Heavy-Mineral Assemblages In Sandstone Intrusions: Panoche Giant Injection Complex, California, U.S.A.

Andrew Hurst, Andrew Morton, Anthony Scott, Mario Vigorito, Dirk Frei

Research output: Contribution to journalArticle

3 Citations (Scopus)
28 Downloads (Pure)

Abstract

Excellent exposure from part of the Panoche Giant Injection Complex in the San Joaquin Valley is used to examine provenance characteristics of sandstone intrusions with respect to two parent sandstone units that are known to feed the sand-injection complex. The succession is part of the upper Mesozoic to lower Tertiary Great Valley Group, and was deposited in a deepwater part of an evolving deep-water forearc basin. The section examined is mudstone-dominated, and the sand injection is constrained to have occurred in the Danian. Sandstones in the Dosados Member (Moreno Fm) are identified as the main parent unit on the basis of total heavy-mineral-assemblage compositions and varietal studies of selected minerals (tourmaline, garnet, titanite, apatite, and zircon). Fluidized sand is emplaced in turbulent flow conditions creating high-velocity inter-grain collisions. Evidence of comminution and diminution of minerals that are less hard than quartz is documented using indices for the relative hardness (TAH) and durability (TAD) of heavy minerals. Preferential settling of high-density zircon relative to lower-density tourmaline produces density-controlled variations of zircon:tourmaline upward through the injection complex. Heavy-mineral dissolution occurred in the most permeable sandstone intrusions and is believed to record the effects of mid-Eocene deep weathering, when subtropical climate prevailed in the study area. Detrital heavy-mineral assemblages, which are dominated by titanite and garnet, record erosion of the Sierran metamorphic terrane with mafic and alkaline plutonic rocks. Zircon with U/Pb ages of c. 140–160 Ma and c. 90–110 Ma, consistent with earlier independent analyses, record erosion of Sierran granitoids. On the paleo-seafloor, enrichment of Ca-amphibole and epidote is indicative of Sierran provenance concurrent with sand extrusion. The presence of Na-amphibole in the Uhalde Sandstone supports earlier work that suggested sediment input from obducted seafloor to the west.
Original languageEnglish
Pages (from-to)388-405
Number of pages18
JournalJournal of Sedimentary Research
Volume87
Issue number4
Early online date21 Apr 2017
DOIs
Publication statusPublished - Apr 2017

Fingerprint

heavy mineral
sandstone
tourmaline
zircon
sand
titanite
amphibole
provenance
garnet
seafloor
erosion
valley
Danian
comminution
alkaline rock
forearc basin
plutonic rock
mineral
epidote
extrusion

Cite this

Heavy-Mineral Assemblages In Sandstone Intrusions : Panoche Giant Injection Complex, California, U.S.A. / Hurst, Andrew; Morton, Andrew; Scott, Anthony; Vigorito, Mario; Frei, Dirk.

In: Journal of Sedimentary Research, Vol. 87, No. 4, 04.2017, p. 388-405.

Research output: Contribution to journalArticle

Hurst, Andrew ; Morton, Andrew ; Scott, Anthony ; Vigorito, Mario ; Frei, Dirk. / Heavy-Mineral Assemblages In Sandstone Intrusions : Panoche Giant Injection Complex, California, U.S.A. In: Journal of Sedimentary Research. 2017 ; Vol. 87, No. 4. pp. 388-405.
@article{95c1b48929684562a668cb3091286a75,
title = "Heavy-Mineral Assemblages In Sandstone Intrusions: Panoche Giant Injection Complex, California, U.S.A.",
abstract = "Excellent exposure from part of the Panoche Giant Injection Complex in the San Joaquin Valley is used to examine provenance characteristics of sandstone intrusions with respect to two parent sandstone units that are known to feed the sand-injection complex. The succession is part of the upper Mesozoic to lower Tertiary Great Valley Group, and was deposited in a deepwater part of an evolving deep-water forearc basin. The section examined is mudstone-dominated, and the sand injection is constrained to have occurred in the Danian. Sandstones in the Dosados Member (Moreno Fm) are identified as the main parent unit on the basis of total heavy-mineral-assemblage compositions and varietal studies of selected minerals (tourmaline, garnet, titanite, apatite, and zircon). Fluidized sand is emplaced in turbulent flow conditions creating high-velocity inter-grain collisions. Evidence of comminution and diminution of minerals that are less hard than quartz is documented using indices for the relative hardness (TAH) and durability (TAD) of heavy minerals. Preferential settling of high-density zircon relative to lower-density tourmaline produces density-controlled variations of zircon:tourmaline upward through the injection complex. Heavy-mineral dissolution occurred in the most permeable sandstone intrusions and is believed to record the effects of mid-Eocene deep weathering, when subtropical climate prevailed in the study area. Detrital heavy-mineral assemblages, which are dominated by titanite and garnet, record erosion of the Sierran metamorphic terrane with mafic and alkaline plutonic rocks. Zircon with U/Pb ages of c. 140–160 Ma and c. 90–110 Ma, consistent with earlier independent analyses, record erosion of Sierran granitoids. On the paleo-seafloor, enrichment of Ca-amphibole and epidote is indicative of Sierran provenance concurrent with sand extrusion. The presence of Na-amphibole in the Uhalde Sandstone supports earlier work that suggested sediment input from obducted seafloor to the west.",
author = "Andrew Hurst and Andrew Morton and Anthony Scott and Mario Vigorito and Dirk Frei",
year = "2017",
month = "4",
doi = "10.2110/jsr.2017.22",
language = "English",
volume = "87",
pages = "388--405",
journal = "Journal of Sedimentary Research",
issn = "1527-1404",
publisher = "SEPM Society for Sedimentary Geology",
number = "4",

