I _; The Sierra Nevada Batholith A Synthesis. of Recent Work Across the Central Part By PAUL C. BATEMAN, LORIN ~- CLARK, N. KING HUBER, JAMES G. MOORE, and C. DEAN RINEHART SHORTER CONTRIBU.TIONS TO GENERAL GEOLOGY· G E 0 L 0 G I CAL SURVEY P R 0 FE S S I 0 N A L PAPER 414-D Prepared in cooperation with the State of Caltfornia, Division of Mines and Geology · ti II R fA u 0 F u' N f I ._rBRARV SPUI\ANf:.. !NASH. JUN 31971 . ·~-~ - ~ ... -- --s PtfASf RfT,fJR~ fO liBRARY UNITED S.TATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C., 20402 CONTENTS Page Abstract------------------------------------------- D1 Constitution' of the batho1ith-Continued Introduction ______________________________________ _ 2 Contact relations _______________ ~ ______ - -- _----- D22 Genernl geologic relations _______________________ _ 2 Contacts between different granitic rocks _____ - 22 Previous geologic work _________________________ _ 4 Contacts between granitic rocks and meta- Acknowledgments _____________________________ _ 5 morphic rocks or diorite ___________ -- __ ---- 22 Wu.llrocks u.nd roof rocks ___________________________ _ 5 Felsic dike swarms __________________ - ___ -------- 24 Pu.leozoic rocks ________________________________ _ 5 Mafic dike swarms _________________________ ----- 25 Mesozoic rocks ________________________________ _ 6 Structure _____________________________________ _ Chemical and mineralogic trends ______________ - ___ ---- 27 6 Analytic data ______________________ ---_-------- 27 Evolution of the gross structure _________________ _ 8 Broad chemical and mineralogic trends ___________ - 28 Metamorphism ________________________________ _ 9 Age of the batholith ________________________________ _ Zoning within plutons ___________ - ___ ------------ 30 11 Changes across the batholith ____________________ _ 32 Older plutonic rocks of the west walL ________________ _ 12 Correlation of normative compositions of the granitic Constitution of the batholith ________________ ---- ____ _ 12 rocks with experimental data ___ - ___ ------------ 33 Lithologic groupings of the plutonic rocks _________ _ 13 Comparison of compositional trends with trends of Compositionn.l classifica.tion ______________________ · 13 granitic suites from other areas_- ___ ---_-------- 35 Mafic plutonic rocks ___________ ----- ___________ _ 14 Emplacement of the batholith ____ - ___ - __ --- __ -------- 38 Granitic rocks _________________________________ _ 14 Evidence of magma ___________ -_- __ ------------ - 38 Minerals ______________ - ___ ---_-_----------- 14 Evidence of mechanical processes of emplacement_ __ 38 Textures ___________ -----_------------------ 15 Evidence for thermochemical emplacement_ _______ _ 40 Mafic inclusions ___________________________ _ 16 Granitization of mafic rock _______________ ---- 40 Primary folin.tion n.nd lineation and flattening of Assimilation of mafic rock __________________ _ 42 mafic inclusions __________________________ _ 19 Assimilation of pelitic rock _______ -- __ - ___ ---- 42 Layered fu.cies u.nd schlieren _________________ _ 19 Tentative evaluation of the processes involved in em- Sequence of intrusion ___________________________ _ 20 placement __________________________________ _ 42 Yosemite sequence _________________ --- _____ _ 20 Eu.stern Sierru. Nevada-Huntington Lake se- References cited ________________ - - - _ - ___ ------------ 44 quence---------------------------------- 21 ILLUSTRATIONS PLATE 1. Geologic map and ~ections of the central Sierra Nevada _______________________________________________ In pocket Page FIGURE 1. Genemlized geologic map showing distribution of pre-Cenozoic rocks in part of eastern California and location of area discussed in this report ____________________________________________________________ ------------ D3 2. System of cln.ssificn.tion of the granitic rocks ____________________________________________ -- __ ------------ 13 :3. Number of mafic inclusions per square yard of horizontal outcrop within the granodiorite of Cartridge Pass_--- 17 4. Amphibolite penetrated by anastomosing Wheeler Crest quartz monzonite.:._________________________________ 18 5. Two views in mu.rgin of Mount Givens granodiorite at Courtright Reservoir sho.wing the association of mafic in cl usi ons with schlieren ________________________________________________________________________ ---- 20 6. Grn.vity layered schlieren in inclusions and in a dike _________ ·--------------~---------------------------~- 21 7. External contacts of the Inconsolable granodiorite in the drainage basin at the head of the South Fork of Big Pine Creek ____ ~----------------------------------------------------------------------------------- 