Petrography and geochemical characterization of the Lower Cretaceous deposits of the Vandam zone (southern slope of the Greater Caucasus, Azerbaijan): implications for maturity, paleoclimate and paleoweathering
Guliyev E.Kh.
Azerbaijan National Academy of Sciences, Institute of Geology and Geophysics, Azerbaijan H. Javid Ave., 119, Baku, AZ1073: guliyevemin@outlook.com
Summary. This study presents
a detailed petrographic and geochemical analysis of Lower Cretaceous deposits
of the southern slope of the Greater Caucasus (Vandam zone). By analysing the
siliciclastic rocks of the Kepuch and Gyrkhbulag formations, this research aims
to assess the compositional maturity of the sediments and to reconstruct the
paleoenvironmental conditions, including paleoclimate paleoweathering
processes. Petrographic analysis reveals that the sediments were poorly sorted
and made of angular to subangular grains, implying deposition relatively close
to the source area. The mineralogical maturity of the sediments was assessed
through the Index of Compositional Variability (ICV), while weathering
intensities were evaluated using the Chemical Index of Alteration (CIA),
Chemical Index of weathering (CIW), and the Plagioclase Index of Alteration
(PIA). Based on geochemical classification, the sediments were classified as
litharenites and wackes. The Al2O3-(CaO*+Na2O)-K2O
(A-CN-K) diagram, along with weathering indices, suggest low to moderate
weathering in the source area, consisted with the arid-to-semi-arid climate of
the studied area. On the other hand, the Index of Compositional Variability
(ICV), ranging from 0.9 to 1.59, indicates low compositional and mineralogical
maturity. In addition, the discriminant diagrams of Zr/Sc-Th/Sc and Al2O3-Zr-TiO2
suggest that the sediments were primarily first-cycle deposits derived from
igneous rocks, with minimal evidence of obvious recycling and hydraulic
sorting.
Keywords: maturity, paleoclimate, paleoweathering, ICV, CIA,
PIA, CIW, recycling, sorting
REFERENCES
Alizadeh Ak.A. Geology of Azerbaijan. Vol. 1. Stratigraphy, part 2: Mesozoic Cenozoic. Nafta Press. Baku, 2005b, 580 p. (in Russian).
Alizadeh Ak.A. The modern problems of geology and geophysics of Eastern Caucasus and the South Caspian depression. 34th International geological congress. Nafta Press, Baku, 2012, 286 p.
Alizadeh Ak.A. Geology of Azerbaijan. Volume 4: Tectonics. Nafta Press. Baku, 2005a, 580 p. (in Russian)
Baiyegunhi C., Liu K., Gwavava O. Geochemistry of sandstones and shales from the Ecca Group, Karoo Supergroup, in the Eastern Cape Province of South Africa: Implications for provenance, weathering and tectonic setting. Open Geosciences, Vol. 9, No. 1, 2017, DOI:10.1515/geo-2017-0028.
Boggs Jr.S. Principles of Sedimentology and Stratigraphy. 4th Edition, Pearson Education Inc., Upper Saddle River, NJ 07458, USA, ISBN 0-13-154728-3, 2006, 662 p.
Boggs S. Principles of Sedimentology and Stratigraphy, (5th ed.). Upper Saddle River, N.J.: Prentice Hall. ISBN 0-13-099696-3. 2009.
Cox R., Lowe D.R., Cullers R.L. The influence of sediment recycling and basement composition on evolution of mudrock chemistry in the Southwestern United States. Geochimica et Cosmochimica Acta, Vol. 59, No. 14, 1995, pp. 2919-2940, https://doi.org/10.1016/0016-7037(95)00185-9.
Crook K.A.W. Lithogenesis and geotectonics: the significance of compositional variation in flysch arenites (graywackes), In: Modern and ancient geosynclinal sedimentation (Dott R.H. and Shaver R.H. eds.). SEPM Spec. Publ., 19, 1974, pp. 304-310.
Eric B.E., Fralick P., Emile E., Betrant B.S., Ntoboh T.C., Nkongho A.E., Cedric B.B. Geochemical constraints on the provenance, paleoweathering and maturity of the Mamfe black shales, West Africa. Journal of African Earth Sciences, Vol. 175, No. 3, 2021, https://doi.org/ 10.1016/j.jafrearsci.2020.104078.
Fedo C.M., Nesbitt H.W. and Young G.M. Unravelling the effects of potassium metasomatism in sedimentary rocks and paleosols, with implications for palaeo-weathering conditions and provenance. Geology, Vol. 23, No. 10, 1995, pp. 921-924, https://doi.org/10.1130/ 0091-7613(1995)023<0921:UTEOPM>2.3.CO;2.
Fei X., Liu J., Tang C., Zou X., Zhang L. Supergene weathering of ore deposits and geochemical prospecting. In: (Advances in Earth Science Research (Shandong J. and Fu X. eds.), Springer. 2017, pp. 119-137.
Garcia D., Fonteilles M., Moutte J. Sedimentary fractionations between Al, Ti, and Zr and the genesis of strongly peraluminous granites. The Journal of Geology, Vol. 102, No. 4, 1994, pp. 411-422. https://doi.org/10.1086/629683.
Jin Z., Cao J., Wu J., Wang S. A Rb/Sr record of catchment weathering response to Holocene climate change in Inner Mongolia. Earth Surface Processes and Landforms, Vol. 31, No. 3, 2006, pp. 285-291, DOI:10.1002/esp.1243.
