Skip to Main Content
Book Chapter

Crustal fluid flow in hot continental extension: tectonic framework of geothermal areas and mineral deposits in western Anatolia

By
Klaus Gessner
Klaus Gessner
1
Centre for Exploration Targeting, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
2
Present address: Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, Australia
Search for other works by this author on:
Vanessa Markwitz
Vanessa Markwitz
3
School of Earth & Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
Search for other works by this author on:
Talip Güngör
Talip Güngör
4
Department of Geological Engineering, Dokuz Eylül University, Buca 35160, İzmir, Turkey
Search for other works by this author on:
Published:
January 01, 2018

Abstract

Lithospheric thinning and crustal extension have shaped the Alpine orogen in western Anatolia since the late Oligocene, resulting in the denudation of one of Earth’s largest metamorphic core complexes, the Menderes Massif. We review locations and characteristics of geothermal fields and of Miocene mineral deposits in the context of crustal structure and geodynamic processes. Thermal spring locations show a close spatial association with active fault zones; the largest geothermal areas are located in the widest graben and at fault intersections, but show little relation to volcanic activity. During the first stage of tectonic denudation in the Miocene, epithermal, porphyry-type gold and structurally controlled base-metal deposits formed synchronously with K-rich volcanic and plutonic complexes in the northern Menderes Massif. Depositional environments favoured the formation of lignite, sedimentary uranium and borate deposits. Throughout this phase of extension in a hot continental setting, secondary porosity caused by brittle faulting of metamorphic basement rocks provided the key pathways for fluids and magmas. Although the Menderes Massif has remained in a similar position relative to active plate boundaries from the Miocene to the present, three significant changes in subcontinental mantle dynamics affected the nature of hydrothermal flow. First, the partial removal of lithospheric mantle changed the primary source component of magmatic rocks and metals from metasomatized lithosphere mantle to asthenospheric mantle. Secondly, surface uplift and progressive crustal extension led to segmentation of the Miocene land surface along NNE–SSW- and east–west-orientated fault zones, which changed the overall structural control on crustal permeability. Finally, hydrothermal flow changed from locally magmatic driven, to focused flow of topographically and thermally driven fluids in the crust, with high background heat flow caused by regional upwelling of the asthenosphere. The Menderes Massif is a continental tectonic domain that has experienced rapid thinning of lithospheric mantle and crustal extension in an overall convergent plate tectonic setting. The tectonic and geodynamic framework for evolving hydrothermal activity in western Anatolia may be applicable to other ore-forming systems in hot, extending continental crust in Earth’s history.

Supplementary material: Supplement 1: Compilation of 124 thermal spring temperature measurements from Akkuş et al. (2005); Supplement 2: Compilation of 127 geothermal well temperature measurements from Akkuş et al. (2005) is available at https://doi.org/10.6084/m9.figshare.c.3803935

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

Characterization of Ore-Forming Systems from Geological, Geochemical and Geophysical Studies

K. Gessner
K. Gessner
Geological Survey of Western Australia, Australia
Search for other works by this author on:
T.G. Blenkinsop
T.G. Blenkinsop
Cardiff University, UK
Search for other works by this author on:
P. Sorjonen-Ward
P. Sorjonen-Ward
Geological Survey of Finland, Finland
Search for other works by this author on:
Geological Society of London
Volume
453
ISBN electronic:
9781786203342
Publication date:
January 01, 2018

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal