Oil Inclusions Found in Skeleton Crystals of Quartz Indicated the Existence of Organic Matter Surrounding Ancient Growth Environments

Yuki Sugiura; Naoko Tobita; Takashi Tobita; Masaru Taga; Shu Nakachi; Kazumichi Yokota; Etsuko Yamada; Masanori Horie; Koichi Momma; Satoshi Matsubara

doi:10.1021/acsomega.3c00272

Oil Inclusions Found in Skeleton Crystals of Quartz Indicated the Existence of Organic Matter Surrounding Ancient Growth Environments

ACS Omega. 2023 Jun 5;8(24):21464-21473. doi: 10.1021/acsomega.3c00272. eCollection 2023 Jun 20.

Authors

Yuki Sugiura^{1

2}, Naoko Tobita³, Takashi Tobita³, Masaru Taga⁴, Shu Nakachi⁵, Kazumichi Yokota¹, Etsuko Yamada¹, Masanori Horie¹, Koichi Momma⁶, Satoshi Matsubara⁶

Affiliations

¹ Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14, Hayashi-cho, Takamatsu 761-3095, Kagawa, Japan.
² Research Planning Office, Headquarters of Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Umezono, Tsukuba 305-0035, Ibaraki, Japan.
³ Friends of Mineral, 4-13-18, Toyotama-naka, Nerima, Tokyo 176-0013, Japan.
⁴ Faculty of Agriculture, Ryukoku University, 1-5, Yokotani, Seta-Ohe, Ohtsu, Shiga, Japan 520-2194.
⁵ Natural History Lab., 120 Suoh-kata, Ohtsuki-Town, Hata, Kochi 788-0313, Japan.
⁶ Department of Geology and Paleontology, National Museum of Nature and Science, 4-1-1, Amakubo, Tsukuba 305-0005, Ibaraki, Japan.

Abstract

In nature, minerals record various origins and information for geology and geobiochemistry. Here, we investigated the origin of organic matter and growth mechanism of quartz with oil inclusion revealing fluorescence under short ultraviolet (UV) light, obtained from the clay vein at Shimanto-cho, Kochi, Shikoku Island, Japan. Geological investigation indicated that the oil-quartz was formed in hydrothermal metamorphic veins found in the late Cretaceous interbedded sandstone and mudstone. The obtained oil-quartz crystals are mostly double-terminated. Micro-X-ray computed tomography (microCT) indicated that oil-quartz crystals have various veins originating as skeleton structures along the quartz crystal {111} and {1-11} faces. Spectroscopic and chromatographic studies indicated that aromatic ester and tetraterpene (lycopene) molecules, which revealed fluorescence, were detected. Large molecular weight sterol molecules, such as C40, were also detected in the vein of oil-quartz. This investigation indicated that organic inclusions in mineral crystals would form with ancient microorganism culture environments.