THIS IS AN ORIGINAL MANUSCRIPf If llAY NOT BE COPIED WITHOUf 1'BE AUTHOB'S PEIUlISSIOll 
THE TRAVIS PEK. FORMATION 
Approved: 
~a;~ 
.~ 

.A.pproved: 
THE TRAVIS PEA..X

.
FOffiUTIOl 
THESIS 
Presented to the Faculty of the Graauate School of the University of Texas in Partial Fulfill­ment of the Requirements 
For the Degree of 
....
i 
STER OF ARTS By 
Virgil Aug.t1st Brill,B.A• 
At1stin, Texas 
June, 1928 

t.,._ CICN0'1'1LEDG2:::100TT 
Notes, suggestions
.

and fos si1 collections 
made by Professor F.L. Vlhitney have proved of 
1e . 

much assists,nce in t 
prepara.tion of this thesis • 
THE TRAvrs PEAK Fbmvi..\TION 
The purpose of this thesis is to present the worthwhile published information on the Travis Peak rtnation together with the v,,rriter' s kn v'lledge of 
	. . 
f 
this f tion. 	Little attention has been given to
a.rt  . 
-rtnat ion, partJ;y due to the diffi  . 
the Travis Pea.k f 
"-~­
culty entailed in separating it from the form.ation vvh ich directly overlies i t, and partly due to the 
-	f accurate knowledge regarding the forma  . 
absence 
tion. 
T'he divisions of 	the Cretaceous period in Texas 
are as follows: ( .trontana Division Upper Cretaceous or Gulf Series( Colorado Division ( Dakota Division 
Lower Cretaceous 	or C tnanchean (Viashita Division 
 . 
1rg . 
Fredericlcsb( 
{ Division (Trinity Division The Trinity division is subdivided into the fol­lowing formations: 
ation.
rt  . 
Paluxy f( 
Trinity division 	(Glen Rose formation {Ease1nent sands and eq_u i valent 
•a t ions.rrt" . 
f applied  . 
The Travis Pealc formation is tl1e tert 
to that part of the Basement sands existing in and south of :Bu.rnet Count~r , Texe.s • from the ~exico the
tning south across I. Trinity 	.
C 
epiconte.atal sea .first reached the Texas borders 
del :r the Rio

orte on . . 
f Presidi  . 
in tl1e region· 
Grande. Gravel and sand deposited in this region 
constitute the lowest Cretaceous beds of which there 
is any knowledge in Texas. From the border area 
there was a gradual extension of the waters to the 

•vaters to t11e south  .. 
north and a deepening of t_he 
The sea vas shallow and encroached rapidly upon the 
 . 

i11erates indicate the  . 
older rocks. Sands and congl 
shallow, near shore conditions and the rapid encroaoh­ment of the early Trinit.sr sea. The Palaeozoic floor 
upon which the Trinity sea encroacl1ed rises gently · 

ent  ... 
this the baset  . 
to the nortl1 and west. Incident t 
sands are by no means of the same age in all localities• The Base1nen t sands become y .tunger and younger in age as they progress across Texas, and it is very probable that the Baser11e 11t SC:3,nds of north Texas, Kansas, and 
-re even 11",ter than Trinity in age, al ~..
evv Ivlexico .
J' 
e first encroacl1m nt f the 
 . 
~ :..
though they represent t 
Cretaceous sea• 
The old continental shield, Llanoria, possibly 
extended -all over east Texas, west Louisiana, and 
south Arkansas. In Texas this old land mass is sup­
-ned the southern and eastern boun  . 
posed to have fo 
epicontinental seas f early Cre­
 . 
daries of the 
taceous times • s urces of supply of Trinity sedi­
 . 
The chief 
(1) Lla11 ria; (2.) the upturned Palae­
 . 
were:ments 
(3)ins;.nt2 .- 
t.!
,  . 
f the 
uacJ1ita I the Llano  . 
ics.
o z 
Uplift; (4) the older sedilnentary f r1nations in 
 . 

general. T:he Travis Pealc fortnation contains rounded pebbles f Cambro-Ord vician li1ne­
. . . 
coarse 
stones, granite, scl1ists, and quartz derived from the adjacent Palaeozoic rocks • There was a gradual subsidence of the land 
1e of deposition of the  :. 

during the "Gi Travis Peak formation. With a deepening of the waters the de­posits char.g ed from conglon1erat es ana.. coarse sands to finer material, becoming m6re calcareous at the top • The Travis Pea.k passes a.lmost imp ercepti bly 
hich is composed  . 
se for1nation v  . 
into the Glen R 
largely of calca.r·eous tllil terial• Incident to being deposited on e.n neven sea 
 .. 

botto:n, the Travis Pea.};: for1112.tion is by no ineans uniform in thickness. It thic~ens to the east and to the south. In centrs.l Et1rnet County the average thiclcness of the for:a.. tion is less th8.n fifty feet • 
County the Travi s Pe2 c is ent ire­
 .. 
In northern Burr1et -noon .. 
1t formation lies  . 
ly missing, and the Vfaln 
formably on the Ellenberger (Catnbro-Ordovioian ) 
rtnation. 1\.t the t:rpe section near the Tre.vis  . 
f 
Pea l<: post-office , B..rnet Co1 1'1t y , the .tion is
form2. . 

