Around 70 million years ago, during the very latter stages of the Cretaceous period, the Western Interior Seaway was moved by the steady elevation of the continent, and it finally disappeared. This occurrence occurred during the Cretaceous period.
What caused the Western Interior Seaway to disappear?
The Western Interior Seaway Can Be Traced Back To: During the time period known as the Cretaceous, the ancient tectonic plates known as the Farallon and Kula were in the process of being subducted beneath the North American Plate. This caused the land that was overlaying to twist, which resulted in the formation of a massive back-arc basin.
During the Cretaceous period, there was a string of sea level rises, sometimes known as incursions, which caused the basin to start filling with ocean water. The result of this was the creation of the Western Interior Seaway. The previously listed plates suffered partial melting as a result of the process of subduction.
The upwelling of the melt at the margin of the sea caused volcanic activity, which may be seen today as a sequence of ash layers (or bentonites) preserved in various strata. This activity is documented today. Stratigraphic correlation, also known as matching rocks of the same age, may be accomplished more effectively across the WIS with the help of these ash layers, which can be dated.
How deep was the Western Interior Sea?
Origin and the study of the geology – By the end of the Cretaceous period, Eurasia and the Americas had become geographically distinct from one another along the south Atlantic. At the same time, subduction had begun along the west coast of the Americas, which led to the Laramide orogeny, the first stage in the formation of the modern Rocky Mountains.
It’s possible to think of the Western Interior Seaway as a downwarping of the continental crust that occurred in front of the developing Laramide/Rockies mountain system. An arm of the Arctic Ocean moved south over western North America at the middle of the Cretaceous era, which resulted in the formation of the Mowry Sea, which was called after the Mowry Shale, which is an organic-rich rock formation.
This was the beginning of the first phase of the Seaway. When it was first formed, the Gulf of Mexico was an extension of the Tethys Sea in the southern hemisphere. After a period of time, the southern embayment eventually united with the Mowry Sea during the late Cretaceous period, producing the “full” Seaway and isolating the ecosystems in which land animals and plants evolved.
Each time a margin of land momentarily rose above the ocean along the original Transcontinental Arch, relative sea levels decreased. This caused the separated, divergent land populations to reunite, which allowed for the temporary mixing of younger species before the populations were once again divided.
At its widest point, the Western Interior Seaway was approximately 1,000 kilometers (620 miles) long and spanned from the Rockies to the Appalachians in the east. It is possible that even at its deepest point, it was just 800 or 900 meters (or 2,600 or 3,000 feet) deep, making it relatively shallow in comparison to oceans.
It received drainage from two major continental watersheds, one from the east and one from the west, which diluted its waters and brought resources in the form of eroded silt that created changing delta systems along its low-lying shores. On the eastern banks of the Seaway, there was very little sedimentation; on the other hand, the western barrier consisted of a strong clastic wedge that had eroded eastward from the Sevier orogenic band.
Therefore, the western coast was extremely changeable, since it was subject to changes in both the sea level and the supply of silt. The presence of carbonate deposits all across the Seaway provides evidence that this body of water once had a tropical climate and was rich in calcareous planktonic algae.
- The northwestern part of the state of Kansas has remnants of these deposits.
- One notable example is the chalk structure known as Monument Rocks, which is exposed and towers over the surrounding range land by more than 70 feet (21 meters).
- It has been deemed one of the Eight Wonders of Kansas in addition to its status as a National Natural Landmark.
It may be found around 25 miles (40 kilometers) to the south of Oakley, Kansas. The Western Interior Seaway passed through many phases of anoxia throughout the late Cretaceous period. During these times, the bottom water was oxygen-free and the water column was stratified.
Towards the end of the Cretaceous period, continued Laramide uplift hoisted the sandbanks (sandstone) and muddy brackish lagoons (shale), creating thick sequences of silt and sandstone that are still visible today as the Laramie Formation. At the same time, low-lying basins in between them gradually descended.
After passing through the Dakotas, the Western Interior Seaway eventually split in two and headed south into the Gulf of Mexico. This diminished and concluding phase of regressive development is frequently referred to as the Pierre Seaway. The region that is now Memphis was covered in water during the early Paleocene because sections of the Western Interior Seaway still inhabited areas of the Mississippi Embayment.
When did the Western Interior Seaway exist in North America?
The Western Interior Seaway existed some 100 million years before the current day, around the middle of the Cretaceous period. The Western Interior Seaway, also known as the Cretaceous Seaway, the Niobraran Sea, and the North American Inland Sea, was a massive inland sea that existed during the majority of the Cretaceous period and was responsible for dividing the continent of North America in half.
