DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEOKGE OTIS SMITH, DIRECTOR BULLETIN 389 THE MANZANO GROUP OF THE RIO GRANDE YALLEY, NEW MEXICO BY WILLIS T. LEE AND GEORGE H. GIRTY WASHINGTON GOVERNMENT PRINTING OFFIGE 1909 CONTENTS. Page. I3TRATIGRAPHY OF THE MANZANO GROUP, BY WlLLIS T. LEE................. 5 Introduction........................................................... 5 Purpose of report................................................... 5 Preliminary statement of results..................................... 5 Field work......................................................... 7 Location and character of area............................'............... 7 Formation names. ..................................................:.: 8 Explanatory statement............................................. .8 Magdalena group.............................'...................... 9 Sandia formation.................................................. 9 Madera limestone. .............. '. ................................. 10 Manzano group.................. '. ................................. 10 Abo sandstone...................................................... 12 Yeso formation.............. '. ...................................... 12 San Andreas limestone................................................ 12 Stratigraphic relations.................................................. 13 Underlying rocks.................................................. 13 Subdivision of the Manzano group:................................. 14 Overlying rocks.................................................... 15 Generalized section................................................. 15 Descriptive details of sections........................................... 18 Galisteo Canyon........ .......................................... 18 Sandia Mountains. ................................................. 19 Abo Canyon...................................................... 20 Mesa delYeso...................................................... 21 Alamillo........................................................... 24 Blackinton's ranch. .............................................. 24 Carthage............................................. : ............ 24 Fra Cristobal Mountains:.......................................... 25 Nogal Creek....................................................... 26 Engle............................................................ 27 Elephant Butte................................................... 27 Caballos Mountains................................................. 28 San Andreas Mountains............................................. 28 Extension of Manzano group to the northeast............................ 30 Introductory statements............................................. 30 Apache Canyon................................................... 31 Rowe.............................................................. 33 Bernal............................................................. 35 Las Vegas.......................................................... 36 Summary.............................................................. 39 3 4 CONTENTS. Page. PALEONTOLOGY OP THE MANZANO GROUP, BY GEORGE H. GIRTY............ 41 Introduction.......................................................... 41 Description of species................................................... 50 Coelenterata........................................................ 50 Echinodermata..................................................... 50 Bryozoa............................................................ 52 Brachiopoda...................................................... 53 Pelecypoda...................................................;.... 72 Scaphopoda....................................................... 95 Gasteropoda....................................................... 96 Cephalopoda...................................................... 112 Ostracoda....:.................................................... 115 Trilobita........................................................... 118 Register of localities................................................... 119 INDEX. ................................................................... 137 ILLUSTRATIONS. .Page. PLATE I. Map of the Rio Grande region in New Mexico.................... 8 II. A, Caballos Mountains; B, Gypsum beds in Galisteo Canyon....... 10 III. Columnar sections showing relations of the Manzano group to neigh­ boring formations.............................................. 14 IV. A, Mesa del Yeso; B, Saddle Peak, Fra Cristobal Mountains....... 22 V. A, Western face of Fra Cristobal Mountains; B, Fault plane at the western base of Fra Cristobal Mountains......................... 26 VI-XII. Fossils of the Manzano group.................................. 124-136 FIGURE 1. Partial section of sedimentary rocks exposed in Galisteo Canyon west of Cerrillos............................................... 18 2. Section of a part of the beds exposed at the north end of the Sandia Mountains, near Tejon......................................... 19 3. Section near Mesa del Yeso, 12 miles northeast of Socorro........... 22 4. Section 2 miles north of Carthage................................. 25 5. Section at Saddle Peak, near the south end of Fra Cristobal Moun­ tains. ......................................................... 26 6. Section in Caballos Mountains west of Upham..................... 28 7. Section near the north end of the San Andreas Mountains, near Rhodes's ranch................................................ 29 8. Section of red beds 1 mile east of Rowe, N. Mex.................... 34 9. Section 5 miles northwest of Las Vegas, N. Mex.................. 37 THE MANZANO GROUP OF THE RIO GRANDE VALLEY, NEW MEXICO. STRATIGRAPHY OF THE MANZANO GROUP. Bv WILLIS T. LEE. INTRODUCTION. Purpose of report. The purpose of the present paper is to describe the red beds of that part of the Rio Grande valley which lies between Santa Fe and Rincon, a distance of about 200 miles, and to establish, their position in the geologic column. The rocks, consisting of sand­ stone and shale, prevailingly red in color, and containing gypsum and limestone, constitute a part of the so-called "Red Beds" of the Rocky Mountain region. On account of their general similarity in color and composition to .the red beds that are exposed in the eastern foothills of the Rocky Mountains and that extend from the mountains east­ ward and southeastward into Kansas, Oklahoma, and Texas, they have been regarded as Permo-Triassic in age. While my principal object is to present the evidence that tends to fix the geologic age of the red beds of the Rio Grande valley, the rela­ tion of these to other beds of similar nature is also considered, flow- ever, I have no intention to discuss the various aspects of the com­ plicated "Red Beds" problem or even to review the numerous contributions to it. I purpose, rather, to confine attention to such phenomena as I have personally observed in the field and to such considerations as may have a direct bearing upon the interpretation of these observations. Preliminary statement of results. The red beds of the Rocky Moun­ tain region are unfossiliferous in many places, but on account of their stratigraphic relations have frequently been called " Jura-Triassic " a term still in common use. The name "Red Beds" has been so con­ stantly applied to these rocks that it has come to have more or less of a time significance, and red sediments of undetermined age in the 5 6 MANZANO GROUP OF RIO GRANDE VALLEY. Rocky Mountain region are sometimes referred to as the "Jura- Triassic Red Beds." In the Texas-New Mexico region the occurrence of red sediments that are older than the recognized Triassic beds and that are referred by many geologists to the Permian has given the name " Permo-Triassic " to some of the red beds in the Southwest. Investigation has shown that some of the red beds of the Rocky Mountain region are much older than Triassic and that others are much younger, the geologic age extending from Mississippian ("Lower Carboniferous") to late Cretaceous. I have formerly called atten­ tion to the fact that the base of the red beds in Perry Park, Colorado,0 is of lower Carboniferous age, and the evidence presented in this paper shows that a large part of the red beds in central New Mexico is of upper Carboniferous or Pennsylvanian age. Furthermore, there are red beds of late Cretaceous age, called Galisteo sandstone by Hayden,6 and later described more fully by Johnson,0 that are simi­ lar in general appearance to the older red beds and that have some­ times been mistaken for them. I have shown d that red sediments of late Cretaceous age occur also near Engle, N. Mex., about 150 miles south of Galisteo Canyon, the type locality of the Galisteo red beds.' The red beds of the Rio Grande valley, here called the Manzano group, are shown on faunal evidence to constitute the upper part- of the Pennsylvanian ("Upper Carboniferous") series. It is not cer­ tainly known that the Manzano group is the exact time equivalent of any part of the red beds of the Rocky Mountain or Plains regions, as it has not been traced continuously from the one region to the other. However, certain data recently obtained indicate that the base of the red beds south and east of the mountains are of lower Pennsylvanian age, and it is reasonable to assume that some part of these apparently conformable beds is to be correlated with the Man- zano or