Journal of Palaeogeography 2014, 3(4): 359-383 DOI: 10.3724/SP.J.1261.2014.00062

Biopalaeogeography and palaeoecology

Review of molar tooth structure research

Hong‑Wei Kuang* Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China

Abstract For more than a century, molar tooth structure (MTS) has been studied. The study developed in three stages. During the first stage (before 1980), researchers described three basic morphologies of MTS, mainly from the Belt Supergroup in North America, and they provided several hypotheses for the origin of MTS. During the second stage (1980-1999), the frequent discoveries of MTS on all continents resulted in many detailed descriptions of their shape and in several hypotheses concerning the origin of MTS. Notably, hypotheses of MTS’s origin such as seismic activity and biological activity were developed. Since 2000, research has progressed into a new stage (the third stage). This is due to discoveries of MTS in the Me- so-Neoproterozoic of China and elsewhere, and the ongoing debate on the seismic or biologi- cal origin is replaced by a hypothesis that involves gas expansion and chemically-controlled carbonate precipitation (both of them possibly affected by biological activities). This latter idea has gradually been commonly recognized as the mainstream theory. Despite continued disa- greements, researchers now agree that microsparry calcite played a controlling role regarding the development and the global distribution of MTS in time and space during the Proterozoic, the morphological diversity, and the impact on the sedimentary environment. The present con- tribution analyses the three major hypotheses regarding the origin of MTS; it also discusses the shortcomings of the hypotheses regarding a seismic or biologic origin, and it details the modern hypothesis that links formation of cracks to the precipitation of sparry calcite. It is de- duced that important questions dealing with the Precambrian can be answered, among other aspects regarding the depositional palaeogeography and stratigraphic correlations.

Key words molar tooth structure, sparry calcite, Precambrian

1 Introduction * vertical and horizontal sheet-like features and the pod- like shape (O’Connor, 1972; Horodyski, 1976), but also Since Bauerman (1885) first introduced the term “molar discussed the origin of MTS, particularly of those found tooth (MT)”, more than 300 papers have been published to in the Mesoproterozoic (1.47-1.1 Ga) of the Belt Super- discuss this special sedimentary structure that only developed group in North America. Three potential origins for MTS in the Proterozoic carbonate rocks. Examination of 336 were recognized that (1) MTS might have resulted from papers related to molar tooth structure (MTS) indicated that cleavage of lithified rock due to shear forces, and thus MTS studies represent at least three main stages. would be secondary in nature (Daly, 1912; Fenton and During the first stage (before 1980), researchers not Fenton, 1937; Rezak, 1957); (2) similarly to the stroma- only focused on the morphology of MTS, including the tolites, MTS was created by algae and represented an in- situ biological-origin structure (Ross, 1959; Plfug, 1968; * E‑mail: [email protected]. Smith, 1968; O’Connor, 1972); and (3) MTS resulted from Received: 2014-03-21 Accepted: 2014-07-03 multiple origins, such as sheet MTS formed by organisms 360 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014 directly, and podlike MTS originating from other activity Jia et al., 2003; Kuang, 2003; Gao and Liu, 2005; Liu et of organisms (e.g. the decayed organic materials producing al., 2005). Subsequent to the reports of MTS discovery air bubbles) (Horodyski, 1976). Thus, people can imagine in the