What formed the Western Interior Seaway?
The Western Interior Seaway, also known as the Cretaceous Seaway, the Niobraran Sea, and the North American Inland Sea, was a massive inland sea that existed during the majority of the early and middle Cretaceous Period and was responsible for dividing the continent of North America in half.
Other names for this sea include the Cretaceous Seaway and the Niobraran Sea. The collision of the Pacific tectonic plate with the North American tectonic plate resulted in the elevation of the Rocky Mountains, which led to the formation of the Seaway. The Western Interior Seaway is responsible for the existence of a great number of fossil sites in North America.
It was a sea that was relatively shallow and home to a wide variety of aquatic life, including some marine reptiles that were carnivorous, such as mosasaurs, ichthyosaurs, and plesiosaurs, which could grow up to 18 meters in length. There were several sharks, such as Squalicorax, and advanced bony fish, such as Pachyrhizodus and Enchodus, as well as the enormous Xiphactinus, which measured 18 feet in length and was a fish larger than any bone fish that is still alive today, as well as another monster called Ichthyodectes.
Other forms of marine life include invertebrates such as mollusks, ammonites, and squid-like belemnites, as well as plankton such as coccolithophores, foraminiferans, and radiolarians. The Cretaceous period gets its name from the chalky platelets that coccolithophores emitted. In most locations, the depth of the sea was most likely less than 200 meters (600 feet), and it had a bottom that was relatively flat, mushy, and oxygen-depleted mud that encouraged fossilization.
The so-called Kansas Chalk is one of the most well-known fossil locations in the world (Niobrara chalk formation). At a pace of nearly an inch of compacted chalk every 700 years, sediments were deposited at a rapid rate in what is now the state of Kansas, which is located in the middle of the sea.
- This area has yielded the discovery of some of the most exquisite fossils in the whole globe.
- Two instances of this would be the crinoid Uintacrinus and the fish Ichthyodectes.
- There are fossils of early birds that were discovered in the Western Interior Seaway.
- These fossils include the flightless Hesperornis, which had stout legs for swimming through the water and small wing-like appendages that were used for marine steering rather than flight; and the tern-like Ichthyornis, which was an early bird that had teeth.
Both of these birds had their origins in the Western Interior Seaway. The Pierre Shale is known to include fossils of the enormous clam Inoceramus. Paleontologists believe that the enormous size was an adaptation for living in murky bottom waters, where the animal would have needed a proportionally big gill area to be able to survive in anoxic circumstances.
Was the US once underwater?
Did you know that many of the sites that are presently included in the United States’ several national parks were at one time covered entirely by water? A massive inland sea existed more than one hundred million years ago, and it was responsible for dividing North America into two smaller landmasses.
Was Wyoming once under water?
During the time period known as the Precambrian, Wyoming was submerged beneath a warm, shallow sea. There, stromatolites began to develop. In the Medicine Bow Mountains, there are still some Precambrian stromatolites that have been preserved. There is a possibility that some geological formations in this area are a record of the actions of previous occupants of this sea that have been preserved as trace fossils.
In the beginning of the Paleozoic era, Wyoming was still submerged under a sea that was relatively shallow. During this historical period, the state was inhabited by brachiopods and trilobites. By the end of the Cambrian period, calcareous algae may be found in Wyoming. The Gros Ventre Formation was able to maintain significant quantities of this kind of algae.
During the time period known as the Ordovician, the region of Wyoming that is today dominated by the Bighorn Mountains was covered in a marine environment. There were ostracoderms swimming in this ocean. During the Silurian period, the sea level dropped, causing Wyoming to become landlocked, which led to the erosion of the local deposits.
The sea eventually made its way back into the state during the Devonian epoch, where it remained until the beginning of the Permian epoch, when it began to recede once more. During the Triassic period, the sea continued to recede from Wyoming’s coastline. As the sea level dropped, much of Wyoming became land that was covered by a coastal plain environment that was cut up by rivers.
In western Wyoming, during the Late Triassic period, dinosaurs walked the land, leaving behind tiny footprints that would eventually become fossilized. It has been determined that the ichnospecies Agialopus wyomingensis is responsible for leaving these traces.
Some of the red beds that date back to the Triassic period in Wyoming contain peculiar “scrape mark” trace fossils. These fossils were most likely left behind by aquatic animals. It has been hypothesized that turtles were responsible for the traces that were discovered in France. During the Jurassic period, a large portion of the state was made up of sand dunes.
