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Zhao J.,State Oceanic Administration | Zhang H.,State Oceanic Administration | Wu G.,State Oceanic Administration | Lu B.,State Oceanic Administration | And 2 more authors.
Acta Oceanologica Sinica | Year: 2014

Organic matter in cobalt-rich crust (CRC) from the Marcus-Wake Seamounts of the western Pacific Ocean, Sample CM1D03, has been analyzed to understand the source, geochemistry and mineralization of organic matter, and the mineralization environment. Biomarkers, including n-alkanes, isoprenoids, terpanes and sterols, have been detected in various layers of the CRC sample, using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The content of organic carbon (OC) and its stable isotope (δ13C), and the combined features of the biomarkers show that the mineralized organic matter in CM1D03 CRC was mainly derived from microorganisms and lower plankton (e.g., bacteria and algae, respectively) from marine surface water, with some terrestrial higher plant components. The ratio of chloroform bitumen “A”: OC was high in the CRC, between 10.51 and 20.66, showing significant migration characteristics of n-alkanes. Four mineralization categories of organic matter were recognized based on GC chromatograms of n-alkane molecules: (1) primitive type (bacteria and algae), which is characterized by moderately mature of n-alkanes preserving the original characteristics of the organic matter from microorganisms and lower plankton; (2) microbial degradation type, which is characterized by low contents of n-alkanes and rising baseline in the chromatogram, with the “bulge” being the products of organic matter by biodegradation; (3) organic matter migration type, which is characterized by low carbon number of n-alkanes with nC18 as the main peak carbon, without odd even predominance, and low concentrations of isoprenoids and hydrocarbons with high carbon number; and (4) organic matter hydrothermal type, which is characterized by relatively low concentration of small molecular weight n-alkanes, pristane, and phytane, accompanied by higher concentration of n-alkanes with carbon number greater than nC18. This study shows that biomarkers can record controlling factors of mineralization and their variation. © 2014, The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg. Source


Zhang H.,State Oceanic Administration | Zhao J.,State Oceanic Administration | Han Z.,State Oceanic Administration | Lu B.,State Oceanic Administration | And 2 more authors.
Acta Geologica Sinica | Year: 2013

A biostratigraphic study on calcareous nannofossils from the CM3D06 Co-rich ferromanganese crust from the Magellan seamounts in the northwestern Pacific enabled estimation of depositional age. The bio-imprinting of calcareous nannofossils and other fossil species suggests six age ranges for the nannofossils: late Cretaceous, late Paleocene, (early, middle, late) Eocene, middle Miocene, late Pliocene, and Pleistocene. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were used to test the Co-rich crusts, and a variety of molecular fossils were detected, such as chloroform bituminous "A" , n-alkane, isoprenoid and sterol. Peak carbon and molecular indices (such as ΣC23 -/ΣC24 +, CPI, Pr/Ph, Pr/nC17, Ph/nC18 and σ13C) indicate that the parent organic matter is dominated by marine phytoplankton and thallogen whereas there is little input of terrestrial organic matter. Researches on calcareous nannofossils, molecular fossils and molecular organic geochemistry data reveal that the Paleocene/Eocene (P/E) global event is recorded in the cobalt- rich crusts from the northwestern Pacific Ocean. A succession of biomes can be observed near the 85 mm boundary (about 55 Ma), i.e., the disappearance of the late Cretaceous Watznaueria barnesae and Zigodicus spiralis, and Broisonia parka microbiotas above the P/E boundary, and the bloom of Coccolithus formosus, Discoaster multiradiatus, Discoaster mohleri and Discoaster sp. below the boundary. Typical parameters of molecular fossils, such as saturated hydrocarbon components and carbon-number maxima, Pr/Ph, Pr/C17, Ph/C18, distribution types of sterols, Ts/Tm ratios and bacterial hopane, also exhibit dramatic changes near the P/E boundary. These integrated results illustrate that the biome succession of calcareous nannofossils, relative content of molecular fossils and molecular indices in the cobalt-rich crusts near the 85 mm boundary faithfully record the P/E global event. ©[2013] Geological Society of China. Source


