Sea-level and ocean-current control on carbonate-platform growth, Maldives, Indian Ocean

2012 ◽  
Vol 25 (2) ◽  
pp. 172-196 ◽  
Author(s):  
Christian Betzler ◽  
Jörn Fürstenau ◽  
Thomas Lüdmann ◽  
Christian Hübscher ◽  
Sebastian Lindhorst ◽  
...  
2015 ◽  
Vol 23 (04) ◽  
pp. 1540005
Author(s):  
Tingting Zhang ◽  
Yuefeng Sun

On the Southern Marion carbonate platform, dolomitization is triggered by the circulation of normal or slightly modified seawater and is related to changes in sedimentation rate and sea level change. Dolomitization further modifies formation permeability and fluid flow patterns. Dolostone/calcareous dolostone with large vuggy or moldic porosity is formed by fabric-preserving dissolution and recrystallization, which increases the pore space and facilitates the fluid flow effectively, with permeability ranging from 1[Formula: see text]mD to 10,000[Formula: see text]mD. The frame flexibility factor ([Formula: see text]) is a rock physics parameter which is a proxy of pore structure. We find that at given porosity dolostone with larger pores, higher permeability and higher sonic velocity usually has lower values of frame flexibility factor than limestone. After strong compaction and cementation, the limestone frame occludes fluid flow, prevents dolomitization and has permeability as low as 0.02[Formula: see text]mD. Acoustic impedance inversion confirms that the asymmetric geometry of the Southern Marion platform is shaped by the oceanographic currents, which are caused by the southward-flowing East Australian Current. Three layers of dolostone with large pores in the upper platform reveal strong fluid flow within the carbonate platform, leading to dolomitization and dissolution. These three strongly dolomitized zones follow the platform topography, indicating that the diagenetic fluid flow is driven by oceanographic currents. Three large-pore-formation dolomitization events match well with three highstands of sea level events, illustrating that the highstand of sea level induces the formation of dolomitization zones with large pores. This study demonstrates the positive feedback loop of dolomitization and ocean current circulation, as well as the relationship between dolomitization and sea level change, which could be applicable for better understanding subsurface fluid-rock interactions and dolomitization pore systems in other carbonate environments.


Sedimentology ◽  
2012 ◽  
Vol 59 (5) ◽  
pp. 1640-1658 ◽  
Author(s):  
ANDREAS PAUL ◽  
JOHN J. G. REIJMER ◽  
JÖRN FÜRSTENAU ◽  
HANNO KINKEL ◽  
CHRISTIAN BETZLER

2021 ◽  
Vol 95 (2) ◽  
Author(s):  
Shiva Shankar Manche ◽  
Rabindra K. Nayak ◽  
Prakash Chandra Mohanty ◽  
M. V. R. Shesasai ◽  
V. K. Dadhwal

2001 ◽  
Vol 24 (1) ◽  
pp. 53-63 ◽  
Author(s):  
S. K. Singh ◽  
Sujit Basu ◽  
Raj Kumar ◽  
Vijay K. Agarwal

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