The members of the Cu Maurice River listen to Mark Demitroff when he describes the periglacial characteristics on the Maurice River Bluffs Preserve. Photo: Joan Lawrence-Rhads
On March 15th I was lucky enough to take part in a CU Maurice River -Walk under the direction of Mark Demitroff on the Bluff Preserve of Nature Conservancy (TNCS) in Millville. This area is located south of Center-City Millville on the west bank of the Maurice River and is one of the most visited packages of the TNC. You may have been there, but I hope that by sharing some of Mark's esoteric facts you consider the concepts when you return – or visit for the first time.
Answering the question “Who is Mark Demitroff?” can lead to a complicated reaction. He has lived a life in the intellect with great variety of interests, many of which are centered as an old -fashioned geographer in the Pinelands. His activities are at the interface of cultural, ecological and natural stories. Demitroff was an extraordinary professor in the geology department at Stockton University, was twice a member of the US Permafrost Association and is a board member of South Jersey Culture & History Center from Stockton.
Demitroff's expertise is the periglacial geomorphology-das examination of non-glacial processes in past and current cold areas. He focuses on the ice age environments when the deep seasonal frost and the past were deeply affected by the land surface of the South -Jersey. He has written and co-established numerous magazine publications about cold climate, frost-cracks, permafrost upright, wind-packed stones and old dune fields, which were largely carried by the cold, dry and windy conditions during the late Pleistocene era, especially in the New Jersey Pine Barrens.
Mark's book, book, Wetter soil: a geography of pine from Barren's wetlandsdiscusses how the wetlands of the pine bars are interpreted by land surface processes. The advertising description of the book states: “The less well -known land forms of the ice age offer plants and animals a critical habitat for plants and animals. Places such as contain, crippling, blue holes and savannas are combined in a geographical wall carpet of interactions between nature and society.
Our walk looked with a view of Venifact-Desert gravel, which were shaped by wind-driven sand or dust loaded ice crystals. These geological time travel has surface characteristics that can be analyzed for indications in the distant past. Mark showed us small stones, which would have been polished and etched by strong winds on frozen soil and etched the polar desert landscape, which sat down through the continental ice plate that came closest to the southern New Jersey. He explained how the surface of a single grain can be analyzed to disclose the cold temperatures that it was exposed to in the past, the time of grain wind transport and when this grain was thawed as an permafrost. All of these are data used to create climate models. He worked with colleagues nationwide and worldwide and opened the Paleo -surrounding secrets of deceptively complex quartz grains from Cumberland County. Mark is currently working with Canadian, Polish and US research institutions for Ice Age Dunes systems, old river channels, permafrost in the appales and prehistoric frost tears, which are kept in Devonian rock record.
The Nature Conservancy offers excellent mapping and marking of the Bluff paths. Source: TNC website also released at the Kiosk car park.
White dots show the course of the Cu walk as described in this article.
To draw conclusions and adequate assumptions about an earlier landscape by looking at what is currently there, you have to know the full history of a location. In the case of the Maurice River Bluffs, it is important to know that sand mining takes place on the site to know the earlier topography more than 12 million years ago. Mark looks beyond the current disturbed state of a location to formulate how it was formed and to understand its past nature.
Early miners searched for the first time for sugar sand pebbles from the banks of the Maurice River. Well -sorted, clean, loose grains made of wind -blown sand would have been deposited in a ceiling in which old valleys and recesses were filled into the banks. Excavations were labor -intensive and hand -given. The mining at the time was selective and was carried out surgically than today machine operations, which is why the patchwork nature of the Bluff's Diggings. In the mid-1800s, the tools of the workers' shovels, pick-axles and animal wagon-not with large excavated excavators were.
Today's mapping instruments (short for “easy detection and reach”) enable scientists such as Mark to see the remaining carved landscape of hills and valleys who have apparently caught wind -flushed sands. There is a lot to learn. The resulting topography of the bluff provides further evidence of Mark's many years of conviction that our local landscape was frozen and thawed, while it was thawed through cold, dry catabatic winds (a wind that throws down a slope or hill) that flows from a nearby continental ice shield. Lidar is a laser technology that maps the topographical surface of the earth from above using aircraft, drones and satellites. You can be familiar with the fact that it is used to discover the huge realm of the Mayan, in which the trained eye enables the degree of clarity to see the outlines of old cities and village foundations in Central America.
The sand was preserved on Kai on today's Nature Conservancy Maurice River Bluffs. Photo: Joann and Dale Wettstein, Steelman Photo
Pettinos Sand Co. About 1900 received the Maurice River Bluffs on cars. Photo: Joann and Dale Wettstein, Steelman Photo
With these images and an abundance of additional scientific evidence, geomorphologists like Mark can find that the Laurentide ice sheet (2.5 million years ago) stopped about 51 times north of our region – with the last advance, which in the vicinity of today's exit 11 at New Jersey Turnpike – indeed from a glacial past. Periglacial processes are effective – albeit badly understood – geomorphic active ingredients that devastated our landscape. The Laurenide ice sheet was a maximum of 30 percent larger than its today's counterpart in Antarctic. It was fully one or two miles thick. In the maximum glacier, the sea level was 433 feet lower than today.
We visited the Old Stone Ferguson Farm House and our geologist guide asked us where the big stones came from. My first guess was Pennsylvania, but Mark explained that some stones used in local construction were actually fiber from European ships. In fact, ports in Philadelphia often acquired cobblestones for streets when fiber was unloaded and replaced by freight. We called Richard Weatherby, whose grandfather owned the house to Ferguson. Richard told him it was told that they were actually fiber stones in New York, which are unloaded on the return journey and exchanged for sand. This was estimated at both ends of a trade agreement. As early as the 1790s, Maurice River Glass Sand was transferred to the Pitkin Glass Works near Hartford, Connecticut. Simply fascinating, I think you will agree!
Next week we will continue our story about the cold, dry and windy conditions of New Jersey during the late Pleistocene era, starting with tools that are used to determine the past. Cards by Charles Hartman and today's Lidar mapping will be part of this discussion.
Find out more about the outdoor options of the CU Maurice River. Visit Cumauriceriver.org and select the calendar on the homepage.
Sources
Demitroff, Mark, Feugy Ground: A geography of Pine Barren's Wetlands, South Jersey Culture & History Center, February 9, 2024
Coal was an early product of Pine Barrens, by JG Wilson, Batsto Citizens Gazette, 1987. Www.co.ocean.nj.us