During the Jurassic period, there was a return to the previous pattern of fluctuating sea levels. Oysters and belemnites both called the sea their home. On land, dinosaurs have been shown to have left behind a large number of footprints over floodplains.
In the time period known as the Jurassic, the region of Wyoming that is today known as Dinosaur Canyon was inhabited by archaic relatives of contemporary mammals and crocodilians. There is a possibility that pterosaurs were responsible for leaving imprints in the sediments that are now known as the Sundance Formation.
The ichnogenus Pteraichnus is where you’ll find them organized and categorized. Laramide Orogeny was the name given to the period of time during the Cretaceous when the state was through a period of mountain building activity. During the Cretaceous period, a large portion of Wyoming was covered by a sea that was known as the Western Interior Seaway.
- Enchodus was a frequent resident of the Western Interior Seaway that existed throughout the Cretaceous period in Wyoming.
- Its large fangs led to it being incorrectly referred to as “the sabre-toothed herring,” despite the fact that Enchodus was really a relative of current salmon.
- Although they give the impression of being threatening, it is more likely that these fangs were utilized to capture smaller food than to puncture larger species.
Because there were so many specimens of Enchodus, about one quarter of the fossils that are still present in the Pierre Shale layers of the state may be attributed to this species. Cimolichthys was the predator that tore into Enchodus. Cimolichthys was a cousin of current salmon, but it had a body shape that was more like a barracuda or a pike.
The Cimolichthys was a vicious hunter that targeted animals that were on the larger side. Its attempts to kill prey that was too huge for it often ended up being its own undoing. A Cimolichthys that was trying to eat a gigantic squid named Tusoteuthis longa ended up suffocating to death because the squid was too big for it to swallow in its whole and obstructed the fish’s gills.
Michael J. Everhart, a researcher working on the Western Interior Seaway, has referred to the species as “one of the oddest ‘death by overeating’ instances in the fossil record.” Dolichorhynchops osborni, a kind of plesiosaur, lived in the Cretaceous sea that formerly covered Wyoming at the time.
- This state has a greater number of sites containing its remnants than does Kansas.
- There was also the sea turtle, Toxochelys latiremis, that was there.
- One of the specimens was found to be connected with prehistoric excrement that had fish bones preserved within it.
- If these feces did really come from a Toxochelys, then the presence of fish in its diet would set it apart from all other sea turtles that exist today, none of which are known to consume fish as part of their diet.
During the Cretaceous period, Wyoming was home to a diverse population of animals, and dinosaurs called the region surrounding Powell their home. When compared to other western states with current deposits, the Late Cretaceous dinosaur footprint fossils that have been found in Wyoming are remarkably uncommon.
This might be because the local ancient habitats are not well adapted for the preservation of tracks, or it could simply be owing to the fact that scientists have not yet searched in the appropriate locations. The state of Wyoming was covered with thick vegetation during the earlier portion of the Cenozoic era.
The present-day vegetation in this area is likely to have left behind considerable coal deposits. The low-lying regions in between the local mountains eventually became home to enormous lakes. The fossil that represents this condition is called Knightia eocaena, and it formerly lived in one of these lakes.
- Volcanic eruptions were generated by the ongoing process of mountain formation in the Rocky Mountains, which at the time was still in progress.
- The Big Horn Basin was home to a diverse collection of mammalian species throughout the Paleocene epoch.
- During the time period known as the Eocene, Wyoming was home to a number of major freshwater lakes.
This lake supported the growth of the chlorella-like algae known as Chlorellopsis. The sediments that were deposited along the banks of these lakes have preserved its remains to this day. Not far from Bridger, in the Green River deposits, you’ll find some of the world’s most well-preserved examples of freshwater fish fossils.
- Diatryma was an enormous, flightless bird that stood seven feet tall and wandered the country.
- Creodonts and a diverse range of insects lived on land in Eocene Wyoming, and their fossils have been found in the area of Henry’s Fork, which is not too far from the state line with Utah, which is a neighboring state.
The Bridger Basin was once inhabited by a wide variety of animals, including whales, whale-like cousins of camels, carnivorans, elephants, horses, monkeys, rodents, and Uintatherium. Volcanic activity occurred over much of the state during the Quaternary period, and glaciers left substantial deposits in the western part of the state.
Did Oklahoma used to be an ocean?
During the Ordovician Period, which occurred around 455 million years ago, Oklahoma was covered by rocks that originated in a sea. In the distant past, the area that is now the state of Oklahoma was covered by shallow seas. Today, Oklahoma is a landlocked state that is located far from the shore.
How long did the Western Interior Seaway last?