}

TY - JOUR

T1 - Heavy-Mineral Assemblages In Sandstone Intrusions

T2 - Panoche Giant Injection Complex, California, U.S.A.

AU - Hurst, Andrew

AU - Morton, Andrew

AU - Scott, Anthony

AU - Vigorito, Mario

AU - Frei, Dirk

PY - 2017/4

Y1 - 2017/4

N2 - Excellent exposure from part of the Panoche Giant Injection Complex in the San Joaquin Valley is used to examine provenance characteristics of sandstone intrusions with respect to two parent sandstone units that are known to feed the sand-injection complex. The succession is part of the upper Mesozoic to lower Tertiary Great Valley Group, and was deposited in a deepwater part of an evolving deep-water forearc basin. The section examined is mudstone-dominated, and the sand injection is constrained to have occurred in the Danian. Sandstones in the Dosados Member (Moreno Fm) are identified as the main parent unit on the basis of total heavy-mineral-assemblage compositions and varietal studies of selected minerals (tourmaline, garnet, titanite, apatite, and zircon). Fluidized sand is emplaced in turbulent flow conditions creating high-velocity inter-grain collisions. Evidence of comminution and diminution of minerals that are less hard than quartz is documented using indices for the relative hardness (TAH) and durability (TAD) of heavy minerals. Preferential settling of high-density zircon relative to lower-density tourmaline produces density-controlled variations of zircon:tourmaline upward through the injection complex. Heavy-mineral dissolution occurred in the most permeable sandstone intrusions and is believed to record the effects of mid-Eocene deep weathering, when subtropical climate prevailed in the study area. Detrital heavy-mineral assemblages, which are dominated by titanite and garnet, record erosion of the Sierran metamorphic terrane with mafic and alkaline plutonic rocks. Zircon with U/Pb ages of c. 140–160 Ma and c. 90–110 Ma, consistent with earlier independent analyses, record erosion of Sierran granitoids. On the paleo-seafloor, enrichment of Ca-amphibole and epidote is indicative of Sierran provenance concurrent with sand extrusion. The presence of Na-amphibole in the Uhalde Sandstone supports earlier work that suggested sediment input from obducted seafloor to the west.

AB - Excellent exposure from part of the Panoche Giant Injection Complex in the San Joaquin Valley is used to examine provenance characteristics of sandstone intrusions with respect to two parent sandstone units that are known to feed the sand-injection complex. The succession is part of the upper Mesozoic to lower Tertiary Great Valley Group, and was deposited in a deepwater part of an evolving deep-water forearc basin. The section examined is mudstone-dominated, and the sand injection is constrained to have occurred in the Danian. Sandstones in the Dosados Member (Moreno Fm) are identified as the main parent unit on the basis of total heavy-mineral-assemblage compositions and varietal studies of selected minerals (tourmaline, garnet, titanite, apatite, and zircon). Fluidized sand is emplaced in turbulent flow conditions creating high-velocity inter-grain collisions. Evidence of comminution and diminution of minerals that are less hard than quartz is documented using indices for the relative hardness (TAH) and durability (TAD) of heavy minerals. Preferential settling of high-density zircon relative to lower-density tourmaline produces density-controlled variations of zircon:tourmaline upward through the injection complex. Heavy-mineral dissolution occurred in the most permeable sandstone intrusions and is believed to record the effects of mid-Eocene deep weathering, when subtropical climate prevailed in the study area. Detrital heavy-mineral assemblages, which are dominated by titanite and garnet, record erosion of the Sierran metamorphic terrane with mafic and alkaline plutonic rocks. Zircon with U/Pb ages of c. 140–160 Ma and c. 90–110 Ma, consistent with earlier independent analyses, record erosion of Sierran granitoids. On the paleo-seafloor, enrichment of Ca-amphibole and epidote is indicative of Sierran provenance concurrent with sand extrusion. The presence of Na-amphibole in the Uhalde Sandstone supports earlier work that suggested sediment input from obducted seafloor to the west.

U2 - 10.2110/jsr.2017.22

DO - 10.2110/jsr.2017.22

M3 - Article

VL - 87

SP - 388

EP - 405

JO - Journal of Sedimentary Research

JF - Journal of Sedimentary Research

SN - 1527-1404

IS - 4

ER -