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ciated portions of both North America and he has named from important towns now Europe, by the occurrence of comparatively on the sites, as Lake Ithaca for the glacial small areas of ice accumulation beyond the form of Cayuga lake, which was 35 miles extreme boundaries of the principal ice- long, 5–10 miles broad and 1100 feet deep. sheets. The latter condition, or ice invasion, It has been long known that when the ice is indicated on the outer part of the drift- covered western New York the great lakes bearing area eastward from Salamanca, N. discharged at Chicago to the Mississippi Y., through Staten and Long Islands, and the great lake formed by them is called Martha's Vineyard and Nantucket, where Lake Warren, and has left a good beach. the soft strata beneath the ice were dis- At a much later stage, when the Mohawk located and folded.

was uncovered, the waters ran to the Hud15. Climatic Conditions Shown by North son, and the great lake on the site of On

American Interglacial Deposits. WAR- tario has been called Lake Iroquois. The REN UPHAM, Somerville, Mass.

intermediate stage between these two, when During the times both of general accu- the discharge of the water covering western mulation and growth of the ice-sheets and New York was through the low pass at the of their final recession, fluctuations of their south end of Seneca lake through Horseborders were recorded in various districts heads near Elmira, Professor Fairchild has by forest trees, peat, and molluscan shells, called Lake Newberry. The elevations of enclosed in beds underlain and overlain by this and the Chicago pass are such that till. Such fluctuations, while the ice accu- when allowance is made for the depressed mulation was in progress, enclosed chiefly condition of the area at that time, the existarctic or boreal species; but when the ice ence of the lake can be demonstrated. was being melted away, in the Champlain The paper was discussed by Messrs. Mcepoch, the remains of the flora and fauna Gee and Gilbert, who commended the thus occurring in interglacial beds, as at choice of the new name as felicitous and Toronto and Scarboro', Ont., may belong timely. J. W. Spenser also spoke, but difwholly to temperate species, such as now fered with the author in some points. exist in the same district. The cold climate Meantime, in the upper laboratory (the of the Ice age appears thus to have been Williams room), the petrographic section, followed by a temperate Champlain climate under the chairmanship of Professor B. K. close upon the waning ice-border.

Emerson listened to 16. Glacial Lakes in Western New York 18. The Relation of Grain to Distance from

and Lake Newberry, the Successor of Lake Margin in Certain Rocks. ALFRED C. Warren. By H. L. FAIRCHILD, Roches- LANE, Houghton, Michigan. ter, N. Y.

A description of the variation in texture The paper presented evidence that the and grain of some quartz diabase dikes of finger lakes of central New York were all Upper Michigan was given, and the same pre-glacial in character and that during the compared with effusive flows of similar presence of the ice-sheet at their outlets mineral composition. These descriptions they were backed up and discharged south- were based on series of thin sections of ward, as is abundantly shown by deltas at known distance from the margin. Intervarious heights on both sides of the present stitial micropegmatite is primary or pneudivide. Professor Fairchild cited eighteen matolytic, and the feldspar crystallization glacial lakes from Attica on the west to the begins before that of the augite, continuing Onondaga river valley on the east. These until later. The distinction between the intrusive or dike type and the effusive type up the whole subject of the classification of was pointed out. The main object of pre- rocks. The general feeling seemed to be senting the paper at this time is to elicit the that rocks could best be named primarily best methods of measuring the coarseness of on a mineralogic and textural basis, and grain of a rock, the object being to express that these principles furnished the best soby some arithmetical or mathematical form- lution of the difficulties presented by the ula based on statistics, or in some other def- paper. The speakers were Messrs. Wolff, inite way, the relation of texture to walls Emerson and Lane. and thickness in a dike. The paper elicited 21. On Some Dykes containing Huronile.' considerable discussion by Messrs. Hovey, By ALFRED E. BARLOW, Ottawa. (Read Kemp, Iddings, Cross, and G. P. Merrill, in by F. D. ADAMS.) which the following points were made ; the This paper contained a brief petrographilarge size of the phenocrysts in some very cal notice of certain dykes of diabase connarrow dikes; the importance of not meas- taining "Huronite,' as the mineral was uring minerals of the intratelluric stage ; originally named by Dr. Thomson, of Glasthe great variability of circumstances under gow, in his Mineralogy of 1836. Dr. B. J. which dikes cooled, as heated or cold walls, Harrington's re-examination of this mineral pressure, mineralizers, etc., and the difficult- in 1886 showed some very grave errors in ies of getting reliable data of the kind re- Thomson's work and the 'huronite' must quired by Dr. Lane.

