Microstructural study on the process of silicification and the formation of fossil woods.
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants |
|Research Institution||Shimane University |
FURUNO Takeshi Faculty of Agriculture, Shimane University, 農学部, 助教授 (90032573)
SUZUKI Noriyuki Faculty of Science, Shimane University, 理学部, 助手 (00144692)
WATANABE Teruo Faculty of Science, Shimane University(the present: Hokkaido Univ.), 理学部, 助教授 (40135900)
|Project Period (FY)
1986 – 1987
Completed (Fiscal Year 1987)
|Budget Amount *help
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,400,000 (Direct Cost: ¥1,400,000)
|Keywords||Fossil wood / Silicified wood / Silicification / Process of silicification / Silica minerals / Silica replacement by cell wall / Resinous contents / 化石木の組織構造 / 珪化過程 / 化石木の形成 / 樹脂細胞の樹脂様物質の化石化|
Microstructural study on the formation of fossil wood and the process of silicification was conducted and the following results were obtained.
1. Process of silicification
From the experimental results, the process of silicification in the structureof silicified wood was summarized as follows:
(1) Silica mineral types in the cell lumen Opal A infiltrated into the woodwas deposited in an acidic environment, and the disordered silica mineral(opal CT) was formed. Afterwards silica minerals in the cell lumens were converted into quartz.
(2) Penetration and replacement of silica in the cell wall Silica mineral penetrated only into the lumen but not into the wall, and some of the wall substance was replaced by silica. Finally, most or all of the wall was replaced by silica.
(3) Organic carbon remaining in the wall
The good preservation of prganic material in the wall with a filling of silica only in the lumen was seen. Organic material decreased in proportion to the replacement of silica with wall
(4) Cell morphology
As the replacement of the walls by silica progressed and organic carbon in the wall decreased, the structure of cells is lost, but traces of their original forms still remains.
(5) Organic carbon remaining in the resinous contents
Even in specimens as old as the Miocene, organic carbon of the resinous contents of resin cells was found to be well preserved and become fossilized.
2. Role of resinous content in silicification
Resinous contents proved to have abundant aliphatic structures and to be structurally similar to amber. They plays an important role in silicification by attaching hydrophobic structures and acidic functional groups which lower the pH of the environment. Silicic acids penetrating into the wood are easily deposited around resinous contents so that the replacement of silica by the walls is enhanced.
3. Artificial synthesis of silicified wood
In the experiment that the recent wood(Hinoki) was soaked in the reaction system of silicic acids for more than several months, long angular or cylindrical forms of silica mineral were formed in wood cells such as tracheids and ray parenchyma cells. Less
Report (2 results)
Research Products (11 results)