Imágenes de páginas

LYMAN, B. S.—Metallurgical and other Features of Japanese Swords. From the Advance Sheets Journ. Franklin Inst., Jan., 1896. —The Yardley Fault; and the Chalfont Fault Rock, so-called. Extr. Proceeds. Am. Philos. Soc., Vol. XXXIV, 1895. From the author. Maggi, L.—Manuali Hoepli CXCVI-CXCVII. Tecnica Protistologica. CVI-Cxc

Mi. lano, 1895. From the Pub., U. Hoepli.

MATTHEW, W. D.—The Effusive and Dyke Rocks near St. John, N. B. Extr. Trans. New York Acad Sci., XIV, 1895. From the author.

MERRIAM, C. H. AND G. S. MILLER, JR.–North American Fauna No. 10. Washington, 1895. From the U. S. Dept. Agric.

Miller, S. A. AND F. E. Gurley.—Some New and Interesting Species of Paleozoic Fossils. Extr. Bull. No. 7, Illinois State Museum, 1895.

Mivart, St. G.–The Skeleton of Lorius flavopalliatus compared with that of Psittacus erithacus. Pt. I. Extr. Proceeds. London Zool. Soc., 1895. From the author.

Newton, E. T.—On a Human Skull and Limb-bones found in the Paleolithic Terrace gravel at Galley Hill, Kent. Extr. Quart. Journ. Geol. Soc., 1895. From the author.

PAQUIER, V.—Etude sur quelques Cétacés du Miocene. Extr. Mém. Soc. Geol. de France, Tome IV, fac. IV, Paris, 1894. From the author.

PERACCA, M. G. D.-Sul fatto di due distinte dentizioni nella Tiliqua scincoides White. Extr. Boll. Mus. Zool. ed Anato Comp., 1895. From the author.

Powell, J. W.-Fourteenth Annual Report of the Director of the U. S. Geological Survey for the year 1892-3, Pts. I and II. Washington, 1893. From the Survey.

Proceedings of the Seventh Annual Session of the Association of American Anatomists, Dec. 28, 29, 1894.

PUMPELLY, R., J. E. WOLFF AND T. Nelson DALE.—Geology of the Green Mountains of Massachusetts. Monographs of the U. S. Geol. Surv., Vol. XXIII. From the Survey.

RAUFE, H.-Paleospongiologie. Paleontographica Bd. XLI, 5 u 6 Lief. Stutt. gart,

1895. Reis, O. M.-Illustrationen zur Kenntnis des Skeletts von Acanthodes bronnii Agassiz. Aus Abhandl. Senckenb. naturf. Gesell. Frankfurt, a. M., 1895. From the author.

Report of the Trustees of the Australian Museum for the year 1894.

SMYTH, C. H.–Lake Filling in the Adirondack Region. Extr. Amer. Geol., Vol. XI, 1893.

-Report on a preliminary examination of the general and economic Geol. ogy of four Townships in St. Lawrence and Jefferson Counties.

Extr. Rept. State Geol. New York for 1893. Albany, 1894.

-On Gabbros in the Southwestern Adirondack Region. Extr. Amer. Journ. Sci., Vol. XLVIII, 1894.

-A Geological Reconnaissance of the Vicinity of Gouverneur, N.Y. Extr. Trans. N. Y. Acad. Sci., 1893.

-Petography of the Gneisses of the town of Gouverneur, N. Y. Extr. I. c., -Die Hämatile von Clinton in den östlichen Vereinigten Staaten.

Aus Zeitschrift f. praktische Geologie, 1894

-Alnoite containing an uncommon variety of Melilite. Extr. Amer. Jour. Sci., 1893.

-A Group of Diabase Dykes among the Thousand Islands, St. Lawrence River. Extr. Trans. New York Acad. Sci., Vol. XIII, 1894.

-On a Basic Rock derived from Granite. Extr. Journ. Geol., Vol. II, 1894.

-Crystalline Limestones and Associated Rocks of the Northwestern Adirondacks. Extr. Bull. Geol. Soc. Amer., 1895. From the author.

SPENCER, J. W.-Geographical Evolution of Cuba. Bull. Geol. Soc. Am., Vol. 7, 1895. From the Soc.

