ABSTRACT
The middle Ordovician rocks of the Albany 15 minute quadrangle comprise
interbedded graywacke and shale, and in the east, coarse cobble or
olistostromic
deposits. The detrital composition, westward fining and regional
westward
transgression of these deposits indicate that these were sediments shed
off the westward thrusting Taconic Allochthon. Primary sedimentary
structures
show that these rocks were deposited by turbidity currents flowing into
a longitudinal trough, probably formed in response to increased load
during
overthrusting. Although strongly dependent on lithology, deformation
intensity
generally increases from west to east; from essentially undeformed
bedded
flysch through asymmetrically folded and thrust beds to highly deformed
melange containing isoclinally folded, transposed and boudinaged beds
within
a phacoidally cleaved shaly matrix. Folds in the least deformed flysch
are generally open and have horizontal hinge lines. In more highly
deformed
rocks folds are isoclinal with hinge lines plunging to the SE. This
suggests
that with increased strains overturned folds in the flysch rotated into
the direction of maximum finite extension. This direction corresponds
with
the overthrust direction indicated by slickenside striations on minor
fault
planes. Fold development apparently occurred as a two phase progressive
event, with initiation of buckle folds followed by the development of
extreme
noncylindrial hinge lines accompanying brittle failure and boudinage.
Locally,
a third phase of folding has occurred. In addition, an early phase of
chaotic
folding occurred within a chert and siliceous argillite unit. The
formation
of the Taconic melange in this area can be explained through the
progressive
disruption of a syndepositionally deformed turbidite fan complex, which
included coarse proximal or olistostromic facies. Additionally,
thrusting
has led to the incorporation of slivers or klippes of older facies into
the melange.
Unpublished MSc. thesis, State University of New York at
Albany.
151pp., +xi; 6 folded plates (maps)
University at Albany Science Library call number: SCIENCE
Oversize
(*) QE 660 V65X
MS thesis scanned
text
pdf
(17 MB);
Geological Map (uncoloured
outcrop map, scale 1: 50,000,
cross-sections;
detailed outcrop maps)
Plate
1a
-
Geological
map
of
a
portion
of
the
Albany
15
minute
quadrangle, New
York
Plate
1b
-
Schematic
cross-sections,
Albany
15
minute
quadrangle,
New
York
Plate
2
-
Structural
Map
of
Vly
Creek,
New
Scotland,
New
York
Plate
3
-
Structural
Map
of
Vloman
Kill,
Bethlehem,
New
York
Plate
4
-
Structural
Map
of
Normans
Kill
Gorge,
Albany,
New
York
(coloured outcrop map compilation by W. Kidd;
combines the map in Vollmer's thesis with the map in the MS
thesis of A. Plesch)
Geological
map
of
the
New
York
Capital
District
(scale 1: 69,000)
Return to MS Theses completed in the
Geological
Sciences Program, University at Albany