Hudson River: a Detailed and Comprehensive Geological History

Contents Introduction†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 2 Hudson River Formation†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 5 Hudson Canyon†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã ¢â‚¬ ¦Ã¢â‚¬ ¦12 Glacial History†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 14 Conclusion†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦17 Bibliography†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚ ¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦18 Maps & Diagrams†¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. 19 Hudson Canyon†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 19 Geological Processes†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. 2 1|Page Introduction In 1872, a naturalist and surveyor by the name of Verplanck Colvin found the source of the Hudson River. It is a small pond on the south western slope of Mt. Marcy, the highest peak in the Adirondacks, called Lake Tear of the Clouds. So little is Lake Tear of the Clouds that if no water was to feed it for seven days it would be reduced to just an empty basin. Nevertheless, the Hudson starts right in its waters. One could say the Hudson River is divided into two distinct sections differentiated by geology and appearance.The first section winds its way through the Adirondack Mountains spanning 166 miles from Lake Tear of the Clouds to the Federal Dam in Troy. This section is un-navigable by boat and in some places somewhat rapid. The second section, which is quite different from the first, starts at the Federal Dam and runs for 149 miles through the â€Å"rolling hills† all the way to the Narrows between Brooklyn and Staten Island. Back up north at Lak e Tear of the Clouds is fed by natural springs and runoff from the sheer steepness of Mt. Marcy and other streams winding down from the high peaks of the Adirondacks.Throughout the whole Adirondack mountain range, the watershed drains and dumps runoff from 3,400 foot peaks into the lowlands less than 410 feet above sea level. From Lake Tear of the Clouds [in the space of a mile] the river drops 1,000 feet down a deep trench to join the Opalescent River1. A bit more southward, the Mohawk River drains much of the runoff from central New York into the Hudson. In fact, over half of the Hudson Rivers water volume comes from the Mohawk, and without it, the Hudson would be practically non-existent.Further south of Albany tributaries flow westward to the Hudson from the Taconic Mountains and eastward from the Catskills. Still further south the tributaries for the Hudson begin to appear rectangular, almost following the trend of the faults and 1 The Opalescent River is not a separate river f rom the Hudson but merely a section named by old Native American tribes. 2|Page ridges that run northeast to southwest of the river while other tributaries join at right angles to the faults along the joint planes.At this point in its path, the river begins to occupy its original bedrock gorge formed millions of years ago, flowing over rock ledge rapids and the coarse cobble point bars2 that are very common from Mt. Marcy to Glens Falls, until it is partially blocked by mountains. It is here that the river makes a sharp turn to the east and flows through the Luzerne Mountain gorge in western New York and then emerges quickly onto glacial lake sediments deposited in the Pliocene Glaciation and forms a very broad, almost meandering path on the lowlands (supported by shale) for the nearly 130 miles to Newburgh.South of Newburgh the river cuts laterally through the hard crystalline rocks of the Hudson Highlands, shifting back and forth in its valley (almost like a cradle) until it emerg es from the highlands and starts to exhibit fjord like characteristics within the towering rock walls around it. The river’s course then slightly curves in front of the Palisades escarpment3, which towers more than 328 feet above the water’s surface. At the Narrows the Hudson breaches its final barrier, the terminal moraine4 of the last glaciation (more on this in the Glacial History section) before it reaches the Atlantic Ocean.At the Atlantic (although tidal) the Hudson behaves as any other river would and deposits its bed load (sediments carried by the river) and some of the fine-grained suspended load (basically fine grained sand and dirt floating in the water) into the form of sandbars. Over millions of years, these have contributed to building up many islands including Staten Island, Hoffman Island, Swinburne Island and many others. The very low slope of the Hudson plays a great role in the amount of discharge and island buildup, too, as it only rises about 0. 4 inches per mile for the last 150 miles of the rivers path. To give some perspective, the Mississippi river rises approximately 6 inches per mile during its course, and discharges about 700 million tons of sediment per year into the Gulf of Mexico 2 Coarse cobble point bars are essentially pointed cobble that has been piled into bar like formations. These formations are generally formed when sediments carrying cobble leave it behind. 