UPHAM, W.-Drumlins aud Marginal Moraines of Ice Sheets. Extr. Bull. Geol. Sec. Amer., 1895. From the Soc.

VEEDER, M. A.- Magnetic Storms and Sunspots. Lyons, N. Y., 1895. From the author.

WHITEAVES, J. F.—Paleozoic Fossils, Vol. III, Pt. II, 1895. From the Canadian Geol. Survey.

- List of Publications of the Geological Survey of Canada. Ottawa, 1895. From the Survey.

WHITFIELD, R. P.-Mollusca and Crustacea of the Miocene Formations of New Jersey. Monographs of the U, S. Geol. Survey, Vol. XXIV. From the Survey.

WILLIAMS, T.-The Future of the College. Extr. Proceedings Assoc. Coll. & Prep. Schools, 1894. From the author.

General Notes.

PETROGRAPHY Malignite, a New Family of Rocks.-Lawson uses the name malignite for a family of basic orthoclase rocks constituting an intrusive mass, possibly laccolitic, in the schists around Poohbah Lake, in the Rainy River district, Ontario. Three phases of the intrusive mass are recognized—a nepheline-pyroxene malignite, a garnet-pyroxenemalignite and an amphibole-malignite. The constituents common to all phases are orthoclase, aegerine-augite and apatite. In the nepheline variety the nepheline occurs as patches in the orthoclase, or as micropegmatitic intergrowths with it. The orthoclase is in poikilitic relations with all the other minerals, surrounding them like the glass in a partially crystallized lava. It was evidently the last component to solidify. The composition of the rock is as follows:

1 Edited by Dr. W. S. Bayley, Colby University, Waterville, Me. 2 Bull. Dept. of Geol. Univ. of California, Vol. I, p, 337.

SiO, A1,0, Fe,0, FeO Cao MgO Na, K,0 H,0 P,0; Total 47.85 13.24 2.74 2.65 14.36 5.68 3.72 5.25 2.74 2.42

= 100.65 This composition is so similar to that of the Vesuvian leucitophyres, that the rock is regarded as the plutonic equivalent of these lavas. The low percentage of silica and the high lime percentage separate the rock from the eleolite syenites.

One form of the nepheline-malignite is panidiomorphic through the development of the orthoclase and all the other components in crystals. In the garnet-pyroxene phase of the rock the orthoclose is intergrown with albite in the form of phenocrsyts imbedded in a hypidiomorphic aggregate of aegerine-augite, melanite, biotite, titanite and apatite. The augite, melanite and biotite are allotriomorphic. They seem to have crystallized contemporaneously with each other, and with a part of the orthoclase. In the amphibole-malignite the distinguishing characteristic is the prevalence of a very strongly pleochroic amphibole, and the absence of any large quantity of aegerine. The augite that is present occurs intergrown with the amphibole. Melanite is wanting, otherwise this rock is very much like the mellanite-pyroxene malignite.

The author points out the fact that the great mineralogical differen ces observed in the three types of malignite, are accompanied by very slight differences in chemical composition. The three types are regarded as differentiation phases of the same rock mass.

Foliated Gabbros from the Alps.-Schäfer gives an account of the olivine gabbro and its dynamically metamorphosed forms which constitute the rocks of the region in the vicinity of the Allalin glacier between the Zermatthal and the Saarthal in the Alps. The normal gabbro contains in its freshest fornis much or little olivine. In its altered forms it consists of saussurite, amphibole, talc, actinolite and garnet. Ottrelite is often found enclosed in the talc and sometimes imbedded in the saussurite. In one of the granular varieties of the metamorphosed gabbro a blue amphibole is very abundant. It is intergrown in part with omphacite. The granular alteration forms of the gabbro pass gradually into foliated forms and through these into rocks called by the author "green schists." The schistose gabbros are mineralogically similar to the granular alteration phases of the rock, except that they contain in addition to the minerals named above a newly formed albite, zoisite and white mica. The final stage of the alteration is a zoisite-amphibole rock. The green schists are composed of ellipsoids of zoisite, feldspar and epidote imbedded in a schistose green amphibole clinochlor aggregate. Some of the schists are rich in garnets, and others are practically chlorite-schists. All are supposed to be derived from the gabbro.