1 
two hu ndred and. sixty-three fe!::t th ick. The log 
10\'VS  . 
ell at .~.11stin s  . 
of the State Ins9.ne ~\sylu.:n v 
•1ndred anc1 n.inety feet in thio~rness. . 
r h .. . 
i t to b ~ fo 
!~ineteen miles northv·1est of Fredericlcsb11rg the .Travis 
hile:. .. .:,
11e hundred feet ·thic  . 
.1,r.t eloximG.
1:r:..i s a: . 
Pea rg i t is a oxitnotel,';r or1hu ndred and..
sb1::.

e .
1 .
i .:. 
at 5'redericl 
2 seventy-five feet thick. A well drilled on the 
Leon Springs Reserve.t i on in Bexar 
y,1nt..
C 
starting 
gh. .. 
passed ent i.rely thro,..rt io .::.
e Gle n Rose form ..'
in t 
the Tra vi s Pea.lc formation and int g schists • 
 .. 
1nderlyi. . 

Alexander Deussen has assigned the bottome four hun­dred and. ei ghty feet of strata in th is well to the 
Travis Pea:: f orm t i on•

. . 

The Travis Pea f orrna ti on v-1a.G na1R. T•·
ned by  :. 

IIill. The na1ne Travis Pea k was c:;i ,ren beca se of
. . 
~ 
the excellent exposures of this formation in the 
vicinity of the Travis Peak post -office , .B. rnet 
1 
c . 
1'Geog raphy and Geology of the Blac·R.T.:,..
Hil 
nd Prairies, Tex <3.s, 121st .Re t. U.S • 
 . 
n.At1' .
»and Gr 
S rvey,Ft. 7 ,1900,p.t . 50D,.o7;15os -.
. .. 
Geological 
2 
rces'. . 
iner·e.l Reco~. 
 . 
d.H.: 11 The Geolo~sY anSelle.rds,E.,11.1932,1919.. . 
1nty," Univ. of Texas B  . 
of Bexar Co 
pp •21,22• --­
~Taff ....
The follovving sect ion, by JCounty. 
4
in which Hill interpolates the division and formation natnes, will give a,n idea of the sequence 
and composition of the fora.a. tion 
hole, exposed in the valley of the Colorado River, be­
,een Travis PeaJ.-c post-office and St11itl1wick 1Jiill .
tv 
•t1!1ty . 
Burnet C 
Hickory Creek Section of the Travis Pea.~ 
Forrnation, beginning at the top of the 
divide between Hickory and Cow Creeks 
and continuing to the Colorado River 
11th of the Jiickory  .level at the tn •Burnet Count,>r  ,Creek  
Thickness Feet  Total Depth to bottom, of strata Feet  
;.n.ati.rti .Glen Rose f :Tra,vis Peak formation 12.Bands of conglomerate -ancl calcareous sand stone, alternating -with beds of arenace ous limestone, the arenaceous limestone •••••••predominating :I1ensell .sand -11.1,Iarly magnesian litne •••••••••••••••stone  40 40  40 80  
3  

Taff,J •. !\..: 1•Reports on the Cretaceous Area. :r~ orth 
o f the Colorado Ri ver 3rd Ann. Rept • eol. Sur­
 ..  .. 
, ...:-
92::.
29•1891,ppTexas,~vey 
l-Iill, R. T.: 11Geography and Geology of the Blaclc and 
s, 11 
•GeolU.S.t..
Re.itnn.~ :..
:TexPrairies,Grand. 
Survey, 1900, .P • 141 • 
as a
.
v 
as 
,careous sand at base 	.
Ca10. 
grading upward to a sili­ceous limestone at the top , barren of fossils ••••••••• 55 
9. 	Yellow calcareous sand, stratified •••••••••••••••• 15 
8. 	Conglomerate, sitnilar in character to ·No.2, with the exception that the peb­bles ~re smaller and more worn, grading ir1to sand below and calcareous sand above •..............•••.•• 25 
7. 	Red sand, unconsolidated••• 3 
6. Friable yellow sand ••••••• 5 Cow Creek beds : 
5. 	Cross-bedded shell breccia, containing many Stnall round­ed grains and pebbles of quartz flint and granite sand. Fos­sils: Tri~onia and small bi­valves an Ammonites justin­ae •••••••.•••••••••••••••• 7 
4. 	O'Strea beds, magnesian lime qement, fossils en masse •• 3 
coinposed  . 
Brecciated grit	3. 
of \v.. rn fraginents of oyster shells and shells of other llusca, vi th sand and peb­
 . !:.!.

