Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Unnamed MOuntains tuff 1. Firat published use Doumani , G . A. Geologic Observations in West Antarct ica during recent overanov traverses : IGY Bull . 41 , Trans . Am. Geophya . Union 41(4) , p . 706 -7 10 , 1960 . 2 . Definit ion "The eastern mountain is predominantly composed of light-colored tuffs and tuff-breccias with conspicuous lamination and stratificat ion. " (Doumani , 709 ) 3 . Type section a. Location Eastern peak of unnamed mountains ( 76° S , 123° - 12 5⢠W) b . Relat ion to other units 4. Remarks "Brownish bas alt (Unnamed MOuntains basalt) crops out east of the tuff and probab ly overlies it unconformably . " (Doumani , 709) Locality nov known as Benes Peak , USAS Escarpment , Marie Byrd Land Weddell alate 1 . Fira t published use Knowles , P . H . Geology o f Southern Palmer Peninsula, Antarctica : Am. Phil . Soc . Proc . 89 ( 1) , p . 139 ·140 , 1945 . 2 . Definition "S late , which varies slightly in color and in metamorphic effects , extends along the Weddell Coas t for at leas t 90 mi les , from latitude 68° S to 69° 30 1 s . The a late has several cleavages , one of which is very well developed ; it has an average dip of 36° S 82° W , and the strike is N 8° W . " (Knowles , 139 â¢140) 3. Type sect ion a. Locat ion Weddell Coast , from lat itude 68 ° S to 69° 30 ' S - 121 -
b . Lithology Dark-colored , fine -grained a late with one major and two minor cleavages . Composed of quartz and feldspar , - leas than . 03 mm and aubangular. Small amounts of andalua ite . c . Evidence for age Marked lithologic s imilarity to the Mesozoic s lates of Graham Land . Cleavage suggests s imilar orogenic forces acted on the two units and environments of depos ition are both non-marine . No foss il plants in Weddell a late , however. Welcome MOuntain acid intrus ive 1 . Firat published use Weihaupt , J . G . Reconnaissance of a newly dis covered area of moun tains in Antarct ica : Jour . Geol . , vol . 68 , p . 669 -672 , 1960 . 2 . Definition "The acid intrus ive varies from granit ic to pegmatit ic in texture and occurs as dikes and s ills in the metasediment . The pegmatite ia mass ive in some areas , ranging up to 100 m vide as viewed from some points , and intrudes the host at various att itudes , cutting and often paralleling the bedding . The east face of the south peak ia of mass ive pegmatite . Feldspar and quartz crystals comprise an estimated 9 5 per cent of this rock and are from 1 mm. to 5 em. in diameter . The remaining 5 per cent ia composed Of red garnet , 11118COvite and amphibole . " (Weihaupt , 672) 3 . Type section a. Location Welcome MOuntain, northern Victoria Land , 72° 1 5 ' s , 160 ⢠E b . Litho logy Acid intrus ive , mostly feldspar and quartz c . Relation to other units Intrudes Welcome MOuntain metaaed imentary rocka - 122 -
Welcome MOuntain metasedimentary rocks 1 . Firat published use Weihaupt , J . G . Reconnaissance of a ·newly discovered area o f mountains in Antarct ica : Jour . Geol . , vol. 68 , p . 669 -672 , 1960 . 2 . Definition "The firs t group , typified by Welcome MOuntain , cons ists of a metasediment host which shows distinct bedding and varies somewhat in texture from sChis tose to gneis s ic , although the gneis s ic phase is comparatively fine -grained . It · is dark gray to black. The beds are generally thin , ranging from 3 . 5 to 43 em in width , and composed of granular quartz with lesser amounts of biot ite and some limonite s tain . No foss ils were observed . " (We ihaupt , 671-672 ) 3 . Type section a. Location Welcome MOuntain , northern Victoria Land , 72° 1 5 ' s , 160° E b . Lithology Metasedimentary rocks , dark , thin-bedded . Contains quartz , b iotite with halos , z ircon, garnet , locally plagioclase and s illimanite c. Relation to other units Intruded by Welcome MOuntain acid intrus ive . Wexler MOuntains metasedimentary rocks 1 . Firat published use Thiel , Edward Antarctica , One Continent or Two? : Polar Record 10 (6 7) , p . 