3 Ground formed into a steep slope as part of fortification. â€Å"Moraine† is a word used to describe the earth, stones and debris a glacier deposits. â€Å"Terminal† describes that these items were deposited where the glaciers maximum extent was, in this case Long Island. 3|Page and its mouth is approximately a ? -mile wide. The Hudson River discharges about 175 million tons of sediment per year and its mouth is about the same width at a ? mile. With a 2 inch increase in slope geologists predict the discharge rate of the Hudson would spik e up to about 450 million tons per year and the mouth of it would close up to about 250’ wide.This would place Manhattan underwater and greatly limit boat traffic as well as make Long Island more of a true island separated from land by at least 3 miles or so of water5. And so, the geography of the Hudson River today ends here in Manhattan, but the geology of what lies underneath is much more important. Continue reading if you must, and dwell into a mystery of time and a lot of pushing and pulling. 5 Do not worry about this happening now though because the rivers overall slope has not changed more than a centimeter in the last couple thousand years and shows no signs of speeding up. 4|Page Hudson River FormationThe Geology of the Hudson River is complex. Billions of years of folding, pushing, pulling, separating, and moving have formed, deformed and reformed the Hudson River valley into what it is today, a â€Å"giant palimpsest6, a great parchment on which the hand of nature has written and rewritten her bold signature for more than a billion years†7. In the next section, I am going to attempt to condense over a billion years worth of Geologic History into less than ten pages. Despite complex knowledge and strange words it is a simple story of time and rocks, moving and changing: the formation of the Hudson River and its valley.The Hudson’s geological â€Å"personality† very much reflects its structure and the changes made on it, underneath it and all around it from the Pleistocene glaciations8 . The bedrock foundation of the Hudson was established in the space of three oregany’s (mountain building periods) beginning over a billion years ago. These mountain-building episodes re-triggered long intervals of underground erosion and periodic submersion by the epicontinental seas (or oceans) to help start forming the Hudson River Valley. At a point much later in this story, glacial erosion reshaped the landscape of the HRV into wh at it appears as today.The first major mountain building episode, the Grenville Orogeny began about 1. 2 billion years ago. It was one of the biggest Oregany’s and affected a broad region along the coast of what was Ancient North America, from the northeast waters of Canada to northwestern Mexico. The mountains created by the Grenville Orogeny were most likely as tall as or taller than the Himalayas and were driven to these heights by a collision of Laurentia (Ancient N. America) and Gondwana (Africa) in which Gondwana overrode Laurentia. The deep burial of Laurentia resulted in the first 7 Written upon, or engraved on more than once. The Hudson: A History, Chapter 1: The River and the Land, pg. 10 8 A period of ice buildup to form glaciers, or the act of glaciation. 5|Page metamorphism, partial melting of rock and the separation of the light and dark minerals found in the Adirondack gneisses9. Many hundred thousand of years later in the Proterozoic period as the continents p eriodically moved, basaltic volcanic rocks merged into the mountains cutting the anorthosites10 and gneisses laterally across.These gneisses are around one billion years old, while the Highland gneisses may be a bit older. The Fordham gneisses are the youngest and can be dated to just under a billion years old. Over the millions of years, long episodes of erosion on the Grenville Mountains and constant lifting of the crust have brought it to the surface. Later in the Proterozoic period, erosion of this crust formed and provided a thick source of sedimentary deposits that partially submerged the upland area of coastal Laurentia (presently this is the area south of and parallel to the Appalachian Mountains).These deposits are now found mostly in the Appalachians, with almost all of them have been removed from the Hudson valley, leaving hard rock and clay for the Hudson River to rest on. In the early Paleozoic, the sand and gravel that was eroded from the mountains during the Proterozo ic period became basal sandstone and conglomerate11, which is more commonly known as the Potsdam Sandstone in northern NY and the Lower Quartzite that is prized throughout the Hudson Highlands.As the Epicontinental sea inundated this (once) mountainous region the sandstone and Lower Quartzite were buried under a thick cover of marine limestone and shale, which was laid down in an elongated trough that formed on the continental shelf where mountains had once been. The limestone was mostly deposited on the shallow edges of the trough while the shale solidified from the mud carried into the deeper seaward part of the trough. The solidified shale then created the bedrock between Glens Falls and the Highlands. 9Coarse, grained metamorphic rock composed of quartz, feldspar and mica. An igneous rock made up largely of soda-lime feldspar. 