Geology of the Roberts Hill area in the Hudson Valley fold-thrust belt, Greene County, eastern New York

Majerczyk, Chris

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https://hdl.handle.net/2142/29626 Copy

Description

Title

Geology of the Roberts Hill area in the Hudson Valley fold-thrust belt, Greene County, eastern New York

Author(s)

Majerczyk, Chris

Issue Date

2012-02-06T20:07:36Z

Director of Research (if dissertation) or Advisor (if thesis)

Marshak, Stephen

Department of Study

Geology

Discipline

Geology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Hudson Valley Fold-thrust belt
• Roberts hill
• greene county

Abstract

The Hudson Valley fold-thrust belt (HVB) is a narrow band of deformed Silurian and Devonian strata, west of the Hudson River, in the region between Kingston and Albany, New York. Previous studies of the HVB at the latitude of Catskill, New York suggest that shortening is accommodated above two distinct detachment faults. The upper fault called Rondout detachment, crops out at or just above the post-Taconic unconformity and forms the floor thrust of a distinct duplex. The lower fault called the Austin Glen detachment, does not crop out but has been inferred to occur at a depth of several hundred meters below the surface. Mapping of a 5 km-long segment of the HVB that includes Roberts Hill, near the belt's northern end (17 km NNE of Catskill), was conducted to characterize how the HVB changes progressively to the north. This mapping reveals a duplex structure just above the post-Taconic unconformity, identical to the duplex structure at Catskill. This observation supports the hypothesis that the Rondout detachment continues from Catskill to the north, along the length of the HVB. The Siluro-Devonian sequence and the Rondout detachment are folded in the Roberts Hill study area, indicating that the Austin Glen detachment also lies at depth in this location. Cross-strike shortening of the Roberts Hill study area is relatively small, compared with regions further south, and the distance between the Helderberg Escarpment and the western deformation front of the HVB is significantly less than in the Catskill area. It appears that the Helderberg Escarpment cuts diagonally across the strike of the HVB, from Catskill to the north, so that only the foreland portion of the belt, where deformation is less intense, remains in the Roberts Hill study area.

Graduation Semester

2011-12

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http://hdl.handle.net/2142/29626

Copyright and License Information

Copyright 2011 Chris Majerczyk

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