Stratigraphy, structure, and metamorphism in the central Panamint ( quadrangle), Death area, : Summary

THEODORE C. LABOTKA* 1 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, ARDEN L. ALBEE J California 91125 MARVIN A. LANPHERE Branch of Isotope Geology, U.S. Geological Survey, 245 Middlefield Road, Menlo Park, California 94025 S. DOUGLAS McDOWELL Department of Geology and Geological Engineering, Michigan Technological University, Houghton, Michigan 49931

INTRODUCTION Spring Dolomite, and Kingston Peak Formation — are recognized in the central Panamint Mountains, but the thicknesses and The Telescope Peak quadrangle is located in the central Pana- lithologies of these units show considerable variation along strike, mint Mountains, which form the western boundary of the central and this variability indicates that the Pahrump Group was depo- part of , California. The central Panamint Mountains sited in a topographically irregular and tectonically active basin. are composed of lower Precambrian gneiss and schist and upper The Crystal Spring Formation rests depositionally on lower Pre- Precambrian sedimentary rocks. These rocks were metamorphosed cambrian rocks and generally consists of siliceous, calcite marble during late Mesozoic time and deformed during late Mesozoic and overlain by argillite, micaceous schist, and arenite. Dolomite mar- Cenozoic time. The stratigraphy of the upper Precambrian rocks ble occurs on Sentinel Peak and in Jail Canyon, and garnet-chlorite indicates a tectonically active depositional environment during the schist makes up the upper part of the formation in Tuber Canyon. initiation of the Cordilleran geosyncline; the petrology of the The Crystal Spring Formation is 200 to 300 m thick throughout metamorphic rocks indicates that the metamorphism occurred most of the quadrangle, but it is greater than 1,000 m thick in along a gradient with a low dp/dT; and the structure suggests an Tuber Canyon, where the base is not exposed. The formation also evolution from a compressional to an extensional tectonic regime thins toward World Beater dome and is absent from the west and during late Mesozoic and Tertiary time. south sides of the dome. This report summarizes the results of geologic mapping in the Beck Spring Dolomite conformably overlies the Crystal Spring Telescope Peak quadrangle, and Figure 1 is a generalized version of Formation and generally consists of thick-bedded to massive the geologic map of the Telescope Peak 15' quadrangle by Albee, dolomite marble, ~200 m thick. Thin laminae and stromatolites Labotka, Lanphere, and McDowell (1980). A more complete dis- are preserved on Sentinel Peak, and the upper part of the formation cussion of the geology occurs in Part II of this article. locally contains intraformational conglomerate and oolite beds. The dolomite is absent in Tuber Canyon and is replaced by a se- STRATIGRAPHY quence of clastic, siliceous, calcite marble interbedded with argillite and metasiltstone. This sequence grades upward with no apparent The oldest rocks in the Panamint Mountains consist of an stratigraphic break into rocks of the Kingston Peak Formation, and l,800-m.y.-old complex of augen gneiss, quartzofeldspathic gneiss, it is here included within the Kingston Peak Formation. Beck Spring and muscovite-biotite-quartz schist. Lower Precambrian rocks Dolomite also thins toward World Beater dome and is absent from consist of quartz schist along the western margin of the range south the west and south sides of the dome. of Happy Canyon; quartzofeldspathic gneiss occurs in the core of Along the western margin of the north-northwest—trending an- the north-northwest—trending anticline north of Happy Canyon; ticline, Beck Spring Dolomite interfingers with overlying clastic and augen gneiss occurs in World Beater dome, which is at the rocks of the 800- to 1,000-m-thick Kingston Peak Formation, but south end of the anticline in Happy and Pleasant Canyons. The locally the Kingston Peak Formation lies disconformably on Beck augen gneiss was intruded by a l,400-m.y.-old porphyritic quartz Spring Dolomite, Crystal Spring Formation, and lower Precam- monzonite in the World Beater dome area. brian rocks. The lowest part of the Kingston Peak Formation con- These lower Precambrian rocks are nonconformably overlain by sists of argillite and arenite interbedded with locally derived con- the upper Precambrian Pahrump Group. The formations that con- glomerate and minor dolomite. The thickness of this lower member stitute the Pahrump Group — the Crystal Spring Formation, Beck is highly variable along strike, and these rocks appear to fill de- pressions between locally uplifted areas which are now represented by World Beater dome and the north-northwest—trending anticline * Present address: Department of Earth and Space Sciences, State Uni- versity of New York at Stony Brook, Stony Brook, New York 11794. (Fig. 2).

The complete article, of which this is a summary, appears in Part II of the Bulletin, v. 91, no. 3, p. 843-933.

