Carbon and Oxygen Isotopic Stratigraphy of Mesoproterozoic Carbonate Sequences (1.6–1.4 Ga) from Yanshan in North China

Hongwei, Kuang; Yongqing, Liu; Jiahua, Li; Nan, Peng; Shunshe, Luo; Chao, Cen

doi:https://doi.org/10.1155/2011/410621

International Journal of Oceanography

On this page

Abstract Introduction Methods Discussion Conclusions References Copyright Related Articles

Research Article | Open Access

Volume 2011 | Article ID 410621 | https://doi.org/10.1155/2011/410621

Carbon and Oxygen Isotopic Stratigraphy of Mesoproterozoic Carbonate Sequences (1.6–1.4 Ga) from Yanshan in North China

Kuang Hongwei,^1,2Liu Yongqing,¹Li Jiahua,³Peng Nan,³Luo Shunshe,³and Cen Chao²

Academic Editor: Henk Brinkhuis

Received13 Oct 2010

Revised22 Dec 2010

Accepted17 Jan 2011

Published06 Mar 2011

Abstract

In Yanshan, located in the northern part of North China, Mesoproterozoic carbonate sequences (1.6–1.4 Ga) form a 10, 000 m thick succession in an aulacogen basin. Carbon and oxygen isotope (δ¹³O and δ¹⁸O, resp.) data were obtained from 110 carbonate samples across three sections of these Mesoproterozoic deposits. From the early to late Mesoproterozoic, low negative values of δ¹³O appear, followed by low positive variation and then a stable increase. An abrupt decrease in δ¹³O values, with subsequent rapid increase, is found at the end of the Mesoproterozoic. During the whole Mesoproterozoic, δ¹⁸O shows a mainly negative trend and occasional highly negative isotopic shifts (from lower to upper deposits). Whole-rock carbon and oxygen isotopic compositions and profiles must be studied to provide a paleogeochemical record that can be associated with paleocean sedimentary environments, temperature, biological productivity, and sea-level fluctuations. Results of the present study correlate well with other international carbon and oxygen isotope profiles, suggesting that a global marine geochemical system existed during the interval of 1.6–1.4 Ga under a globally united tectonic, sedimentary, and geochemical background.

1. Introduction

Yanshan, located in the northern part of North China, has a well-developed Mesoproterozoic marine strata-type section, that is nearly 10,000 m thick (Figure 1). These strata record information on the paleogeography, paleoenvironment, and paleocean geochemistry, providing clues to life and sedimentary evolution at the North China Craton during the Late Precambrian [1]. The Mesoproterozoic stratigraphy of Yanshan displays good depositional succession, very little deformation and alteration of metamorphism, and is widely known nationally and internationally.

Figure 1

Locations of sections and stratigraphic distribution of Mesoproterozoic in Yanshan, North China (modified after Zhu et al. [13]). (1) Gaoyuzhuang Formation and Yangzhuang Formation section in Jianshanzi, Kuancheng, Northern Hebei; (2) Wumishan Formation section in Weizhangzi, Lingyuan, Western Liaoning; (3) Hongshuizhuang -Tieling Formation section in Beizhangzi, Kuancheng, Northern Hebei; (4) Mesoproterozoic section at Guzifang, Chicheng, Northern Hebei (i.e., Xuanlong section); (5) Mesoproterozoic section at Jixian,Tianjin. (a) Mesoproterozoic strata distribution; (b) coastline; (c) locality; (d) section.