02-24-2018 I’ve been working on a fossil of an old shark for the better part of a month now. The shark belongs to the genus Ptychodus, which derives its name from the Greek phrase for “folded teeth.” The unusual teeth of the species, which are more suited for breaking shells than shredding flesh like traditional shark teeth, are where the term “shell crusher” originates from.
- The person from whom I have been carefully removing rock layers has exposed a face that is bizarre and contorted in appearance.
- On either side of plates of rounded, blunt teeth are two eye sockets that have been spread outward.
- Although some of the tooth plates appear to be bent and a few teeth are dispersed throughout the skull, the teeth give the impression that they were formerly organized in perfect rectangles.
The entirety of the shark fossil has been smoothed off, and at this point all that can be seen of it is a black etching in an otherwise light stone. The body is comprised of multiple shattered chunks of rock that are laid out adjacent to one another on a table.
There is a lengthy column of vertebrae that runs along the back in the same general layout as in a living shark, with the exception of a pair of vertebrae that have slipped out of position and formed a depression in the middle of the back. On either side of the body, two fins expose delicate hand-like cartilage skeleton structures.
These structures are revealed by two fins. There is a patch of delicate skin that illuminates the tail, but it is cut off prematurely by chunks of rock on each side that were simply not gathered at the quarry where the Ptychodus was discovered. This is the evidence left behind from the history of the Earth.
- The history of the globe can be stitched together from shattered rock and warped fossilized skeletons using sediment, chemistry, physics, genetics, biology, and geology to show what we know and what we may know about the planet’s history.
- Although this specific species of shark was identified in Texas, the genus Ptychodus was first uncovered in the state of Kansas.
It’s possible that some people may picture wheat fields or Dorothy and Toto and conclude that Kansas is not the most likely spot to find a shark. However, Kansas as it existed during the Late Cretaceous period of the Western Interior Seaway is not even quite comparable to Kansas as it exists now.
What is today known as the United States of America was approximately divided in half by the Western Interior Seaway. At one point in geologic history, the states of Colorado and Wyoming were entirely submerged in water. The majority of the southern region, including the entirety of Texas, was submerged, and the geographic center of Utah and Kansas were located on opposing sides of the sea.
In the little museum in Hill City, South Dakota, that is connected to the Black Hills Institute of Geological Research, where I used to work, there is a skeleton of a very large turtle that is displayed. The turtle is dangling from the ceiling, giving the impression that it is swimming through the air above your head as it peers down inquisitively with its head angled slightly downward.
The reptile is a marine species that has a striking resemblance to the bones of live leatherback sea turtles. The South Dakota turtle belonging to the genus Archelon and current Leatherbacks are mostly distinguishable from one another by their sizes and geographic distributions. Imagine for a moment if the biggest sea turtle ever recorded was found in South Dakota, a state that is almost entirely landlocked.
The biggest known specimen of an Archelon is around 13 feet in length and 16 feet in width. Leatherback sea turtles reach adulthood at a length of roughly 6-7 feet and a weight of approximately 500-1500 pounds. Archelon and Ptychodus both swam in the vast inland sea that Archelon called home.
- At its deepest point, the sea was 2,500 feet deep, and it was inhabited by a wide variety of strange and unusual animals.
- The sea extended from the Gulf of Mexico all the way through Canada and into the Arctic seas.
- Another kind of fish that I worked on was called Xiphactinus, and it lived in the Western Interior Seaway.
At 18 feet long, it was the largest bony fish genus that had ever been discovered. Most of the time, Xiphactinus seems like a regular fish; yet, it has protruding, pencil-like fangs that may cause those who are easily influenced to rethink their decision to swim in the water.
There was a time when our continent was traversed by very bizarre animals such as the long-necked plesiosaurs that had snakes for necks. These creatures resembled sea dragons from folklore. Both flying reptiles like the well-known pterodactyl and aquatic birds like swimming birds fished in the Western Interior Seaway.
There was a subtropical climate along the Western Interior Seaway all the way up to Wyoming. Although there is some evidence that the movement of the North American continent through time contributed to a warmer temperature, there is considerable evidence that the entire planet was warmer.
- In the past, Antarctica was not the completely frozen wasteland that it is now; rather, it was a land where dinosaurs were free to roam.
- The Western Interior Seaway was active for around 60 million years, which is longer than the existence of the human race.
- However, all things must eventually come to an end, and the last time we observed evidence of the seaway was 70 million years ago.
