and the Mudlumps of the Mississippi 



'ill' rise, alter penetrating tlie iipi)erniost el.'iv Knl : whicli 



- liillv also contains cypress stumj)s, and fonn- tip- '-Miu 

 .tiotn •■ of the Gulf coast. Sometimes, tliou.u-h imiv.'^ . ,ir 



- ol marine shells, of living species, apjx-ar in the \n->U m 



uii a moderate distance from the general cki-i lipr: -,. th;r 

 t • ureat body of the formation underlying the ^\\u..\u\ i>:ii-.^h.- 

 " Ka>^t Louisiana, the Attakapas and Cal<-a-u u piMirK-. ;i- \\r!i 



."I I fluviatile deposits, with, probably, nuuiv nn t'lNt ..r i-iu- 

 .>i-> of ;i more or less brackish or marine cIkh-.k tn-. 



■' 'hiiroftiie Gulf coast, the' Alississipj^i ^u\\v^ milu' iirr. ,; 



" ^ in so far, as that its strata have here, ]>robably. thi ir hiiiii 



■- «lute elevation,* and farthest extension nort'hwnnl. Th.' 



■uvumstaiice is the natural consequence of the < \i-triici 



lepressioii whicli, at least since the opening of the ('ivt;i- 



^ Period, has determined the outline of the formation- .-o'lth- 



l ot Cairo — aii embaynicnt which, \uth cxwy -iii cm .Idil 



i"'i'i 'U ol deposition, became less concave, nntil at the (•'>>-(■ n' 



'I'li'iiiLi- the perio<I of slow depression which ^•halM<■r^ fi/cij tin 



- led ; ami' when upon the reversal of the movement of 

 •lice, the waters of the continent began to be discharged 



- ! what is now the lower Mississippi valley, the erosion 

 - to huve been checked evcrvwhere. save perliap? in the 



";""^'h:imid, hy the tough cypress swamp cla> which n..' 

 IunJl^ the immediate substratum of the lower littoral belt, a' 

 extends f u- into the waters of the Gulf 



It IS merediblc that the deposition whieh oedirnd .iloii- 

 whole Gulf coast from Indianola to Mobile. --houM i.ot 1.:. 

 taken place also in the main axis of the depn-non whi.-n. 

 tlje trend of the formations shows, had in a great mea-un- i 

 _^iled up. Yet, inasmuch as this was the deci)est pu ti< .n oi 

 '^r'^',\* ^* **^ ^^ expected that here, if anvwhere, marine 'Icj"- 

 s'wuld extend far inland. We shall not, therefore, be >myi-y-^ - 

 ^o ^»<l that, as Pourtales has proven from the soundings made 

 "jnder the direction of Gen. Ilumphrevs, the Mississippi river 

 n<'\\.s on marine beds, at New Orleans and Bonnet Carre, it 

 ^'ould rather be remarkable if such beds should not appear 

 even much higher up the river, since even in the comparatively 



at \ti St T '"^''' ^'"^^' ^' ^^■^^'' ^''"'"^ ^°^ ^edf thaTal Pon^HudsoQ 