Neoproterozoic in the northeastern, northwestern that these ideas marked the beginning of disputes on the and southwestern China and North China, MTS was origin of MTS. also described from the Mesoproterozoic Gaoyuzhuang During the second stage of MTS investigation (1980- Formation in the Jixian region (Mei, 2005), Tianjing of 1999), additional discoveries of MTS were reported, North China and Wumishan Formation in the western including examples from the Neoproterozoic of North Liaoning Province (Kuang et al., 2009b, 2012; Meng et America (James et al., 1998), Norway (Knoll, 1984), al., 2011). In addition to Chinese occurrences, MTS was Spain (Braga et al., 1995), West Africa (Bertrand-Sarfati continually recognized in the Meso‑ and Neoproterozoic and Moussine-Pouchkine, 1988; Moussine-Pouchkine around the world in Siberia (Bartley et al., 2000; Petrov and Bertrand-Sarfati, 1997), Australia (Calver and Bail- and Semikhatov, 2001; Pope et al., 2003), Russia and the lie, 1990), and India (Sarkar and Bose, 1992), as well as East European Platform (Bartley et al., 2007; Kah et al., Meso-Neoproterozoic of Siberia (Petrov, 1993; Bartley et 2007), India (Chaudhuri, 2003), Norway (Melezhik et al., 1997) (Table1). In addition, during this period, MTS al., 2002), Greenland (Fairchild et al., 2000), West Africa was recognized in China for the first time (Failchild et (Gilleaudeau and Kah, 2010), and South Africa (Bishop al., 1997). Moreover, with regards to the origin of MTS, and Sumner, 2006). several influential theories emerged, including the origins During the third stage, MTS has also been discussed related to seismic activity (Pratt, 1992, 1998, 1999; Qiao in broader terms, than simply its mode of origin, although et al., 1994), and the widespread gas expansion hypothesis the discussions of origin reached the unprecedented levels, that considered how air bubbles played the role to creat particularly with respect to, the seismic origins (represented MTS (Frank and Lyons, 1998; Furniss et al., 1998). by Qiao) and the biological origin (represented by Meng Because of the frequent discoveries of MTS in both Meso‑ and the expansion of understanding combined origins and Neoproterozoic strata, the shapes of MTS became even of MTS and its microsparry infill (Bishop and Sumner, more diverse and complicated, leading to more intricate 2006; Bishop et al., 2006; Pollock et al., 2006; Long, and varied interpretations of origin. 2007; Kuang et al., 2011b; Hazen et al., 2013). Additional During the third stage of MTS investigation (since researches have included investigation of composition, 2000), many researchers turned attention to China. texture, geochemistry morphology, and potential origin Professor Meng, the leader of the International Geoscience of microsparry calcite within MTS (Crawford and Kah, Program (IGCP) 447 (2001-2005, titled of “Microsparry 2004; Crawford et al., 2006; Bishop et al., 2006; Pollock (Molar-Tooth) Carbonates and the Evolution of the Earth et al., 2006; Bartley and Kah, 2007; Goodman and Kah, in the Proterozoic”), greatly promoted the MTS study. 2007), and depositional environments (Stagner et al., These investigations were built upon MTS and related 2004; Gilleaudeau and Kah, 2010). Much of this work has lithologic discoveries during the 1980s; for example, in the only been published in abstract form. northern part of Jiangsu and the Anhui provinces, where Recently, there are only a few published papers MTS was referred to as either abnormal calcite veins or the regarding the MTS study from outside of China. During calligraphy-like structure (Jiangsu Geology and Mineral the period of 2000-2014, among more than 230 papers Exploration Bureau, 1984); in Jilin Province, where it related to