335- 348 , 196 1 . 2 . Definition "The rocks of the wes tern foothills of the Sentinel and "Wexler'' MOuntains are metamorphosed sed iments , Ch iefly quartz ites and s lates , with steep dips and local folding and · faulting (Thie l , 343 ) . 3 . Type section a . Location Wes tern foothills of the Sent inel and ''Wexler" Mruntains (79 °40 1 S , 83°40 1 W) - 123 -
4 . Remarks a. Name obsolete . See Crashs ite Quartz ite . b . ''Wexler Mountains" are now known as the Heritage Range of the E llsworth Mountains . Wh iteout Conglomerate 1 . Firs t published use Craddock , c . , J . J . Ander son �n� G . H. W�b � rs . Geologic outline of the E llsworth Mountains : Antarctic Geology, Proc: Capetown Sympos ium, 1963 , John Wiley and Sons , p . 155 -170 , 1964 . 2 . Definition "The name Wh iteout Conglomerate is proposed for this formation after its type locality at Whiteout Nunatak jus t southeast. of Mount E arp . ⢠⢠From a distance the Whiteout Conglomerate has a da.rk grey , mass ive blocky appearance . "Almost the ent ire format ion is composed of conglomerat e but interbeds of other lithologies were observed in two localities . " ( Craddock and others , 163 -164) 3 . Type section a. Locat ion Whiteout Nunatak , just southeast of Mount Earp , Sentinel Range , E llsworth Mountains b . Thickness 2980 feet minimum c . Lithology Conglomerate with interbeds of a late and sands tone , locally well-developed fracture cleavage , but tough and hard , bedding rare , subrounded pebb les , cobbles , and boulders ( 5%) most ly quartz i te and vein quartz plus other litholog ies ; argillite or fine- to coarse-grained micaceous greywacke matrix , sorting absent , vari-colored fragments in medium to dark gray matrtx . - 124 -
d . Relation to other units Overlies Crashs ite Quartz ite(Devonia� conformab ly OVerlain (poss ibly dis conformably) by Polarstar Format ion ( Permian) Wieneke Island gabbro 1 . Firs t published use Scott , K. M. Geology of the southern Gerlache Strait region , Antarctica : Jour . Geol . 73 , p . 518 -527 . 2 . Definition "Gabbro intrudes the metasedimentary sequence occurring along the base of the S ierra du Fief bordering the Peltier Channel . " (Scot t , 523 ) 3 . Type sect ion a. Location Base of S ierra du Fief , Wieneke Island , Gerlache Straits region off Danco Coas t b . Lithology Black , mass ive equigranular rock cons isting of normally zoned plagioclase , bluish green hornblende with altered pyroxene , and chloritized biot ite . Magnet ite , ilmenite and apatite accessory . c . Relation to other units Intrudes Gerlache Straits metasedimentary rocks Wiens Formation 1 . Firs t published Schmidt , D . L . , P . L . Will iams , W . H . Nelson , and J . R . Ege . Upper Precambrian and Paleozoic strat igraphy and s tructure of the Neptune Range , Antarctica : USGS Prof Paper 525-D , p . 1 12-119 , 1965 . 2 . De finit ion "The Wiens Formation is here named for Wiens Peak , where the - 125 -
