Deglaciation at the New Jersey/ New York Border- Timing and Environment of Ice Sheet Melt with Dr. Dorothy Peteet Earth2Class Organized by Dr. Michael J. Passow April 20, 2021 Ovr 20,000 years ago, much od North America was covered by the Laurentide Ice sheet

• The ice sheets created the Great Lake, Finger Lakes, and many other lakes in the Canadian Shield, as well as such surface features as Long Island and the drumlins so suitable for growing apples. • The ice sheet went as far south as 38o N (southe of Chicago) • Ice over what became New York City was 2,000 feet thick. • The ‘terminus’ oscillated at times before meltin finally about 9 – 10,000 years ago. How Do We Know Where it Was? “Terminal Moraine”

https://www.nytimes.com/2018/06/05/science/how-the-ice- age-shaped-new-york.html Other Evidence—Glacial Erratics (l) and Striations (Scratches on rock surfaces)(r) What is pollen?

• Pollen grains are male microgametophytes of se ed plants, which produce male gametes (sperm cells) • Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of coniferous plants. By Dartmouth Electron Microscope Facility, Dartmouth College - Source and public domain notice at Dartmouth Electron Microscope Facility ([1], [2]), Public Domain, https://commons.wikimedia.org/w/index.php?curid=14840522 Evidence from Palynology (fossil pollen)

https://www.environmentalscience.org/palynology Pollen and Spores among most common fossils (although, as the scale shows, tiny) • Climate change in the past was natural, and evidence of plants can help identify warm from cold periods in a location. • We collect a core from a marsh or other sedimentary deposit, then separate the pollen grains under a microscope. Coring for pollen

Public Domain, https://commons.wikimedia.org/w/index.php?curid=2259195 One location of local interest: Piermont Salt Marsh

https://www.dec.ny.gov/lands/92365.html When the ice sheets began to melt…

• … the surface was just bare rocks • Gradually, “pioneer plants” may be brought in by wind, water, or birds and other ‘vectors’ • They include lichens (algae/ • fungi symbionts) and mosses (bryophytes, non- • vascular plants)

https://commons.wikimedia.org/wiki/File:Plants_Colonizing_a_ Lava_Flow_on_Hawaii.jpg Tundra biomes (polar and high peaks)

• Bearberry (Arctostaphylos) • Labrador Tea (Rhododendron groenlandicum) • Diamond Leaf Willow (Salix planifolia) • Arctic Moss (Calliergon Giganteum) • Arctic Willow (Salix arctica) • Caribou Moss or Reindeer moss (Cladonia rangiferina) • Tufted Saxifrage (Saxifraga cespitosa) • Pasque Flower (Pulsatilla) • http://cookiesandcereal.weebly.com/ plants.html https://www.treehugger.com/life-in-the-tundra-3572160 Taiga (Northern Coniferous Forest)

https://www.britannica.com/science/taiga https://www.pinterest.com/pin/228135537348783147/ Deciduous Biome (locally, Eastern Woodlands)

https://www.britannica.com/science/deciduous-forest https://www.pinterest.com/pin/539728336577027755/