) in the Ishikari, Kabato and Rumoi Coal Fields in Hokkaido, Japan

Heavy Minerals., of the Jurassic Yamaoku Formation, Okayama, Japan

Heavy minerals have been collected from the coarse sandstones of the Jurassic Yamaoku formation., These minerals are allanite, anatase, augite, biotite, clinozoisite, epidote, garnet, hornblende, muscovite, rutile, titanite, tourmaline, zircon, zoisite, and opaque minerals such as hematite, ilmenite, magnetite, and pyrite., Three zones of heavy mineral associations are recognized in the formation., These zones transect the lithologic boundaries of the formation., The cause of this transection is not clear., The source materials of the sediments may be granitic, andesitic, and basaltic rocks as well as pre-Jurassic sedimentary rocks.,

Heavy Mineral Associations in Quaternary and Late Tertiary Sediments of The Gulf Coast of Louisiana and Texas

ABSTRACT A study of the heavy mineral content of the younger Tertiary and Quaternary formations of the Gulf Coast of Texas and Louisiana shows that a considerable variation exists in the composition of the heavy mineral assemblages found in these formations. Mainly on the basis of these variations, it is possible to distinguish several well-characterized heavy mineral zones which are restricted to certain formations, and therefore serve as a means of identifying these formations, particularly in subsurface sections. The study also establishes that there are two mineral provinces present in the Gulf Coast of Texas and Louisiana; one characterizes formations deposited in the Rio Grande embayment, the other, formations of the Mississippi River embayment. Correlation of the heavy mineral zones and their relation to the surface and subsurface formations is shown in two cross-sections.

THE PETROGRAPHY OF SOME JURASSIC SANDSTONES IN ESKDALE

Introduction. During the last two or three years I have collected in a rather casual manner a number of specimens of sandstones from various localities in the lower part of Eskdale, from Whitby as far west as Glaisdale. When examined petrographically in the usual way it appeared that the heavy mineral associations from most of these showed interesting and unusual features, which seemed worthy of record, as there does not appear to be any published systematic description of the petrography of these strata. The following notes are in no sense stratigraphical : there is no attempt to draw up a correlation of the different sandstones, which, as a matter of fact, would be extremely difficult owing to their general similarity, their lenticular character, with rapid lateral variations, and, in my opinion, the frequency of local discontinuities and wash-outs. The treatment is purely descriptive. Most of the specimens were obtained from quarries, now largely abandoned, in the thick sandstones between the Dogger and Ellerbeck bed, which have afforded some good building stone. The best known of these is the Aislaby stone, which was used for part of the University Library (Cockerell’s Building) at Cambridge, and for a portion of Covent Garden Market and other well-known buildings, as well as for the Abbey and piers at Whitby.1 Specimens are also included from the massive sandstones forming the cliff on the west side of Whitby harbour, which are much higher in the sequence, although almost similar petrographically. The following is a list of ...

The heavier accessory minerals in the granites of Scotland

Early in 1915 a trial separation of the heavy minerals from a specimen of granite from one of the apophyses of the Benrinnes mass disclosed the presence of monazite, zircon, anatase, garnet, etc. Quite a number of crystals of monazite, some of them of considerable size, were found in the residue, and as only two occurrences of that mineral,1 so far as known, had previously been recorded from Scottish rocks, the result was considered of such importance as to suggest a general inquiry into the distribution of that and other heavy accessory minerals in the granites of Scotland. Since then about 200 specimens of granite and kindred rocks have been examined from as many different localities throughout Scotland and the results are given below. Apart from the wide distribution of monazite disclosed by the investigation, many other interesting facts have come to light, both as regards the distribution and association of other heavy minerals in the granites examined; and though monazite was the primary object of search, it was soon discovered that a number of other interesting facts, regarding the character, association and distribution of such commonly occurring minerals as zircon, apatite, garnet, etc., were gradually being accumulated. Some of the points in regard to the different minerals will now be briefly discussed. 1. Monazite. —The mineral has been found in about half of the number of specimens of granite from different localities that have been examined—in 85 out of 178. The mineral is found to occur in varying but always