11 Rock composed of rounded fragments of various rocks cemented together in a mass of hardened clay and sand, like a composite. 10 6|Page In the Late Camb rian period,12 Laurentia once again collided, but this time with the ancestral core of Europe, Baltica and a large fragment of what is thought to be the continental crust known as Avalonia. This started the mountain building period known as the Taconic Orogeny, which lasted throughout the Ordovician Period.The Taconic Orogeny also resulted in the new supercontinent Laurasia. While much of the activity involving this collision took place well to the east it also affected the HRV. Island arc volcanic structures such as the Cortlandt Complex have been found in the Hudson Highlands. To the North and West in the mid-Hudson Valley, the sedimentary rocks that were deposited in the early Paleozoic Period were folded (with the trend of the folds and faults already in place) parallel to the southwest to northeast facing the Appalachians.These folds and faults eventually became some of the paths of the HRV tributaries. Closer to the coast than these faults, thin sheets of rock were pushed seve ral dozen miles west. This event is known as the Taconic Thrust and took place in the area where today exists the Taconic parkway. Because of this event, the fine-grained shale that was there was crumpled (as if we crumple paper) and pushed into the narrow channel of water west of the mountains near present day Croton. Over many years thereafter blocks of limestone into the channel and were merged into a jumble of shale clumps.Today millions of years later the river flows past the western edge of the channel and then cuts into the disorganized deposits of shale as it continues south. As we travel through time, sandstone, limestone, shale and Proterozoic bedrock from the Hudson Highlands became buried as Laurentia’s coastal margin was subducted13 close to where it and Europe’s plates met. The rocks that met each other from each plate partially melted and transformed into more gneiss, marble and schist14, which was then folded and moved once more to be in alignment 12 00 million years ago Subduction can be described as the action or process in plate tectonics of the edge of one crustal plate descending below the edge of another, almost like a controlled earthquake. 14 Schist is a metamorphic crystalline rock that has a closely foliated structure and can be split along approximately parallel planes. 13 7|Page with the Appalachians. This set the stage for the modern day continental shelf to form, although it would take millions of more years for it to happen. After the two plates of Europe and Laurentia collided, there was a sort of lull in activity around this area.This allowed streams in the lowlands to follow the valleys formed along the fault lines, or on the softer marble layers around Manhattan. The oceanic crust borders and the rocks around NYC and to the east more or less contained the streams around Manhattan, while the streams in the lowlands and around our area were free to roam and spread out. After the Taconic Orogeny ended, a long inter val of erosion began stripping away the excess crust as the â€Å"new† continent (modern North America, or Laurasia) was very slowly lifted by the compression of the plates.As the upland area was eroded away the epicontinental sea gradually filled the Hudson Valley region from the low lying land of the coastal margin all the way west nearly three-quarters of the way to Pittsburgh. Later during the Silurian and into the early Devonian period shallow seas covered the area and left behind calcium carbonate sediments making the soil very rich. At around the same time rivers formed and flowed from the uplands carrying major amounts of sediment west to the sea to form marine sandstone.While the marine sandstone was being formed, at the shoreline a large delta15 formed over the junk that the marine sandstone left behind. By the midDevonian period, an alluvial plain16 had reached across much the western Catskill region and the shoreline had shifted slightly west about 15 miles or so. At this time, thousands and thousands of feet of sediment from mid-Paleozoic times were piled up over the Hudson Valley and continental red sandstone (one reason why there is so much sandstone around here) from farther east inland were incorporated with the gray marine sandstone from the west closer to the coast.The force of all this happening at once overturned the folds that were in place to the northwest (near present day Schunemunk Mountain along the NYS thruway near Highland Mills) exposing the limestone that 15 A Delta is a triangular alluvial plain, usually where a rivers mouth is. A level or gently sloping flat or a slightly undulating land surface resulting from extensive deposition of alluvial materials by running water 16 8|Page was buried slightly underneath the sediment that had accumulated over the years. This marked the end of the Devonian Period, and the start of the Acadian Orogeny.The Acadian Orogeny began as the North American plates started to compress again and lift up the eastern mountain ranges around New England and western Pennsylvania. This Orogeny was also partially caused and linked to the collision that happened between Laurentia and Gondwana that created Laurasia, and