Since establishment of the strata type in Yanshan in the 1930s [2], numerous studies have examined the stratigraphy, sedimentology, paleontology, geochronology, and geochemistry [3] and reported on carbon and oxygen isotopes [4–12]. Zhong and Chen [4] examined the isotopic composition of the Gaoyuzhuang Formation and the Yangzhuang Formation based on oxygen and carbon isotopic data (152 values) collected from the Gaoyuzhuang to Yangzhuang Formations at the Ming Tombs, Beijing and in Jixian, Tianjin. Wang and Chen [5] studied oxygen-carbon isotopic changes of the Tieling Formation using isotopic data (94 values). Zhao [6] obtained 17 samples mainly from Mesoproterozoic carbonates in Jixian, Tianjin. Zhao et al. [7] analyzed 29 samples from Mesoproterozoic carbonates at the Ming Tombs, Beijing, while Xiao et al. [8] reported oxygen and carbon isotope findings from Mesoproterozoic carbonates from Jixian, Tianjin. Li et al. [9] studied the oxygen and carbon isotopic composition and characteristics of the Wumishan Formation at the Ming Tombs, Beijing. Li et al. [11] and Chu et al. [12] also studied the oxygen and carbon isotopic compositions, respectively, of Mesoneoproterozoic samples from Jixian, Tianjin.

Previous studies have focused mainly on Mesoproterozoic samples from the Ming Tombs in Beijing and Jixian, Tianjin. Among these studies, Chu et al. [12] were particularly systematic, although they only represented the Mesoneoproterozoic oxygen and carbon isotope compositions in Jixian and the Ming Tombs and their relation to paleoclimate and sea-level fluctuations, biotic alternation, and tectonic events. To better understand paleoceanic geochemistry of the Yanshan Mountains during the Mesoproterozoic (1.6–1.4 Ga) and regional, or global, Mesoproterozoic stratigraphic correlation, this study examined oxygen and carbon isotopes in the Mesoproterozoic stratigraphy of Yanshan, North China.

2. Geologic Setting and Samples

The Yanshan area is tectonically attributed to a Mesoproterozoic aulacogen basin, which extends on an east-west axis and contains thick deposits from the Mesoproterozoic. In ascending order, these deposits are labeled the Mesoproterozoic Changzhougou, Chuanlinggou, Tuanshanzi, Dahongyu, mainly clastic rocks, Gaoyuzhuang, Yangzhuang, Wumishan, Hongshuizhuang, and Tieling Formations. The latter five formations are the stratigraphic interval of focus here and are chiefly carbonates except for the Hongshuizhuang Formation shale.

The samples for carbon and oxygen isotopic analysis (110 samples), as well as analysis of trace elements and oxides, were collected from three individual sections, numbered (1), (2), and (3) in Figure 1. Together, these three sections make up one complete stratigraphic succession of the Mesoproterozoic in northern Hebei Province (Figure 2); Figure 2 shows the regional stratigraphic correlation.

Recent studies have advanced understanding of Mesoproterozoic geochronology in the Yanshan area. Wan et al. [14] studied the Ming Tombs in Beijing and obtained an age range of 1.75–1.80 Ga (SHRIMP age) for the bottom of the Changzhougou Formation. Gao et al. [15–17] reported SHRIMP zircon ages of 1.37 Ga for the Xiamaling Formation and 1.63 Ga for volcanic rocks in the Dahongyu Formation at Jixian, Tianjin [17]. On the basis of these dates, Qiao et al. [18] and Gao et al. [15–17] suggested the following geochronological framework for the Mesoneoproterozoic: the Changcheng system (Changzhougou Formation, Chuanlinggou Formation, Tuanshanzi Formation, and Dahongyu Formation) is <1.75 Ga; the Jixian system (Gaoyuzhuang Formation, Yangzhuang Formation, Wumishan Formation, Hongshuizhuang Formation, and Tieling Formation) is 1.6–1.4 Ga; the Xishan system (Xiamaling Formation) is 1.4–1.2 Ga the top unnamed unit is 1.2–1.0 Ga.

Lithology in the research area can be subdivided into three types: (1) primarily micrite carbonate, such as micritic limestone and dolomite; (2) grained carbonate such as algae clastics dolomite, sparry oolitic dolomite, calcarenite, and calcirudite; (3) terrigenous rocks and some siliceous rocks (Table 1).