simply be regarded as an impure or altered 19. Crystallized Slags from Coppersmelting. form of anorthite, which has undergone

ALFRED C. LANE, Houghton, Michigan. either partial or complete saussuritiza

This paper described (with exhibition of tion,' owing to metamorphic action. Cerspecimens) slags from the cupola furnaces tain localities were mentioned north and used in coppersmelting, which contained northeast of Lake Huron, where these dykes large melilite crystals, between one and two have been noted cutting the Huronian as centimeters square, interesting optically and well as the granitoid gneisses usually classed in mode of occurrence. Crystallized hema- as Laurentian. Mr. A. P. Low, of the Cantite was also noted.

adian Geological Survey, noticed dykes conThe specimens elicited great interest on taining this mineral cutting the Laurentian account of the size and perfection of the and Cambrian in the Labrador Peninsula. crystals.

22. The Granites of Pike's Peak, Colorado. 20. On the Nomenclature of the fine-grained EDWARD B. Mathews, Baltimore, Mary

Siliceous Rocks. L. S. GRISWOLD, Cam- land. (Introduced by W. B. CLARK.) bridge, Mass.

This paper gave an areal and petrographiThe writer described the difficulties met cal description of the granites composing first, in his study of novaculite, and later, the southern end of the Rampart or Coloin connection with other siliceous rocks, rado range and showed that great macrosuch as cherts, jaspers, etc., in applying defi- scopic variation may result, while the micronite names. The troublesome characters of scopic characters remain monotonously uniopaline, chalcedonic and quartzose silica, as form. Four types in all were distinguished, regards the origin of each, presented obsta- based on the size of phenocrysts and coarsecles both for mineralogic and genetic classi- ness of grain. The paper was discussed by fication.

Whitman Cross and J. P. Iddings, after This paper elicited an interesting dis- which the section adjourned to meet again cussion which threatened at times to take at 4:30 P. M.

sources,

About the same time the main section tern slides Dr. Adams gave a very graphic also adjourned for lunch, which was most account of the region in question. Some hospitably served to the visiting societies thin sections of rocks as large as an ordiin the Johns Hopkins gymnasium. High nary lantern slide were used to illustrate praise is due the local committee for the ex- the

passage

of a massive rock into a crushed cellent arrangements. After lunch the so- and sheared or gneissoid form. The paper ciety reconvened and the first paper was : formed not only an important contribution 23. Notes on the Glaciation of Newfound- to the geology of the region, but to our land. By T. C. CHAMBERLIN.

knowledge of dynamic metamorphism as The paper brought out the very interest- well. Discussion was reserved until after ing facts that the glaciation of Newfound- the reading of the next two. land is local and that the moraines and 26. The Crystalline Limestones, Ophiolites, strive show that it proceeded from the cen- and Associated Schists of the Eastern ter of the island to the coast. The drift is Adirondacks. J. F. KEMP, New York. all peripheral and can be easily traced to its After a brief introduction and sketch of

what others had done on the subject in 24. The Pre-Cambrian Floor of the North hand, the areas of these rocks, especially in

western States. By C. W. Hall. (Read Essex county, were outlined and described in the absence of the author by WARREN with geological sections. It was shown UPHAM.)

that they are generally small, usually less The paper pointed out the distribution of than a square mile; that they consist of the Pre-Cambrian areas in the territory (a) white graphitic crystalline limestone, under investigation so far as it is known at with great numbers of inclusions of silithe present time. It then showed by means cates, (b) of ophiolites, (c) of black garnetiof records of deep and artesian well bor- ferous hornblende schists, (d) of lighter ings, within reasonable limits of probability, quartz schists, and (@) in one area, of closely the depth of the Pre-Cambrian rocks over involved granulite very like the Saxon a considerable area beyond the surface area granulite. The evidence of the plasticity outlined.