most likely, if this Orogeny had not happened the Hudson River would be a completely different river, and possibly would be connected to the Mississippi River. As the plates began to compress each other again they created volcanic arcs and granite intrusions somewhat east of the Hudson Valley near the coast.Around this time in our little history story the seas started to retreat from the east to west and started to expose the incredibly thick layer of sediment and rocks from the Acadian Mountains all the way to the Catskills. The final compressions dating back to the Paleozoic era continents and the Alleghenian Orogeny now ended and the earth came together to form Pangaea. Because of all this land being pushed up, the Epicontinental Sea retreated from the Catskills to the Poconos in Pennsylvania leaving much of New York and New England dry once again.Now above sea level the strata from the Devonian period became subject to erosion for 250 million years. At some point during this time, the drainage patterns shifted and aligned the ancient Hudson River along a NorthSouth line much like it is today. This was the biggest directional change the Hudson ever underwent. As the strata and sediment were worn away from this new path of drainage, it revealed the granite, marble and schist underneath which became the building materials for our modern world.With the Taconic Mountains now more to the east and the Catskill Mountains to the west the Hudson worked its way down deep into the sediment it was on top of leaving behind a hard bedrock base nearly 5,000 feet deep in places17. This created a solid foundation and left the Hudson with a relatively stable path 17 Over the last several million years, and an Ice age this has all been filled in and now the H udson has an average depth of 32’. 9|Page that has not changed tremendously since. The breakup of Pangaea followed soon thereafter and the coastline of North America began to resemble what it is now.At the same time, the Hudson was filling its banks; basaltic magmas were merged along the fault lines and into the bedrock forming the Palisades Sill18. After that, compression and buildup of sediment and rock slowly built the Palisades up. Today the part of the Palisades that stands is almost like a canyon above the Newark Basin. The â€Å"tabular†19 Palisades still slope to the west, and the eastern edge forms the escarpment, or â€Å"palisade†20 21 of rock joined vertically that we recognize today from miles around New York and from the air as we fly to new places and heights.But to learn how, we must travel to another time in this story, the Mesozoic Period. Some time in the late Mesozoic period, igneous rock deposits were moved yet again and placed along a line going Northwest to southwest from Canada to New England lifting the mountains in its path by several hundred feet and in some cases over 1,000 feet. Because, as you might infer, rock takes up space, and as it lifted up the mountains and separated them, it started to separate North America’s continental plate away from the mid-ocean ridge22 and over a very hot area above the earth’s layer of magma near where the present day Appalachians exist.This caused what geologists think was a shot of magma that melted through that particular part of the plate (which was quite thinner than today) and uplifted the Northern part of the Appalachians. This, in turn reactivated erosion and brought the domed like anorthosites to the surface which is most likely the reason that the Appalachian Mountains are not scraggly and sharp like the Alps, but more rolling with large boulders and open expanses of rock. The Catskills and Adirondacks also experienced lifting, but in a much smaller amou nt. Almost at the same time as all this uplifting was happening, a 18 19Think of this as the palisades foundation. L. Sirkin & H. Bokuniewics – The Hudson River Valley: Geological History, Landforms, and Resources pg. 17. 20 L. Sirkin & H. Bokuniewics – The Hudson River Valley: Geological History, Landforms, and Resources page 17 21 Palisade literally means â€Å"a fence of stakes for defense† The Palisades are called the Palisades by Native American Tribes because they helped as defense for them from other tribes. 22 The mid-ocean ridge is a undersea mountain ridge that is where the North American and European plate meet. While this ridge has hardly ever changed, the plates do move.In this case it is the biggest moves it has ever made. 10 | P a g e hole began to form from sinkholes on the western slope of Mt. Marcy and soon filled with water. This was Lake Tear of the Clouds. After Lake Tear of the Clouds formed and filled with water, the Newark basin reached i ts fullest capacity of water and the Hudson began to â€Å"drive† into its flood plain and carve out its gorge in the gneisses of the Highlands of southern New York. This area is now mostly between West Point and Hastings on Hudson, but it continues as a much smaller â€Å"weaker† gorge almost down to Fort Lee.The Hudson was now a true river, but would still undergo massive changes over the next several million years. At this time in the Hudson River’s history, Long Island did not exist as what it does today. It was a tiny, almost alcove piece of land that was in no way an