3. Methods and Analysis Results

3.1. Methods

A total of 110 hand samples of carbonate were collected from three sections at Beizhangzi, Kuancheng (no. 3), Weizhangzi, Lingyuan (no. 2), and Jianshanzi, Kuancheng (no. 1) (Figure 3). These sections represent a successive stratigraphic column of the Mesoproterozoic in ascending order. The carbonate samples were first washed and cleaned and then powdered into 75 um grain size. The powdered carbonate samples were reacted with phosphoric acid in an on-line carbonate preparation system (SY/T 6039-94) [SY]. [19]). Carbon and oxygen isotope (δ¹³C and δ¹⁸O, resp.) ratios of bulk rocks were analyzed at the Institute of Geology and Mineral Resources (Tianjin, China) using a mass spectrometer (MF-ISOPRIME). All values are reported as per mil (‰) relative to Vienna Pee Dee Belemnite (V-PDB) in a standard of GBW04405, GBW04406, and TB2GB04417. The precision and accuracy of the isotopic analyses are σ < 0.1‰, respectively. Concentrations of Mg, Sr, Mn, Fe, and Ca in bulk rocks were also analyzed by inductively coupled plasma mass spectrometry (ICP-MS) at the same institute in Tianjin.

3.2. Analysis Results

3.2.1. Diagenesis

Because of the possible complex postdepositional history of carbonates in the study area, we expected that all samples would show geochemical evidence and nonalteration; however, many carbon isotopic studies of Paleozoic and Proterozoic carbonates have shown that carbon isotopic composition is less sensitive to diagenetic alteration than are δ¹⁸O or trace element (Fe, Mn, Sr) compositions, as long as diagenetic fluids are relatively carbon-poor. Tests of diagenesis in Mesoproterozoic carbonates are expected to identify the most chemically altered samples as those that are least likely to preserve meaningful carbon isotopic signatures.

Identification of diagenetic alteration was based on the following: the δ¹⁸O-Mg/Ca ratio, δ¹⁸O-Sr, δ¹⁸O-Mn, δ¹⁸O-Fe, and Fe-Mn (Figure 3). Ratios of Mg/Ca cover a range of 0.1 to 0.7, mainly 0.6. The Mg/Ca ratio is >0.5 in dolomite and 0.1–0.5 in limestone. δ¹⁸O is a very sensitive indicator of diagenetic processes. Mineralogical examinations of δ¹⁸O values show that dolostone is isotopically heavy and limestones have low δ¹⁸O.

Previous results indicated that δ¹⁸O values in Precambrian carbonates generally ranged from approximately −6 to −9‰ except in samples formed in evaporated marine environments [20, 21]. The current δ¹⁸O results reveal a higher trend in dolomite than in limestone. Because of evaporation and salinization, peritidal (intertidal-supratidal) carbonates have higher values than coeval subtidal carbonates; the former have values of −2‰ in dolomite, and the latter have values of −8‰ in limestone and dolomitic limestone or dolomite.

Trace element content also provides a powerful tool for assessing the degree of diagenesis. The trace elements Sr, Mn, and Fe exhibit predictable behavior during diagenetic alterations. In general, the Sr content decreases through interaction with relatively Sr-poor fluids. However, examination of the Sr content in more than 50 carbonates samples showed low Sr content, mainly 5–50 ppm (Table 2), suggesting poor postdiagenetic alteration.

Contents of Mn and Fe typically increase with water–rock interaction in the presence of reduced fluids and therefore generally reflect either carbonate precipitation in the presence of Mn and Fe-rich waters, or postdepositional alteration under burial conditions. Relationships of δ¹⁸O-Mn, δ¹⁸O-Fe, and Fe-Mn reveal that Fe and Mn present distinct and similar trends for limestone and dolostone in the Mesoproterozoic (Table 2 and Figure 3). In most of the samples, Mn is <600 ppm and Fe is <8000 ppm. Relationship of δ¹³C-Fe and δ¹³C-δ¹⁸O also suggests that the carbonate samples underwent poor postdepositional diagenetic alterations and well-preserved information on synsedimentary marine oxygen and carbon isotopes in the Mesoproterozoic.

