Sulphide oxidation and carbonate dissolution as a source of CO2 over geological timescales

Mark A. Torres; A. Joshua West; Gaojun Li

doi:10.1038/nature13030

Local Sulphide Oxidation Drives Carbonate Dissolution in Modern Shallow Marine Carbonates: Evidence from Oxygen and Sulphur Isotope Composition of Pore Water Sulphate

Mineralogical Magazine ◽

10.1180/minmag.1998.62a.2.99 ◽

1998 ◽

Vol 62A (2) ◽

pp. 820-821

Author(s):

T. C. W. Ku

Keyword(s):

Pore Water ◽

Isotope Composition ◽

Carbonate Dissolution ◽

Sulphur Isotope ◽

Shallow Marine ◽

Sulphide Oxidation ◽

Sulphur Isotope Composition ◽

Marine Carbonates

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Carbonate and silicate weathering in glacial environments and its relation to atmospheric CO2 cycling in the Himalaya

Annals of Glaciology ◽

10.1017/aog.2019.5 ◽

2018 ◽

Vol 59 (77) ◽

pp. 159-170 ◽

Cited By ~ 6

Author(s):

Tanuj Shukla ◽

Shipika Sundriyal ◽

Lukasz Stachnik ◽

Manish Mehta

Keyword(s):

Regional Scale ◽

Silicate Weathering ◽

Carbonate Dissolution ◽

Sea Salts ◽

Carbonation Reaction ◽

Sulphide Oxidation ◽

Silicate Dissolution ◽

Glacial Environments ◽

Global Carbon ◽

The Himalaya

ABSTRACTThis paper presents new insights into the global carbon cycle related to CO2 consumption from chemical denudation in heavily glacierised Himalayan catchments. Data from previous studies of solute concentrations from glacierised catchments were reprocessed to determine the regional scale of CO2 consumption and solute hydrolysis. The results show that ~90% of the SO42− is derived from crustal sulphide oxidation and ~10% from aerosols and sea salts. However, HCO3− flux calculation estimates contribution from sulphide oxidation to carbonate dissolution (SO-CD) (~21%), similar to the contributions from silicate dissolution and simple hydrolysis (~21 and ~20%, respectively). Furthermore, the atmospheric CO2 consumption estimations suggests 10.6 × 104 mole km−2 a−1 (19%) through silicate weathering, 15.7 × 104 mole km−2 a−1 (28%) through simple hydrolysis, 9.6 × 104 mole km−2 a−1 (17%) through SO-CD reaction and 5.9 × 104 mole km−2 a−1 (11%) through carbonate carbonation reaction. Our solute provenance calculations clearly indicate that HCO3− production and CO2 consumption via silicate weathering reactions is balanced by the simple hydrolysis and coupled SO-CD process. This shows a counter mechanism operating in subglacial environments of the Himalaya as a source of CO2 to runoff rather than a sink.

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Glacier naled evolution and relation to the subglacial drainage system based on water chemistry and GPR surveys (Werenskioldbreen, SW Svalbard)

Annals of Glaciology ◽

10.1017/aog.2016.9 ◽

2016 ◽

Vol 57 (72) ◽

pp. 19-30 ◽

Cited By ~ 9

Author(s):

Łukasz Stachnik ◽

Jacob C. Yde ◽

Marta Kondracka ◽

Dariusz Ignatiuk ◽

Magdalena Grzesik

Keyword(s):

Ground Penetrating Radar ◽

Chemical Weathering ◽

Drainage System ◽

Carbonate Dissolution ◽

Drainage Pattern ◽

Sulphide Oxidation ◽

High Carbonate ◽

Polythermal Glacier ◽

Ground Penetrating ◽

Subglacial Drainage

ABSTRACTGlacier naledi are extrusive ice masses that appear in front of glaciers as a consequence of refreezing of meltwater seepage during the accumulation season. These structures provide a unique opportunity to understand subglacial drainage activity during the accumulation season; however, only few detailed studies have previously focused on their characteristics. Here, we investigated glacier-derived naled assemblages in the proglacial zone of the polythermal glacier Werenskioldbreen (27.4 km2) in SW Svalbard. We determined the spatial distribution of naledi using ground penetrating radar surveys. The main subglacial drainage pattern was related to a channel under the medial moraine, and three sources are linked to a distributed subglacial drainage network. The relation between atmospherically-corrected (Ca2+ + Mg2+) and (SO42−) in sub-naled waters was closely related to sulphide oxidation coupled with carbonate dissolution (r = 0.99; slope = 1.6). This is consistent with the local lithology, which is dominated by schist containing carbonates. We also found high carbonate saturation indices in pale white ice layers within the naled. We conclude that sulphide oxidation coupled with carbonate dissolution is the dominant chemical weathering process in the subglacial drainage system of Werenskioldbreen during the accumulation season.

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CARBONATE DISSOLUTION AND ULTRASTRUCTURAL BREAKDOWN IN PLANKTONIC FORAMINIFERA IN THE SEA OF OKHOTSK

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.31519/conferencearticle_5b1b93b6ac2b30.99187085 ◽

2017 ◽

Author(s):

Alexandra Romanova ◽

Vladimir Anin ◽

Sergey Pletnev ◽

...

Keyword(s):

Sea Of Okhotsk ◽

Planktonic Foraminifera ◽

Carbonate Dissolution ◽

Calcite Dissolution ◽

The Sea Of Okhotsk ◽

Globigerina Bulloides ◽

Neogloboquadrina Pachyderma ◽

Thin Walled ◽

Shell Fragments ◽

Degree Of Fragmentation

80 sediment stations collected along the meridian transect across the Sea of Okhotsk were studied in order to reveal patterns of dissolution based on planktonic foraminifera. The degree of calcite dissolution intensity from planktonic foraminifera determined by different indices (degree of fragmentation, presence of susceptible to dissolution species, benthos/ plankton ratio). The highest degree of dissolution evidenced by a large number of shell fragments and corroding walls were found in sediments from the area of the Kuril Islands. The most revealing measure of probable dissolution of foraminiferal shells in the central part of the sea is a low number and lack of thin-walled species. The effects of dissolution on foraminiferal shells were studied for dominated species Neogloboquadrina pachyderma sin and Globigerina bulloides using a scanning electron microscope. The results are important for understanding processes of sedimentation, the paleo-oceanologial reconstructions and for obtaining reliable results in isotope analyzes.

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