Geological Society of America Bulletin, Part 1, v. 91, p. 125-129, 2 figs., March 1980, Doc. no. S00301.

125

Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/3/125/3418872/i0016-7606-91-3-125.pdf by guest on 02 October 2021 Figure 1. Geology of the Telescope Peak quadrangle, California, generalized after Albee and others, 1980. The symbols for the Ter- tiary monolithologic breccia indicate the clast type. Tbh: granitic clasts derived from the Hall Canyon pluton; Tbn: dolomitic clasts derived from Noonday Dolomite; Tbk: metasedimentary rock clasts derived from the Kingston Peak Formation; Tbb: dolomitic clasts derived from Beck Spring Dolomite.

Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/3/125/3418872/i0016-7606-91-3-125.pdf by guest on 02 October 2021 EXPLANATION FOR FIGURE 1

Qq 01 QUATERNARY a.alluvium I: landslide min ffi^fiii* TO6:.- monolithologic breccia, symbol indicates clast-type TERTIARY

Little Chief stock CRETACEOUS Hall Canyon pluton

CAMBRIAN - PRECAMBRIAN

Stirling Quartzite . (säf.

Johnnie Formation

Noonday Dolomite PRECAMBRIAN

Kingston Peak Formation Pahrump Beck Spring Dolomite Group - c ^ diabase

Crystal Spring Formation i^rz J

World Beater Complex

Quartzofeldspathic gneiss

scarp in alluvium, ball on downthrown side

low-angle fault, hachures on downthrown side LOCATION OF x TELESCOPE PEAK QUADRANGLE slide surface, beads on downthrown side

0 2 miles

- —«— Tremolite + calcite isograd

—Diopside isograd

-— Sillimanite isograd

Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/3/125/3418872/i0016-7606-91-3-125.pdf by guest on 02 October 2021 Figure 2. Geologie features in the cen- trai Panamint Mountains. A. Interfingering of Beck Spring Dolomite (light) with the overlying Kingston Peak Formation on the west flank of the west-northwest-trending anticline. B. Zone of disharmonic folding within the Limekiln Spring Member of the Kingston Peak Formation on the west flank of the anticline. C. Low-angle normal fault which places Kingston Peak Formation (dark, top left) on top of Beck Spring Dolomite and older rocks. D. Late Tertiary slide mass near the mouth of Surprise Can- yon. The contact between Kingston Peak Formation (dark) and Hall Canyon pluton (light) is displaced from upper left to lower right. E. Wildrose graben represents the dis- continuous, normal faults that make up the fault zone adjacent to the central Panamint Mountains. These photo- graphs appear in Part II of this article as Figures 6B, 13A, 14B, ISA, and 15B.

Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/3/125/3418872/i0016-7606-91-3-125.pdf by guest on 02 October 2021 PANAMINT MOUNTAINS, CALIFORNIA: SUMMARY 129