3.2.2. Chemostratigraphy

Table 2 lists the isotopic and elemental compositions, and Figure 4 shows secular change of δ¹³C and δ¹⁸O. The δ¹³C record of the Mesoproterozoic obtained in the current study shows an overall trend of low negative mainly within the Gaoyuzhuang and Yangzhuang Formations. Subsequently, δ¹³C displays low positive variations and stable increase, although with occasional negative values, in the Wumishan Formation; this is followed by a decrease to a negative level of approximately −1.7‰ in the Hongshuizhuang Formation. A rapid increase of δ¹³C occurs from the bottom of the Tieling Formation to the top of the Mesoproterozoic, with δ¹³C values varying between approximately −1.6 and 1‰. Oxygen isotope values (δ¹⁸O) from this study (Table 2 and Figure 4) show a distinctly negative trend varying from −2.1 to −10‰, excluding diagenetically altered values lower than −10‰. A few highly negative oxygen isotopic shifts occur within the middle Gaoyuzhuang and Yangzhuang Formations and the middle and upper Wumishan Formation. These δ¹³C and δ¹⁸O results are comparable to previous reports of Mesoproterozoic geochemistry [4, 8, 12] in Jixian, Tianjin.

4. Discussion

The carbon and oxygen isotopic compositions display regular variations that correspond to the evolutionary sedimentary environments in a tidal setting from the Gaoyuzhuang to Yangzhuang Formations. The δ¹³C values vary from approximately 0 to 1.5%. Micritic and stromatolitic dolomite in the Gaoyuzhuang Formation yields a δ¹³C value of approximately −0.5‰. The relatively low δ¹³C value of nodular limestone (−0.5 ~ 1.5‰) is consistent with a deep water environment and low biological productivity [22, 23]. Although showing good continuity with δ¹³C values of the Gaoyuzhuang Formation, the Yangzhuang Formation reveals a level of slightly negative δ¹³C values, with a minimum of −1.35‰ in the middle of the formation, possibly due to postdiagenetic alternation, dolomitization, silicification, or terrigenous sediments input. For the Gaoyuzhuang and Yangzhuang Formations, excluding diagenetically altered samples (10‰), δ¹⁸O shows highly negative values, mostly ranging from approximately −4 to −7‰ with a minimum of −9.89‰. The Wumishan Formation is interpreted as peritidal deposits in an epicontinental sea [6] and characterized by dolomite with stromatolitic laminations. A majority of stromatolites in the Wumishan Formation suggest high biological productivity. The δ¹⁸O value in this formation varies between −8.8‰ and −2.3‰, displaying a slight decrease upwards. Except for two positive drifts of δ¹³C, reaching 1.56 at the bottom and 1.49 at the top, the other values vary around zero, probably induced by high-frequency sea-level changes, palaeotemperature, or productivity. The Hongshuizhuang Formation is composed of dark-gray shale rich in organic material with dolomitic intercalations and a lower negative δ¹³C value (−1.7‰) and a moderate δ¹⁸O value (−5.5‰). The Tieling Formation shows a lower negative trend of δ¹³C varying between −1.7‰ and 1.18‰ in the lower part, with an increase of positive values (−0.6 ~ 1‰) upwards. The δ¹⁸O of this unit maintains a stable level of −6.9 ~ 5.3‰, possibly reflecting a response to the sedimentary environmental transition from supratidal to intertidal-subtidal and an increase of biological activity.