Harnois L. The CIW index: A new chemical index of weathering. Sedimentary Geology, Vol. 55, No. 3-4, 1988, pp. 319-322, https://doi.org/10.1016/0037-0738 (88)90137-6.
Herron M.M. Geochemical classification of terrigenous sands and shales from core or log data. Journal of Sedimentary Petrology, Vol. 58, No. 5, 1988, pp. 820-829.
Kangarli T.N. Mass overthrust within the structure of Greater Caucasus (Azerbaijan). In: The modern problems of geology and geophysics of Eastern Caucasus and the South Caspian Depression. 34th International Geological Congress. Special Issue Papers. Nafta-Press. Baku, 2012, pp. 163-201.
Kroonenberg S.B. Effects of provenance, sorting and weathering on the geochemistry of fluvial sands from different tectonic and climatic environments. In: Proc. 29th Int. Geol. Congr. Part A. (Kumon FYu. K.M. eds.), Kyoto, Japan 1992. VSP Publ., Utrecht, 1994, pp. 69-81.
Long X., Yuan C., Sun M., Xiao W., Wang Y., Cai K., Jiang Y. Geochemistry and Nd isotopic composition of the Early Paleozoic flysch sequence in the Chinese Altai, Central Asia: Evidence for a northward-derived mafic source and insight into Nd model ages in accretionary orogens. Gondwana Research, Vol. 22, No. 2, 2012, pp. 554-566, DOI:10.1016/j.gr.2011.04.009.
Maynard J.B., Sutton S.J., Robb L.J., Ferraz M.F., Meyer F.M. A paleosol developed on hydrothermally altered granite from the hinterland of the Witwatersrand Basin: characteristics of a source of Basin Fill. Journal of Geology, 103, 1995, pp. 357-377, https://doi.org/10.1086/ 629757.
McLennan S.M. Rare earth elements in sedimentary rocks: influence of provenance and sedimentary processes. In: Geochemistry and Mineralogy of Rare Earth Elements (Lipin B.R. and McKay G.A., eds.), De Gruyter. Berlin, Vol. 21, No. 1, 1989, pp. 169-200, https://doi.org/ 10.1515/9781501509032-010.
McLennan S.M. Weathering and global denudation. Journal of Geology, Vol. 101, No 2, 1993, pp. 295-303, http://dx.doi.org/10.1086/648222.
Nesbitt H.W. and Young G.M. Early Proterozoic climates and plate motions inferred from major element chemistry of lutites. Nature 299, 1982, pp. 715-717, https://doi.org/ 10.1038/299715a0.
Nesbitt H.W. and Young G.M. Prediction of some weathering trends of plutonic and volcanic rocks based on thermodynamic and kinetic considerations. Geochimica et Cosmochimica Acta, Vol. 48, No. 7, 1984, pp. 1523-1534, DOI:10.1016/0016-7037(84)90408-3.
Nesbitt H.W. and Young G.M. Formation and diagenesis of weathering profiles. Journal of Geology, Vol. 97, No. 2, 1989, pp. 129-147, DOI:10.1086/629290.
Nichols G. Terrigenous clastic sediments. Blackwell Science. Oxford, 2015, pp. 1-14.
Oni S.O. and Olatunji A.S. Depositional environments signatures, maturity and source weathering of Niger Delta sediments from an oil well in southeastern Delta State, Nigeria. Eurasian Journal of Soil Science, Vol. 6, No. 3, 2017, pp. 259-274, https://doi.org/10.18393/ejss.297245.
Pettijohn F.J., Potter P.E., Siever R. Sand and sandstone. Springer-Verlag. Berlin, Heidelberg, New York, 1972, 583 p.
Potter P.E. Petrology and chemistry of modern Big River Sands. The Journal of Geology, Vol. 86, No. 4, 1978, pp. 423-449. https://doi.org/10.1086/649711.
Roser B.P. and Korsch R.J. Determination of tectonic setting of sandstone-mudstone suites using SiO2 Content and K2O/Na2O Ratio. The Journal of Geology, Vol. 94, No. 5, 1986, pp. 635-650. https://doi.org/10.1086/629071.
Roser B.P., Cooper R.A., Nathan S., Tulloch A.J. Reconnaissance sandstone geochemistry, provenance, and tectonic setting of the lower Paleozoic terranes of the West Coast and Nelson, New Zealand. New Zealand Journal of Geology and Geophysics, Vol. 39, No. 1, 1996, pp. 1-16, DOI:10.1080/00288306.1996.9514690.
Suttner L.J. and Dutta P.K. Alluvial sandstone composition and paleoclimate, I. Framework mineralogy. Journal of Sedimentary Research, Vol. 56, No. 3, 1986, pp. 329-345, DOI:10.1306/212F8909-2B24-11D7-8648000102C1865D.
Taylor S.R. and McLennan S.M. The continental crust: Its composition and evolution. Blackwell Scientific Publications. Oxford, 1985, pp. 1-312.
Taylor S.R. and McLennan S.M. The geochemical evolution of the continental crust. Reviews in Geophysics, Vol. 33, 1995, pp. 241-265.
Weltje G.J. and von Eynatten H. Quantitative provenance analysis of sediments: review and outlook. Sedimentary Geology, Vol. 171, No. 1-4, 2004, pp. 1-11, https://doi.org/ 10.1016/j.sedgeo.2004.05.007