" THE GEOLOGICAL SOC IET OF WAS HINGTON PRESIDENTIAL A DDRESS A R N O L D H A G U E ' W ITH 0 ABSTRACTS OF M INUTES FOR 1897 AND 1898 AND LI T F FFI ERS AND M EMBER S S O O C . S 1 8 9 8 DI D B Y T W S D D W E ETA . O AND V I H I S EC R RIES E TE TANT N A T , WASHINGTON PUBLISHE D BY THE SOCIETY APRIL 1 99 , 8 " EARLY TERTIARY VOLCANOES OF TH E ABSA ROKA RANGE . B Y ARNOLD HAGUE . Address as President delivered Februar 29 ( , y , l u cc b m n l c n c n It is , I s ppose , a epted y a y geologists that vo a i e erg y has played an im portant part n ot only in bringi ng about th e p rese nt con n Of c M n n in u n u n n n figuratio the Ro ky ou tai s , but b ildi g pth e e tire orther c n m n n n W m n Cordillera . stret hi g fro the Fro t Ra ge alo g Colorado , yo i g , and M n n c c c n . o ta a , westward to the Pa ifi o ea Over this wid e area th e volcanic ph en om ena of Tertiary ti me present a varied an d com plex m ode cc n c ff n m ff n n V m n m of o urre e , o eri g fro di ere t poi ts of iew a y proble s of m h n c geological i nterest . Th ese proble s ave bee vigorously atta ked both in l an d in a n d m n h as n acc m the fie d th e laboratory, so ethi g bee o plished n n n n n c te di g toward th eir fi al elucidatio . Th e literature upo the subj e t m n n u n is already volu i ous , bei g scattered widely through th e p blicatio s Offi l and n and i n c n s of cia reports , both State Natio al , th e pro eedi g of n W c n n m s cie tific societies . hile I desire to all your atte tio to so e of these do n ot mm n features , I propose to su arize th e work that has already bee done in this direction in a m an ner whi ch is perhaps usual o n occasio ns . n n o m m ow n like the prese t , either d I wish to review the field fro y n n c m u n c sta dpoi t, possibly be ause , although ch has bee ac omplished , such a vast am ou nt of work remai ns to be don e that the broad field seems ‘ n c c . e c m eve yet s ar ely explored I prefer, th er fore , to pla e before you so e results Of personal observatio n In a region in whi ch I h ave worked for a n in c c m n several years d whi h I have be o e d eeply i terested . - n n w n The Absaroka ra ge lies alo g the east side of th e Yello sto e Park . r Of an d n n S u n u Seve al its higher peaks its lo g wester p rs , slopi g grad ally W n n n . n toward th e Park , lie ithi th e Natio al reservatio Duri g several cc su mm ers w hil e n in c e n in su essive , e g aged geologi al obs rvatio s the Park , ‘ I foun d it n ecessary to pen etrate beyond its boundaries i nto the higher n M x n enc ircling mountai s . y first e cursio i nto the Absarokas was u nder n in the mm 1885 and m d take su er of , , thereafter for several years I a e lo ng an d protracted journ eys in to this rugged and at that tim e alm ost n n n n n and n n c m u k ow regio , studyi g its geology , retur i g ea h year ore ‘ at hi d r is l o rin d in S i n 11 v l i x 4 5—4 4 2 1 d t c c . s o 2 899 . T s a ess a s p e e e , . , . , pp. , A N 4 THE GEOLOGICAL SOCIETY OF W SH INGTO . a nd m n m m n m . In 1893 ore profou dly i pressed by its a y arvels the year , and n in 1897 mm cu in agai , th e greater part of the su er was oc pied ex ploratio n of th e wild recesses of the Absarokas . n c in W m n m The ra ge , whi h lies wh olly the State of yo i g , stretches fro an d n n o n n the Beartooth S owy ra ges th e orth , southward to the Owl " n n n n In S M n . ou tai s width it is less harp y defi ed , certai outlyi g plateau ch M a nd - c n n m like areas , su as irror Two O ea plateaus , bei g separated fro G c ma b n the mai n body by deep valleys . eographi ally they y e co sidered G m m c a i n . o s d sti ct physical features eologically , fro their de of o cur en and n c n m r ce the ature of th e ro ks , they are i ti ately associated with he C n m a nd fo r h m a con t e tral ass , th e purposes of this address t ey y be m n n n sidered a . as for i g part of th e Absaroka Ra ge As thus defi ed , the n m 80 m in n 50 m in d n an ra ge easures iles le gth by iles wi th , coveri g area m o f n early square iles . m o ne en d n m n Fro to the other the Absarokas prese t a high , i posi g t n n n m plateau , with eleva io s ra gi g fro to over feet above en m m m t sea level . This tire ass is ade up al ost exclusively of Ter iary n n fl nk a nd n ig n eous rocks . Near the orth er a s Archean schists g ei ss es ‘ m n n n h c c . n n rop out fro be eath the overlyi g ro ks Resti g upo the Arc ea , n c m n and an n n n e uptur ed Paleozoi li esto es s dsto es , havi g a co sid erabl n s m a nd n t n n thick es , co e to th e surface , alo g the eas er borders of the ra ge , in r W n c . exposed by erosio the b oader valleys , occur Cretaceous ro ks ith e c n n n m a n o f a lbm er thes ex eptio s , the ra ge co sists of a vast accu ul tio gg fiS a a nd n m t u . ates , , l va flows , i trusive asses n m n o n n l u n Degradatio of the ass has take place a gra d sca e . Vast q a c n ct m n v n renioved m mm tities of vol a ic ej e a e ta ha e bee fro the su it , but n o reliable data exist by which the amount can be estimated eve n ap n n proximately . All the higher portio s have bee sculptured by glacial n m m n c h a lom ice . E or ous a phitheatres have bee arved out of t e l oose gg c an d nn c a nd n f in m rates , peaks , pi a les , relics of great tablela ds testi y so e n l u m m easure to the forces of erosio . Th e p atea is s cored by a co plete n l an d c in c n etwork of deep val eys gorges , which disse t it every dire tio nd c u l n l a lay bare the stru t re of the vast vo ca ic pi e . Nowhere In the northern Rocky Mou ntains do I kn ow grander a nd m n n n ore rugged sce ery tha can be fou d in the Absarokas . But few n m n n and e and atural passes lead across the ou tai ous tract, th se are high diffi cult to scale . For years the ra nge stood as an impassable barrier to the earlier explorers in their attempts to reach the sources of the Yellow sto ne from th e east ; and ev en t oday the regio n is seldom penetrated to its inm ost recesses except by those engaged in scientific e xploration of c n c in S e c c m l b a few the ou try , by the pros pe tor ar h of pre ious eta s, or y n m n in m of Rooki s M ch adve turous sports e pursuit of the big ga e the e .