It is probable that climate change caused the inner seaway to become dry and kept its waters frozen in the poles. Because the history of the world is one of cycles rather than one that is fully linear, one may ask if the seaways that were previously ancient may also be part of the future.
How long ago was New Mexico underwater?
Between 280 and 250 million years ago, a shallow sea called the Permian Sea covered a portion of the southwestern United States, including what is now southern New Mexico. This sea was known as the Permian Sea.
What did North America look like 50 million years ago?
The polar ice sheets were far smaller, and the sea level was significantly higher. In the western section of North America, the climate was warm and humid, and the Rocky Mountains were only beginning to form. Nebraska had a climate similar to that. This graphic illustrates what the continent of North America looked like fifty million years ago.
What was one of the biggest marine reptiles in the Western Interior Seaway?
During the time of the Cretaceous, a group of marine reptiles known as the Mosasaurs would have been prevalent.
When did the Western Interior Seaway end?
Around 70 million years ago, during the very latter stages of the Cretaceous period, the Western Interior Seaway was moved by the steady elevation of the continent, and it finally disappeared. This occurrence occurred during the Cretaceous period.
When did Shallow seas cover Western Canada?
A warm, shallow interior sea that stretched from the Arctic Ocean to the Gulf of Mexico and was at least 1000 miles wide at the present-day boundary between Canada and the United States once covered the mid-continent 80 million years ago. This sea extended from the Arctic Ocean to the Gulf of Mexico.
Unstable mountains had just emerged to the west of the area. During the process of volcanoes forming, there were numerous earthquakes. Both wind and water currents were responsible for transporting volcanic ash and fine muds, which eventually accumulated as sediment at the ocean floor. WESTERN INTERIOR SEAWAY During the Cretaceous period, the majority of what is now the province of Manitoba was submerged beneath a warm, shallow sea that was known as The Western Interior Seaway.
Temperatures around the globe were hotter, sea levels were higher, and there was considerably less or even no permanent ice present at the poles. The sea rose up and overwhelmed the low-lying parts of the continents located all over the earth. The Seaway spanned the all of North America, from the southern Gulf of Mexico all the way up to the Arctic Circle.
It effectively cut the continent in half, creating two enormous islands, and it did so for millions of years. CLIMATE The sea, also known as the “Mid-Continental Seaway,” must have maintained a climate that was relatively consistent over a significant number of eons. The weather conditions of the past were very unlike to those of the present day.
There was not much of a difference in temperature from day to day or season to season. During the entirety of the Upper Cretaceous Period, the climate of the region never changed much from that of a tropical or subtropical climate. LIFE OF THE ANIMALS The animal life that existed throughout the Upper Cretaceous epoch was both abundant and diverse.
In these warm, salty waters, there was a dense population of various reptiles, such as four different kinds of mosasaurs, plesiosaurs, and huge sea turtles. In addition, there were at least two species of birds, known as Hesperornis and Ichthyornis, in addition to various kinds of fish, sharks, and squids.
There have been fossil discoveries of each of these types in the southern region of Manitoba, as well as in Saskatchewan and Alberta.
How are inlands formed?
The concept of a “inland sea” is difficult to pin down and must inevitably be left with some room for interpretation. According to the definition provided by the United States Hydrographic Office, a sea is “a body of water virtually or fully surrounded by land, particularly if it is quite vast or consists of salt water.” Heinrich Ries and Thomas L.
Watson, both geologic engineers, believe that an inland sea is nothing more than a very big lake. Inland seas are “more or less” disconnected from the ocean, according to Rydén, Migula, and Andersson of the Environmental Law Institute and Deborah Sandler of the same organization. It may be semi-enclosed, or it could be linked to the ocean by a narrow channel known as a “arm of the sea.” A bay is distinguished from an inland sea in that a bay is immediately connected to the ocean, but an inland sea is not.
Joseph Barrell is credited with having first using the phrase “epeiric sea” in 1917. He gave the definition of an epeiric sea as a body of water that is shallow and has a bottom that is inside the wave base (e.g., where bottom sediments are no longer stirred by the wave above).
A sea that is shallow, has a restricted link to an ocean, and is known as an epeiric sea. When a continental interior is flooded by marine transgression owing to rising sea levels or epeirogenic movement, an inland sea transforms into an epeiric sea for the first time. The term “epeiric sea” can also be used interchangeably with “epicontinental sea.” The seas that are located above a continental shelf are sometimes referred to as a “epicontinental sea.” This is not a geological phrase; it is a legal one.
Epeiric, epicontinental, and inland seas are all found on a continent itself, rather than in its immediate vicinity. Inland seas are not subject to the laws that govern international waters.