bles stratified in false beds•5 
2. 	Bands of friable bluish shale and calcareous sand, strati­fied; fragtnents of oyster shells are common in calcar­eous sandstone ••••••••••••••15 
Sycaihore sand : 
1. 	Basal conglomerate of pebbles ql artz, chert , 
	 .
limestone,of 
granite and schist, wellround­ed, in a cement of fer..r.ginous yellow and red gritty sand• Some of the pebbles at the base are from 4 to 6 inches in diameter. They decrease in size, however, upward from the base, until we obtain a false bedded calcareous grit at the top ••••••••••••••••••••••••• 50 
135 
150 
175 
178 183 
190 
193 
: 198 
213 
263 

Total T11iclcness of T'ravis Peak beds 
Carboniferous: 

0. 	Laminated, flaggy. carbonifer­ous sandstones and friable light-blue clay of Carbonifer­ous ( Coal measures) age, from the Colorado river level up­ward to the base of the Trin­i ty co nglomerate the lamin­
 . 

ated sandstones containing 
f ferns, nearly ••.•• 100 363  . 
prints -a.renaoe ,.
v . 
5At the top of tl1e sandy beds a yell s limestone appears. This tnarl{S the . .. 
fo ssilifer  . 
ous 
f irst or lowest appearance of the peculiar fossils 
ienia (Caprot ina), ancl indi cates 	.. . 
1Ionopleura and Req. . 

the beginning of the Glen Rose formation • The lovvest division of the Travis Pealc formation, n d, is, in a general v ay, persistent 
	 .
.t..re sa  . 
the Sycat
throughout the horizontal extent of the forlnation. The Syca1nore division consists of conglomeratio ma­terials and sands. This division is barren of fos­sils, and ve.ries locally in thickneSs and character. In t h e vicinity of the type section the division is fifty feet in thickness. At Austin, according to the log of the State InsaneAsylum well,this division is approximat~ly three hundred feet thick• 
-1t e the divi sion im 	 .
The Cow Creek beds const i t 
Ibid, p. 144. 
mediately above the Sycamore division. The Cow 
Creek beds are composed of clay. calcareous sand, 
-	t1s limestone, and are very fossilifer  . 
and arenace 
ous. The followir.ig section of the Cow Creek at the 
ws the  . 
rmation sh 	 .
f the Travis Peak f  . 
n . 
type secti 
character of these beds and the stratigraphic rela­
t ion of the fauna. 
Cow 	Creek Iieds: Feet 
4. 	Cross-bedded shell breccia, con­taining many Stnall rounded grains of quartz and granite sand. Fos­sils: _D.frenoya justinae (Hill,) an undetei'tninable fr2.gment of am­monite probably·Douvilleiceras , an undescribed species of Trigon­ia (2), C{rena, Tapes, Corbicula, Prnna. js rocoenia. and shark 1s 
t 0 0 th .•.•••••••••• •.. . . •• . . . • •• •. • 7 
3. 	Ostrea beds, magnesian li1ne cetnent. Fossils: two undescribed. speciesof Ostrea .•••••••••••••.•••••••.• 3 
2. 	Brecciated grit. composed of worn 
-fragments of Ostrea and. otl1er 1'Iol l11sc•::, , with s2.nd. ancl fine pebbles :stratified. in false beds. Fossils  
strea si1nilar to . o.  fre.nlclini  •var  
-11cullaea, t er111inalr.,)ragsdalei (IIill )is (Conrad), Cardium (Protocardia..................)texanum (Conrad  5  
1.  Band.s of friable bluish shale and  
calcareous sand,  stratified.  -Fos  
.T  sils: Fragments of Ostrea, Exog*ra weatherfordensis (Cragin), Gryp:aea ---.ana-vaughan} •••••••••wardi (Hill •••w Creek beds  .tal thickness of C  15 -m.  

c . 
llowing is a section of the Cow Cree 	 . 
The f 
beds as exposed in the cliffs at Hammett's Cross­
ing 	on the Pedernalis River, Rays County: 
Cow 	Creek beds : Feet 
4. 	1.fassi ve shell breccia, cont2.in­
and.	nded. .. 
ing an abundance of ro 
subangu.lar s::-.nd grains. Fossils : Du.frenoya justinae (Hill), Car­·dium (Protocardia) texanum .con ­,raa.T two undescribed species of 
 .. 
Trigonia identical vvi t"!.1 t!ie tv nia in the Cow  .~ 
species of Tri 
Creek beds ofhe type section, an undescribed species of Ger­villia ....................:-:-:-... 9 
3. 	Ostrea beds, arenaceous lime ce­ment. Fossils: Sa e species of 

 . 