formation is well exposed along a ridge ves t of the sumadt . The type section is located on the southeas ternmos t part of E lliott Ridge , where the Wiens Formation conformably overlies the Gamba cor ta Formation and is d is conformably overlain by the E lliott Sands tone . E lsewhere , the lower part of the Wiens intertongues with vo lcanic sedimentary rocks of the upper part of the Gamacorta Format ion. " (S chmidt and others , 115) 3 . Type sect ion a . Locat ion Southeaaternmos t portion of Elliott Ridge , Neptun.e Range , Pensacola MOuntains b . Thickness Leas than 1 , 000 feet in southern Neptune Range ; doesn ' t occur in north c . Lithology Some non-diagnos tic fucoidal impress ions , interlayered green and red -brown thin-bedded shale , s iltstone and fine sandstone . Several thin-bedded gray oolitic limes tone members occur in this format ion . d . Relation to other units Overlies Gambacorta Formation , intertonguea elsewhere . Dis conformably overlain by Elliott S andstone . e . Evidenc e for age Probably lower Paleozoic . Windmill Is lands intrus ives 1 . First published use Robertson , R. The Geology of the Windmill Is lands : IGY Antarctic Sympos ium, Buenos Aires , p . 78 , 1959 . 2 . Definition "The two mos t c0111110n rock types are migmatite and acid to intermediate intrus ives ⢠⢠⢠The intrus ive rocks occur as a s tock or larger igneous - 126 -
3 . body , which intrudes the migmatite . " Type section a. Locat ion Windmill Is lands , Budd Coast b . Relat ion to other units (Robertson , (66° 1 5 I S , Intrudes Windmi ll Is lands migmatite 78) 1 10°31' E) Windmill Is lands migmatite 1 . Firs t published use Robertson , R. The Geology of the Windmill Islands : IGY Antarctic Sympos ium, Buenos Aires , p . 78 , 1959 . 2 . Definition "Five broad groups of Precamrian · igneous and metamorphic rocks , including migmat ite ( the oldes t ) ⢠⢠⢠were mapped . The two moat common rock types are migmatite and acid to intermediate intrus ives . On the bas is of fie ld relations , the migmatite is cons idered to be a metamorphosed sequence of altered , broadly folded , sedimentary--volcanic rocks which generally dip eas t . " (Robertson , 78) 3 . Type sect ion a. Locat ion Windmill Is lands , Budd Coast ( 66° 1 5 ' S , 1 10°31 1 E ) b . Relation t o other units Intruded by Windmill I sland intrus ives Windy Gully Memer (of Beacon Group) 1 . Fira t published uae Zeller , E . J. , · E . E. Angine , M. D . Turner . Basal Sedimentary Sect ion at Windy ·Gully , ·Taylor Glacier , Victoria Land , Antarctica : GSA Bull . 72 , p . 781-5 , 1961 . - 1 2 7 -
2 . Definition The section begins with a very th in discontinuous conglomerate , whiCh grades into a sands tone ranging in thickness from 5 1 - 100 1 in outcrops West of Windy Gully . In most places the basal beds are somewhat darker than the overlying units . The lover unit is brownish to light tan sands tone , cross -bedded . ⢠⢠⢠above the base a �e dis continuous cobble and boulder beds (Zeller , 196 1 ) . 3 . Type sect ion a. Location Windy Gully , Upper Taylor Valley , Victoria Land b . Thickness 40 - 140 feet c . Litho logy Cross -bedded sandstones with some cobble beds ; fucoidal s tructures near the top . d . Relation to other units Section res ts on granitic gneissose basement cnn,lez and is overlain by int erbedd ed s andstones aad shale s of the Terra Cot ta Mountain Memer . e . Evidence for age Wyatt Formation K-Ar date of underlying basement in another area is 520 m. y. , but th is date mus t be used with caution . Beacon Group a s a whole thought t o b e Devonian-Triaas ic . 1 . First published use Minshew, V.H. Petrologic investigat ions in the area of the Scott Glacier - Wiscons in Range : Ant . Jour. u . s . , VoL I I , No . 4 , p . 109 -110 , 1967 . 2 . Definition "The Wyatt Format ion , which overlies the LaGorce Format ion , is composed of pyroclastic rock of rhyodacitic compos it ion ; in the area - 128 - ⢠J
of the Scott Glacier , the format ion varies in metamorphic grade in a south to north direction from unaltered pyroclas tics to rocks of the biotite zone . " (Minshew , 110) 3 . Type section a . Locat ion Near Scott Glacier b . Relat ion to other units Overlies the LaGorce Format ion c . Evidence for age Believed to be Precambrian or Cambrian. - 129 -
J
