Apatite fission-track study on the thermo-tectonic history of the Huainan Coalfield in Anhui Province, China: Tectonic implications for the potential coalbed methane resource |
| |
作者单位: | Key Laboratory of Marginal Sea Geology, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China |
| |
摘 要: |
|
关 键 词: | apatite fission-track (AFT) thermo-tectonic history coalbed methane (CBM) Huainan Coalfield |
收稿时间: | 6 June 2005 |
Apatite fission-track study on the thermo-tectonic history of the Huainan Coalfield in Anhui Province,China: Tectonic implications for the potential coalbed methane resource |
| |
Authors: | Xiaoming Li Gelin Peng |
| |
Institution: | Key Laboratory of Marginal Sea Geology, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences Guangzhou 510640, China |
| |
Abstract: | Coalbed methane (CBM) is a kind of burgeoning and enormously potential clean energy resource, and the temperature of the thermogenic
CBM generation is close to that of the partial annealing zone (PAZ) of apatite fission tracks (AFT). In this study the thermo-tectonic
history of the Huainan Coalfield and the potential CBM resource were studied and discussed by using the AFT method.
The AFT data indicate that the apparent ages of AFT vary from 45.5 to 199.1 Ma. They are younger than the ages of their host
strata (255–1800 Ma) except one sample, and the single-grain ages of AFT can be classified as a single age group for each
sample. In combination with the geological setting, modeling results of the AFT ages, average lengths, and the thermal history
based on the AFT single-grain ages and length distributions, some preliminary conclusions can be drawn as follows: (1) at
least three thermo-tectonic events (in the periods of ~240, 140 and 80 Ma, respectively) have occurred in the study area since
the Late Paleozoic. The occurrence of both the first (during 240–220 Ma) and second (during 160–120 Ma) thermo-tectonic events
is possibly responsible for the establishment of the patterns of gas generation and reservoir formation. The second thermo-tectonic
event also led to slight accumulation of hydrocarbons and generation of thermogenic gas; (2) the AFT ages of most coal-bearing
strata lie between 50 and 70 Ma. They should represent the cooling ages and the ages of inferred uplift and denudation, as
well as the possible CBM release history. Therefore, the maximum burial depth of coal-bearing strata and the denudation thickness
of the overlying strata are over 3000 and 2000 m in the Upper Cretaceous and Paleogene series, respectively; and (3) subsequently,
a spot of secondary biogenic and scarcely thermogenic gas generation occurred due to negligible sedimentation during the Neogene
and Quaternary periods. Thus, it can be presumed that subsequent tectonism would destroy the CBM reservoir after its formation
in the Huainan Coalfield, especially in its structural development region. These AFT data may be helpful for a better understanding
of the thermo-tectonic history of the Huainan Coalfield, as well as of CBM generation, storage and release in the Huainan
Coalfield. |
| |
Keywords: | apatite fission-track (AFT) thermo-tectonic history coalbed methane (CBM) Huainan Coalfield |
本文献已被 维普 万方数据 SpringerLink 等数据库收录! |
|