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Seafloor under the hypothesized East Asian Sea vanished 10 million years ago as surrounding plates swallowed it up, according to new reconstructions of plate tectonics in the Philippine Sea region.

Seafloor under the hypothesized East Asian Sea vanished 10 million years ago as surrounding plates swallowed it up, according to new reconstructions of plate tectonics in the Philippine Sea region.

Lava-covered piece of continent is an ancient remnant, left over from the break-up of the supercontinent, Gondwana, which started about 200 million years ago.

Surprising Christmas Island Seamounts Mystery Solved.

On a remote tropical island in the Indian Ocean lies a geologic enigma. Some 4 million years ago, volcanic eruptions on the seabed piled lava upward almost two miles, until it broke above the waves. Then it kept piling up, to form what is now the craggy, densely vegetated island of Anjouan. Like all islands formed this way (think Hawaii) Anjouan is 100 percent dark volcanic basalt. Except for the part that is not. That part-a mass of pure white quartzite, apparent remains of a river or beach deposit formed on some faraway, long-ago continent-is not supposed to be there.

Geological Insights from Malaysia Airlines Flight MH370 Search.

Detailed imaging of the seafloor used to search for Malaysia Airlines flight MH370 is providing unprecedented insights into the geological development of the Indian Ocean.

Researchers find more evidence of 14th-century tsunami that wiped out Sumatran villages.

New research suggests the source of morphologic variation on mid-ocean ridges might be deeper than scientists thought.

Expedition SO307 Investigates the Geology and Biology of the Madagascar Ridge.

A new CURTIN University study investigating the complex evolution of two iconic Western Australian landmarks, has traced their transformation over thousands of years and offers a glimpse into their future.

Marine hardgrounds are common features during the Phanerozoic and hold significant sedimentological and economic importance. Intriguingly, previous reports of marine hardgrounds are concentrated in Calcite Seas, despite elevated seawater CaCO3 saturation in Aragonite Seas. This bias remains unclear in origin and requires more hardground information, especially from Aragonite Seas, for clarification. Well-developed Holocene marine hardgrounds at Abu Dhabi provide such a good opportunity. This study focused on a widespread and well-developed Holocene marine hardground layer at Abu Dhabi and analyzed its chronostratigraphy, petrology, mineralogy, and geochemistry. The results show that the studied hardground layer can be divided into lower and upper parts, characterized by planar upper surface and no borings nor encrustations. The lower part (with a 14C age of 6945−6368 cal yrs BP) formed during a sea-level transgression, and is laterally traceable along both a seaward and a landward direction. The upper part (with a 14C age of 5871−5452 cal yrs BP) formed during following sea-level transgression and/or stillstand, and disappears along a landward direction. Compared with the lower part, the upper hardground part is higher in δ13Ccarb and δ18Ocarb, supporting formation within more evaporated seawater settings depositing more high-Mg calcite. Both parts consist mainly of aragonite and high-Mg calcite in both carbonate grains and intergranular early-marine cement, but the lower hardground part contains more protodolomite within the early-marine cement. Moreover, an inverse relation in contents indicates a diagenetic transition from aragonite to dolomite during hardground formation and early diagenesis. Further, in combination with previous studies, the findings of this study confirm the rapidity, lateral diachronicity, and composite nature of Holocene marine hardgrounds with mineralogy controlled by sea-level changes. Similar hardgrounds may also be well developed i