Previous studies on carbon isotopes of the Mesoproterozoic [7, 8, 11, 12] showed that δ¹³C values during 1.8–1.6 Ga were mainly negative (−3 to 0‰) and increased slowly, reaching a level of zero, with abrupt oscillation occurring at the beginning of 1.6 Ga. Zhai and Piao [24] and Chu et al. [12] concluded that the evolutionary trend of carbon isotopes was a geochemical record that corresponded to break up of the supercontinent in the Early Mesoproterozoic. Li et al. [11] suggested, based upon geochemistry, that high salt concentration of the paleocean spurred the evolution of the microorganism community, which resulted in the variation of δ¹³C isotopes in sediments during this period.

Knauth and Lowe [25], De La Rocha [26], and Robert and Chaussidon [27] suggested that during the interval of 1.4–1.2 Ga, ocean temperature reached around 70°C based on study of global average δ¹⁸O and δ³⁰ Si isotopes in carbonates. The δ¹³C values of Mid-Riphean carbonate from the southern Urals of Russia (1.4–1.2 Ga) show a low positive range of 0–3‰ and a negative anomaly below −20‰ (Bartley et al., [28]) in black shale. The δ¹³C in the Mesoproterozoic Belt Supergroup (1.45–1.20 Ga) in North America and Canada, consisting mainly of carbonate-bearing molar-tooth structure, varies from −0.2 to 1.4‰ from down to up [20], while δ¹³C in carbonates of 1.70–1.60 Ga in the McArthur and Mount Isa basins in northern Australia displays stable variation of −0.6 to 1‰ [29]. A carbon isotope curve for ca. 1.6–0.6 Ga reported by Kah et al. [21] presents a slow increase in δ¹³C values above 0‰, comparable to the δ¹³C profiles of the present study and suggesting that a global marine geochemical system prevailed and was universally correlated during the interval of 1.6–1.2 Ga, in response to the global tectonic background.

5. Conclusions

The bulk-rock carbon and oxygen isotopic compositions and profiles obtained from carbonates from central and northern Yanshan provide a paleogeochemical record of ocean depositional environments, temperature, biological productivity, and sea-level fluctuations. From the early to late Mesoproterozoic, low negative δ¹³C values appear in both the Gaoyuzhuang and Yangzhuang Formations. This is followed by low positive variations and a stable increase with occasional negative value in the Wumishan Formation. An abrupt decrease in δ¹³C values, down to −1.7‰, occurs in the Hongshuizhuang Formation; δ¹³C values then rapidly increase from the bottom of the Tieling Formation to the end of the Mesoproterozoic, varying between −1.6‰ and1‰.

The main δ¹⁸O trend is negative value, varying from −2.3‰ to −10‰. A few highly negative oxygen isotopic shifts occur within the middle Gaoyuzhuang Formation, the Yangzhuang Formation, and the middle and upper Wumishan Formation.

The carbon and oxygen isotope profiles of this study correspond well with results of other international studies, suggesting that a global marine geochemical system existed during the past 1.4 Ga interval and revealing a globally united tectonic, sedimentary, and geochemical background.

Acknowledgment

Financial supports from the National Natural Science Foundation of China (no. 40772078), SINOPIC (no. GB0800-06-ZS-350) and Geology Institute of CAGS (no. J0903) are all acknowledged.