MTS, there are 130 papers involving Chinese was called the vermicular limestone (Jilin Geology and MTS research approximately (Table 1 and Figure 1). Mineral Exploration Bureau, 1988); and in Liaoning, Moreover, the theme of concern is no longer the origin of Shandong, and Jiangsu Provinces, where they were called MTS oftentimes, but using it as a symbol of subtidal facies mesh-like calcite veins or calcareous veinlets (Liaoning or as a specific facies useful for geochemical analysis Geology and Mineral Exploration Bureau, 1989). During (Bartley et al., 2007; Kah et al., 2007; Petrov, 2011; Bose this period, additional MTSs were discovered in the et al., 2012; Hoffman et al., 2012; Kah et al., 2012). Meso‑ and Neoproterozoic across China. These Chinese Eventually, the upsurge of MTS research just comes to MTS sites are located in Jilin, Liaoning, Jiangsu, Anhui, China in the recent decades. Shandong, Henan and Yunnan Provinces, Xinjiang and We are left with a series of questions: What is MTS? And Inner Mongolia (Qiao et al., 1994, 2001; Qiao and Gao, what characteristics does it have? Why is it of so frequent 1999; Du et al., 2001; Meng and Ge, 2002; Liu et al., 2003; debates? Why researchers cannot reach a consensus after Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 361 et al ., ., 2004a, 2004b, et al ., 2000 et al ., 2000 et al ., 2010 et al ., 2000 et al ., 2004; Liu et al ., 1997; Gao ., 1995 ., 2011 et al ., 2000 2009 2005 ., 2007; this paper al ., 2003 References ., 2007; Liu Young, 1982 Young, 2004c, 2006a Siedlecka, 1978 Tosca et al Tosca Braga et al Semikhatov, 1962 Semikhatov, Walter Walter Gao and Liu, 2005 ., 1997, 2000; Yang et al ., 2012 Yang et al ., 1997, 2000; Wang et al Wang Swett, 1990; Fairchild Zhang et al Jackson, 1986; Fairchild Young and Long, 1977; Young, 1981 Young, and Long, 1977; Young Fairchild, 1989; Fairchild Meng and Ge, 2002, Kuang et al Bertrand-Sarfati and Caby, 1976; Herrington and Bertrand-Sarfati and Caby, Knoll, 1984; Fairchild and Spiro, 1987; Knoll Petrov and Semikhatov, 1998, 2001, 2009; Pope et Petrov and Semikhatov, Qiao et al ., 1994; Fairchild ., 2011; Liu Jia, 2004; Jia et al ., 2011; - Unit tions tions Kwagunt orld Formation Huainan group Kunyang Group Hejiayao Formation Mid - Upper Riphean Tindir Group (lower) Tindir Xingmincun Formation Fairchild and Roaldtoppen groups and Wynniatt formations and Wynniatt Akademikerbreen Group Thule Group: Narssârssuk Shaler Group: Reynolds Point Burovaya and Shorikha Forma- Akademikerbreen, Polarisbreen Wanlong and Qinggouzi Forma Wanlong - cen- Occurrence of MTS in the W Occurrence of MTS in the

Svalbard Location tral Alaska tral Spitsbergen North China Southern Jilin Grand Canyon Western Arctic Western Central Yunnan Central Southeast Spain Table 1 Table Jiangsu and Anhui Song Mt. in Henan Southern Shandong Shiwangzhuang Formation Northern Cordillera/ East USA Spain China China China China China Southern Liaonng and Jinlin Xingmincun Formation China Russia Region, Siberia Turukhansk Russia Ridge, Siberia Yenisei Canada Norway Norway Norway Finnmark, Northern Norway Båtsfjord Formation Canada/ USA 700 1000 >742 (850) <1000 890 - 930 800 - 700 800 - 600 Greenland Central East Greenland Eleonore Bay Group (upper) 700 - 900 700 - 1200 700 - 1200 Greenland Northern Greenland 1030 - 800 Age range (Ma) Country < 1077 to > 723 1000 - 600?; <1121 China 800 - 1200;1270 779 Era Neoproterozoic 362 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014 et al ., 1998 et al ., 2012 Table 1, continued Table et al ., 2010 et al ., 2000 1998 1991 References Shields, 2002 Shields, 2002 Kah et al ., 2001 Chaudhuri, 2003 Pratt, 1998, 1999 Miller et al ., 2009 Bartley Sarkar and Bose, 1992 Calver and Baillie, 1990 Jackson