of limestone under pressure was graphically Maps and a series of profiles accompanied shown by lantern slides. The trap dikes

that often cut the limestones were referred The paper was discussed by G. K. Gil- to, and the relations with the intrusive gabbert, who called attention to the importance bros were set forth, and the argument of the results.

made that the limestones are older than 25. A Further Contribution to Our Knowl- the gabbros and anorthosites of the Norian

of the Laurentian. FRANK D. ADAMS, series, and that they are the remnants of Montreal, Canada.

an extended formation which was cut up by After referring briefly to the author's pre- these intrusions, metamorphosed largely by vious work on the anorthosite intrusions of them and afterward eroded. A comparison the Laurentian, the paper gave a condensed was drawn with those on the western side account of the results of a study of the of the mountains. stratigraphical relations and petrographical 27. The Relations of the Crystalline Limecharacter of the gneisses and associated stones, Gneisses and Anorthosites in St. rocks of the Grenville series in that portion Lawrence and Jefferson Counties, N. Y. of the protaxis which lies to the north of C. H. SMYTH, JR., Clinton, N. Y. the Island of Montreal. By means of lan- The paper dealt especially with areas in

the paper.

the towns of Diana, Pitcairn and Wilna, But certain Devonian forms as Leiorhyncus but was really a review of the relations of quadricostatum and Productus lachrymosus of these rocks in a wider region and was based the New York Devonian are found with on extended field experience. Petrographic them, which are lacking in the Mississippi details were presented of the several kinds of Valley, but are found in the Devonian of rocks, and especially of the varieties of the the West. The interpretation was then anorthosites, which were shown to shade made, that the Arkansas fossils indicated a into angite-syenites, and apparently into red Devonian incursion from the westward. gneiss. Many irruptive contacts of anor- During the reading of this and the sucthosites and limestone were cited and the ceeding titles the petrographers reconvened location of the classic mineral localities of in the upper laboratory, as later recorded. this region was shown to be along these 30. The Pottsville series along the New contacts. The same important thesis was River, West Va. DAVID WHITE, Washingworked out as in the preceding two papers,

ton, D. C. that the great intrusions of the Norian se- This paper was a careful description of ries were later than the gneisses and lime- the stratigraphy of the series, the determistones.

nations being based on the fossils, which The papers were discussed by Whitman evidence was presented in full. Cross, who called attention to the close 31. The Cretaceous Deposits of the Northern parallelism of the geology in the Pike's Half of the Atlantic Coast Plain. WM. Peak district of Colorado ; and by C. D. B. CLARK, Baltimore, Md. Walcott who referred to his own studies in The several formations established as a the Adirondacks and similar conclusions to result of a detailed study of the Cretaceous those advanced.

strata of Monmouth county, New Jersey, 28. Lower Cambrian Rocks in Eastern Cali- were shown to have a wide geographical fornia. CHARLES D. WALCOTT, Wash- range towards the south. They have been ington, D. C.

traced throughout the southern portion of An account of the discovery of the Lower that State, while all except the highest Cambrian rocks and fauna in the White members of the series are found crossing Mountain range of Inyo County, Cal. See Delaware and the eastern shore of Maryalso No. 2 above. This important discov- land. Several representatives of these forery affords a means of correllating the early mations appear on the western shore, reachCambrian life in the remote West with ing to the banks of the Potomac. those already known in the East.

32. Stratigraphic Measurements of Creta29. Devonian Fossils in carboniferous strata. ceous Time. G. K. GILBERT, Washington, H. S. WILLIAMS, New Haven, Conn.