3 Neues Jahrb. f. Min., etc.. B.B., p. 91.

In addition to the gabbros there are also in the region several ex. posures of serpentine whose contact with the green schists with which they are associated are always sharp. The original form of the rock is unknown, but it is supposed to have been a peridotite. Its most interesting feature is the possession of light yellow and brown crystals of some member of the bumite family.

On the west side of the Matterhorn the author also found normal and olivine gabbros, both more or less altered. The former is cut by little veins of aplite. The peak of the Matterhorn is scarred by numer. ous fulgurites. Its rocks are fine grained green schists, some of which are like those described above, while others are dense and homogeneous in appearance. They cousist of amphibole, clinochlor, zoisite, altered plagioclase, talc and alkali-mica. These rocks are defined as zoisiteamphibolites.

The Rocks of Glacier Bay, Alaska.-Cushinggives a few additional notes on the petrography of the boulders and rocks of Glacier Bay, Alaska. The principal rocks of the region are diorites, altered argillites and limestones that are cut by dykes of igueous rocks. In addition to the diorites and quartz.diorites reported by Williams from this vicinity, there are also in the region mica and actinoliteschists. The dyke rocks are mainly diabases. The author gives some additional information concerning the diorites and briefly describes the schists. The’actinolite schists are aggregates of finely fibrous actinolite needles, in whose interpaces is a granular mixture of quartz and epi. dote and an occasional grain of plagioclase. The mica schists present no unusual features except that some of them are staurolitic.

Petrographical Notes.- As long ago as 1836 Thomson reported the occurrence of light yellowish-green rounded masses which he called huronite, imbedded porphyritically in a boulder of diabase from Drummond Island. Other occurrences of the same substance have been found by the Canadian geologist in diabase dykes cutting the rocks of the Lake Huron region. These have been investigated by Barlow

4 Trans. N. Y. Acad. Sci., Vol. XV, p. 24. • Cf. AMERICAN NATURALIST, 1892, p. 698. 6 Ottawa Naturalist, Vol. IX, p. 25.

and are pronounced by him to be aggregates of zoisite, epidote, sericite and chlorite in a mass of basic plagioclase. In other words, huronite is a saussuritized plagioclase. Descriptions of a number of dyke rocks containing ‘huronite' are given by this author.

Bauer' describes a number of specimens of snow-white, lilac and emerald-green jadeite from Thibet and upper Burmah. One of the green varieties is cut by little veins of nepheline, containing plates of basic plagioclase and little bundles of a monoclinic augite (jadeite) with the same properities as that which constitutes the mass of the jadeite. The rock, according to the author, is made up of this augite and nepheline, the latter mineral acting as a groundmass. The veins are those portions of the rock in which the augite is in very small quantity. In other specimens nepheline occurs in small quantity, and plagioclase is abundant. His conclusion is that the rock is a jadeiteplagioclose-nepheline rock in which locally the one or the other component is most prominent. If the rock is, as the author supposes, a crystalline schist, the occurrence of nepheline in it is of extreme interest.

In a second article the same author describes a serpentine from the jadeite mines at Tauman. It is composed of olivine, picrolite, chrysotite, webskyite and a few other accessories in an albite hornblende matrix, consisting of an aggregate of single individuals of untwinned albite, in the midst of which lie brown and gray hornblendes surrounded by zones of a bright green variety of the same mineral. Between this zone and the albite there is a fringe of green augite needles. The rocks associated with the jadeite and the serpentine are also described. Among them is a glaucophane-hornblende-schist. All the rocks exhibit the effects of pressure.

In a very short note Becko calls attention to the fact that the molecular volume of dynamically metamorphosed rocks, i. e, of the minerals composing these rocks—is less than that of the original rocks from which they are derived. For instance, a mixture of plagioclase, orthoclase and water in the proportion to form albite, zoisite, muscovite and quartz has a molecular volume of 547.1, while the corresponding mixture of albite, zoisite, etc., has a volume of 462.5,

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? Neues Jahrb. f. Min., etc., 1896, I, p. 85.

Record of Geol. Survey of India, XXVIII, 3, 1895, p. 91. 9 Kais. Ak. Wiss. in Wien. Math. Naturw. Class, Jan., 1896.

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