﻿11] 
  General 
  Geology 
  : 
  Lignitic 
  Eocene 
  69 
  

  

  as 
  seen 
  in 
  those 
  thrown 
  out 
  in 
  the 
  cuts 
  of 
  the 
  R. 
  R., 
  perhaps 
  

   lyi 
  miles 
  southeast 
  of 
  Many, 
  sometimes 
  marine 
  shells 
  (generally 
  

   Venericardia 
  planicosta) 
  as 
  seen 
  in 
  the 
  boulders 
  near 
  Tar 
  river, 
  

   south 
  of 
  Many 
  and 
  in 
  others 
  from 
  near 
  Ft. 
  Jessup. 
  

  

  Lagoon 
  and 
  off-shore 
  conditions 
  evidently 
  alternated 
  geograph- 
  

   ically 
  and 
  stratigraphically 
  during 
  the 
  deposition 
  of 
  these 
  beds. 
  

   Layers 
  of 
  lignite 
  are 
  reported 
  from 
  varioiis 
  places 
  in 
  this 
  

   vicinit5\ 
  

  

  Casts 
  of 
  fossils 
  are 
  fairly 
  abundant 
  in 
  the 
  dark 
  sandy 
  mica- 
  

   ceous 
  clay 
  on 
  La 
  Nana 
  bayou, 
  as 
  it 
  crosses 
  the 
  29-30 
  section 
  

   line. 
  This 
  material 
  is 
  strangely 
  similar 
  to 
  the 
  lower 
  Eocene 
  

   beds 
  of 
  Maryland 
  and 
  Virginia. 
  The 
  most 
  characteristic 
  fossil 
  

   species 
  are 
  : 
  Turritella 
  mortoni, 
  J 
  'olutilithes 
  petrosiis, 
  Pleurotoma 
  

   siphus, 
  Astarte 
  smithvellensis, 
  var. 
  Venericardia 
  planecosta, 
  Pseti- 
  

   doliva, 
  sp. 
  (See 
  further 
  under 
  Paleontolog}^ 
  Lignitic 
  Stage.) 
  

  

  In 
  the 
  little 
  ravines 
  or 
  washouts 
  near 
  the 
  Many 
  school-house 
  

   castsof 
  several 
  lignitic 
  species 
  of 
  mollusca 
  are 
  found. 
  They 
  are 
  

   embedded 
  in 
  indurate 
  ferruginous, 
  crust-like 
  layers 
  of 
  argilla- 
  

   ceous 
  concretions. 
  Similar 
  beds 
  were 
  noticed 
  for 
  a 
  mile 
  or 
  more 
  

   to 
  the 
  southeast 
  of 
  this 
  locality. 
  Such 
  casts 
  are 
  also 
  abundant 
  

   in 
  the 
  S. 
  E, 
  % 
  of 
  the 
  S. 
  W, 
  % 
  of 
  Sec. 
  13 
  near 
  Jerusalem 
  Church. 
  

   Just 
  across 
  the 
  township 
  line 
  in 
  Sec. 
  19, 
  7 
  N., 
  10 
  W. 
  shells 
  have 
  

   been 
  found 
  in 
  a 
  well. 
  » 
  

  

  Ft. 
  Jessup. 
  — 
  In 
  this 
  locality 
  many 
  yellowish 
  concretionary 
  

   boulders 
  are 
  to 
  be 
  seen. 
  In 
  fact 
  the 
  rocks 
  that 
  were 
  used 
  in 
  con- 
  

   structing 
  the 
  Fort 
  were 
  of 
  this 
  character. 
  We 
  observed 
  none 
  con- 
  

   taining 
  plant 
  remains. 
  They 
  were 
  either 
  barren 
  or 
  with 
  traces 
  of 
  

   molluscan 
  life. 
  A 
  fragment 
  picked 
  up 
  at 
  the 
  old 
  Fort 
  contained 
  

   a 
  perfect 
  mass 
  of 
  a 
  small 
  univalves. 
  Another 
  fragment 
  found 
  

   nearby 
  contained 
  many 
  l^enericardia 
  planicosta. 
  

  

  Just 
  to 
  the 
  east 
  of 
  the 
  village 
  Rocky 
  creek 
  sets 
  in 
  and 
  

   extends 
  nearly 
  by 
  the 
  Williams 
  place. 
  Its 
  banks 
  are 
  high 
  and 
  

   precipitous 
  and 
  afford 
  the 
  best 
  view 
  of 
  the 
  geology 
  of 
  the 
  region 
  

   yet 
  seen. 
  The 
  characteristic 
  or 
  predominating 
  material 
  is 
  dark 
  

   clayey 
  sand 
  or 
  sandy 
  clay 
  containing 
  shining 
  particles 
  of 
  mica 
  

   and 
  quartz. 
  

  

  On 
  the 
  Williams 
  place 
  perhaps 
  one 
  mile 
  east 
  of 
  the 
  Fort, 
  

   several 
  fossiliferous 
  boulders 
  were 
  seen. 
  In 
  the 
  banks 
  of 
  a 
  

  

  