Ostrea enco nt ered. in Covi Creek 
 ... 

beds at the type section •••••••• 4 
2. 	Shell breccia with subangular sand. 
grains and calcareous s2.nd.. Fos­sils: cucullaea terminalis (Con­
-mo  . 
undescribed species of H	rad), 
moya, Aporrl1ais, !~erinea. ••••::::-7 
1. 	Yellow and. bluish clay with some 
calcareous sand.. Fossils: frag­
-	f Ostrea, Exogyra weather  . 
ments 
ford.ensis (Cragin), Gryphaea wardi Hill and. Va • ••• •••• •• • ••• 19
)ghan	 ...
( 
Total Thickness of the Cow Creek bed.s at 
this locality ••••••••••••••••••• 

39 
The follovving section of the Cow Creel: beds 
1e fe.11n2, and composition 	 .
vvill give an idea of t 
of these beds as exposed n the cliffs of the 
 . 

,	JVO miles ea.st of Cox' s Cro ssing  . 
Pedernalis River t 
Travis County: 
Cow 	Creek beds: Feet 
4. 	Shell breccia containing 2,n abundance of calcareous sand• Fossils: Chione (?) d.ece~te, (Hill), and. undeterminedherk's tooth different from the one found in the Cow crreek beds of 
twon,.
secti
the 	type speciis 
of Trigonia id.entical with the 
species previously listed., two species of Gervillia one of 
 . 

vvhich is identic2.l \'Vi th the 
-	e preceeding sec  .: 
species in t 
tion of the Cow Creek beds , 
undescribed species of _Proto ­card.ia, Cl .e_a.L Ptycl1omya••• 9
cull2 . 

3. 	Ostrea beds, lime eement. Fos­sils: sa~e species of Ostrea 
encountered. in the previons . 

1e C v Greel\: bed.s •• 3 
 ... 
~sections of t 
· 2. 	Sands and calcareons sands con­taining 1i.2.ny S;'lf'.11 fra.gmen ts of 
shells. Fossils: Cucullaea ter­minalis (Conrad), an undescri'5ed 
species of Lunatia, an und.escrib­ed s~ecies of Aporrhais identical 

tn  . 
ith the species of Aporrhais fr 	. 1
v 
the preceed.ing section of the Gow Creek beds •••••••••••••••••••••• 6 
1. 
•	vv clay and calcareous s2.nd .
Yell1. 
Fossils: frag:nents of Ostre2,, 
Exog*ra weatherfordensis :} aea vve.rdi 
(Cragin ,) 
ryp 
ii11 .
( 
l'\ .
C 
16••)gh2.n.
.li.nd V2::­
Total Thicl::ness of the Cree:c bed.s . in 
this locality ••••••••••••••••••.••• 34 
,ole	 .
s2.n'![.. . 
In the surrounding cliffs of Dead 
Hays County, there is an excellent exposure of 
atelya..xi.
ap;?rTl1ese bed.s 2.re	s.,c.c be  . 
the Co11v Cree 
forty-five feet thick in this locality, and are very fossiliferot1s. The fallovving fossils were 
ty:1n this lo cali  . 

oollected fr Dufrenoya justinae (Hill), Cucullaea terminalis {Gonrad), Trigonia (Gragin), two other species f Trigon­
 . 
conoentrica 
ia identical with the species of t11e previous 
beds,ow Creek  . 

sections of the three undescribed 
1nya different species .
tn  . 
species of H 
fro.n the at the Hatninett 's cro ssing sect io of t11e C...v. Creek 
 .: 

beds, and en undescribed species of Astrocoenia• One mile west of Cox' s Crossing on the Peder­
r,~u.1:1t.
C 
vJere collected by Professor F.L. \mitney fro111 the Cow Creel:: beds: three ndescribed species of Na­
 ... 

tica, anC undescribed speoies of Aporrhais, an un­described species of Astrocoenia similar to the one fro1n Dead !vian' s Ifole, Dufrenoya justinae (Hill .) 
Ia Comal County the base of the Travis Peak mation is not exposed, but t11ere are S tne good 
..
fo1 
nalis River, B11rnet 
the following fossils 
expo s·ares of the uppe r portion. The follo11v ing tvv 
-lhit'.'
•F.Lri1plete sections 1neas11red b ~r Professor .
inc 
idea of t e character of the form­
 ... 
ney will give an 
ation as exposed in Comal County : 
 . 

Section at Speck's Crossing n the 
 . 

