B8: GLACIAL LAKE ALBANY IN THE CHAMPLAIN VALLEY
G. Gordon Connally
New York State Museum
Research Associate
Albany, NY 12230
Donald H. Cadwell
Research and Collections
INTRODUCTION
The purpose of this article is to document and discuss the expansion of Glacial Lake Albany from the northern Hudson Valley into the southern Champlain Valley. The area under consideration extends ±115 km from Crown Point to the Hoosic River. Crown Point is on Lake Champlain at 44° 02' N. The Hoosic River is an eastern tributary to the Hudson River at about 42° 55' N.

B8: GLACIAL LAKE ALBANY IN THE CHAMPLAIN VALLEY

Diamond Point Flats
Diamond Point Flats are on the Rebounded Lake Coveville "water plane"

Bolton Landing, built on a Lake Coveville delta.

Picture Stop; view of southern Lake George

Sabbath Day Point; pit on left in a Lake Coveville delta.

Silver Bay Lake Coveville delta below, on right.
Rebounded Lake Albany, Stable Lake Albany, and Coveville features from here to the Hague.

The Hague

Trout Brook Valley, at left, filled with lake clay

Lake Champlain on the horizon, ahead to the left

Rise up the foreset slope of the Streetroad delta

STOP 1. Heustis Gravel Pit
This stop is in a gravel pit developed in one of the deep kettle holes in the 520 ft Streetroad Delta (p. B.8-7; Crown Point 7.5' Quadrangle) of Rebounded Lake Albany. Obviously this delta was deposited upon or within a large block of stagnating ice. This ice was left behind following the Bridport Readvance. Note the lithologies present and the size, sorting, and degree of abrasion of the clasts. There were no lower erosional or depositional levels on the foreset slope. Thus, the ice margin must have receded before any lower lake levels developed.

STOP 2. Raffety Sand and Gravel pit
This stop is in a recently developed gravel pit developed in an inversion ridge. This ridge, originally mapped as a kame terrace, is made of sediment deposited by glacial Putnam Creek, diverted southward by the ice of the Bridport Readvance (p.B.8-5). The sediment was deposited in a low channel held in by high banks of ice. When the ice left, the sediment became the high ridge above the area where ice had been. Thus, the topography is inverted. The inversion ridge is evidence of deposition from higher parts of an ice-free drainage basin, onto, into, or next to the ice. This deflected sediment is part of the evidence for the Bridport readvance.
The 520 ft, Rebounded Lake Albany level, is shared with the Crown Point Delta (p.B8-7; Crown Point 7.5 Quadrangle). When the ice margin receded, Putnam Creek again flowed eastward into the lakes of the Champlain Valley. Thus, Rebounded Lake Albany continued to exist for some time after northward withdrawal of the ice margin. We will cross lower levels of the Crown Point delta as we proceed to Stop #3.

Cross 440 ft delta flat of Stable Lake Albany

Descend to a 360 ft Coveville delta

Descend a 260 ft Lake Fort Ann delta

Then to a 200 ft Fort Ann delta; exposures of sandy beds on left

Putnam Creek bridge

Lake Greens Corners delta
rise back up to the sandy,160 ft, Lake Greens Corners delta inset into lake clays

Sandy 340ft Coveville delta at left against Bulwagga Mt.

STOP 3. St. Pierre Farm for Core #3
This is a brief stop to view the St. Pierre Farm where Core #3 was retrieved (p. B.8-l4; Port Henry 7.5' Quadrangle). The upper 4-4.5 m is Champlain Sea sediment with marine shells. Below this is at least 11 m of varved lacustrine clay.

STOP 4. Crown Point State Park
Turn right (east) into Crown Point State Park (Port Henry 7.5' Quadrangle). Here we will discuss the results of the coring program (p. B.8-16) and examine the polished, striated limestone bedrock beneath the Crown Point bluffs. After our discussion, this will be our lunch stop.

STOP 5. Champlainside Farm for Core #2
This will be another brief viewing stop to point out the location for Core #2 (p. B.8-15; Bridport 7.5' Quadrangle) on Champlainside Farm. The West Bridport section (p. B.&-Figure 10) is immediately southwest on the shore of Lake Champlain.

Two (or three) tills over striated limestone at lake level.

STOP 6. Type Locality for Bridport Readvance
This will be another brief viewing stop (Bridport 7.5' Quadrangle) to see the location of the former gravel pit that was the type locality for the Bridport Readvance (p. B.8-4 and Figure 4)

Drive up alluvial fan surface graded to 420 ft Lake Coveville

Climb to 540 ft Rebounded Lake Albany delta

Ice-contact inversion ridge on left
Ice-contact inversion ridge on left; marks channel that carried Middlebury River waters south to the delta; ice must have blocked westward drainage

Abandoned gravel pit to left
Abandoned gravel pit to left; in 1965 showed ice-contact deposits at proximal end of Lake Albany delta as a mirror image of the Streetroad/Crown Point deltas on the west side of the Champlain Valley

Descend the foreset slope of the East Middlebury delta.
Abandoned pits on left and right displayed the foreset slope in 1965; mirror image of foreset slope of the Streetroad delta of New York

Left would take you to 460 ft Stable Lake Albany delta
A left turn would have taken you into Brandon and the 460 ft Stable Lake Albany delta of the Neshobe river.

340 ft Stable Lake Albany delta

STOP 7. Bishops Commercial Sand and Gravel
At this stop (Thorn Hill 7.5' Quadrangle) we will examine the bottomset sands of the 280 ft. Fort Ann delta of the Hubbardton River (p. B.8-6) for signs of varves. Then we will climb up to the pit and look for ice-contact structures (and the toe of a Taconian thrust fault).

380 ft Stable Lake Albany surface of the Fair Haven delta

440 ft Rebounded Lake Albany leve
Climb to 440ft Rebounded Lake Albany level of Fair Haven delta of the Castleton River

STOP 8. 440 and 400 ft levels of Fair Haven delta
This will be a brief drive-by stop (Poultney and Thorn Hill 7.5' Quadrangles) on the 440 and 400 ft levels of the Fair Haven delta (p. B.8-6), unless a recent exposure is available.

Slate Quarry on left

To the left is the Lake Coveville delta
To the left is the Lake Coveville delta, to the right is the Poultney River. Large logs in the alluvium date at 5,580 yrs BP.

Cross 450 ft delta of Rebounded Lake Albany.

Enter the Hudson River Gorge

STOP 9. Type locality for the Luzerne Readvance
This is the type locality for the Luzerne Readvance (p. B.8-2 and Figure 3; Glens Falls 7.5' Quadrangle). Compare the texture, color, and clast lithologies between the lower grayish-black till and the overlying readvance till. Many times in the past it has been possible to observe a stone line at the base of the readvance till. This has been interpreted as a thin layer of lodgement facies beneath the subglacial melt out till.

460 ft Stable Lake Albany delta
Ascend to the 460 ft Stable Lake Albany delta of the Hudson ruver (Glens Falls delta)