References

J. Chen, H. Zhang, S. Zhu, Z. Zhao, and Z. Wang, “Research on Sinian suberathern of Jixian, Tianjin,” in Bureau of Geology and Mineral Resources of Tianjing, Research on Pricambrian Geology, pp. 56–114, Tianjin Science and Technology Press, Tianjin, China, 1980.
View at: Google Scholar
Z. Gao, Y. Xiong, and P. Gao, “Preliminary notes on Sinian stratigraphy of North China,” Bulletin of Geological Society of China, vol. 13, pp. 243–388, 1934 (Chinese).
View at: Publisher Site | Google Scholar
T. Wu, “Late Precambrian (Meso-to Neoproterozoic) lithostratigraphic units in North China and their multiple division and correlation,” Geology in China, vol. 29, no. 2, pp. 147–154, 2002 (Chinese).
View at: Google Scholar
H. Zhong and J. Chen, “Carbon isotope evidence for lower biomass about 1400 Ma ago,” Scientia Geologica Sinica, no. 2, pp. 160–168, 1992 (Chinese).
View at: Google Scholar
K. Wang and J. Chen, “Constaints on the stable isotopic composition of sedimentary carbonates from the Tieling Formation in the Yanshan region,” Geochimica, no. 1, pp. 10–17, 1993 (Chinese).
View at: Google Scholar
Z. Zhao, “Characteristics of Proterozoic carbonate rocks in Jixian by means of the oxygen and carbon isotope composition,” Acta Sedimentologica Sinica, vol. 13, no. 3, pp. 46–53, 1995 (Chinese).
View at: Google Scholar
C. Zhao, R. Li, and J. Zhou, Sedimentology and Petroleum Geology of the Meso-and Neo-Proterozoic in North China, Geological Publishing House, Beijing, China, 1997.
S. Xiao, A. H. Knoll, A. J. Kaufman, L. Yin, and Y. Zhang, “Neoproterozoic fossils in Mesoproterozoic rocks? Chemostratigraphic resolution of a biostratigraphic conundrum from the North China Platform,” Precambrian Research, vol. 84, no. 3-4, pp. 197–220, 1997.
View at: Google Scholar
R. Li, J. Chen, and S. Zhang, “Stable carbon and oxygen isotopic compositions of carbonates in middle Mesoproterozoic Wumishan Formation and sea-level change,” Chinese Science Bulletin, vol. 44, no. 23, pp. 2130–2136, 1999 (Chinese).
View at: Google Scholar
R. Li, J. Chen, and Z. Chen, “Characteristics of the C-and O-isotopic compositions of carbonates in the weathering profile at the unconformable boundary between the early cambrian and late Proterozoic in Ji County, North China,” Chinese Journal of Geology (Scientia Geologica Sinica), vol. 35, no. 1, pp. 55–59, 2000 (Chinese).
View at: Google Scholar
C. Li, P. Peng, G. Sheng, J. Fu, and Y. Yan, “A carbon isotopic biogeochemical study of Meso- to Neoproterozoic sediments from the Jixian section, North China,” Acta Geologica Sinica, vol. 76, no. 4, pp. 433–440, 2002 (Chinese).
View at: Google Scholar
X. Chu, T. Zhang, Q. Zhang, L. Feng, and F. Zhang, “Carbon istopic variations of Proterozoic carbonates in Jixian, Tianjin, China,” Science in China Series D, vol. 47, no. 2, pp. 160–170, 2004.
View at: Google Scholar
S. Zhu, X. Huang, and S. Sun, “New progress in the research of the Mesoproterozoic Changcheng system (1800–1400) in the Yanshan range, North China,” Journal of Stratigraphy, vol. 29, no. B11, pp. 437–449, 2005 (Chinese).
View at: Google Scholar
Y. Wan, Q. Zhang, and T. Song, “SHRIMP ages of detrital zircons from the Changcheng System in the Ming Tombs area, Beijing: constraints on the protolith nature and maximum depositional age of the Mesoproterozoic cover of the North China Craton,” Chinese Science Bulletin, vol. 48, no. 22, pp. 1970–1975, 2003 (Chinese).
View at: Publisher Site | Google Scholar
L. Gao, C. Zhang, X. Shi, H. Zhou, and Z. Wang, “A new SHRIMP age of the Xiamaling formation in the North China plate and its geological significance,” Acta Geologica Sinica, vol. 81, no. 6, pp. 1103–1109, 2007.
