ABSTRACT
The Ganson Hill study area is located in the Giddings Brook Slice
of the Taconic Allochthon. It contains rocks of Cambrian(?),
Cambrian and Ordovician age. The predominant rock type is slate
with subordinate lithologies including quartzite, limestone,
micrite, arenite and graywacke. The lithostratigraphy identified
in the Ganson Hill area extends from the basal Bomoseen wacke to
the Poultney slate. A more precisely defined lithostratigraphy is
derived from the study area by the occurrence and recognition of
the Middle Granville Slate Formation and the documentation of a
second Cambrian black/green boundary. Previous workers have
included this formation in different places, in two different
formations creating much confusion.
Three stages of deformation have been recognized in the Ganson
Hill study area. They are: pre-slaty cleavage folding, slaty
cleavage development with associated folding, and faulting and
seen only sporadically, crenulation cleavage development with
associated folding and faulting. Documented in this thesis is the
Hubbardton Gulf Thrust Fault which places Cambrian green slate
(Undifferentiated Bull Fm.) over black and gray slate with
interbedded quartzite (Poultney Fm.).
An early Ordovician contourite deposit has been identified in the
Poultney unit. The grain size, the composition and the lateral
extent of the quartz-rich beds in the Poultney Formation in
addition to sharp top and bottom bedding contacts and preserved
sedimentary structures are distinguishing characteristics of the
contourite deposit. Paleocurrent directions indicate northerly
flowing bottom currents depositing and reworking material fed from
the North American Platform adjacent to and south of the present
area of the Taconics.
Aparisi, M., 1985. Stratigraphy and structure of the Ganson Hill
area: northern Taconic Allochthon. Unpublished MSc. thesis, State
University of New York at Albany. 128 pp., +ix; 3 folded plates
(maps)
University at Albany Science Library call number: SCIENCE
Oversize (*) QE 40 Z899 1985 A65
MS thesis scanned
image pdf (10 MB)
Plate 1 - Map
of Occurrence of the Poultney Formation
(uncoloured geological
outline map, scale 1:250,000) - 1MB pdf file
Geological Map and cross-sections
Plate 2 - Geological
Map of the Ganson Hill area - northern Taconic Allochthon
(coloured outcrop map, scale
1: 12,000) - 9 MB pdf file
Plate 3 - Cross
sections of the Ganson Hill area
(uncoloured geological cross
sections, scale 1: 12,000) - 1.5MB pdf file
Return to MS Theses completed in the
Geological Sciences Program, University at Albany