and Ianelli, 1981 Aitken, 1981; Hofmann, 1985 Southgate, 1991; Shields, 2002 Mei, 2005, 2007; Li Shields, 2002; Shields-Zhou Bertrand-Sarfati and Moussine-Pouchkine, 1988; Aitken, 1981; Hofmann, 1985; James Taylor and Stott, 1973; Marshall and Anglin, 2004 and Stott, 1973; Marshall Taylor Young and Long, 1977; Young, 1981; James et al ., Young, and Long, 1977; Young Keller and Chumakov, 1983; Maslov and Krupenin, Keller and Chumakov, Unit - Purcell - Purcell stone Wonoka Formation Belt Belt Dismal Lakes Billyakh Group Tambien Group Tambien Middle Riphean Taoudenni basinTaoudenni Moussine-Pouchkine and Bertrand-Sarfati, 1997 Godavari rift valley Godavari Supergroup group: Little Dal Group Bitter Springs Formation Gao Yuzhuang Formation Gao Yuzhuang Mackenzie Mountains Super- Rocky Cape Group: Irby Silt- Atar Group: I - 5 and 7 units Bylot Supergroup: Society Cliffs Society Cliffs Bylot Supergroup: Location Tasmania south India West Africa West South Urals Uchur Maya Central India Eastern Arctic Eastern Victoria Island Victoria Western Arctic Western Mackenzie Mt. Flinders Ranges Flinders Ranges Tianjing, Beijing Tianjing, Central Australia Central Northwest Africa Central Cordillera Northern Ethiopia Northern Cordillera Columbia and Alberta Western USA to Southern British USA Western India India China Russia Russia Uplift, Siberia Turukhansk Miroedikha Formation 1997 Gorokhov et al ., 1995; Petrov and Semikhatov, Canada Canada Canada Ethiopia Australia Algeria-Mali USA/Canada USA/Canada 1560 ~750 750 - 900 Mauritania 700 - 1200 Canada 700 - 1000 1000 - 700 - 10001100 Australia <1500 - 1400 <600 to > 550 Australia Age range (Ma) Country < 1270 to > 723 < 1083 to > 781 1650/1350 - 680 Russia 1080 - 723 (850) 1080 - 850 (850) Canada 1600 - 700 (1450) 800 - 700 (750); >827 Australia Era Meso - Neoproterozoic Neoproterozoic Mesoproterozoic Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 363 et al ., 1998 et al ., 2001 ., 1995 Table 1, continued Table ., 2007 ., 2013 et al. (2010). References Shields, 2002 Delaney, 1981 Delaney, Cai et al Kah et al ., 2012 Qiao et al , 1997 1983; Höy, 1993 1983; Höy, Donaldson, 1973 Donaldson, 1973 Jaffrés et al Jaffrés Furniss et al ., 1998 Sumner and Grotzinger, 1996 Sumner and Grotzinger, Ricketts and Donaldson, 1981 Petrov, 1993; Knoll et al Petrov, Campbell and Cecile, 1976, 1981 Semikhatov and Serebryakov, 1983 Semikhatov and Serebryakov, Kuang et al ., 2009b; Zhang 2009 ., 1995; Petrov, 2011 Ovchinnikova et al ., 1995; Petrov, Taylor and Stott, 1973; Ross Taylor Jackson and Ianelli, 1981; James Connor, 1972; Schieber, 1992; 1972; Schieber, Smith, 1968; O ’ Connor, Connor, 1972; Horodyski, 1976, Smith, 1968; O ’ Connor, Unit Ghaap et al. (1998), Pratt Shields (2002), and Liu Belcher Group Belt Supergroup Kavabulake group Sailinhudong Group Muskwa assemblage Dismal Lakes Group Gillespie Lake Group Atar/El Mreiti groups Goulburn Supergroup Belt/Purcell Supergroup Sukhaya Tunguska Formation Sukhaya Tunguska Location Transvaal Hudson Bay Ghaap plateau Western Arctic Western Western Arctic Western Taoudeni Basin Taoudeni Inner Mongolia Southern Africa Great Bear Lake Borden Peninsula Central Cordillera Northwestern USA Northern Cordillera Northern Cordillera Kavabulake of Xinjiang, USA China China Lingyuan, western Liaoning Formation Wumishan RussiaRussia Uplift, Siberia Turukhansk Uplift, Siberia Turukhansk Lower Riphean sequence Canada Canada Canada Canada Canada Zimbabwe South Africa South Africa 1900 2550 2520 >1200 1750 Ma 1200 - 850 1200 - 1100 Mauritania 1465 - 1440 1200 - 17001200 - 1700 Canada Canada 1345 - 1353 <1500 - 1440 Canada 1035 ± 65 Ma Age range (Ma) Country 1270 - 730 (1200) 1450 - 680 (1000) Russia Uchur - Maya Region, Siberia Mid - Upper Riphean 1400 - 1200, 800? China 1600 - 1270 (1300) Era Neoarchean Paleoproterozoic Mesoproterozoic Note: Compilation of MTS reported in the literatures, some detailed references which can be found James 364 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

