| OCR Text |
Show [ 174 J 300 No. 107 is an im-r:>u~e litnestoue, but little harder tl.la~ common chalk· and but for it" assocmtwns, won lei be rPg:ndcd as of stnular oricrin." 1 No. lOG is ttpparently a vitrified ·alldstonc, the grains all rot~ndcd ~ the surfaces of tlte mass high I y polished. 'an No. 102 is a beantiful black obsidian. No. 94 is a manunillary or ~otryoida.l lava; tlte cc~ucretion havingara. diated strncture, the mass IS ea lly fruugtblc, and. readLly separates into,mall angular fragments. . The whole of this suries. with tlw r.xrrpl 1n11 of' No. 107, may he rPnard. ed as of volcallic otigin; f(>r the apparently vitrified ~a ltd s tOil C 111ay be in its composition, not very distinct frot~l trap or ba ·a ll, tiiOll~Sll it is more~it· reous, and it.· fracture fr esher and bnghtcr. Lon~itnde 114 .~ 0 , lat ituclc 4 2 .~ 0.-The specin1ens 1narkrd No. 3 arc of light-color d tuf'n.ceons limcstoll <' all.d silic.eon.c; limestone. The speci. mctts appear as i [ from some rugn htr lorn mt10n h ro knn n p a11d thinly coat. eel by calcareons matter front sp rin gs. From tlte fact ob~ervcd by Captain Frcnwnt, tltat these fragm uts et~tcr.largcly into tile c01upo. itionufthcsoil we may prt'" ttlllC that tire sallle ts highly cal ·an;ou~. 1 Tltc ~qH'cimett No. 1.2, from tlte same locality, con ·ists llHtiuly of small frao-mc'tJ ts of tltc crust, claws, &c., oC ~o tn e ctnstaccn lt-probahly of frc)n· water origin. T'hcre arc also .-orne vcrtebrm and ribs of fi~hc~. ThP whole is so unchanged, and of snell recent appearance, as to i11dncc a heliei that the deposito is of fresh-water ori~in, and dtH~ to tlte de. icration of some lake or strea lll. Should such ad •po ·ito be exten ivc its prospective value to rut agric11ltnral community will !Jean important con_-ideration. But, a1 before rent:t rkt!d, the re i · evidently a prrpond •rn11ce of calcareous matte! throughout the whole extent of cottlltry traversed. Lougitude 115°, latitude 43°.-Tilc specinwus from tlti~ locality arcJHlln· bcre<..l lG, 21, and 39. No:-;. lG and 21 aw augular fragm 111s of impure lim 'stone 1)f' ome recent g<'ologic[ll period and No. ~~n COil'ists of nnaa. grcgation of pebbles and gravel. The pebbles :He or black ~iliCl'O il s~ale. which are repr cscnlL'd as fonuing a conglom1.:rate wi t It the limestone lrag· meuts just nwutioncd. The limestone spccitttcns are probably broken fra~. me11ts from .-omc st rat111n in situ in the srunc vicinity, and the conglom· crate i~ one of very recent formation. The slnt pchble.s arc from a rocK of much oldct date~ and worn very round and ·nwo!h, while the lime tone bears little 'widence of attrition. Tile gray siliccons lime tone :specimens co!ltain a species of Turritclla. and n smnll bivalve shell. (See dcscriptiotl aud figures.) . Longitude ll5,1°, latitude 43~ 0.-Tit<' two pec.imens from tl1is loralttyare of volcatJic origin. No. 4G is a reddi. 11 compact trap or lava, with small nod nics or cavirie' ftlled with analcime and stilhitc. No. 52 i:. a coarse and porous trn p, or ancient Ia va. Longitucle ll6°, lati tnde 4 3~ 0.-The "ingle srccimen frO Ill tit is plnce IS • :-,incc this was written, n sp •einH'Il of No. l07 has been snhmitted to thr rxaminution of Pro· frsHor Bailey, who finds it hig-hly charr•<•d with "catcurcouf:l polythnlnmia" in rxrellrnl prr~na· tion. Ho remarks, that "the fornts ar~, nwuy of them, Huch as are eotutuon in chalk uud c~ctnrroul marls; but :u; tltoso forms arc still living in our pn'scnt oceans, tht'ir pn'scnro ch>es thlll\!lord .c~~· cluHivocvithalc.e UH to tho ago of tho tlt-positr in whi<'h tlwy occur. I ltavr, how<'1't'r, tnr:t~utiJr ,. l tl t · t t' l · · · 1 I l·tt·gc• RIX'rtr• 0 JOtiiH 11\ ut our Pr tary < cpoHtleH thr chalk }lolythalnmm art' accmnJMIIH'< ,.Y • ' · · ~rr11' m 7H'Cit 1L· fl1' to l 11 0 tcrtt· ary. N' ow :u; these an' on ln. cl y wantl.l lg- 1· n tit!' HJW!