Reykjavik is a smokeless city. Almost 100% of the electricity and the heating depends upon hydropower and geothermal energy.| J-STAGE
Palagonite ridge formed by subglacial eruption. Langjokull glacier in the background.| J-STAGE
Lakagigar fissure eruption. The 1783-84 Laka- gigar eruption resulted in a great famine, due to which Iceland lost 20% of its population.| J-STAGE
The braided course of the Jokulfell downstream from Hofsjokull.| J-STAGE
Geyser Strokkur. The geyser erupts at 5-10 minute intervals.| J-STAGE
Jokulsarlon lagoon. The Breidamerkurjokull glacier has been retreating since about 1920. The lagoon formed at the glacial front shows a yearly increase.| J-STAGE
Basaltic lava field, the Svartshengi geothermal power plant (right), and the Blue Lagoon (left).| J-STAGE
Normal fault at Thingvellir. The boundary between the North American plate on the left-hand side and the Eurasian to the right.| J-STAGE
Valley of Eldgja. The 934-40 Eldgja eruption occurred along a 75 km-long fissure.| J-STAGE
Dettifoss waterfall. The waterfall is 44 m high. The river water is rich in suspended sediments and the waterfall volume is the greatest in Iceland.| J-STAGE
Earth hummock. Earth hummocks are among the periglacial phenomena. The knoll covered with vegetation is |about 0.5 m high.| J-STAGE
Gullfoss waterfall. The two-step cataract has a total drop of 32 m.| J-STAGE

Latest Issue

Journal of Geography (Chigaku Zasshi), 2019 Vol.128 No.4

2019 Vol.128 No.4

The Prebiotic Chemical Reaction Process and the Emergence of the First Proto-life through Water–Rock Interactions

The cover figure schematically illustrates the production mechanism of various metallic proteins. Through water–rock interactions, a number of elements in rocks dissolve in water. This process is probably significant in supplying mineral-derived nutrients for proto-life. Such materials can evolve into more complex organic compounds by reacting and mixing with other building blocks of life originating from the atmosphere. The three main rock types exposed on the Hadean Earth were KREEP basalt, anorthosite, and komatiite. These rocks included anhydrous reducing minerals, such as schreibersite (Fe₃P) crystallized from the magma ocean. At approximately 4.37 Ga when the ABEL Bombardment (Part I) began, an oxidized atmosphere (CO₂–H₂O–N₂) formed to initiate water–rock interactions. These interactions supplied Fe²⁺, S, P, Ti, Zn, Mo from KREEP basalt, Ca, Cr, Mg, Fe²⁺, Mn³⁺ from anorthosite, and Fe²⁺, S, Ni, Mg from komatiite. The surface of each type of rock allowed metallic protein to form, utilizing elements extracted from the rock. In an energy-material circulation system driven by a natural nuclear reactor, more complex building blocks of life were generated. Through this process, the first proto-life emerged with the creation of three different types of bio-film-like community on each rock surface (Refer to Yoshiya et al., 2019).

(Shigenori MARUYAMA)

Reference

Yoshiya, K., Sato, T., Omori, S. and Maruyama, S. (2019): Birthplace of proto-life: Role of secondary minerals in forming metallo-proteins through water–rock interactions. Journal of Geography (Chigaku Zasshi), 128, 625–647. (in Japanese with English abstract)

Special Issue: The Hadean World (Part II): Preparing a Site for the First Life

Overview of the Special Issue
　“The Hadean World (Part II): Preparing a Site for the First Life”

Shigenori MARUYAMA, Yukio ISOZAKI,
Ken KUROKAWA and Toshikazu EBISUZAKI

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 479.

DOI:10.5026/jgeography.128.479

Introduction to the Special Issue
　“The Hadean World (Part II): Preparing a Site for the First Life”

Shigenori MARUYAMA, Yukio ISOZAKI,
Ken KUROKAWA and Toshikazu EBISUZAKI

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 485.

DOI:10.5026/jgeography.128.485

Serpentinite-hosted Hydrothermal System on the Early Earth (Original Article)

Hisahiro UEDA and Yusuke SAWAKI

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 491.

DOI:10.5026/jgeography.128.491

Review of the Nine Requirements for the Birthplace of Life
　and the Nuclear Geyser Model:
　The Only Possible Site for the Birthplace of Life on Hadean Earth (Review Article)

Shigenori MARUYAMA, Toshikazu EBISUZAKI and Ken KUROKAWA

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 513.

DOI:10.5026/jgeography.128.513

Geology around Natural Reactors and Birthplace of Eukaryotes (Review Article)

Yusuke SAWAKI, Tomohiko SATO, Wataru FUJISAKI,
Hisahiro UEDA, Hisashi ASANUMA and Shigenori MARUYAMA

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 549.

DOI:10.5026/jgeography.128.549

History of the Hadean “Living Microfossil” OD1 and Ultra-reducing Environments
　(Review Article)

Tomohiko SATO, Kazumi YOSHIYA and Shigenori MARUYAMA

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 571.

DOI:10.5026/jgeography.128.571

Compositions of Carbonate Rocks and Carbon Isotope Ratios of Graphite
　in Nulliak Supracrustal Rocks, Labrador:
　The Oldest Evidence for Life and Seawater Composition (Original Article)

Satoshi YOSHIDA and Tsuyoshi KOMIYA

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 597.

DOI:10.5026/jgeography.128.597

Birthplace of Proto-life: Role of Secondary Minerals
　in Forming Metallo-proteins through Water‒Rock Interactions (Review Article)

Kazumi YOSHIYA, Tomohiko SATO,
Soichi OMORI and Shigenori MARUYAMA

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 625.

DOI:10.5026/jgeography.128.625

The Role of Natural Radiation in the Evolution of Ancient Microbes (Review Article)

Issay NARUMI and Shigenori MARUYAMA

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 649.

DOI:10.5026/jgeography.128.649

A Significantly High He Isotopic Signature
　from the End-Paleozoic (250 Ma) Extinction-related Interval:
　For Detecting Ancient Extraterrestrial Fluxes through the Earth’s History
　since the Hadean (Original Article)

Naoto TAKAHATA, Tetsuji ONOUE, Yuji SANO and Yukio ISOZAKI

Journal of Geography (Chigaku Zasshi), 2019, 128(4), 667.

DOI:10.5026/jgeography.128.667

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