lievfeir of jACccnf Geohniiral Literdtiivp. 
265 
•j^ranititf, ['I] uranopliv i-ic-iiranitilc. ciPiilacl-zoin'. (:>) ;uiuili'-iic|)lic'liMi'- 
svenitt'. (4) lu>nil>I<'ii(li--(li(>ritc. (•">) qiiart/.-aiiiiitr-dioriti'. ((>) muscovilc- 
hi()tiLc-<;raiiil(', (7) jii-anitir-li\ pi-rst licnc-diahasi' i noritc)- AnKuii; I'li'ii- 
si\e vdlcaiiif i-ocl<s of |Mir]ili vrilii- si i-iict hits. iiicliidiiiL:' inHs. \ nlcMiiic 
breccia and a^nlornci-alc. arc fS) rhyolilcs or (|iiarl/-|ior|il)y r\ . under 
wliicli head arc united all llic so-called Iclsiies. eic. ( )!' olivine rocks with 
no felds|tatliic constituent. Mr. Sears reports outcrops of (D) seriieiitiiie- 
yteridotite in Newbury. (10) l)iotile-niica-|)eri(i()tile in Andover. 
.\rclia>aii rucks occur in the forin of (II) horiiblende-jiranitic-i^neiss 
in Jliddleto?!, Iioxl'ord. and (itH)r<rct()wn. (12) porpliyrit ic-uranit ic-i:iieiss 
ill (ieoriietowii, A\'est Xewliury. and Amesl)ury. .\s aikose or "con- 
i^lomerate-jiranite"' is noted (VA) a niusco\ite-<;ranitic-i:neiss held b\ the 
author "to behuii;' to a sei'ies of nioi'e or less crushed uranile con^^loni- 
erates which ha\ebeen washed and reconsolidated from the decay of 
till! muscovite-biotile-uranite of the reiiion or from some similar rock 
farther to Mie north. ■■ Of the schistose rocks is (14) ampiholite-irncis.s 
of different orij;in in sexi-ral jiarts of the field. 
Members of Die Flower Cambrian sediments occur as (I.")) mica-schist, 
(](*») c()rderite-<;neiss, (IT) zoisite-gMieiss. (IS) limestone, slate, (juiirtzile, 
and sandstone, (lit) .\nother deiK)sit is com|K)Sed of lai-ii'e pebbles of 
iiranite, limestone, and mica-schist. ("30) IJostoniteor keratophyre covers 
a breccia anil other meml)ers of the rliyolite and (piartz-poi'iihy ries slop- 
ing into Jlarblidiead harl)or. lioslonite is a name iiiven b\ Rosenbusch 
to a rock like keratophyre. which occurs as a dike instead of as a sur- 
face flow. (21 ) A tingiiaite dike in Manchester, the sole recorded oc- 
currence in Massachusetts, cuts the hornblende liranitile and auuite- 
ne])helinesyenile at Pickard's jioint. (22) Esse.xile. a l)asic auj;ite- 
nepheline rock of porphyritic habitus outci-ops t>n Salem Neck, AVinter 
island, and in Beverly and Marblehead. (2I>) Dikes of ((uarlz-porphyry 
are shown on the map in the [ilaces where they cut more ancient rocks 
■of the same series or the old rhyolites. (24) .\s arkose or conulomerate- 
iiranite is descr-ibed a small deposit at .Maunolia and in Sauiius Centre. 
The map al.so shows (2")) diallaj!:e-<4abl)ro. rocks first noticed b\ Dr. M. 
K. "Wadsworth: (2()) a liparite dike about seven feet wide cult iiii^diorite 
and Iiranite, in Throckmorton's cove on thi' ]\larbleliead side of Forest 
river: (27) red shite, tlie "jasi)ilite" of Saujius Centre, T.,ynn. and Nahant, 
a meml)erof the Olenellus Cambrian: (28) aiulalnsite-scliist on Nahant, 
at Ijvnn, etc.: (29) vein rocks, carryini;' lead, silver, ami copper ores. 
\ list of publications referrinii- to the <<eology of Ksse.x county closes 
tliis report. In the field work on which this map is based. Mr. Sears 
(•ollected scNcral thousand specimens, and oM'r one thousand thin 
sections have been examined under the microscope. M.-iterial h:is also 
been collected for the i)rei)aratioii of a map of the irlacial jreolof::y of the 
.same area. To Mr. Sears is due sjreat credit for the indef.atiirable in- 
dustry with which he ha.s worked out this intricate maze (»f hi;,'hly al- 
tered setliments anil entanirled series of intrusisc and elfusive iirneous 
rocks. As a field f()r pet ron'raphic study, this area promises to be un- 
surpassed l)y any upon the .\llanlic coast. It is hoped that the 