Guadalupe River 
Feet Travis Pea...'c forrnation: 
2. 	~ell~ :' paclc-sB.nd. 11 , barren of 
.
v 
rossils .•••••••••••••••••••• 36 
1. 	Arenaceous limestone, fossils 
1nd at 	 .
sitnilar to those fo 
type section in the Cow Creek 
beds • • • • • • • • • • . . . • • • • • • • • • • • 78 
... 
nal 	 .
Section at Rebecca.-·Creelc, Co 
•nty.
Cot 
Glen Rose formation• 
Travis Peak foru..a tion: 

2. 	Yellow "pac%-sand" and calcar ­eous sand containing an abun­danc e of geodes a.nd. large un­described Ostrea •••• .......~ 45 
1. 	Arenaceous limestone, fossils similar to thos e found at 
Creelc 	 ;...
type sect ion in the Co 
beds, approximat ely ••••••••• 80 
tion above the Cow	a..rt  . 

The Travis Peak f Creelc beds is barren of fossils except in one locality 
' 
discovered by Professor F.L. Whitney. Near Rebec­ca Creek, Comal County, thirty feet from the top of the for1nation an undescribed species of Ostrea different from the Ostrea of the type section and an undet er minable species of Trigonia are f ound. 
•tl1ese for:ns been fouc1d 	..=
·lity ha-v  .. 
1er loc  . 
At no ot 
Of the thirty-six species of fossils listed from the Travis Pealc format ~on, thirty-four are 
-	vv Creek bed;;; and tvJo from tl1e upper  . 
found in tl1e C 
rination.f the fo  . 
beds
most Seven of the species belongiag to the Travis Peak for~nation have been. described, the other twen.ty-nine are new species , and will be desaribed by th e writer in a later pa­per. The described species are: Cucullaea termia­alis ( Conrad) , carcliutn (Protooarclia) texanu1n (Con­rad), Trigonia concentrica (Cragin), Exogyra weather­forclensis {Cragin), Chione (?) decepta (Hill), Du.­frenoya justinae (Hill~·, Gryphaea wardi (Hill and Vaughan.) 
All of these speoies, with the possible except­ion of Dufrenoya justinae {Hill) and Chione {?) de­
and  .: 
are common to both the Tra·vis Pealcepta{Hill), 
Glen Rose formations. It is highly probably that the majority of the undescribed species from the are also present in tl1e Glen R se forma­
 . 
Travis Pealc 
tion. 
1nal differences  . 
r fai.JThere are several notewort 
between the Glen Rose and Travis P'3al<: for[nations • No Foraminifera have been found in the lowgr forma­tion; there are, however, several prominent hori­
zons of Orbitolina in the Glen Rose formation. Ac­
cording to Professor F.L. 1~/hitney, there are at 
least four different genera of Brachiopoda in the Glen Ro se • but none are kn vvn fro1n the Travis 
 . 

Peak. N representatives of the echinoderrns are 
 . 

t1gh Crinoids  . 
known from the lower for1na t ion, th 
and Echinoids are present in the Glen Rose. Of 
and  . 
Caprinidae  . 
1{onopleuridaethe Pelecypoda the 
" 
Rudistae are well represented and constitute oon­spicuous horizon markers in t e upper formation ; 
 ... 

but are absent from the Travis Peak. 
Incident to the difficulties encountered in any attempt at separating the Glen Rose and Travis Pea.l;: formations, the importance of th'e above faun­al differences can not be overemphasized. 
R.T. Hill6 begins the Glen Rose formation with the first oacurrence of the fossils Requien­
evers­ . 
This is, hovleura. . 
and ~.TonoCaprotina)(!!, 
a more or less arbitrary basis upon which to separ­the Travis Pe8.k from the Glen R se formation• 
 . 
ate 
!1lty in using the  . 
The chief diffic 
_..
onople~· 
ra 
and 
Reg_uienia for1ns as indicative of the beginning of the Glen Rose fdr ation is that these forms are 
 . 

not alviays found at the ba.se of the forma.tion. In Ibid, P• 144. 
the vicinity of the type section of the Travis 
bu t  . 
forma tion the3e fo rins are generallyPea.k 
not always present in the base of the Glen Rose• At one locality near the Travis Pea...~ post-office 
-s (Giebel), a Glen Rose fos  ., 
Porocystis globular 
sil, is found below the first occurrence of the 1.1ono12leura and Requienia forins. In parts of Coinal and. :Hays 6ounties an undescribed species of Astrocoenia discovered by Professor F.L. \'Jhit ­ney appears iil abundance at the base of tl1e Glen Rose formation. In many localities the base of the Glen Rose is barren of fossils. Incident to the si:nila.rity of the lithology of the top of 
-e be.se of th e Glen Ro se form  ... 
the Travis Peak s.nd t 
a t ions, and to the lacl{ of sufficient faunal evi­
dence, the arbi~rary eontaot established by Hill 
seein.s to be of little importance. Doubt exists 
as t ·o t 11e advisability of separating the two form­
ations; i t is 11ighly probabl~ that the two forrna­
tions are in r eality only two divisions of one 
major formation. In any event the contacts of the 
two formations as nov1 }{novvn are f 2.r fr tn being 
 . 

