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A cumulus-transport-deposition model for the differentiation of the Palisades Sill

Jeffrey C. Steiner, Robert J. Walker, Richard D. Warner and Todd R. Olson
A cumulus-transport-deposition model for the differentiation of the Palisades Sill (in Eastern North American Mesozoic magmatism, John H. Puffer (editor) and Paul C. Ragland (editor))
Special Paper - Geological Society of America (1992) 268: 193-217


The Upper Nyack (UN) section of the Palisades sill is comprised principally of pigeonite-augite and augite diabases with an interstitial (remnant) glassy mesostasis. Major- and trace-metal analyses of 110 diabases, 20 being analyzed for rare-earth elements (REE), provide data regarding the source of chemical variations within the UN section and suggest a unifying theory, the propsed C-T-D Model, for differentiation within the Palisades sheet. Preliminary work establishes that the chemostratigraphic horizons present in the type section at Englewood Cliffs (ENG)are broadly continuous from south to north and that important petrographic facies have undergone substantial mineralogic reorganization. The three most significant S --> N transitions include: (1) holocrystalline subophitic chilled diabase (ENG) --> hyalosiderite chilled diabase (Piermont) --> glomeroporphyritic to intersertal chilled diabase (UN); (2) olivine zone (ENG) --> (augite diabase) [UN]) --> bronzite diabase (Nyack Beach State Park); and (3) fayalite granophyre and related "sandwich" horizon facies (ENG) --> altered (porphyritic) augite ferrodiabase (UN). Bulk compositional and trace-metal plots establish that south to north petrologic tiers comprise a single differentiation series. Differentiation series data are consistent with three-stage model that involves early olivine fractionation followed by pyroxene- and plagioclase-dominated sequences. The cumulus horizons are modeled principally in terms of the accumulation of pyroxene-dominated fractionation products by varying proportions of olivine fractionated or later liquid. It is proposed that crystals collect in convection cells or like environments at deep levels within the sheet are partially remelted, resorted, and/or recrystallized during epizonal emplacement due to: magma decompression, shallow level flow differentiation, and magma-wall rock interactions. The Cumulus-Transport-Decompression (C-T-D) Model, based on these observations, is advanced to integrate multiple differentiation factors within a single interpretive framework for Palisades sill evolution.

ISSN: 0072-1077
EISSN: 2331-219X
Serial Title: Special Paper - Geological Society of America
Serial Volume: 268
Title: A cumulus-transport-deposition model for the differentiation of the Palisades Sill
Title: Eastern North American Mesozoic magmatism
Author(s): Steiner, Jeffrey C.Walker, Robert J.Warner, Richard D.Olson, Todd R.
Author(s): Puffer, John H.editor
Author(s): Ragland, Paul C.editor
Affiliation: City College of New York, Department of Earth and Atmospheric Sciences, New York, NY, United States
Affiliation: Rutgers University, Geology Department, Newark, NJ, United States
Pages: 193-217
Published: 1992
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
ISBN: 0813722683
References: 53
Accession Number: 1993-006082
Categories: Igneous and metamorphic petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 5 tables, 1 plate, sketch map
N38°55'00" - N41°21'00", W75°34'60" - W73°52'60"
N40°30'00" - N45°00'00", W79°45'00" - W71°55'00"
Secondary Affiliation: Florida State University, USA, United StatesOregon State University, USA, United StatesClemson University, USA, United StatesAlbert Einstein College of Medicine, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute.
Update Code: 1993
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