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Unpublished MSc.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