Тип публикации: статья из журнала
Год издания: 2014
Идентификатор DOI: 10.1134/S1028334X1402007X
Ключевые слова: Arctic, basalts, dolerites, Earth's crust, Mendeleev Rise, seafloor sampling, Argon, Buildings, Geochronology, Igneous rocks, Isotopes, Silicate minerals, Structural geology, Underwater drilling, Isotopic dating, Sea floor, Basalt, argon-argon dating, diabase, Paleozoic, seafloor, Arctic Ocean, Mendeleyev Ridge
Аннотация: We present results of 40Ar/39Ar isotopic investigations concerning the dating of dolerites and basalts that were sampled during the Arctica-2012 polar expedition. Basalts were sampled by means of deep underwater drilling with wells up to 2 m in outcrops on the seafloor (basalts), and dolerite samples were obtained from the bottom oПоказать полностьюf an escarp of Mendeleev Rise using a manipulator on the research submarine. The analysis results of the obtained mono-mineral fractions (amphibole, plagioclase, pyroxene) from the studied rocks yielded an Early Paleozoic age of the dolerites and basalts from Mendeleev Rise. The oldest ages obtained for amphibole reach 471.5 ± 18.1 and 466.9 ± 3.3 Ma, which corresponds to the Early-Middle Ordovician. The isotopic composition of argon was measured on two mass spectrometers: the Micromass Noble Gas 5400 (UK) and the Thermo Scientific Argus (Germany). The determined Early Paleozoic age of igneous rocks of Mendeleev Rise and seismic data obtained during the last Russian expedition Arctica-2012 [2] let us suppose that this continental block of the Earth's crust has a Precambrian basement similar to the basement identified for the New Siberian islands including the De Long archipelago. © 2014 Pleiades Publishing, Ltd.
Журнал: Doklady Earth Sciences
Выпуск журнала: Vol. 454, Is. 2
Номера страниц: 97-101