View in EDS

Geology and ore-forming fluids of the Dayingezhuang gold deposit, Jiaodong Peninsula, eastern China: Implications for mineral exploration.

Saved in:
Bibliographic Details
Title: Geology and ore-forming fluids of the Dayingezhuang gold deposit, Jiaodong Peninsula, eastern China: Implications for mineral exploration.
Authors: Chai, Peng1 (AUTHOR) cx001chaipeng@163.com, Zhang, Hong-rui1 (AUTHOR) zhanghr@yeah.net, Dong, Lei-lei1 (AUTHOR), Zhang, Zhi-yu1 (AUTHOR)
Source: Journal of Geochemical Exploration. Sep2019, Vol. 204, p224-239. 16p.
Subjects: Gold ores, Prospecting, Quartz, Geology, Fluid inclusions, Fault zones, Fluid pressure
Geographic Terms: China
Abstract: The Dayingezhuang deposit is a representative large gold deposit within the Zhao-Ping fault zone in Jiaodong Peninsula, eastern China, and contains gold reserves of 170 t with an average grade of 3.10 g/t. The orebodies are hosted in the Late Jurassic Linglong granite intrusion and are Jiaojia-type (disseminated- or stockwork-style) ores. Mineralization and alteration are structurally controlled by the NE- to NNE-striking Linglong detachment fault located near the central section of the regional Zhao-Ping fault zone. Mineralization can be divided into primary and supergene periods. The primary period can be further divided into four hydrothermal stages: I) pyrite–(K-feldspar)–sericite–quartz; II) auriferous quartz–pyrite; III) quartz–gold–polymetallic sulfides; and IV) quartz–carbonate. Gold was mainly deposited in the second and third stages. Three types of fluid inclusion were observed (in decreasing order of abundance): AC-type (aqueous–carbonic), A-type (aqueous), and PC-type (pure carbonic). Based on petrographic, microthermometric, and laser Raman spectroscopic analyses of these fluid inclusions, three types of fluid inclusion assemblage (FIA) were identified in the quartz grains: FIA1 (AC- and PC-type), FIA2 (AC-, PC- and A-type), and FIA3 (A-type). First stage quartz grains contain mainly FIA1-type inclusions, with trapping temperatures of 305–388 °C and salinities of 4.28–8.51 wt% NaCl equivalent. Quartz grains that formed in the second and third mineralization stages contain all three types of FIA. Second stage inclusions homogenize completely at temperatures of 219–317 °C and have salinities of 1.56–11.12 wt% NaCl equivalent, while third stage inclusions homogenize completely at temperatures of 195–319 °C and have salinities of 2.73–13.33 wt% NaCl equivalent. In contrast, quartz grains that formed during the last mineralization stage contain mainly FIA3-type inclusions that yield homogenization temperatures of 126–233 °C and salinities of 0.48–6.72 wt% NaCl equivalent. The microthermometric data indicate that the ore-forming system evolved from a CO 2 -rich mesothermal fluid into a CO 2 -poor fluid. The existence and microthermometric characteristics of AC-, PC-, and A-type inclusion assemblages (FIA2) within a single thin section of grains that formed during the second and third stages show that ore fluids underwent unmixing during the syn -ore mineralization stages, due to pressure and temperature fluctuations. The microstructural deformation of auriferous samples indicates that both ductile and brittle deformation occurred during the syn -ore mineralization. Based on the inference that fluids were immiscible in FIA2, trapping pressures during ore formation are estimated at 127–276 MPa. Assuming a fluid pressure regime controlled by fault-valve activity, these pressures are equivalent to a mineralization depth of 9.2–14.0 km. The depth to which erosion occurred in the study area has been calculated as ~10.3 km since the formation of the deposit at 130 Ma, which suggests good prospecting potential for gold at depth in Dayingezhuang. Unlabelled Image • Three types of FIA were identified in the Dayingezhuang deposit. • Large scale fluid immiscibility did take place in syn -ore stages. • Metallogenic depth vs. erosion depth can be used for prospecting potential. • The space with deep gold exploration is expectable at Dayingezhuang gold. [ABSTRACT FROM AUTHOR]
Copyright of Journal of Geochemical Exploration is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
FullText Text:
  Availability: 0
Header DbId: egs
DbLabel: Engineering Source
An: 137372685
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Geology and ore-forming fluids of the Dayingezhuang gold deposit, Jiaodong Peninsula, eastern China: Implications for mineral exploration.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Chai%2C+Peng%22">Chai, Peng</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> cx001chaipeng@163.com</i><br /><searchLink fieldCode="AR" term="%22Zhang%2C+Hong-rui%22">Zhang, Hong-rui</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> zhanghr@yeah.net</i><br /><searchLink fieldCode="AR" term="%22Dong%2C+Lei-lei%22">Dong, Lei-lei</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Zhang%2C+Zhi-yu%22">Zhang, Zhi-yu</searchLink><relatesTo>1</relatesTo> (AUTHOR)
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+Geochemical+Exploration%22">Journal of Geochemical Exploration</searchLink>. Sep2019, Vol. 204, p224-239. 16p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Gold+ores%22">Gold ores</searchLink><br /><searchLink fieldCode="DE" term="%22Prospecting%22">Prospecting</searchLink><br /><searchLink fieldCode="DE" term="%22Quartz%22">Quartz</searchLink><br /><searchLink fieldCode="DE" term="%22Geology%22">Geology</searchLink><br /><searchLink fieldCode="DE" term="%22Fluid+inclusions%22">Fluid inclusions</searchLink><br /><searchLink fieldCode="DE" term="%22Fault+zones%22">Fault zones</searchLink><br /><searchLink fieldCode="DE" term="%22Fluid+pressure%22">Fluid pressure</searchLink>