island. In addition to that, there was no opening to the Atlantic for the Hudson. At the place where the Hudson empties into the Atlantic at the Narrows was a big solid mass of land. The Hudson by definition was a lake. So, as the Hudson filled up and he water put immense pressure on the piece of landmass blocking it from the Atlantic it began to carve out and widen an outlet. It took only a f ew hundred years23 for the Hudson to make it to the Atlantic, bringing with it thousands upon thousands of tons of sediment that had piled up in the Newark Basin. This created the new continental shelf to form the coastal â€Å"plain† we see today that stretches for about a hundred miles out to sea from New York, only in that time and age it stretched for nearly 425 miles, nearly halfway to Bermuda.The Hudson now had an outlet, and the waters started moving south digging, and bringing sediment to the mouth building up Long Island a little bit24, as well as separating it from the mainland with what is now the East River. The sea levels around North America also dropped a few centimeters as the waters made their way up the Hudson forming the Hudson River estuary. This raised the Hudson’s waters by a few centimeters and created its almost permanent banks that have 23This is an extremely short time in geologic history and greatly shows how much the pressure was on the land mass blocking the Hudson from the Atlantic. 24 Although Long Island did get built up at this time, the majority of it was built up during the last ice age nearly 20,000 years ago. 11 | P a g e not changed very much since. Because the sea levels were much lower in that time period the Hudson also began its excavation of the Hudson Canyon with the help of the naturally occurring currents (more on this in the Hudson Canyon section) and more than doubled its length to nearly 895 miles (about 1,440km) long.After nearly 500 million years the Hudson rivers formation had ended and all that was left to change it was its own water wearing away at its bottom and a glaciation that would come in a few million years. Hudson Canyon The Hudson Canyon is possibly the biggest mystery of the Hudson River. How did it form? When exactly did it form? Why did it form? These are all questions geologists and hydrologists ask when looking at it. Most people in fact have never heard of it. To them the Hudson is a river that starts in the Adirondacks and ends at the narrows.To the few that know of the Hudson Canyon, the Hudson River starts in the Adirondacks and ends nearly 925 miles south halfway to Bermuda right after falling over a half mile down a [now] underwater canyon and then fanning out and spreading to the Atlantic Ocean. There, even though underwater it still carries small amounts of the Hudson’s freshwater (out to sea), and most geologists still consider it a part of the Hudson. This makes the true length of the river from Lake Tear of the Clouds to the end of the Hudson Canyon 922 miles, more than double of what we consider the â€Å"Hudson†.As explained in the last section (Hudson River Formation) in the late Mesozoic Period the Hudson River broke the land barrier that held it from emptying into the Atlantic. When it broke the barrier it began to carve a new path out to sea towards Bermuda. At some point, it reached the Continental Shelf and dug into it creati ng a canyon that eventually connected the shelf to the ocean basin, which is about 1. 5-2. 5 miles deep. Technically the canyon begins as a natural channel many miles wide at the mouth of the Hudson in a depression about 12 feet deep in the rivers bed. It 12 | P a g e ontinues then through the Hudson channel and under the Ambrose light25. Soon after the Ambrose light, it reaches the shelf and goes through the real canyon part of it that is called the Hudson Canyon proper. The Hudson Canyon proper is located about 100 miles east of Battery Park City and has walls almost ? mile in height, which can be compared to the Grand Canyon whose cliffs are about 1-1/8 mile deep. The Hudson Canyon is the largest â€Å"submarine† canyon in the United States, partially due to the currents that pass over, and carrying away sediment and rock, thus carving it deeper and deeper.Over the past 30 years since it was discovered, tracking equipment has logged a nearly 12-inch change in its depth and width making the Hudson Canyon also the fastest growing canyon in the Atlantic Ocean. At the same time it is growing wider and deeper, it is also getting closer to the magma underneath and behind the continental shelf. In simple terms, one day in the next couple hundred or thousand years it will break through and magma will come out creating a new island, possibly connecting the East Coast of the United States with a land bridge that extends more than halfway to Bermuda.Many tributaries around the canyon would be raised by the magma, creating a new network of rivers and streams on the land bridge that could host many kinds of wildlife as well as marsh like environments. In addition to this, the Hudson Canyon has large stores of methane hydrates which according to scientists is a very promising clean burning natural energy source, and could help reduce oil consumption. It is a Canyon of great importance to the Hudson River, and also a big clue into the Glacial history surrounding th e HRV. 25The Ambrose light is the site of a Light House that ships going into the New York Harbor and other harbors in the area use for navigation purposes. 