Oxygen-isotope trends and seawater temperature changes across the Late Cambrian Steptoean positive carbon-isotope excursion (SPICE event)

Geology ◽  
2011 ◽  
Vol 39 (10) ◽  
pp. 987-990 ◽  
Author(s):  
Maya Elrick ◽  
Sarah Rieboldt ◽  
Matt Saltzman ◽  
Robert M. McKay
Keyword(s):  
Oxygen Isotope ◽  
Carbon Isotope ◽  
Seawater Temperature ◽  
Temperature Changes ◽  
Late Cambrian ◽  
Carbon Isotope Excursion ◽  
Spice Event

The geochemistry of the late Cambrian carbonate in North China: the Steptoean Positive Carbon Isotope Excursion (SPICE) record suppressed in a coastal condition?

2019 ◽  
Vol 156 (10) ◽  
pp. 1805-1819 ◽  
Author(s):  
Jing Huang ◽  
Yali Chen ◽  
Xuelei Chu ◽  
Tao Sun
Keyword(s):  
Sea Level ◽  
Carbon Isotope ◽  
North China ◽  
Coastal Environment ◽  
Sedimentary Records ◽  
Late Cambrian ◽  
Geochemical Proxies ◽  
Carbon Isotope Excursion ◽  
Globally Distributed ◽  
Shallow Coastal Environment

AbstractThe Steptoean Positive Carbon Isotope Excursion (SPICE) is globally distributed in late Cambrian sedimentary records but controversially heterogeneous in its magnitudes. Here we use multiple geochemical proxies to investigate the late Cambrian carbonates from the Tangwangzhai section in North China, which were deposited in a shallow coastal environment with three depositional sequences (S1–S3). Each sequence comprises a transgressive systems tract (TST) and a highstand systems tract (HST). The REE + Y and trace element records are consistent with the depositional condition and indicate that terrigenous influence was more significant in the TST than HST. δ13Ccarb and δ34SCAS are low in the TST relative to HST, consistent with the scenario that terrigenous inputs were profoundly aggressive to seawater by introducing 13C-depleted and 34S-depleted materials. Within the TST of S2, the SPICE excursion shows a scaled-down δ13Ccarb positive shift (∼1.7 ‰) relative to its general records (∼4–6 ‰); the corresponding δ34SCAS show no positive excursion. This ‘atypical’ SPICE record is attributed to enhanced 13C-depleted and 34S-depleted terrigenous influence during the TST, which would reduce the amplitude of δ13Ccarb excursion, and even obscure δ34SCAS excursion. Meanwhile the subaerial unconformity at the base of TST would also cause a partially missing and a ‘snapshot’ preservation. Our study confirms significant local influence to the SPICE records, and further supports the heterogeneity and low sulphate concentrations of the late Cambrian seawater, because of which the SPICE records may be vulnerable to specific depositional conditions (e.g. sea-level, terrigenous input).

scholarly journals The Furongian (late Cambrian) Steptoean Positive Carbon Isotope Excursion (SPICE) in Avalonia

2011 ◽  
Vol 168 (4) ◽  
pp. 851-862 ◽  
Author(s):  
Mark A. Woods ◽  
Philip R. Wilby ◽  
Melanie J. Leng ◽  
Adrian W.A. Rushton ◽  
Mark Williams
Keyword(s):  
Carbon Isotope ◽  
Late Cambrian ◽  
Carbon Isotope Excursion

Questioning a widespread euxinia for the Furongian (Late Cambrian) SPICE event: indications from δ13C, δ18O, δ34S and biostratigraphic constraints

2015 ◽  
Vol 152 (6) ◽  
pp. 1085-1103 ◽  
Author(s):  
THOMAS WOTTE ◽  
HARALD STRAUSS
Keyword(s):  
Elemental Concentrations ◽  
Carbonate Carbon ◽  
Late Cambrian ◽  
Seawater Ph ◽  
Carbon Isotope Excursion ◽  
Sulphate Sulphur ◽  
Almost All ◽  
Spice Event ◽  
Resolution Study ◽  
Peak Value

AbstractResults from a high-resolution study of δ13Ccarb, δ18Ocarb, δ34SCAS, δ34SCRSand elemental concentrations (Ca, Fe, Mg, Mn and Sr) in the Furongian Kyrshabakty section, southern Kazakhstan, are reported here. The investigated interval covers the Drumian to Jiangshanian stages of the Cambrian Period, respectively the regionalPtychagnostus atavustoIvshinagnostus ivshini-Irvingella majortrilobite zones. δ13Ccarbdata include the Steptoean positive carbon isotope excursion (SPICE) with a local peak value of +5‰. The onset of SPICE corresponds to theKormagnostus simplex–Glyptagnostus stolidotuszones and pre-dates the base of the Paibian Stage/Furongian Series. δ34SCASdata already increase during theLejopyge armatabiozone culminating in three positive excursions prior and after the SPICE maximum. Differences in onset, peak values and shape of the δ13Ccarband/or δ34SCASexcursions at Kyrshabakty, but also in almost all sections characterized by the SPICE, are pointing towards Furongian seawater that was low in sulphate concentration and heterogeneous in its carbonate carbon and sulphate sulphur isotopic composition. The occurrence of benthic faunal elements in almost all SPICE-related sections strongly supports oxygenated conditions at the seafloor, therefore excluding widespread anoxia or euxinia. Regional anoxic conditions are most probable. A positive δ18Ocarbexcursion parallel to the SPICE could probably be explained by a decline in seawater pH associated with a sea-level rise. Again, no euxinic conditions would be mandatory for explaining the SPICE event.

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