View at: Google Scholar
L. Gao, C. Zhang, X. Shi, H. Zhou, and Z. Wang, “Zircon SHRIMP U-Pb dating of the tuff bed in the Xiamaling formation of the Qingbaikouan System in North China,” Geological Bulletin of China, vol. 26, no. 3, pp. 249–255, 2007.
View at: Google Scholar
L. Gao, C. Zhang, C. Yin et al., “SHRIMP Zircon ages: basis for refining the chronostratigraphic classification of the Meso-and Neoproterozoic Strata in North China Old Land,” Acta Geoscientica Sinica, vol. 29, no. 3, pp. 366–376, 2008.
View at: Google Scholar
X. Qiao, L. Gao, and C. Zhang, “New idea of the Meso-and Neoproterozoic chronostratigraphic chart and tectonic environment in Sino-Korean Plate,” Geological Bulletin of China, vol. 26, no. 5, pp. 503–509, 2007.
View at: Google Scholar
China National Petroleum Corporation (CNPC), “The standard method of phosphorolysis for carbon and oxygen isotopes determination of carbonate rocks (SY/T 6039-94)[SY],” 1995.
View at: Google Scholar
T. D. Frank, T. W. Lyons, and K. C. Lohmann, “Isotopic evidence for the paleoenvironmental evolution of the mesoproterozoic Helena formation, belt supergroup, Montana, USA,” Geochimica et Cosmochimica Acta, vol. 61, no. 23, pp. 5023–5041, 1997.
View at: Google Scholar
L. C. Kah, T. W. Lyons, and J. T. Chesley, “Geochemistry of a 1.2 Ga carbonate-evaporite succession, northern Baffin and Bylot Islands: implications for Mesoproterozoic marine evolution,” Precambrian Research, vol. 111, pp. 203–234, 2001.
View at: Google Scholar
Z. Yan, F. Guo, J. Pan, G. Guo, and R. Zhang, “Application of C, O and Sr isotope composition of carbonates in the research of paleoclimate and paleooceanic environment,” Contributions to Geology and Mineral Resources Research, vol. 20, no. 1, pp. 53–56, 2005.
View at: Google Scholar
C. Guo, Z. Wang, and F. Wang, “Stable isotopic characteristics of diagenesisin deep water carbonate rocks,” Oil & Gas Geology, vol. 20, no. 2, pp. 48–51, 1999.
View at: Google Scholar
M. Zhai and A. Piao, “The amalgamation of the supercontinent of North China Craton at the end of Neo-Archaean and its breakup during late Paleoproterozoic an Meso-Proterozoic,” Science in China, Series D, vol. 43, supplement 1, pp. 129–137, 2000 (Chinese).
View at: Google Scholar
L. P. Knauth and D. R. Lowe, “High Archean climatic temperature inferred from oxygen isotope geochemistry of cherts in the 3.5 Ga Swaziland Supergroup, South Africa,” Bulletin of the Geological Society of America, vol. 115, no. 5, pp. 566–580, 2003.
View at: Publisher Site | Google Scholar
C. L. De La Rocha, “Palaeoceanography: in hot water,” Nature, vol. 443, no. 7114, pp. 920–921, 2006.
View at: Publisher Site | Google Scholar
F. Robert and M. Chaussidon, “A palaeotemperature curve for the Precambrian oceans based on silicon isotopes in cherts,” Nature, vol. 443, no. 7114, pp. 969–972, 2006.
View at: Publisher Site | Google Scholar
J. K. Bartley, L. C. Kah, J. L. McWilliams, and A. F. Stagner, “Carbon isotope chemostratigraphy of the Middle Riphean type section (Avzyan Formation, Southern Urals, Russia): Signal recovery in a fold-and-thrust belt,” Chemical Geology, vol. 237, no. 1-2, pp. 211–232, 2007.
View at: Google Scholar
J. F. Lindsay and M. D. Brasier, “A carbon isotope reference curve for ca. 1700–1575 Ma, McArthur and Mount Isa Basins, Northern Australia,” Precambrian Research, vol. 99, no. 3-4, pp. 271–308, 2000.
View at: Publisher Site | Google Scholar

Copyright

Copyright © 2011 Kuang Hongwei et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

PDF Download Citation

Download other formats

Order printed copies

Views

2498

Downloads

865

Citations