13 | P a g e Glacial History The Glacial History of the Hudson River is probably the one of the most important geological event that happened in the Hudson Valley in the last 50,000 years. Evidence points mostly to the Pleistocene Glaciation, which was the last and only Glaciation to reach this far south into the United States for the change that happened on the Hudson River since it was originally formed.The topography of the Hudson Valley enabled the ice from the Pleistocene Glaciation to form a Lobate Ice margin26 about 50 miles north what is now Manhattan long island. Around 22,000 years ago the Ice over the Catskills and Taconic uplands thinned, while it thickened in the Hudson Valley and expanded southward closer to the mouth of the Hudson. Scientists today doing Pollen analysis and radiocarbon dating have found that the c limate back then right before, and as the last Ice age started was much warmer than today. As one can expect, warmer conditions meant more plants, and the sea level was much higher than today27.When the climate cooled and the Glaciers expanded south all these trees, plants and debris were ground down and immense pressure pushed them into the ground, almost dissolving them into dirt. This not 26 Lobate means resembling of a lobe. In this context it is used to describe the shape of the edge of the Glacier, or its maximum extent which was a short of lobe shape. 27 Evidence shows that the waters might have been as far north Albany. 14 | P a g e only made the area much more barren, but also flattened the Adirondacks, and Hudson Highlands down many thousands of feet.The glacier continued to expand 26,000 years ago and merged with smaller glaciers up north to form one big glacier known as the â€Å"Laurentide Glacier†28. This Glacier covered all of Ontario, the St. Lawrence River, M anitoba, Nunavut, and parts of Quebec, as well as the Great lakes down to Chicago where it almost ran parallel to the US/Canada border before dipping slightly down towards present day Manhattan and following the coast of the US up north. At the height of this glaciers advance the ice most likely was more than 1,000 feet thick over the tops of the Appalachians (if you do the math this means that it was over 1. miles deep) meaning immense pressure was being placed on everything flattening the landscape. This also meant that because there was so much pressure, and the water of the Hudson never froze 100%29 the Hudson’s waters literally pushed the earth and carved the floor of the Hudson to a depth similar that of what it was before it broke its barrier at the Narrows. 30 The dirt being compressed turned back into soft metamorphic rock, and created marble where none existed near Warrensburg.A few miles south at Glens Falls the Ice naturally deepened because of the drop in elevati on and gained momentum31 carving out the fjord previously made even bigger, which created Storm King, Beacon and Bear Mountain. All this rock carved out of the Fjord eventually made its way south where it was dumped over Manhattan and Long Island, somewhat accounting for all the Limestone and shale and schist around that area. At this time, the Hudson Canyon was also carved out by the glacial ice melt flowing through it with rocks and debris and became much deeper and wider.When the Laurentide glacier made it to the Narrows its front stopped moving forward, but its back kept on moving forward compressing everything together (Like an accordion) and melting a lot of the ice. Why this happened is not really known by Scientists because glaciers can float. This area became the Glaciers â€Å"dumpster† and the Terminal Moraine was officially formed. Long Island was 28 29 Yes, it was named after Laurentia, ancient North America. Meaning the whole time there was a glacier over this a rea, the Hudson was still flowing but now mostly with ice melt from the glacier itself. 0 Of course this all filled back in as the glacier melted. 31 A glacier is always moving, whether it is 1 foot a year or 1 inch a year. 15 | P a g e built up and out to its current state and the Moraine extended west into New Jersey and Pennsylvania, carrying with it glacial melt creating many of the glacial lakes in that area such as Lake Hackensack, Glacial Lake Hudson and many others. Clay also being carried was dumped all over the region (mostly on the current Rockland County side) and created a nice thick, slippery layer on which the glacier to slide on.This process of dumping and melting continued for many thousand years and started the recession of Laurentide. In a 2,000 year period from 26,000 years ago to 24,000 years ago Laurentide melted and receded so that all of Long Island, Staten Island, New Jersey, Pennsylvania and pretty much everything south of present day Hartford Connecticut w as ice free. The Ice continued to melt over the next 4,000 years until everything south of Glens Falls was free of ice. The ground, sort of like a sponge when you fill it with water, rose a few meters and went nearly back to its state before the glacier.At Glens falls The