Characteristics of helium accumulation in the Guanzhong Basin, China
Min Dong a, b,*, Zong-xiu Wang a, b , Hui Dong a, c , Li-cheng Ma a, b , Lin-yan Zhang a, b
a
Institute of Geomechanics , Chinese Academy of Geological Sciences , China Geological Survey , Ministry of Natural Resources , Beijing 100081, China
b Key Lab of Shale Oil and Gas Geological Survey , Chinese Academy of Geological Sciences , China Geological Survey , Ministry of Natural Resources , Beijing 100081, China c
Xi’an Center , China Geological Survey , Ministry of Natural Resources , Xi’an 710054, China
A R T I C L E I N F O
A B S T R A C T
Article history:
Received 8 March 2019
Received in revised form 27 April 2019Accepted 7 May 2019
Available online 7 June 2019
Keywords:
Guanzhong Basin Fluid inclusions Thermochronology
Helium reservoir accumulation
Guanzhong Basin is located in the transitional zone between the Qinling orogenic belt and the Ordos plateau. Analyses of drill and geothermal wells depict that the Guanzhong Basin has abundant gas, and its major source rocks are the U-rich granites. In this study, the granitoid intrusive samples were collected from the Huashan, Baoji, Muhuguan rocks in Guanzhong Basin. A micro laser Raman spectrum examination was used to measure the composition of inclusion in the granite quartz fissures. The results depict that the inclusions include both gas-liquid and H 2O-NaCl-CO 2 inclusions and that their composition primarily includes H 2O and CO 2, with small amounts of CH 4, H 2 and H 2S. These inclusions can be classified into nearly-primary, early secondary, and late secondary inclusions, which have homogenization temperatures of greater than 430 °C, 330–370 °C and 170–230 °C, respectively, based on the inclusion measurements. Additionally, the apatite fission-track investigations of six samples, which were collected from the granites at Huashan, Baoji rocks and the southern margin of Muhuguan along with the Cretaceous Sigou Formation sandstones that are located in the northwestern margin of the Guanzhong Basin reveal that the northern Guanzhong Basin began to receive deposits as early as 84–69 Ma. This period was accompanied by the rapid uplift of the Qinling orogenic belt, which was followed by an uplift of the southern basin margin and the Qinling orogenic belt from 44–28 Ma. The authors obtained an age histogram and a probability density distribution of three sample points. The results show that the age spectra of the zircons in the Cretaceous Sigou Formation sandstones can be divided into four tectonic events. Combined with the ages of apatite fission tracks and zircon, the Guanzhong Basin has experienced five tectonic stages as follows: 28–84 Ma, 170–260 Ma, 280–510 Ma, 610–1200 Ma, and 1210–2870 https://www.doczj.com/doc/5512969543.html,ing the thermal chronology constraints, inclusion composition analyses, which include the homogenization temperature measurements, and regional burial history, this paper conclude that the early secondary inclusions are primarily composed of CO 2 and N 2, whereas the late secondary inclusions are composed of CH 4. Furthermore, this paper identify two periods of reservoir accumulation, out of which the later period is assumed to be the main accumulation period. Therefore, the period of the formation of the late secondary inclusion in the Guanzhong Basin and the Miocene era is observed to overlap with the main helium reservoir accumulation period.
?2019 China Geology Editorial Office.
1. Introduction
Helium, which is a rare inert gas extensively known as the “golden gas ”, is a scarce resource and is listed as a “group zero” element in the periodic table. Helium gas is colorless,tasteless, odorless and nontoxic. Its chemical properties render it to be extremely inactive and unable to burn and support
combustion. Thus, it rarely reacts chemically with any material. Due to its special physical and chemical properties,helium is mainly used in cutting-edge scientific and technological fields, such as aerospace, low-temperature superconducting, laser technology, infrared ray detection,nuclear, national defense and medical treatment. Therefore, it is regarded as an important strategic resource. Currently, the helium that is consumed across the world originates from helium-containing natural gas. The water-soluble helium that is observed in the Guanzhong Basin is considered to be a novel Helium resource. Previous studies (Honda M et al.,1982; Bottomley DJ et al., 1984; Lu JC et al., 2005; Liu JC et
* Corresponding author: E-mail address : dongminyf@https://www.doczj.com/doc/5512969543.html, (Min Dong).
doi:10.31035/cg2018103
2096-5192/? 2019 China Geology Editorial Office.
China Geology 2 (2019) 218?226
China Geology
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