– Name: SubjectGeographic
  Label: Geographic Terms
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22China%22">China</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: The Dayingezhuang deposit is a representative large gold deposit within the Zhao-Ping fault zone in Jiaodong Peninsula, eastern China, and contains gold reserves of 170 t with an average grade of 3.10 g/t. The orebodies are hosted in the Late Jurassic Linglong granite intrusion and are Jiaojia-type (disseminated- or stockwork-style) ores. Mineralization and alteration are structurally controlled by the NE- to NNE-striking Linglong detachment fault located near the central section of the regional Zhao-Ping fault zone. Mineralization can be divided into primary and supergene periods. The primary period can be further divided into four hydrothermal stages: I) pyrite–(K-feldspar)–sericite–quartz; II) auriferous quartz–pyrite; III) quartz–gold–polymetallic sulfides; and IV) quartz–carbonate. Gold was mainly deposited in the second and third stages. Three types of fluid inclusion were observed (in decreasing order of abundance): AC-type (aqueous–carbonic), A-type (aqueous), and PC-type (pure carbonic). Based on petrographic, microthermometric, and laser Raman spectroscopic analyses of these fluid inclusions, three types of fluid inclusion assemblage (FIA) were identified in the quartz grains: FIA1 (AC- and PC-type), FIA2 (AC-, PC- and A-type), and FIA3 (A-type). First stage quartz grains contain mainly FIA1-type inclusions, with trapping temperatures of 305–388 °C and salinities of 4.28–8.51 wt% NaCl equivalent. Quartz grains that formed in the second and third mineralization stages contain all three types of FIA. Second stage inclusions homogenize completely at temperatures of 219–317 °C and have salinities of 1.56–11.12 wt% NaCl equivalent, while third stage inclusions homogenize completely at temperatures of 195–319 °C and have salinities of 2.73–13.33 wt% NaCl equivalent. In contrast, quartz grains that formed during the last mineralization stage contain mainly FIA3-type inclusions that yield homogenization temperatures of 126–233 °C and salinities of 0.48–6.72 wt% NaCl equivalent. The microthermometric data indicate that the ore-forming system evolved from a CO 2 -rich mesothermal fluid into a CO 2 -poor fluid. The existence and microthermometric characteristics of AC-, PC-, and A-type inclusion assemblages (FIA2) within a single thin section of grains that formed during the second and third stages show that ore fluids underwent unmixing during the syn -ore mineralization stages, due to pressure and temperature fluctuations. The microstructural deformation of auriferous samples indicates that both ductile and brittle deformation occurred during the syn -ore mineralization. Based on the inference that fluids were immiscible in FIA2, trapping pressures during ore formation are estimated at 127–276 MPa. Assuming a fluid pressure regime controlled by fault-valve activity, these pressures are equivalent to a mineralization depth of 9.2–14.0 km. The depth to which erosion occurred in the study area has been calculated as ~10.3 km since the formation of the deposit at 130 Ma, which suggests good prospecting potential for gold at depth in Dayingezhuang. Unlabelled Image • Three types of FIA were identified in the Dayingezhuang deposit. • Large scale fluid immiscibility did take place in syn -ore stages. • Metallogenic depth vs. erosion depth can be used for prospecting potential. • The space with deep gold exploration is expectable at Dayingezhuang gold. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of Geochemical Exploration is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=137372685
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1016/j.gexplo.2019.06.001
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 16
        StartPage: 224
    Subjects:
      – SubjectFull: Gold ores
        Type: general
      – SubjectFull: Prospecting
        Type: general
      – SubjectFull: Quartz
        Type: general
      – SubjectFull: Geology
        Type: general
      – SubjectFull: Fluid inclusions
        Type: general
      – SubjectFull: Fault zones
        Type: general
      – SubjectFull: Fluid pressure
        Type: general
      – SubjectFull: China
        Type: general
    Titles:
      – TitleFull: Geology and ore-forming fluids of the Dayingezhuang gold deposit, Jiaodong Peninsula, eastern China: Implications for mineral exploration.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Chai, Peng
      – PersonEntity:
          Name:
            NameFull: Zhang, Hong-rui
      – PersonEntity:
          Name:
            NameFull: Dong, Lei-lei
      – PersonEntity:
          Name:
            NameFull: Zhang, Zhi-yu
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 09
              Text: Sep2019
              Type: published
              Y: 2019
          Identifiers:
            – Type: issn-print
              Value: 03756742
          Numbering:
            – Type: volume
              Value: 204
          Titles:
            – TitleFull: Journal of Geochemical Exploration
              Type: main
ResultId 1