Journal ArticleDOI
Geochemical classification of terrigenous sands and shales from core or log data
Reads0
Chats0
TLDR
In this article, a means of relating geochemical concentrations to existing sandstone classification schemes is proposed based on three chemical parameters: the SiO2/Al2O3 ratio, the Fe 2O3/K2O ratio, and the Ca content.Abstract:
A means of relating geochemical concentrations to existing sandstone classification schemes is based on three chemical parameters: the SiO2/Al2O3 ratio, the Fe2O3/K2O ratio, and the Ca content. In terrigenous sands and shales, the SiO2/Al2O3 ratio separates Si-rich quartzarenites from Al-rich shales, with other sand types showing intermediate values. The ratio of total iron (as Fe2O3) to K2O separates lithic sands (litharenites and sublitharenites) from feldspathic sands (arkoses and subarkoses). In addition, very high Fe2O3/K2O ratios indicate Fe-rich shales (e.g., pyritic, sideritic, hematitic) or Fe-rich sands (e.g., gl uconitic) depending on the silica/alumina ratio. The Ca content is used to differentiate noncalcareous from calcareous sandstones and shales and to separate siliciclastic from carbonate rocks. Sandstones are classified the same by this scheme as by petrographic analysis about 84% of the time, and shales are effectively discriminated from sandstones. The requisite input data can be accurately supplied by geochemical well-logging measurements, enabling unbiased sandstone classification to be displayed on a continuous basis with depth.read more
Citations
More filters
Journal ArticleDOI
Age and chemical composition of Archean metapelites in the Zhongxiang Complex and implications for early crustal evolution of the Yangtze Craton
TL;DR: In this paper, Detrital zircon cores from the metapelites yielded a youngest age of around 2.70 with metamorphic rims dated at 1.95.
Journal ArticleDOI
Geochemistry of Hindoli Group metasediments, SE Aravalli Craton, NW India: Implications for palaeoweathering and provenance
TL;DR: In this article, the authors present geochemical data on metapelite (phyllite) and metagreywackes from the Jahazpur Group, which includes two greenschist facies metasedimentary lithopackages.
Journal ArticleDOI
Granite petrogenesis in the Gander Zone, NE Newfoundland: mixing of melts from multiple sources and the role of lithospheric delamination
David I. Schofield,R. S. D’Lemos +1 more
TL;DR: In this article, the authors show that Silurian to Devonian granites within the Gander Zone of the Appalachian Central Mobile Belt in northeastern Newfoundland formed adjacent to the former Gondwanan continental margin following terminal closure of the Iapetus Ocean.
BookDOI
Principles of Elemental Chemostratigraphy
TL;DR: Craigie et al. as discussed by the authors provide a step-by-step guide to the evolution of elemental chemostratigraphy and its application in the field of oil and gas exploration.
Journal ArticleDOI
Mesoarchaean aluminous rocks at Storø, southern West Greenland: New age data and evidence of premetamorphic seafloor weathering of basalts
TL;DR: In this article, the authors proposed that the premetamorphic alteration at Storo was due to low-temperature interaction between seawater and oceanic crust, and thus essentially represents in situ submarine seafloor weathering.
Related Papers (5)
Early Proterozoic climates and plate motions inferred from major element chemistry of lutites
H.W. Nesbitt,Grant M. Young +1 more
Trace element characteristics of graywackes and tectonic setting discrimination of sedimentary basins
Mukul R. Bhatia,Keith A.W. Crook +1 more