Research

Current Projects

  • Detrital zircon study of Early Cretaceous sediments: Dating and provenance studies of the fluvial metaconglomerates of the newly recognized Goldstein Peak formation and the underlying Tr-J Kings Sequence, with grad students Mike Martin and Chris Buchen and undergrads Crystal Castellanos and Kevin Tomita. In addition, four current undergraduates are studying forearc basin deposits associated with the Sierra and Peninsular Ranges arcs (funded by an ACS-PRF grant).
  • Mineral stratigraphy of layered mafic cumulates: aimed at fleshing out the history of recharge, fractionation, assimilation (and venting?) recorded in these Early Cretaceous ol-plag-opx-hb cumulates with grad alumna Elizabeth Seal and undergrad alumna, Micha Slopko (funded by a CA State Mini-grant).
  • Tungsten skarn nano-mineralogy: Completed research by grad alumna Bev Berekian and undergrad alumna Shayda Nikjoo (in collaboration with Ma Chi, Caltech) demonstrates a high potential for the discovery of new minerals within this deposit, especially within the Stage 3 hydrothermal assemblages. Future undergraduate research projects will involve SEM and electron microprobe work aimed at describing complex reaction textures.
  • Isotope-geochemical study of Orange County groundwater: Collaborative research with Orange County Water District and Lawrence Livermore National Lab using isotopic tracers to study recharge and mixing of groundwater in the Tustin-Irvine sub-basin. Stable isotope work being conducted by grad student Patty Robards on the CSULB-IIRMES mass specrometer, for which I am a co-PI (funded by a CA State Mini-grant).

 

Selected References

  • Clemens-Knott, D, 2011, Geologic map of the Stokes Mountain region, western Sierra Nevada Mountains, California, GSA Map and Chart series MCH-100 (plate + text).

  • Clemens-Knott, D., 2010, REE-isotope study of mafic to felsic differentiation Stokes Mountain region, western Sierra Nevada batholith, CA. GSA Abstracts with Programs.

  • Clemens-Knott, D., and Martin, M., 2009, Stratigraphic context of the Early Cretaceous Goldstein Peak unit, west-central Sierra Nevada batholith, California: Pacific sections AAPG-SEPM-SEG annual meeting.

  • Clemens-Knott, D., 2008, Mafic roots of a satellite cone, eastern Ring Dike Complex, western Sierra Nevada, CA: Emplacement of the Auckland gabbro by forceful intrusion along an Early Cretaceous unconformity: GSA Abs.

  • Clemens-Knott, D and Saleeby, JB, 2005, Geochronologic constraints on Early Cretaceous deposition of nonmarine sediments and volcanics, and synplutonic deformation, western Sierra Nevada batholith, CA, GSA Abstracts with Programs.

  • Clemens-Knott, van der Kolk, Cooper, J, and Sturmer, D, 2003, Deposition, eruption and metamorphism of the Goldstein Peak pendant protoliths, western Sierra Nevada batholith, CA, GSA Abstracts with Programs.

  • Saleeby, JB, Ducea, M, and Clemens-Knott, D, 2003, Production and loss of a high-density batholithic root, southern Sierra Nevada, California: Tectonics, v. 22, p. 1064-1088.

  • Clemens-Knott, D., Wolf, MB, and JB Saleeby, 2000, Middle Mesozoic plutonism and deformation in the western Sierra Nevada foothills, CA, in Lageson, DR, Peters, SG, and MM Lahren, eds., Great Basin and Sierra Nevada: Boulder, CO, Geological Society of America Field Guide, v. 2, p. 205-221.

  • Clemens-Knott, D and Saleeby, JB, 1999, Impinging ring dike complexes in the Sierra Nevada batholith, CA: Roots of the Early Cretaceous volcnic arc: Geological Society of America Bulletin, p. 111, p. 484-496.

  • Batten, K and Clemens-Knott, D, 1997, Mineralogic analysis of orbicular gabbro, Sierra Nevada batholith, in Girty, GH, Hanson, RE and Cooper, JC, eds., Geology of the western Cordillera: Perspectives from undergraduate research, Pacific Section SEPM, v. 82, p. 103-110.

  • McManus, S and Clemens-Knott, D, 1997, Geochemical and oxygen isotope constraints on the petrogenesis of the Independence dike swarm, San Bernadino Co., CA, in Girty, GH, Hanson, RE and Cooper, JC, eds., Geology of the western Cordillera: Perspectives from undergraduate research, Pacific Section SEPM, v. 82, p. 103-110.

  • Clemens-Knott, D., 1996, Neodymium isotope constraints on the character of the central Sierra Nevada deep crust and upper mantle: Chinese Peak xenoliths, GSA Abstracts with Programs

  • Sinigoi, S., Quick, JE, Clemens-Knott, D, Mayer, A, Dimarchi, G, Mazzucchelli, M, Negrini, L, Rivalenti, G, 1994, Chemical evolution of a large mafic intrusion in the lower crust, Ivrea-Verbano Zone, northern Italy: Journal of Geophysical Research, p. 21,575-21,590.