glacier stopped for a thousand or so years and slowly melted providing the Hudson valley with a constant stream of fresh glacial water. Around 19,000 years ago the glacier started to recede from Glens Falls and the melt water created Glacial Lake Albany which continued to grow throughout the next several thousand years as Laurentide receded. At 15,500 years the Climate suddenly got cold and the glacier advanced back south to near Poughkeepsie and created the Wallkill, Poughkeepsie, Red hook, Hyde Park ad Pine Plains moraine.As suddenly as the Climate got cold, it got warm again and by 13,000 years the glacier was receded north of present day Quebec City. When the climate got warmer again the sea levels rose, this t ime to near Albany, and caused Glacial Lake Albany to drain. For the next couple thousand years as the climate cooled, the Hudson was tidal up to Poughkeepsie and as the Sea retreated. This brought the tides down with it to near Peekskill where it stayed for many thousands of years until around 6,000 years ago it began to go north to nearly 20 miles past Troy32 by 2,000 years ago the sea was at its present place, and the Hudson was in its present 2 The exception to this is the Troy Dam; if it wasn’t built the Hudson would still be tidal nearly 20 miles north of it. 16 | P a g e state. Long Island was as it is now, and the coast was pretty much the same besides what natural erosion as taken away since then. This was the final Glaciation, and the final change to the Hudson River. After nearly 1. 2 billion years, several different Oregany’s, Hundreds of changes, 4 different climate changes and a whole lot of pushing and pulling and moving the Hudson River was finished bei ng formed and all it needed was for Henry Hudson to come sailing to name it†¦. ConclusionIf you have gotten this far along into this history story then you will know that the Hudson River didn’t just appear, it doesn’t formally end at the Narrows between Brooklyn and Staten island and it isn’t just a river. It is the culmination of 1. 2 billion years (and counting) of the earth doing its shtick33 on the world we live on. It took 7 different continents to pull this off, and it worked out beautifully creating a river of outmost importance to our lives, lives before us, and lives to come. I like most of you out there reading this paper did not know a thing about the Geology of the Hudson River when I started this project.It probably took me a proportionate amount of time to learn this as it did to create the whole Hudson. Now, after early 3 months of reading words I don’t know, looking at diagrams I can’t even understand and writing technical ter ms that I can’t pronounce I have learned what it took, and takes to create the Hudson. Like they say, it takes a village to raise a child; it took a whole world and 1. 2 billion years to create this river, a river of small nature compared to others around us such as the Nile, or Amazon which are nearly 5 times the length of the Hudson and took a very disproportionate amount of time to create. 3 â€Å"Piece†, or â€Å"thing† in Yiddish 17 | P a g e So, as I leave you with this 20 page Essay, think about the next time you go to the Hudson and pick up a handful of sand, and know, just know that that handful of sand has been moved around for 1. 2 billion years to end up at your feet. Bibliography L. Sirkin & H. Bokuniewics (2006) – The Hudson River Valley: Geological History, Landforms and Resources Wikipedia (http://en. wikipedia. org/w/index. php? title=Hudson_Canyon&oldid=453958227) – Hudson Canyon Data SIO, NOAA, U. S.Navy NGA, GEBCO (2010)  œ Google Earthâ„ ¢ United States Geological Survey (USGS) (2004) – Sea Floor Topography & Backscatter Intensity of the Hudson Canyon Region Offshore of New York & New Jersey (http://pubs. usgs. gov/of/2004/1441/html/interp. html) Phil Stoffer & Paula Messina (2008) – Introduction to the Geologic History of the New York Bight (http://www. geo. hunter. cuny. edu/bight/Geology. html) Phil Stoffer & Paula Messina (2008) – The Highlands Region (http://www. geo. hunter. cuny. edu/bight/highland. html) R. G.Wilkins Booth (1970) – The Ontario Water resources commission Geology of the upper part of the Severn River basin and the Severn River basin lying within the Hudson River Lowlands. Steven H. Sehimmrich – Geology of the Hudson Highlands Region (www. environmentalconsortium. org) Access Genealogy – Geology of the Hudson (http://www. accessgenealogy. com/newyork/hudson/geology_hudson. html) Charles Merguerian (2010) – Geology 133 Field Tr ip 18 | P a g e Dick Goodman (2013) – Geologist in California, gave much information and advice on this project United States Navy Geological Services (2013) – Maps, Graphs Bradford B.Van Diver (1985) – Roadside Geology of New York John F. Shupe (1996) – National Geographic Atlas of the World Revised sixth edition Kevin Hile (2009) – The Big Book of Answers Tom Lewis (2005) – The Hudson: A History Maps 19 | P a g e The maps presented here on the next couple of pages are all ones used in this essay as reference. They are from many different sources and show many of the things I talked about, visually. Hudson Canyon 20 | P a g e 21 | P a g e 22 | P a g e Geographical Diagrams 23 | P a g e 24 | P a g e 25 | P a g e