These relations indicate that before deposition of Kingston Peak Mesozoic folding episode. This folding episode was accompanied strata, the central Panamint Mountains were underlain by a rela- by retrograde metamorphism, and a north-northwest—trending tively elevated platform of lower Precambrian rocks which stood lineation that is defined by retrograde minerals and stretched cob- above sea level in the vicinity of World Beater dome and which had bles was developed. a northern margin near Tuber Canyon. At the end of Beck Spring The compressional tectonic regime which influenced the forma- Dolomite deposition, portions of this platform were rejuvenated, tion of the anticlines during late Mesozoic time was replaced by an and clasts were supplied to the locally down-dropped areas. Clastic extensional regime during Tertiary time. Faults with shallow west sediments filled the topographic irregularities, but "World Beater dips and normal displacements occur in the northeast part of the Island" continued to be a source for the overlying members of the quadrangle. These faults are intruded by dikes related to the intru- Kingston Peak Formation. sion of the Miocene Little Chief granite stock, and they are offset Upper members of the Kingston Peak Formation include diamic- by faults which developed during the emplacement of the stock. tite and pebbly mudstone that grade northward to thin-bedded Faults with similar geometries and senses of displacement cut the arenite and argillite. These rocks are overlain by a thin, but persis- north-northwest—trending anticline, but later erosion has isolated tent, gray, banded limestone, a cobble conglomerate which con- the hanging-wall blocks on the tops of the west-trending ridges. Ex- tains stretched pebbles in some places, and feldspathic quartzite. tensive monolithologic breccia occurs along the western front of Mafic sills and dikes have intruded the Crystal Spring Formation the Panamint Mountains and is separated from the intact source and Beck Spring Dolomite, and basaltic pillow lava is bedded rocks by a west-dipping surface. The breccia consists of extremely within the diamictite and argillite of the lower part of the Kingston crushed and fragmented rocks derived principally from the Kings- Peak Formation. Diabase clasts occur in the Kingston Peak Forma- ton Peak Formation. Although the rocks are finely pulverized, gross tion below the pillow lava, and thus mafic igneous activity must stratigraphic relations are preserved, and the displacement can be have occurred over a large period of Precambrian time. estimated by the offset of the syncline with Noonday Dolomite in The Pahrump Group is disconformably overlain by upper Pre- the core, the Cretaceous granodiorite Kingston Peak Formation cambrian Noonday Dolomite, Johnnie Formation, and Stirling contact (near Surprise Canyon), and the Kingston Peak—Beck Quartzite, and Precambrian to Cambrian Wood Canyon Forma- Spring Dolomite contact (near Jail Canyon). The magnitude and tion. The Noonday Dolomite consists of a lower member of mas- sense of displacement of the breccia is similar to those of the low- sive dolomite which contains eyes and mounds of possible algal angle normal faults, and the breccias probably formed in response origin, a middle member of thinly laminated and interbedded lime- to the late Tertiary uplift of the Panamint Mountains and the for- stone and argillite, and an upper member of massive dolomitic mation of Panamint Valley. limestone. The Johnnie Formation consists of a lower member of The breccia is overlain by Pliocene and younger fanglomerate. dolomite interbedded with argillite, and an upper member of thin- These fanglomerates have been uplifted along faults related to the bedded argillite and calcareous argillite. Quartzite and some Panamint Valley fault zone. The Panamint Valley fault zone con- feldspathic quartzite compose most of the Stirling Quartzite, tains discontinuous normal faults which are antithetic in some although a prominent purple argillite unit occurs in the lower part places rather than strike-slip faults, which are prominent to the of the formation. The Wood Canyon Formation consists predomi- south and north; Wildrose graben and the re-entrant near Ballarat nantly of thin-bedded quartzite and siliceous siltstone and argillite. are conspicuous expressions of the fault zone near the central Panamint Mountains. METAMORPHIC AND STRUCTURAL HISTORY ACKNOWLEDGMENTS The rocks in the Panamint Mountains were regionally metamorphosed and intruded by a leucocratic, muscovite-bearing Field work in the Panamint Mountains was supported by grants granodiorite (Hall Canyon pluton) during the late Mesozoic (K-Ar from the National Science Foundation to Albee and from the muscovite age of ~80 m.y. from the Hall Canyon pluton). Geological Society of America to Lanphere, McDowell, and Metamorphic isograds based on the stability of tremolite + calcite, Labotka. The staff members of Death Valley National Monument diopside, and sillimanite indicate an increase in grade from east to have been of great assistance during the course of the field work. west. The diagnostic assemblages andalusite + biotite + staurolite We have benefited from stimulating discussions about Death Valley and andalusite + biotite + cordierite which occur in pelitic rocks geology, many of them in the field, with R. H. Jahns, R. E. Powell, are characteristic of low-pressure—intermediate facies series. Pres- L. T. Silver, J. H. Stewart, G. R. Tilton, B. W. Troxel, G. J. Was- sure during metamorphism is estimated at 2.5 to 3.0 kb, and tem- serburg, and L. A. Wright. Critical reviews by B. C. Burchfiel and peratures are estimated to have attained ~650 °C in the highest B. W. Troxel have improved the readability of the manuscript. grade area. Subsequently, the rocks were folded along north-northwest- trending axes, and the prominent anticline and World Beater dome REFERENCE CITED which dominate the structure of the central Panamint Mountains were formed. Much of the uplift across the anticline was accom- Albee, A. L., Labotka, T. C., Lanphere, A., and McDowell, S. D., 1980, Geology of the Telescope Peak 15' quadrangle, California: U.S. plished by vertical displacement along north-trending, high-angle Geological Survey Geologic Quadrangle Map GQ1532, scale normal faults. The faults trend north, but the anticline trends 1:62,500 (in press). north-northwest, and the faults have scissors-type offset across them. Because of this complex offset and because one north- MANUSCRIPT RECEIVED BY THE SOCIETY MARCH 19, 1979 trending fault in Surprise Canyon is buried by the Kingston Peak REVISED MANUSCRIPT RECEIVED OCTOBER 8, 1979 MANUSCRIPT ACCEPTED OCTOBER 24, 1979 Formation, these faults are believed to have been developed during CONTRIBUTION NO. 3315 OF THE DIVISION OF GEOLOGICAL AND PLANE- the Precambrian and have been reactivated during the late TARY SCIENCES, CALIFORNIA INSTITUTE OF TECHNOLOGY

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