19 Ice sheets, glaciers, and landscapes, oh my!

Glaciers and ice sheets shaped the landscape of the Northeast. Ice continues to shape the landscape of alpine and polar regions. We welcome submissions on glaciers &  ice sheets of any size, shape, age, and location.

Monday, 23 March 2026
8:00 AM - 12:00 PM
CCC, Room 26

Evidence for A Mosaic of Tundra and Boreal Forest at Southern Laurentide Ice Margin and Rates of Plant Migration Northward

Paper number: 19-1
Program: Technical Sessions
Time: 8:05 AM – 8:25 AM

Authors

Abstract

Lithologic and macrofossil stratigraphy from eight lakes and bogs along the southeastern Laurentide margin from Pennsylvania, New Jersey, New York, and Connecticut reveal various patterns of primary succession following ice retreat.  Basal sediments of glacial clays and silts containing less than 5% organic matter contain scattered cranefly remains and bryophytes, sometimes sterile or absent of any higher plant macrofossils for as much as 50 cm.  Uniformity of sediment layers and the absence of “trash layers” sometimes visible in lake sediments from remnant ice blocks indicates continuous lacustrine deposition as the glacier retreated, and suggests landscape stability.

 Singular tundra species such as willow (Salix) buds, mountain avens (Dryas integrifolia) leaves, dwarf birch (Betula nana) cone scales and seeds, and bog blueberry (Vaccinium uliginosum) seeds often are the next plants to arrive. While some of the records record aquatic plant seeds (ie. Nuphar, Potamogeton) and animal remains (ie. fish scales), others reveal needles and seeds of boreal trees which advanced on mineral soils as primary succession took place. Larix laricina and Picea glauca arrive first, followed by Abies balsamea, with rare Pinus banksiana.  We document the first arrival of tundra as well as the arrival of the boreal trees at each site, and then calculate the migration rates for the trees northward to the Catskills and the Adirondacks.  These rates are compared with those in coastal Alaska and Canada.

 

Geological Society of America Abstracts with Programs. Vol. 58, No. 2

doi: 10.1130/abs/2026NE-411311

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