satisfactory. · 7
rn Gilles.pie County, Hill has given the term 11Gillespie fortnation to t 'h.e b[1.setnent beds of the
' . 

section,ing is a  . 
The follov
Gretaceous. measured 
11'hitney nineteen mile s' . 
with ?..n anero id by Pro fesso r 
north-west of Fredericksburg at t he Fredericksburg 
and J,[ason County line: Feet Co~nanche Peal\: and ~Valnu.t forrnations : 
s......
.reosands, and c2.lcaClays,3. 
sandst one containing \'/aln11t 
50•••••manche Peak fossils  . 
and C 
Glen Rose formation: 
2. Sandy limestone, w11ite to yello.v\ 45 
:ti ona.1•r . 
Gillespie f 
l.Crosi-bedded brown to brownish red sands wi th pyritifero s cor1­
......

cretions •••••••••••••••••••••• 100 
18 sediments this locality ...

The Cretaceo at rtnably upon t e Jiickory .~ formation , 
..: . 
rest unconf 
Upper Cambrian). This S.rea vas relatively high 
 . 1
( 
d11rin~3 .lretaceous depo sit ion, ancl receiV9d very 
1er north .
rt..
..F•s seditnent s ......
little of the Cretaceo 
Hill,R. T. and aughan, T.VI.: 11Geol g.)r of the Ed­
 . .. 

v-vards Plo.. t es.u and Rio G-rande P ain adjacent to 
 ., 

n and San Antonio, Texas, rr Eight eentl1 . 
.­
nnu!i.....
st...
A.. 
•221•Sur·vey, 1898, pGeol.; •S.-:-ort, . 
al Re 
and west around t11e old Llano uplift none of the C'retaceou-s s edia1ents ~re represented. Hill8 is of the opinion that the so-called Gillespie ··· forrnatio.a is p.robably equivalent to the Glen Rose rather tha.a the Travis Peak. There are no fossils present, b t the 11thology seetns to indi cate that
. .. 

Gillespie formation is t he eq i ·valent of the · 
 _.. 
the 
Hensell sand of t he upper Travis Peak. The lime­stone above the Gillespie resembles uome limestone 
se fa rther ea st. At  . 
in the
seen ba sal Glen R the 
csbl1rg the vari-colored. sands and  . 
town of Fred.eric 
clays, undoubtedly belonging to t he Travis Pealc for111at i on, are approxitn t ely one h 1ndred and seven­
 . ~..

feet thic c according to aneroid measure­
.
.vety-fi rtn2.t ions  . 
The Glen Ros e and Travis Peak fments. 
thicken rapidly to the east and southwest of Fred­ericlcsburg. 
9In Europe and most other parts of the earth the Cretaceous has been subd.ivided g enerally into two great groups: Infracretaceous and. Supracreta­ceous. These have been f\1rther subdivided in the 
Ibid, p •222• 
1The Cretaceous and! .\..:
".and Cavins , 0E.8e,.t9B  . 
,exico . 
t1thern Tex2.s and Nort:1ern t  . 
Tertiary of S 
Univ• f Texas Bull. ~-748, 1927,p•12• 
 . 

:ving way  \. 
the foll 
Maestrichtian 
i \ 
ca.mpanian ) 
} 
Santonian ) 

) 
.coniacia n or Emscherian) SU:pracretaceous 
) 
Turo11ian ) 
Ceno1ne.nie.n 
Albi&..n 
~ 

P~ptie.n ) 
) 
Barremian ) ) Infracretaceous 
) ) 
Haut erivi [;.n ) ) 
) 

:Neocomian )
Valanginian) ) 

j)  . 
Berriasian 
10 
ill atte1npts correlate .: .: 
•R.r:' 
t o t he \'vhole of 
rope.. 1. 
miRn of .:.
·eo . . 
t11e Trin.tj' division ~vi th t1
e 
on the basis of t he similar ity f some f ew bivalves 
 . 

tion to some of..n8r  . 
se f  . 
f the Glen R  . 
nd univa.lves2.
the .:uropean !Jeoco1niR.n for:ns. Hill correlates the 
 . 
er T~inity wi th tl1e lowest Cret e..c eou.s of Europe .~
lo 
middle and u_pper Gler1 R becls are correla.t­
~s . 
and the 
~Jith t e r11iddle r-i.nd. uppe r eocomia.n• 
 .! ~. 
·ed 
"Invertebrat e Paleo tology of the Trin­
 .. 
T.:R.  . 
Hill 
i ty Division, 1' Proc. Biol. Soc·. ·,"/ashington, Vol •8 1893 , pp • 17-20:------.
 . 