D. C. The paper described the fauna of the The writer described a great series of Spring Creek limestone of Arkansas, which Cretaceous rocks, 3500–4000 ft. thick, lying lies between the Keokuk-Burlington strata in the Arkansas River Valley, west of below and the Batesville sandstone above, Pueblo, Colo. They consist of layers of limeand is at about the horizon of the Warsaw stone 1 ft. to 1 ft. 6 in. thick, separated by and Chester of the Lower Carboniferous in 1 in. of shale—this alternation being unithe Mississippi Valley. The fossils are formly repeated through the whole thickclosely related to the carboniferous fauna ness. The writer argued that frequent condescribed by Walcott from Eureka, Nev., tinental oscillation from deep to shallow and by J. P. Smith from Shasta County, Cal. water deposits was unlikely as having caused

the beds, and hence appealed to climatic found in Georgia, which closely simulate cycles.

lithophyse, and remarks were made on The cycles of a year's changing seasons is them by W. Cross and J. P. Iddings. too short to account for the limestone; the 35. The Peripheral Phases of the Great Gabnext longer cycle, the lunar, involves no bro Mass of Northeastern Minnesota. W. changes of climate; hence the cycle of the S. BAYLEY, Waterville, Me. precession of the equinoxes, 21,000 years On the northern border of the great gablong, was selected, and allowing four feet of bro mass in northeastern Minnesota are deposit for each cycle, this portion of Cretace- basic and granulitic rocks whose composious time was estimated at 21,000,000 years. tion indicates their relationships with the

There was no discussion, but a very evi- gabbros with which they are associated. dent feeling of solemnity at the announce- The basic rocks are aggregates of the basic ment.

constituents of the gabbro. They are char33. Notes on the Cretaceous of Western Tec- acterized especially by the abundance of

as and Coahuila, Mexico. E. T. DUMBLE, titanic iron. The granulitic rocks differ Austin, Texas.

from the central gabbro mainly in strucThe author being absent the paper was ture. They consist of aggregates of rounded only read by title.

diallage, hypersthene and plagioclase, all of The main section then adjourned until which minerals are present also in the northe presidental address at 7:30 the same mal rocks. The basic rocks are probably evening. Meantime the petrographers lis- differentiated phases of the gabbro, of eartened to

lier age than the great mass of the nor34. Spherulitic Volcanics at North Haven, mal rock. The granulitic phases are simply

Maine. W. S. BAYLEY, Waterville, Me. peripheral phases. Closely parallel cases

In the Journal of Geology a few months were brought out in the discussion as ago the late Dr. George H. Williams referred existing in the Adirondacks (by C. H. to the existence of old rhyolites on the Smyth, Jr., and J. F. Kemp), and in Quecoast of Maine. The author described very bec (F. D. Adams), where they have been briefly the occurrence of these rocks, and been called granulites, augite-syenites and exhibited specimens of them. The speci- augite gneisses. H. D. Campbell mentioned mens showed very perfect spherulites, litho- the same phenomena in similar rocks in physæ and all the common features of glassy Rockbridge county, Virginia, and all the volcanics. They brought out an interesting speakers commented on the peculiar develdiscussion regarding the abundance of these opment of orthoclase feldspar in the border rocks along the Altantic sea-board. J. E. facies of a gabbro mass. Wolff spoke of their great extent near Bos- 36. The Contact Phenomena at Pigeon Point, ton, and especially at Blue Hill, where the Minn. W. S. BAYLEY, Waterville, Me. relations with the Quincy granite are a hard The speaker distributed copies of his reproblem. A. C. Lane mentioned their fre- cent Bulletin U. S. Geol. Survey, No. 109, quency in central Maine, as shown by the and exhibited a series of specimens which collections of L. L. Hubbard. T. G. White illustrate the peculiar contacts and transireferred to those near Mt. Desert. J. F. tion rocks at Pigeon Point. Discussion folKemp spoke of recent field and petrogra- lowed by by J. P. Iddings and others. phic work in progress on the great areas 37. A New Discovery of Peridotite at Dewitt, near St. John, N. B. W. S. Yeates brought 3 miles east of Syracuse, N. Y. N. H. DARup the curious phosphatic spherulites lately TON. Petrography of same, J. F. KEMP.

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