Mass fractionation during isotope measurement by mass spectrometer hinders the acquirement of true isotopic composition and tedious and complex mathematical calculations are required to correct for mass bias. This study provides a Matlab program named "IsotopeMaker" for convenient isotopic data reductions. IsotopeMaker has two main aspects of application. For in-situ LA-MC-ICP-MS isotopic analyses, IsotopeMaker can process Sr, Nd and Hf isotope data. For double spike data, IsotopeMaker provides a fast and convenient mass bias correction for all elements that have at least four isotopes. The visualization windows of IsotopeMaker make it easy to operate. Isotopic Sr, Nd and Hf data of a modern coral, a reference zircon and an in-house apatite and Mo isotopic data measured using the double spike method have been used to test the program capability.
The accurate identification of species is a prerequisite and guarantee for biodiversity conservation and evolutionary studies (Hong, 2016;Kemler, 2015;Trias-Blasi & Vorontsova, 2015). Traditional taxonomy and identification of species based on morphological features can be difficult due to a variety of factors, especially for biological materials that do not bear diagnostic characteristics (Mishra et al., 2016;Shen et al., 2019). DNA barcoding is an efficient molecular method that utilizes one or several short and standardized DNA regions for
The recently discovered Onnuri hydrothermal vent field (OVF) is a typical off-axis ultramafic-hosted vent system, located on the summit of the dome-like ocean core complex (OCC) at a distance of ∼12 km from the ridge axis along the middle region of the Central Indian Ridge (CIR). The plume chemistry with high methane anomaly was consistent with the precursor of hydrothermal activity; however, the fundamental characteristic of the OVF system, such as the hydrothermal circulation process and source of heat, remains poorly understood. Here, we focus on the geochemical features of surface sediments and minerals collected at and around the OVF region in order to better understand this venting system. The results reveal that the OVF sediments are typified by remarkably high concentrations of Fe, Si, Ba, Cu, and Zn, derived from hydrothermal fluid and S and Mg from seawater; depleted C-S isotope compositions; and abundant hydrothermally precipitated minerals (i.e., Fe–Mn hydroxides, sulfide and sulfate minerals, and opal silica). Notably, the occurrence of pure talc and barite bears witness to strong hydrothermal activity in the OVF, and their sulfur and strontium isotope geochemistry agree with extensive mixing of the unmodified seawater with high-temperature fluid derived from the gabbroic rock within the ultramafic-dominated ridge segment. The findings reveal that the OVF is a representative example of an off-axis, high-temperature hydrothermal circulation system, possibly driven by the exothermic serpentinization of exposed peridotites. Given the widespread distribution of OCC with detachment faults, furthermore, the OVF may be the most common type of hydrothermal activity in the CIR, although the paucity of data precludes generalizing this result. This study provides important information contributing to our understanding of the ultramafic-hosted hydrothermal vent system with a non-magmatic heat source along mid-ocean ridges.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.