An assessment of the seawater effect by geochemical and isotopic data on the brackish karst groundwater from the Karaburun Peninsula (İzmir, Turkey)

Abstract Understanding of the recharge origin, runoff channels, and discharge characteristics of karst groundwater is very important for construction of underground projects and identification of water supply targets. Complex structural systems, lithological differences, and extreme heterogeneity of aquifers combine to create a complex karst aquifer structure in alpine and gorge areas; however, because of the topography, direct investigation of aquifer structure is difficult. In this study, field survey, hydrochemical, and isotopic data are analyzed to reveal the development of karst groundwater and to describe the karst water cycle in Genie Mountain, Qinghai–Xizang Plateau. The results show that atmospheric precipitation and melting ice and snow are the groundwater recharge sources, and groundwater circulation is shallow, with groundwater ages generally no more than 60 yr. The groundwater cycle can be divided into three levels: epikarst water circulation; mid to deep karst water circulation; and deep geothermal water circulation. The karst springs located in the outlet of the Huolong gully contain markedly higher levels of Na + and SO 4 2 − than other karst springs because of the leaching effect of groundwater on mirabilite. The presence of evaporites also indicates that the groundwater of Huolong gully is influenced by evaporation. The runoff of thermal springs undergoes deep circulation and is controlled by faults. This water mainly dissolves carbonate rock, with little influence of evaporation. This study shows that hydrochemical and isotopic methods can be used to discriminate different water types, and can be applied to study the characteristics of complex groundwater runoff in alpine and gorge areas.

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A prospective Early Late Paleocene event (ELPE) from the expanded Río Gor hemipelagic section (Betic Cordillera, southern Spain): foraminifera, nannofossil and isotopic data

Rendiconti online della Società Geologica Italiana ◽

10.3301/rol.2014.110 ◽

2014 ◽

Vol 31 ◽

pp. 181-182

Author(s):

Victoriano Pujalte

Keyword(s):

Betic Cordillera ◽

Southern Spain ◽

Isotopic Data ◽

Late Paleocene ◽

Early Late

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The Gedan floristic assemblage from the Late Cretaceous deposits of the Kholchan Formation of the Okhotsk-Chukotka volcanogenic belt

Palaeobotany ◽

10.31111/palaeobotany/2014.5.73 ◽

2014 ◽

Vol 5 ◽

pp. 73-93 ◽

Cited By ~ 3

Author(s):

L. B. Golovneva ◽

S. V. Shczepetov

Keyword(s):

River Basin ◽

Late Cretaceous ◽

Middle Part ◽

Isotopic Data ◽

Volcanogenic Belt ◽

Stratigraphic Position ◽

Cretaceous Deposits

The Gedan floristic assemblage occurs from upper layers of the Kholchan Formation of the Okchotsk-Chukotka volcanogenic belt (OCVB). The locality is situated at the Gedan River in the middle part of the Arman River basin. The Gedan assemblage is composed of 6 taxa: Cladophlebis sp., Sphenobaiera sp., Ginkgo ex gr. adiantoides (Ung.) Heer, Taxodium amguemensis (Efimova) Golovn., Metasequoia sp., Pagiophyllum sp. The similarity of the Gedan floristic assemblage with the Karamken and the Khirumki floristic assemblages from the Kholchan Formation of the Okhotsk sector of the OCVB allows us to join them in the Kholchan flora. This flora is distinct from more ancient Arman flora, which dated as the Turonian-Coniacian and from younger Ola flora, which dated as the Santonian-early Campanian. The age of the Kholchan flora is estimated as the Coniacian on the basis of stratigraphic position, presence of Podozamites, Metasequoia and Quereuxia and also isotopic data. This flora is equivalent with the Chaun flora of Central Chukotka, with the Aleeki flora from the Villigha and Toomahni Rivers interfluve and with the Ulya flora from the southern part of the Okhotsk-Chukotka volcanogenic belt.

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Ultramafic-alkaline-carbonatite complexes as a result of two-stage melting of mantle plume: evidence from the mid-paleoproterozoic Tiksheozero intrusion, Northern Karelia, Russia

Доклады Академии наук ◽

10.31857/s0869-56524864460-465 ◽

2019 ◽

Vol 486 (4) ◽

pp. 460-465

Author(s):

E. V. Sharkov ◽

A. V. Chistyakov ◽

M. M. Bogina ◽

O. A. Bogatikov ◽

V. V. Shchiptsov ◽

...

Keyword(s):

Fractional Crystallization ◽

Mantle Plume ◽

Large Igneous Province ◽

Intrusive Complex ◽

Incongruent Melting ◽

Isotopic Data ◽

Two Stage ◽

Similar Composition ◽

Igneous Province ◽

Alkaline Magmas

Tiksheozero ultramafic-alkaline-carbonatite intrusive complex, like numerous carbonatite-bearing complexes of similar composition, is a part of large igneous province, related to the ascent of thermochemical mantle plume. Our geochemical and isotopic data evidence that ultramafites and alkaline rocks are joined by fractional crystallization, whereas carbonatitic magmas has independent origin. We suggest that origin of parental magmas of the Tiksheozero complex, as well as other ultramafic-alkaline-carbonatite complexes, was provided by two-stage melting of the mantle-plume head: 1) adiabatic melting of its inner part, which produced moderately-alkaline picrites, which fractional crystallization led to appearance of alkaline magmas, and 2) incongruent melting of the upper cooled margin of the plume head under the influence of CO2-rich fluids that arrived from underlying zone of adiabatic melting gave rise to carbonatite magmas.

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Episodic tectono-thermal activity in the southern part of the East Greenland Caledonides

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v186.5214 ◽

2000 ◽

pp. 42-49 ◽

Cited By ~ 2

Author(s):

A. Graham Leslie ◽

Allen P. Nutman

Keyword(s):

Thermal Activity ◽

Isotopic Data ◽

Zircon Age ◽

East Greenland ◽

Original Series ◽

Age Determinations

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Leslie, A. G., & Nutman, A. P. (2000). Episodic tectono-thermal activity in the southern part of the East Greenland Caledonides. Geology of Greenland Survey Bulletin, 186, 42-49. https://doi.org/10.34194/ggub.v186.5214 _______________ Isotopic data from the Renland augen granites of the Scoresby Sund region (Figs 1, 2) provided some of the first convincing support for relicts of potentially Grenvillian tectono-thermal activity within the East Greenland Caledonides. In Renland, Chadwick (1975) showed the presence of major bodies of augen granite (Fig. 2) interpreted by Steiger et al. (1979), on the basis of Rb–Sr whole rock and U–Pb zircon age determinations, to have been emplaced about 1000 Ma ago.

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