Pirate. I. 
XI. 
XII. 
#XIII. 
XIV-XXVIII. 
XXIX-XXXV. 
XXXVI-XL. 
XLI. 
XLII. 
XLITI. 
XLIV. 
XLV. 
XLVI. 
XLVII-LXI. 
Outline map showing the position of the Seaman and Rudd wells, north-central Texas, and their 
Ficure 1. 
\ 
ILLUSTRATIONS. 
Page. 
Logs of the Seaman and Rudd wells and a generalized log for north-central Texas .-.....- In pocket. 
» Species of Orthar laa ono oc.cco ns 2 coo neisieie we nines ss be SRE SEE oe SSIs eee A eee 33-37 
. Alinement chart for graphic computation of thickness of strata.........-------------++-+-- 44 
. Alinement chart for graphic computation of depth to a stratum. ......-----------e--eee ee eee 48 
. Alinement chartfor graphic solution of right triangles...........--.----------+eeeeee eee eeeee 50 
. A, Coconino sandstone and Kaibab limestone in Hurricane fault scarp, 6 miles south of Hurri- 
cane, Utah; B, Closer view of middle part.of scarp shown in A; C, Upper part of Kaibab 
limestone and basal member (Rock Canyon) of saxiisagicss formation in Virgin Canyon, 1} 
miles westiof Virgin City, Utah cco. lees eetionent cineca eee teuwiess se meaueies 58 
. A, View northward toward Smith’s Mesa from a point just south of Virgin City, Utah; B, 
Panorama along east:side of Coalpits Wash near Grafton, Utah.............-.--.-----+----- 59 
A, Chinle formation and overlying maasive Jurassic sandstone in Zion Canyon above Spring- 
dale, Utah; B, Cross-bedding in white upper part of massive Jurassic sandstone 12 miles 
north: of St.:George, Utah... <<. 2)2c/cciscicciae.c cpe.cncsene acisicice  wicie dorcsersbeisisia(e(e:arbja ace Mate BERRY 62 
A, Group of cinder cones of late date and associated lava, Diamond Valley, 12 miles north 
of St. George, Utah; B, Nearer view of larger cone of group shown in A............-.-.---- 66 
A, Shinarump conglomerate resting on upper Moenkopi shale and sandstone, Smith’s Mesa, 
3 miles north of Virgin City, Utah; B, Late basalt flow resting on a conglomerate of basalt 
and other bowlders, on road from Toquerville to La Verkin, Utah..............-.--------- 67 
Foraminifera of the Byram marl..........-.--.22. 2222-22-22 e ee eee ee nee eee een eeee 107-122 
Foraminifera of the Mint Spring calcareous marl................0000022-ceeeceeeeeee sees 146-152 
Fossil plants from the Woodbine sand.........-..2- 2222-222 eee eee ee tee cee ee eee 181 
A, Hills of chloritic schist at the northern end of Big Horn Mountains, near Palo Verde mine, 
Maricopa County, Ariz.; B, Gonzales Wells, Dome Rock Mountains, Yuma County, Ariz.. 184 
A, A: plug of latite of Tertiary age in the Dome Rock Mountains, about 4 miles southwest of 
Quartzsite, Yuma County, Ariz,; B, Black Butte, Cactus Plain, near Osborne’s Well, Yuma 
County, Ariz cspcciticsioarocstene Ga sasocgsmen ebm tates visca ce esitnodd te eee i Ateneacns 185 
A, Osborne Wash, about 2 miles southwest of Osborne’s Well, Yuma County, Agia B, Saddle 
Mountain, Maricopa County, Ariz., looking south.......-.--2 2-22. ececee eee c ence cee ence 188 
A, Bank of wash near Woolsey Tank, Gila Bend Mountains, Maricopa County, Ariz.; B, Woolsey 
Tank, Gila Bend Mountains, Maricopa County, Ariz..............200cceeeeee ccc ee een nee 189 
Reconnaissance geologic map of the lower Gila region, Ariz. ....-...-2-e.2.20000 cececees “In pocket 
Osage Rock, about 1 mile north of Belvidere, Kans............ 2.02.22... - ee eee eee eee eee eee 202 
Fossil plants from the Cheyenne sandstone.......-...--- 2-20 - cece eee ence cece eee eee eeecens = 225 
relation ‘to:the “Bend arch) see es jsnije0 conn ccisprewe es siaeiels oeyaien ee s'salayee eee g Sys deieiaioe eee es eldlee 6 
2. Geometric representation of the thickness of a stratum when the dip of the stratum and the relative 
‘positions of a point on the upper surface of the stratum and another on the lower surface are given’. 40 
3. Diagram to illustrate the method of calibrating the diagonal seale of a Z chart...............-..... 43 
4. Diagram to illustrate the method of determining the locus of the curvilinear scale in an alinement 
chart consisting of two parallel straight-line scales and a curvilinear scale...,.........-...2--00- 44 
5. Geometric representation of the distance to a stratum when the dip of the stratum, the position of a 
point on the stratum relative to the starting point of measurement, and the horizontal and vertical 
directions of the line of measurement are given......-- 222-222-2222 eee eee ee ence eee ene 47 
6. Right-angled triangle showing the relations of slope distance, horizontal distance, difference of eleva- 
tion, and vertical angle between two station points..............-00cecececeeecececccaceccceccce 48 
7. Diagram illustrating the combination of three alinement charts for the solution of right-angled 
triangles... ..- 22-2222 e cree eee enn ee eee teen eee rene ene e nena e eee e cw cen enn eter eeeee 49 
8. Diagram illustrating the use of an alinement chart for the solution of the tangent condition in right- 
angled triangles. ...-....---------- nin setis a ha raiareceiaransloSicie a ened elaeeccieibae divisinisingscrg ive e.stersianina lass 50 
9. Trigonometric computer for the solution of such problems as are readily solved with the 12-inch 
straight: elide: rule oo...2scces evsaainicnmsnne's s aleleaicuivaiens «se eeseniwee neweseecicee ss cena nca cee 51 
10. Map showing localities where sections were measured in Washington County, Reh; and Michie 
COUR EY,, AUN Sa i a aeixres ciao asaiaseeBisaaninisiesnve win lemicicyacd cc aera had C.acranarsme Camere ental 53 
11. Cut in the Woodbine sand near Arthurs Bluff, Tex... 2.02.22... eee e cece cece en cee eee eens 180 
Iv 
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