2009 Portland GSA Annual Meeting (18-21 October 2009)
Paper No. 115-17
Presentation Time: 9:00 AM-6:00 PM

CHANGING STYLE OF DEFORMATION AT THE NORTHERN LIMIT OF THE EXTENT OF THE SHAWANGUNK CONGLOMERATE; ULSTER COUNTY, N.Y

SCHLEIFER, Stanley1, KHANDAKER, Nazrul I.2, AHMED, Masud3, NARINE, Keshaw4, LORING, Arthur P.1, and SHAMI, Malek5, (1) Geology Discipline, Department of Earth and Physical Sciences, York College Of CUNY, 94-20, Guy R. Brewer Blvd, Jamaica, NY 11451, schleifer@york.cuny.edu, (2) Geology Discipline, Earth and Physical Sciences, York College Of CUNY, 94-20 Guy R. Brewer Blvd, Jamaica, NY 11451, (3) New York City Department of Environmental Protection, Geotechnical Section, NYCDEP, 59-17, Junction Blvd, Queens, New York, NY 11373, (4) Earth and Physical Sciences, York College of CUNY, 94-20 Guy R. Brewer Blvd, Jamaica, NY 11451, (5) Geology Discipline, Earth and Physical Sciences, York College Of CUNY, 94-20, Guy R. Brewer Blvd, Jamaica, NY 11451

The Upper Silurian Shawangunk Conglomerate thins to the north and does not outcrop north of the Town of Rosendale, N. Y. It thickens to the south to approximately 20 feet just east of the location of the former Williams Lake Hotel in Rosendale. It is observed to be still thicker farther to the south. The Shawangunk Conglomerate and, in the northern part of the study area, the High Falls Shale, lie unconformably over the Ordovician Hudson River Shale. The Upper Silurian and Lower Devonian rocks of the Helderberg sequence, as well as the Ordovician shales below, were intensely deformed during the Acadian Orogeny. The Ordovician rocks were deformed during the Taconic Orogeny as well. Detailed field mapping in the vicinity of Fourth and Fifth Lakes in Rosendale, N. Y. confirms a distinct difference from the surrounding area, in the style of deformation at the northernmost extent of the Shawangunk Conglomerate, where décollment type structures are observed. This appears to be due to a ductility contrast between the Shawangunk Conglomerate and the surrounding rock units.

2009 Portland GSA Annual Meeting (18-21 October 2009)
General Information for this Meeting
Session No. 115--Booth# 355
Geological and Environmental Sciences Research Forum: Greater Visibility and Interactions between the Undergraduates and K–12 Students (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Monday, 19 October 2009

Geological Society of America Abstracts with Programs, Vol. 41, No. 7, p. 321

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