2004 Denver Annual Meeting (November 710, 2004)
Paper No. 94-4
Presentation Time: 8:00 AM-12:00 PM

ON THE ENIGMATIC ORIGIN OF MAGNETITE IN THE BEDROCK OF NEW YORK CITY

SCHLEIFER, Stanley1, KHANDAKER, Nazrul I.1, AHMED, Masud2, LEBOURNE, Selwyn1, and PERSAUD, Poonraj1, (1) Natural Sciences Department, York College of CUNY, 94-20 Guy R. Brewer Blvd, Jamaica, NY 11451, Schleifer@york.cuny.edu, (2) New York City Department of Environmental Protection, Geotechnical Section, NYCDEP, 59-17, Junction Blvd, Queens, New York, NY 11373

High concentrations of magnetite have been found in mica schist in several locations in Manhattan, New York. The preliminary laboratory investigations have confirmed a range of 20% to 30% magnetite by weight, within the samples studied. Most of the magnetite occurrences are located at, or near, intrusive contacts and within muscovite-rich zones in biotite schist. Surprisingly, magnetite is not found in such high concentrations in hornblende schists or amphibolites. Unusual concentration of moderate to abundant magnetite in mica schist perhaps indicates release of iron oxide from the mafic components during thermal metamorphism or metasomatism. Geochemical investigations are underway to provide a viable mechanism for the observed magnetite concentrations in the mica schist of Manhattan.

2004 Denver Annual Meeting (November 710, 2004)
General Information for this Meeting
Session No. 94--Booth# 125
Involvement of Undergraduates in Geological Research: Critical Tools for Background Enrichment (Posters)
Colorado Convention Center: Exhibit Hall
8:00 AM-12:00 PM, Monday, 8 November 2004

Geological Society of America Abstracts with Programs, Vol. 36, No. 5, p. 233

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