Zhang H.,CAS Qingdao Institute of Oceanology | Zhang H.,State Oceanic Administration | Han Z.,CAS Qingdao Institute of Oceanology | Han Z.,State Oceanic Administration | And 10 more authors.
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | Year: 2014

It enriches the geological history of Co-rich crusts (CRC) formation and the paleoceanography for us to understand the growth ages and periods of CRC. CRC samples collected from the Magellan and mid-Pacific seamounts were studied for the growth geological ages and periods by employing biostratigraphy (biological impressions). The primary formation geological ages and calcareous nannofossil assembly are different between CM3D06 CRC from the Magellan seamount and CB14 CRC from the mid-Pacific seamount. Based on the identification of calcareous nannofossil imprints and original fossil remains, five growth periods are determined for CM3D06 CRC, namely, Cretaceous (or older), Late Paleocene-Early Eocene, Middle-Late Eocene, Middle-Late Miocene, and Pliocene-Pleistocene, whereas four growth periods for CB14 CRC are determined as follows: Late Paleocene, Middle-Late Eocene, Middle Miocene, and Pliocene to Pleistocene. Regional characteristics for the nannofossil combination features of two CRC samples indicate the impact of oceanic environment on marine organisms and their adaptation. The unconformity of sub-layers and variation of structure and texture of the two CRC samples show that the main hiatus occurred during Oligocene. Source


Poltarukha O.P.,RAS Severtsov Institute of Ecology | Mel'Nik V.F.,State Scientific Center Yuzhmorgeologia
Zootaxa | Year: 2012

Barnacles (Cirripedia: Thoracica) taken in the Clarion-Clipperton region, central Pacific, during cruises of the Research Vessel Yuzhmorgeologia (2003, 2006, 2007, 2010, 2011) were studied. Three species, Amigdoscalpellum torbenwolffi Zevina, 1981, Arcoscalpellum radiatum Rao et Newman, 1972 and Catherinum tortilum (Zevina, 1973), were collected in five samples from depths of 4680-4877m. The data obtained considerably extend the previously known distributions of these three species. Copyright © 2012 · Magnolia Press. Source


Zhang H.S.,State Oceanic Administration | Hu J.,State Oceanic Administration | Zhao J.,State Oceanic Administration | Han Z.B.,State Oceanic Administration | And 5 more authors.
Science China Earth Sciences | Year: 2015

Two records of the crust laminae from the Marcus-Wake Seamounts and the Magellan Seamount were biostratigraphically studied. Based on biological imprints of the calcareous nannofossils, the geological ages of the two records were determined, with CM1D03 from the Marcus-Wake Seamounts being of late Paleocene to Pleistocene and CM3D06 from the Magellan Seamount of Late Cretaceous (more than 70.0 Ma). There are the obvious temporal-spatial differences in the initial formation period and enrichment characteristics of the cobalt-rich crusts of the two seamount chains and differences in the combination and distribution of microfossils in the inner crust layers between the seamounts. These differences are due to the adaptabilities of oceanic species in different environments. Ecological research was carried out in terms of population size of the calcareous nannofossils preserved in the crustal layers to discern the relation of the geological events at the Eocene-Oligocene (E/O) transition. The results show the transitions and recombination of species in the biotic community during the E/O transition obviously corresponded to 25 mm depth in the CM1D03 crust and 58 mm depth in the CM3D06 crust. The changes in biological species and the formation of particular ecological structures indicate the adaptive response of the paleo-biological community in the western Pacific Ocean to the global cold-climate events and the close correlation between the formation of the crust and the global climate change. © 2015, Science China Press and Springer-Verlag Berlin Heidelberg. Source

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