It is a generRlly co nceded fact that the lowest Cretaceous of !·,!e;cico is much oldsr than the l f Texas. The lower Cre­
 . 
west Cretaceous  . 
oving.
:fexico, . 
n . 
taceous sea passed into Texas fro 
np a gently sloping land surface, and as the .sea passed interiorv ard thro 1,gh Texas t ':.e deposits 
 .  . 1

became younger and yaung::;r in age. 
11The entire Neocomian division is represent­ed in Mexico. Incident to this fact it is, there­fore, obvious that the lowest Cretaceous in Texas 
-lent to the lowest Neo. :. 
could not. po ssibly be equiv 
resting fact in this connecti n is 
.
~An intcomian. 
none of the i a n fossils of r.ti:exico have 
.
t .
eoc.
!that 
been fo11nd in Tex: s, eithe r in t 1 e Travis Peale. or 
 . .:.

Glen Ros e formntions. l2B8se a..i. d. Cavi ns · correlate the Travis. Peak · n . ti on ·~ith the Gar-~asi.r" n (Up_per Aptian},
v ·on  . 
rt.
f 
the basis of the sup_posed occurrence of Dufrenoya 
-justinae (Hill), D. roeD.hardt),::- . 
rc..
(Bttexana 
meri (Cragin), 2.n d. hoplitoides _(Lass1;~ itz) in 
 ... 

-1r species ~ jus. .. 
1e f  . 
the Travis Peal: beds. Of t 
.:r 
Bose, E. ano. Cavins, O.A..: 11The Cretaceous and 
",f Southgrn Texas and Northern Mexico  . 
Terti9.ry 
Univ. of Texas Bull., 2748, 1927, pp •17-18• 1~ ­Ibid, _pp.20-21. 
tin.ae is the only o~e that undoubtedly came 
Thermation. . 
f
from the Travis Peak rest of them might very well be Glen Rose forms. Species 
se . 
of Dnfrenoya appear to be present i.n the (1.len R 
formation.• 
f . 
where has the writer seen any species .
N 
Dufren.oy~ other than D. justinae in the Travis 
1lty of  . 
e diffic  ... 
Peak forrna.tion. Incident to t 
separati..g the two for~a... tions in the field, it is entirely possible t hat the other three species 
 . 
came from the Glen Rose format·ion. In any event Pea.krrelating the Travis  . 
f c  . 
ssibility . 
the p Du.frenoyan the basis of  . 
with the Upper Aptian 
alone is extremely doubtful. 13None of the other fossils cited by Bose and Cavins as co.ming from. the Aptian of Mexico are found in the TravisPeak formation• 
It is significant that Hill c·orrelates the 
tnian while Bose .
c . 
Travis Peak with the lowest Ne 
and Cavins correlate it with t he Upper Aptian• 
rrelate the  . 
It will be impossible accurately to c pean and Mexican  . 
r . 
Travis Peak formation with Et 
r.;-­Ibid, PP• 19-20.
-
rk has been done with  . 
rther w...fCretaceous until -the presA..t.ns. . 
the fauna of the Trinity format i 
ent time it is the opinion of the writer that the 
-c represents a part of the Aptian1 prob  . 
Travis Pea 
ably the Bedoulian r nower Aptia,n. The three 
.
, 
species of Natica c1ted from the Cow Creek beds of the Travis Peak f r;nation are similar to, i:f 
 . 

m the Iower  . 
not identical with species of Natica fr 
Aptian T e species of A,porrhais, Phala­
..:
Spain.f . 
Cr.eekw . 
coenia of the C  . 
and AstrGervillia,domya, 
beds resemble Aptian forms more nearly than they do Neocomian forms • The topography f the Travis Pee.k forma tion is 
 . 

represented for the most part by a rolling, wooded Small buttes and mesas, l w hills and es­
 . 
surface. 
carpmqnts, and small valleys are amollG the topogra:ph­ic features of this formation. Caves, caverns, and sink holes are amo ~g .its characteristic features • Hamilton's Pool, curiosity Cavern, West Cave 1 ~nd Dead ~.~an's Fiole in Travis and Hays counties are beautiful examples of the varied topographic features of this formation• 
Stalactites, stalagmites 1 and travertine depos­
its are common in the oaves and 
caver 
s 
nine inches  . 
cliffsw Geodes from two t
the i diameter vomposed of calcareous and siliceous 
 .. 
and o 
 .. 