·'t tnrtt fn H1 1 Cn!llatn 1,, n;'· monl4, tl. 1(' CVI·.c 1( 'llC'C, U.S jr(.l 1' · ' · · · · · 1 •· ' catm' from a {[If 1/ /{Ut'S, IH 111 favor Of the VI OW that f I(' HJIC< llllUI cretaceous f\Jrmulwu." 301 [ 174 J . 1 J tl ·c grnnitr with a small proportion of quartz, and black a wI JI.IC fp' 1 sIIp a IlI cs cT he 's pceitnell cottial.l L a sm. gl e garne t . rfl 1e s t rue-mica .111 sma slc~t siaty and from appcaronces it is rapidly destructible turc I somcw 1~ ' f 1 nJO~phcnc agcucy · , . rom a. ·1 11 -o latitu<..le 44~ 0.-Tltese specimens from Brnle nver are LongJtlltt.J '' b ·cd •l 1 9 :JI ' n n d 4 . . . num eJ '. ' 1 1No.4 1s a sa 'v. t1·mestonc·., 1nutially aJtcre;d, probably from the proxtmity of jgueons rocl<s. . 1 1 · d .1 f .1 ·}~ N~o. 41 is of similar hnr~l<~t( r, very thm y ammate , anu o a ua1" co~~. 19 is of ~imilar cltaractur, but tno rc altered, and partially crystalline. The lines of deposition n.t c·, however, pre ·crved. . . N 18 1, , tile 'tppearance of a r-ntnpnct gray feluspatbtc lava; but the1c 1 o. l arc souw nlp ct ps,·t t'CJJ~ lines of Jct)O.s itioll ftil l visible, which incline me to the · ion t!Jat it i~ nu altered secl ttlleutary ro~k. . oprongitudc 117 ~ o, latitude 'I 5°.-Tltc spcCllllCil I . U compact, dark-co~ored ba sa I! , s1 10\\r'ttlOo' la tendency. to d• (•sc1uamate upo11 the e.-\pose<..l surfaces. 1 . This rock forms thP- rnouuta1us of Bru 6 n ver. . . I n r 1't11clc 117 • 0 I at it udc 4 52 °.-Tlle ~pecim eu No. 11 0 t.' a fine-grained ~o g 1 basal! or trap, with' a few snw~l ·ell:; fLIIe(l w1· th ann l c.t mc. T I n.s t.s o f tl 10 rock fonuiug the Blue mouutatll., ,, . . , . . LoHgituue ll8o, latitnde 45°.-1 ne Slllgle specm.1Cn (No. 4.3) from th1 .. locality i apparent I y an r~ltered si I i~·eo n · ~la t e. . It IS marlwc.1 by what _appc. ar to be line or depo 'itiou, tlte I hm I cllllll)( \ bcwg separateJ by Ia YCI s of IDICU. • , r: d Lon rituue llfJ0 latirndc 3S~ 0.-'l he specimens Nos. l ·l, 2.3, b. an 51, are all from this locality. . . No. 1-1 appears to be a dccompoc::cd feldspar, havmg a sl1glt tly poron structure ; it i very light, alld adheres strong I y to the ton O'ur. No. 23. A friable, argil laceou .. sandstone, somewhat porons upon the ex-posed ~mrac )s. . . . _1 . Ko. 4.5. A compact lava of a sicnitic structure, cont~unmg ohstu.tn.tl. This specimen appears much like . 01ue oft he porous portwus of trap d1ke which cnt through the sicnitic rocks of cw J~~ngland. No. 51. Fcld ~par, with a little black mica. The specimen is probably from a ~ranitc rock, though its structure ~f.i that of ~ompact feldspa.r. ·s Longttude 120°, latitnde 45 ,~ 0.--'l'he smglc spP.c.unen (No. 20) ftom .t~1 ~~ locality is a compact, fine·graincd trRp, or basalt, wlth a few round cavJttc::> of the size of peas. Longitude 120;2°, latitnJc 38 .~0• -The spucimcns are numbered 91' 109. and 117. No. !Jl has the appeuranc of a porous trap, or basalt, th t?ngh pos ibly the prodnction of a modern volcano. It is tiJickly , potted w1th cry?tals of a.nalcime, sotue apparently ·gregatcd from the mas , and others filhng veSicular cavities. No. 1.17 is a compact basalt, the ~pecimcn exhibiting the character of the basalt ol tlte LltH] ~on aud Connecticut riv .r valleys. .No. 109 is a finc-grailleu grauite, cousisting of whi.te quartz and feldspar, Wllh black mica. Captain t~'r6monl l'emarks that tlns rock fonHs the castern part of the main California mouutaiu. From its grunul.ar and rathe.r 1?ose. structure, it is to be iuferreu that it would undergo rapul dccompostt) on Ill a climate like ours. I o |
