Mineral Composition of Clay Fractions and Oxygen Vacancies in Silt-Sized Quartz in Soils on the Ka-Etsu Plateau, Fukui, Central Japan—Possibility of Eolian Dust Brought from Northern Asia as Parent Material of Soils

Abstract

Fine-to medium-textured soils are distributed on the Early Pliocene rocks and Pleistocene sandy sediments in the Ka-Etau plateau. The Jingaoka (JIN) soil was classified into Aluandic Andosols by WRB, and Low-humic Non-allophanic Kuroboku soils by the Fourth Committee for Soil Classification and Nomenclature of the Japanese Society of Pedology, although it was similar morphologically to Yellow-Brown Forest soils. On the other hand, the Tomitsu (TMI) and Yamamuro (YAM) soils were classified into Hyperdystri-Chromic Cambisols by WRB, and '&pic Yellow-Brown Forest soils by the Fourth Committee for Soil Classification and Nomenclature based on the morphological, physical and chemical propep ties. These soils were influenced considerably by the Akahoya tephra, especially the JIN soil. Based on the results of clay-mineralogical analysis and the measurement of the ESRsignal intensity associated with the oxygen vacancies in fine quartz, a large part of parent materials in the soils distributed on the Ka-Etsu plateau was derived from the eolian dust which was brought with the NW winter monsoon from the Precambrian sediments in the northern part of the Asian continent during MIS 2 (24-11 thousand years ago) at the Last Glacial Maximum. The parent materials of the fine-textured J I N soil located on the highest terrace near the rocky coastline were mostly composed of eolian dust, although the influenced of the Akahoya tephra was recognized. The parent materials of the TMI soil were admixed with a small amount of autochthonous materials from the sandy coast located windward. In the YAM soil which was located on the side of a hilly area distant from the coastline, the ESR-signal intensity in fine quartz was considerably low, and the admixture of autochthonous materials was also considered since the texture of this soil was coarser than that of the J I N and "MI soils. Key Words: clay mineralogy, eolian dust, ESR-signal intensity, 1.4 nm clay minerals, oxygen vacancy in fine quartz.

Origin of terra rossa on Amdo North Mountain on the Tibetan plateau, China: Evidence from quartz

“…One important effect is that dust minerals are taken into the surface soils and ocean (Jackson et al . 1971; Kitagawa et al . 2005; Pettke et al .…”

Dating of Sediments by physics methods Electron Paramagnetic Resonance (EPR) in the region of Iguape – Cananéia, Brazil.

“…Natural quartz shows several EPR signals. Therefore, the vacancies become paramagnetic (with an electron), this characteristic, a procedure was done to stipulate the relative number of found vacancies of oxygen [6,7].…”

“…The use of the E' 1 center in quartz depends on the treatment previously performed. It is observed that the EPR intensity of the center E' 1 of the thermal process used results in the number of oxygen vacancies found in quartz [7][8][9][10].…”