10 Eastern North American Rift Valleys Through Time (Posters)

Monday, 21 March 2016
8:00 AM - 12:00 PM
Convention Hall

CONSTRAINING THE ORIGIN OF CALCITE IN THE VEINS HOSTED IN LOCKATONG AND PASSAIC FORMATIONS USING C-O STABLE ISOTOPES AND FLUID INCLUSIONS: IMPLICATION TO FLUID MIGRATION IN THE NEWARK BASIN

Paper number: 10-2
Program: Theme Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

The calcite veins hosted in the Lockatong and Passaic formations of the Newark basin have been investigated to constrain the genesis of these calcites. The oxygen isotope values of calcite samples in both Lockatong and Passaic formations are narrow and similar (average ~ +24.4 ‰ SMOW). This isotopic composition reflects an isotopic exchange between heavy oxygen of lacustrine carbonates and oxygen of formational waters with long residence time. These calcite samples have an average carbon isotope composition of -3.4 ‰ SMOW indicative of a mixture between the isotopically light organic matter-derived carbon and an isotopically heavy carbon from formational and evolved meteoric waters. Fluid inclusions reveal that the fluid responsible for the precipitation of calcite was hot (>152 °C) and moderately saline (~10.5 wt% NaCl equiv.) This fluid reflects a mixture between formational waters and evolved meteoric waters. The latter descended to deeper lithostratigraphic units during the Late Triassic extensional tectonic activity. Once geothermally heated, these topographically-driven meteoric waters migrated laterally along the Stockton aquifer. Dilatational pump seismically induced-mechanism together with compaction expelled these waters during the Late Triassic extensional tectonic activity. Subsequently, these fluids mixed and interacted with local formational waters leading to the precipitation of calcite in fractures hosted in the Lockatong and Passaic formations.  

Geological Society of America Abstracts with Programs. Vol. 48, No. 1

doi: 10.1130/abs/2016NE-272425

© Copyright 2016 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.