23 8. Septum of metamorphic rock n.cross Bishop Creek below Lake Sabrina _____________________________ -------- 24 9. Brecciated Inconsolable granodiorite _______________________________________________________ .:. ___ -------- 24 10. View of Pine Creek pendant looking north across Pine Creek canyon______________________________________ 25 11. Aplite, pegmatite, and alaskite dikes along Pine Creek ________ ·--~---------------------------------------- 26 12. Diagrammatic section through an intrusive and its marginal dikes to show the amount of deformation in the wu.ll rocks caused solely by the emplacement of the dikes_______________________________________________ 27 Ill IV CONTENTS Page FIGURE 13. Variation diagram of common oxides in granitic rocks of the east-central Sierra Nevada plotted against Si02_ _ D30 14. Plot of norms (listed on table 3) of granitic rocks from the east-central Sierra Nevada______________________ 30 15. Averages of modal analyses of granitic intrusions of the east-central Sierra Nevada; the points represent a total of 597 modes----------------------------------------------------~-------------------------------- 30 16. Concentric zoning in the granodiorite of Cartridge Pass shown in different ways ___________________ ._________ 31 17. Variation in specific gravity of granitic rocks along line D-D' on plate 1 across the central Sierra Nevada from Big Creek to Owens Valley near Bishop ________________. __ - _______ - _- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 32 18. Tetrahedron showing the liquidus relations in the system Or(KAlSia0s)-Ab(NaAlSia0s)-An(CaAbSI20 8)-Qz- (Si02)-H20 at 5,000 bars H20 pressure __ - ____ --------------------------- ___ ---- _________ ----________ 34 19. Plots of norms for a.reas of granitic rocks in the western United States and Canada_________________________ 36 20. Composite of median lines through fields of norms shown in figure 19------------------------------------- 37 21: Typical granitization effects in mafic rock_____________________________________________________________ 40 22. Selective replacement of mafic rock (dike or inclusion) in preference to Lamarck granodiorite by aplitic materiaL 23. Selective reaction of aplite dike with mafic dike in Tinemaha granodiorite_________________________________ 41 24. Mafic inclusion cut by dikes of slightly different ages, all of which are offshoots from the surrounding quartz monzonite similar to the Cathedral Peak granite ____ - ____ --- __ - ___ ---- ___ -____________________________ 43 TABLES Page TABLE 1. Lead-alpha' ages of batholitic rocks from the eastern Sierra Nevada near Bishop, Cali- fornia _________________________________ _ Dll 2. Potassium-argon ages of batholitic rocks from Yosemite National Park and of plutonic rocks of the west walL __________________ _ 12 3. Chemical analyses and norms of granitic rocks from the east-central Sierra Nevada _______ _ 29 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY THE .SIERRA NEVADA BATHOLITH-A SYNTHESIS OF RECENT WORK ACROSS THE CENTRAL PART By PAUL c. BATEl\IAN, LORIN D. CLARK, N. KING HunER, JAMES G. MooRE, and C. DEAN RINEHART ABSTRACT the batholith, and many smaller plutons that lie between the Maps prepnred by the Geological Survey since 1945, in larger ones. conjunction with other vublished and unpublished maps avail­ In general, the major plutons in the western part of the able to ns, cover more than half the area of a wide strip batholith are older, more mafic, and of higher specific gravity across the central Sierra Nevada between 36°45' and. 38·o N. than those in the eastern part; in the Yosemite region the lat. ~l'hls report is an attempt to synthesize ideas acquired by larger plutons were emplaced as a west-to-east succession .. ns during studies of different areas within this strip, and to Nevertheless, some older plutons lie along the east side of the relate them to some of the larger problems of the batholith. batholith, and the sequence of intrusion is probably more Emphasis is on the identification of problems and the sugges­ correctly descri'bed asymmetric than as one sided. tion of hyJ)Otheses for future testing rather than the presenta­ Most of the granitic rocks are medium grained and hypidio­ tion nnd defeuse of unique hypotheses. morphic-granular, but both seriate and porphyritic textures Attitudes of strntigraphic sequences in the wallrocks and are common. The phenocrysts of porphyritic rocks commonly in roof pendants indicate that the batholith occupies the axial are K-feldspar and were formed during the later stages of part of n complex north- to northwest-trending syclinorium. crystallization.