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13-655: The Eromanga Sea was an inland sea across the Australian continent that formed in the Early Cretaceous . The sea extended from the Eromanga Basin northward to the Carpentarian Basin . Its southern extents comprised lagoons and rivers, and to the east it reached Surat Basin , a bay. The sea covered large parts of what is now Queensland and Central Australia at least four times during

26-419: A continent, not adjacent to it. The law of the sea does not apply to inland seas. In modern times, continents stand high, eustatic sea levels are low, and there are few inland seas. The Great Lakes , despite being completely fresh water , have been referred to as resembling or having characteristics like inland seas from a USGS management perspective. Lake Ontario is the only Great Lake connected to

39-440: Is "more or less" cut off from the ocean. It may be semi-enclosed, or connected to the ocean by a strait or "arm of the sea". An inland sea is distinguishable from a bay in that a bay is directly connected to the ocean. The term "epeiric sea" was coined by Joseph Barrell in 1917. He defined an epeiric sea as a shallow body of water whose bottom is within the wave base (e.g., where bottom sediments are no longer stirred by

52-475: Is a geologic event during which sea level rises relative to the land and the shoreline moves toward higher ground, which results in flooding. Transgressions can be caused by the land sinking or by the ocean basins filling with water or decreasing in capacity. Transgressions and regressions may be caused by tectonic events such as orogenies , severe climate change such as ice ages or isostatic adjustments following removal of ice or sediment load. During

65-503: Is complex and somewhat necessarily vague. The United States Hydrographic Office defined it as "a body of water nearly or completely surrounded by land, especially if very large or composed of salt water". Geologic engineers Heinrich Ries and Thomas L. Watson say an inland sea is merely a very large lake. Rydén, Migula, and Andersson and Deborah Sandler of the Environmental Law Institute add that an inland sea

78-666: The Arctic Ocean . The opposite of transgression is regression in which the sea level falls relative to the land and exposes former sea bottom. During the Pleistocene Ice Age , so much water was removed from the oceans and stored on land as year-round glaciers that the ocean regressed 120 m, which exposed the Bering land bridge between Alaska and Asia. Sedimentary facies changes may indicate transgressions and regressions and are often easily identified because of

91-697: The Atlantic Ocean below Niagara Falls . Modern examples might also include the recently (less than 10,000 years ago) reflooded Persian Gulf , and the South China Sea that presently covers the Sunda Shelf . At various times in the geologic past, inland seas covered central areas of continents during periods of high sea level that result in marine transgressions . Inland seas have been greater in extent and more common than at present. Marine transgression A marine transgression

104-584: The Cretaceous , seafloor spreading created a relatively shallow Atlantic basin at the expense of a deeper Pacific basin. That reduced the world's ocean basin capacity and caused a rise in sea level worldwide. As a result of the sea level rise, the oceans transgressed completely across the central portion of North America and created the Western Interior Seaway from the Gulf of Mexico to

117-592: The early Cretaceous . The present-day Winton Formation represents remnants of the river plains that filled the basin left by the Eromanga Sea. The formation is a major source of dinosaur fossils. The Great Artesian Basin (GAB) was flooded by the Eromanga Sea and filled with volcaniclastic sediments eroded from the Cordillera's volcanic arc . A theory was proposed explaining the abundance of opals in GAB. It

130-416: The oldest to the youngest rocks. A regression will feature the opposite pattern, with offshore facies changing to nearshore ones. The strata represent regressions less clearly, as their upper layers are often marked by an erosional unconformity . These are both idealized scenarios; in practice identifying transgression or regressions can be more complicated. For instance, a regression may be indicated by

143-484: The unique conditions required to deposit each type of sediment . For instance, coarse-grained clastics like sand are usually deposited in nearshore, high-energy environments; fine-grained sediments however, such as silt and carbonate muds, are deposited farther offshore, in deeper, lower energy waters. Thus, a transgression reveals itself in the sedimentary column when there is a change from nearshore facies (such as sandstone ) to offshore ones (such as marl ), from

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156-479: The wave above), as one with limited connection to an ocean, and as simply shallow. An inland sea is only an epeiric sea when a continental interior is flooded by marine transgression due to sea level rise or epeirogenic movement . An epicontinental sea is synonymous with an epeiric sea. The term "epicontinental sea" may also refer to the waters above a continental shelf. This is a legal, not geological, term. Epeiric, epicontinental, and inland seas occur on

169-656: Was suggested that the Eromanga Sea was shallow, cold, muddy, and stagnant, which have led to little amount of carbonates in sediments in the Eromanga Basin. However the abundance of iron-rich and organic sediments have led to an anoxic sub-seafloor well-suited for anaerobic, pyrite-producing bacteria. It was suggested that during the periods of uplift, erosion, and denudation opals were formed due to acidic oxidative weathering during 97 to 60 Ma. 26°S 140°E  /  26°S 140°E  / -26; 140 Inland sea What constitutes an "inland sea"

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