The missions of the Isotope Geochemistry Group are to acquire the high-quality data, to revolutionize in technical developments and applications of multidisciplinary sciences, and to maintain instruments as a world-class facility. Their main research topics are material circulation on the Earth, geological processes of water-rock interactions, regional to global environmental changes, and limits of subseafloor life. This has been done by combinations of isotope/elemental analysis with microstructural observation utilizing ultra-high resolution TEM.

Schematic figure of systemAtomic Resolution Analytical TEM JEM-ARM200F installation room

World-class facilities of the Isotope Geochemistry Group

Schematic figure of system
Micro Analysis Laboratory, Isotope Geochemistry Group
Deputy Group Leader Motoo Ito, Ph. D.
Senior Research Scientist Naotaka Tomioka, Ph. D.
Marine Works Japan Ltd. Yu Kodama Ph. D.
The Group have established one of the most comprehensive laboratories in Japan, consisting of TEM, FIB, SIMS, (MC)-ICP-MS and TIMS, to satisfy various needs of scientists, and to support the leading-edge researches.
This powerful and world-class facilities made the highest level on ultrahigh-sensitivity and ultrahigh-precision microanalysis.

Dr. Tomioka
We have adopted a JEOL JEM-ARM200F TEM to realize not only atomic resolution observation but also multiple analyses at one time. We study many precious samples derived from drilling cores or meteorites, so versatility in microanalyses (STEM, EDS, EELS and so on) was a very important factor to minimize structural damages or elemental loss in such samples. Also user interface of the JEM-ARM200F improved for exponentially high throughput was another reason for this choice.
The installation room for the JEM-ARM200F is equipped with the JEOL’s state-of-the-art environmental countermeasure systems which assure stable and quiet environmental conditions, best suited for high-end analytical instruments.

State-of-the-art environmental countermeasure systems

Dr. Ito
We have requested totally controlled operation room for the JEM-ARM200F to the JEOL because it features the highest spatial resolution in our lab and is the key instrument for microstructural observation at sub-nm spatial scale. JEOL proposed us a world best environmental countermeasure which is for vibration, magnetic field and temperature control. Thanks to these systems, the highly stable environment for TEM offers us not only very clear ultra-high-resolution image, but also high stability during prolonged observation and analysis, such as EDS and/or EELS elemental mapping at atomic resolution. We highly appreciate on this comprehensive environmental countermeasure.

Dr. Kodama
We have two FIB instruments installed in the same room. Similar to TEM, FIB requires stable environment for minute and precise sample processing.
The highly stable room environment assures troublefree processes when handling samples, and we are very pleased with this.

Dr. Tomioka
Our samples are often chemically and structurally heterogeneous. Therefore, precisely coordinated multi-microanalysis is required for investigating such samples. The unexpected change of target position may be caused by unstable environmental conditions. When observing samples collected from deep-drilled cores or the asteroid “ITOKAWA”, reanalysis is difficult due to their small sizes and amounts. The stable environmental condition realized by effective environmental countermeasure will be a great help to assure reliability of obtained data.
Schematic figure of system

Future perspective

JAMSTEC is now pursuing the deep ocean floor drilling projects, by the deep sea scientific drilling vessel "CHIKYU", aiming to collect materials from the Earth's mantle which no one has ever reached. Once this has been achieved, it will be an epoch-making event for geosciences.

Dr. Ito
This is our main reason for settling the powerful lab facility. We will conduct wide range of analysis on macro to nano scale, contributing to understand (1) Climate and Ocean Change, (2) Biosphere Frontiers, (3) Earth Connections: Deep Processes and Their Impact on Earth’s Surface Environment, and (4) Earth in Motion: Processes and Hazards on Human Time Scales. We are also preparing for analysis of valuable extraterrestrial materials obtained by "HAYABUSA 2" space craft which will return to the Earth in 2020 just after the Tokyo Olympics. Our investigation does not only understand the Earth’s past, but also predict the future of the Earth. Our research drives the technological breakthrough to solve global environmental issues, which may greatly contribute the sustainable development goals.

Dr. Tomioka
Various information such as origin of the Earth and the Space, past climate changes and evolution history of life could be obtained from drilled cores or asteroid samples. Each natural sample has their own characteristics, thus analytical scheme of the samples should be carefully determined. In order to eliminate uncertainty on analyzed data, observation under the totally stable environment is necessary. The Garnet Crystal image shown on the attached photo has been taken by nanometer scale observation of a meteorite sample. This technique allows us to obtain crystallographic and chemical characteristics of an extremely small region-of-interest. Therefore, it would be a core technology on sample analyses in both deep sea drilling by the IODP (International Ocean Discovery Program) and asteroidal sample return mission "HAYABUSA 2", by the JAXA (Japan Aerospace Exploration Agency).

Dr. Kodama
Besides the research activities at the KOCHI, I sometimes board on the "CHIKYU" and analyze drilled core samples. Once the "CHIKYU" sails out, the expedition will continue for months and the vessel sometimes stays at one drilling site on the ocean floor for a month. Normally, the core samples are analyzed or observed by onboard researchers during the expedition, because some samples deteriorate rapidly and the onsite analyses are necessary to decide the distribution of core samples for the following analyses. Unfortunately, due to unstable environment on shipboard, highly sensitive instruments such as TEM are not available on the vessel presently. We wish to observe such samples in a fresh status onsite, so it will be fantastic if analytical instruments such as electron microscopes could be installed on the vessel, assuring the same performance as installed onshore.

JAMSTEC was established in 1971 as the Japan Marine Science and Technology Center. JAMSTEC has the main objective to contribute to the advancement of academic research in addition to the improvement of marine science and technology by proceeding the fundamental research and development on marine, and the cooperative activities on the academic research related to the Ocean for the benefit of the peace and human welfare.
Schematic figure of systemDeposition core sample which records history of climate changes
Schematic figure of systemTEM image of special Garnet crystal generated under ultra-high pressure caused by collision of meteorite
Schematic figure of systemDeep sea drilling vessel “CHIKYU”

    Kochi Institute for Core Sample Research, KOCHI

    The KOCHI was established in October 2005 as the fifth domestic hub of the JAMSTEC. Since then, it has been highly valued worldwide as a unique research facility which consistently carries out drilled core processing, storage and advanced researches, leading the technology development on geological, biological and scientific drilling field. These activities are performed at "Kochi Core Center", which is co-operated with the Center for Advanced Marine Core Research, Kochi University.

    Kochi Institute for Core Sample Research, KOCHI