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Twenty-five samples from selected cored intervals of problematic Triassic-Jurassic age from Sites 545, 546, and Hole 547B have been analyzed palynologically to aid age determination. Section 545-73-1 yielded a marine palynoflora of Sinemurian-Bajocian age. A palynoflora of nonmarine origin and assigned a Rhaetian-Hettangian age was recovered from halite in Section 546-18-2. Marine palynofloras of Hettangian-early Pliensbachian age were recovered from Sample 547B-24-CC to Section 547B-14-2. Sections 547B-28-1 to 547B-25-3 yielded impoverished nonmarine palynofloras to which only a general Rhaetian-Hettangian age could be given.

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The purpose of this study is to clarify the sedimentary history and chemical characteristics of clay minerals found in sediments deposited in the distal part of the Bengal Fan since the Himalayas were uplifted 17 m.y. ago. A total of seventy-eight samples were collected from three drilled cores which were to be used for the clay mineral analyses by means of XRD and ATEM. The results obtained from the analyses show that individual clay mineral species in the sediment samples at each site have similar features when the samples are of the same age, whereas these species have different features in samples of differing geological ages. Detrital clay minerals such as illite and chlorite were deposited in greater amounts than kaolinite and smectite during the Early to Middle Miocene. This means that the Himalayan uplift was vigorous at least until the Middle Miocene. In the Pliocene chemical weathering was more prevalent so that instead, in the distal part of the Bengal Fan, kaolinite shows the highest concentrations. This would accord with weaker uplift in the Himalayas. In the Pleistocene period, vigorous Himalayan uplift is characterized by illite-rich sediment in place of kaolinite. In the Holocene, smectite shows the highest concentration in place of the illite and kaolinite which were the predominant clay minerals of the earlier periods. Increasing smectite concentration suggests the Himalayan uplift to have been stable after the Pleistocene period. The smectite analyzed here is found to be dioctahedral Fe-beidellite, and it originated largely from the augite-basalt on the Indian Deccan Traps. The tri-octahedral chlorite is subdivided into three sub-species, an Fe-type, a Mg-type and an intermediate type. The mica clay mineral can be identified as di-octahedral illite which is rich in potassium. The chemical composition and morphology of each clay mineral appears to exhibit no change with burial depth in the sedimentary columns. This implies that there was no systematic transformation of clay minerals with time.

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Phycobiliproteins are a family of water-soluble pigment proteins that play an important role as accessory or antenna pigments and absorb in the green part of the light spectrum poorly used by chlorophyll a. The phycoerythrins (PEs) are one of four types of phycobiliproteins that are generally distinguished based on their absorption properties. As PEs are water soluble, they are generally not captured with conventional pigment analysis. Here we present a statistical model based on in situ measurements of three transatlantic cruises which allows us to derive relative PE concentration from standardized hyperspectral underwater radiance measurements (Lu). The model relies on Empirical Orthogonal Function (EOF) analysis of Lu spectra and, subsequently, a Generalized Linear Model with measured PE concentrations as the response variable and EOF loadings as predictor variables. The method is used to predict relative PE concentrations throughout the water column and to calculate integrated PE estimates based on those profiles.

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Here we present results of the first comprehensive study of sulphur compounds and methane in the oligotrophic tropical West Pacific Ocean. The concentrations of dimethylsuphide (DMS), dimethylsulphoniopropionate (DMSP), dimethylsulphoxide (DMSO), and methane (CH4), as well as various phytoplankton marker pigments in the surface ocean were measured along a north-south transit from Japan to Australia in October 2009. DMS (0.9 nmol/l), dissolved DMSP (DMSPd, 1.6 nmol/l) and particulate DMSP (DMSPp, 2 nmol/l) concentrations were generally low, while dissolved DMSO (DMSOd, 4.4 nmol/l) and particulate DMSO (DMSOp, 11.5 nmol/l) concentrations were comparably enhanced. Positive correlations were found between DMSO and DMSP as well as DMSP and DMSO with chlorophyll a, which suggests a similar source for both compounds. Similar phytoplankton groups were identified as being important for the DMSO and DMSP pool, thus, the same algae taxa might produce both DMSP and DMSO. In contrast, phytoplankton seemed to play only a minor role for the DMS distribution in the western Pacific Ocean. The observed DMSPp : DMSOp ratios were very low and seem to be characteristic of oligotrophic tropical waters representing the extreme endpoint of the global DMSPp : DMSOp ratio vs. SST relationship. It is most likely that nutrient limitation and oxidative stress in the tropical West Pacific Ocean triggered enhanced DMSO production leading to an accumulation of DMSO in the sea surface. Positive correlations between DMSPd and CH4, as well as between DMSO (particulate and total) and CH4, were found along the transit. We conclude that both DMSP and DMSO serve as substrates for methanogenic bacteria in the western Pacific Ocean.

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