materials are found i great abundance sc~ttered 
 .. 
f the ground thirty feet  . 
surface
over the from formati n in the vicinity of Rebec­
 . 
the top of the 
tnal County. Arenaceous a d pyritifer­
 .. .
CCreel[,ca. 
ous concretions, calcite, celestite, and some lig­nitic materials are found througl1out the format1on• Up to the present time no minerals of commer­d in the forma,ti n. It 
 .  :. 
cial val11e have been fou 
is entirely possible, h wever, that oil will be 
 . 
· 
encountered i s 01ne of the more porous sandy phases 
 .. 

of the formation. This forrnation is the most pro­
formation in the.icing.
prod 
ceous. .Springs and artesian wells are encountered ,t.hroughout the entire extent of the Travis Peak.•The up.per sands are prod11ctive of large amounts of 
esium .. 
ble water;. ~ut often con tain enough mag.pot?.1desirable for  . 
sulfate (MgS04) to rencler the water u 
'The l r Sycamore sands pro­
 . 
vver . 
1rposes. . 
drinking p f artesian water. The  . 
nt . 
duce the ~reatest amo1 
vvat er from the sands i s highly potable, and const.i ­
lific vvater Texas Creta­
 .. 

tutes the chief source of the water su.pply for ma.ny people living on or ·\vi thin drilling reach · o:f the Travis Peak f r tnation• 
 .

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B6se, E. and Cavins, O.A.: "The Cretaceous and Ter­tiary of So and N rthern 1!exico ",
. . 
thern Texas  ... 

Univ. of Texa s Bu.ll. 2748, Au ~ tin, 1927 • 
. . 
Boyle, C.B.: ."A Catalogue and Bibliography of Nor"th 
-SurQ.eol.S.U.  .. 
,esozoic Invert ebratesl\!!mericaa 
vey Bull. 105, Washi ngton• ~ -­
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P  .. 
ae Cretacique d  .. 
ffat, P.: 'Fa 
Lisbonne, 1S86• · 
.
Ch 
-of Cretaceous and. Ter"Descri9tionsT.A.:  . 
Conrad 
U.S. and :h exican Boundary Sur­
 . .. 
,tiary Fossils 
vey, Vol. 1, \Vashington, 1857 • ­
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giq.
tolr..11~.ronographie Paleo Coquand, 
·r. H:.: L'Eta.gs !l>tien de L' ~spagne, Paris , 1866• ­
A Contribution to the Invertebrate  .. 
:.Cra,isin, F.Vf 
Paleontology of t he Texas Cretaceous, r Fou11 th 

 .
,al Re~ort of the Geol. Survey o f Texas ..
l\.nn. 

Austin, 1 9:3 • --­
f  . 
•Univ  ..• 
11 The Geology of East TexasT.:E.Du.mble, 
Texas ~• 1869, Austin , 1918 • 
f the  . 
ogy  :. 
aphy an"GeogrT.:R.IIill, 
Geol.Black and Grand Prairies, TeXF1s," U.3. Geol. Survey, Tv.,renty­
•1900 ..,
1al R:;pt., pt.7:-Washingto  . 
first Ann 
----------The Invertebrate Paleontolo,of the
sy  .. 
.Vlas"lington, 1893,Soc.Biol.Proc.  .. 
,Trinity Division 
-
. 
a nd Va T. 'll.: "Geolog,v of t:he Ed­
..,
gha. ... 
R.T.Hill,  . 
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1ards Plateau and. Ri.v .~
SurveGeol.u.s. r.,Tex<;,snio.  . 
Austin and San A.nt 
t eenth 1\.nn al Report, Pt• 2 .Na,sh1ngton , 189 • 
... . .:'
Eig 
The L wer Creta6eous 
 . 
"----------------------------
Gryphaeas of the Tex~ s Regioa," U.3. Geol. Survey , 
--•1898 ..,
ashingto .
~,151•11 ...B
-. 
eol6gische . 

 ". 
i t z, R.: "Aminonite.s von Texas .
Lassv 
,tngen, I'feue Folge 6  . 
und Paleontolo~i sche Abhandl 
Jena , 1902-196 • 
-Super  .. 
Le Barremie  .. 
:.M  . 
n .. 
and CossmaE.  . 
Pellat 
ieur a Facies Urgonien," Memoires de la Socie­
t.e (}eologique d! France . emoire }!o •27-;--i.aris •1907 •
~ . 

ineral Resources~, . 
r and.gThe Geolo  .. 
:.E.HSellards, ,2748•Bu.11of Texas Univ.unty," . 
of Bexar C 
Austin, 1927 • 
Taff, J "Repo.rts on t e Cretaceo s A.rea North of
..
. .  ..  . ....:

the Colorado River Thi rd A.nnual Report of the 
 .. 
, --.stin, 1891 .. .. 
rvey of Texas. A ....
SGeol. 
'hitney, F.L.: "Bibliography a d Index of North Amer­
 .. 
~ 
ican J,{esozoic Faun anuscript copy. ) •
~. .) . . 
s.r 
 .