Figure 1 The statistics of MTS papers. Pt = Proterozoic. more than 100 years debate? What is the implication of tion of a few in the Paleoproterozoic to the latest Archean. MTS study? In more than a decade, the author of this paper Until now, no MTS from the Phanerozoic has been reported has the opportunity to study MTS fortunately during the in the literatures (Table 1 and Figure 1). MTS occured in third stage. This paper not only summarized the study the Neoproterozoic carbonates of Greenland, Norway, results in recent years, but it also discussed the implication Finland, Canada, United States, Siberia, India, Australia, and the prospect of MTS study. The most important is in a West Africa, South Africa and China (such as the southern hope of drawing more attentions to this research. Jilin, eastern Liaoning, Shandong, Jiangsu and Anhui, western Henan, Xinjiang and central Yunnan ) (Table 1). 2 Characteristics of MTS In the Mesoproterozoic, MTS is found in Canada, United States, West Africa, Russia, and the East European Platform Molar tooth structure (MTS) is the sedimentary struc- (Table 1). Additionally, limestones of the Mesoproterozoic ture made up of series of variously shaped voids and ptyg- Gaoyuzhuang and Wumishan Formations in the Mt. matical cracks that were filled with unusual, equant micro- Yanshan also contain abundant MTS. Moreover, MTS sparry calcites from the Precambrian (James et al., 1998; has found in the lightly metamorphosed carbonates in the Kuang, 2003; Pollock et al., 2006). Hutuo group (about 2.5 Ga) in theWutaishan region (Liu et al., 2010). 2.1 A limited distribution in the Proterozoic 2.2 Single mineral composition The distributions of MTS are broadly limited in the Meso-Neoproterozoic around the world, with the excep- The molar tooth carbonate (MTC) is a particular car- Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 365 bonate occurred throughout the Meso‑ to Neoproterozoic 2006). Furthermore, in terms of the degree of bending and carbonates that are filled with MTS. MTS can be referred brokenness, the ribbon MTS can be further divided into to a special sedimentary structure within MTC. Investiga- smooth straight ribbon, curved ribbon, and broken ribbon. tions demonstrated that MTS within MTC is made up of The allochthonous MTS shows signs of clastic or debris microsparry calcites (5-15 μm in diameter) (Bishop and flow, which are the secondary deposit of intraclast due to Sumner, 2006; Pollock et al., 2006; Kuang et al., 2011a). reworking of the autochthonous MTS subsequently. Thus, an important scientific definition is summarized: The second category encompasses the orientation of MTS regularly occurs in the Meso‑ and Neoproterozoic contact relationships between the MTS and the surrounding carbonate rocks, has diverse morphologies at the outcrops, strata, which can be horizontal, vertical, or inclined and also contains distinct microsparry carbonates made of (O’Connor, 1972; Kuang et al., 2006a, 2006b, 2008, 2009a; either isogranular or irregular polygonal microsparry cal- Peng and Kuang, 2010; Peng et al., 2010, 2012). It results cites with grain size of 5-15 μm (Meng and Ge, 2002; in the four morphologies, i.e., perpendicular to bedding Kuang, 2003). Thus, MTC is made of two parts, i.e., the surface, oblique to bedding surface, parallel to bedding molar tooth structure (MTS) that consists of microsparry surface, and disordered. Combining these two categories calcites, and the host rock (or matrix) (Figure 2A-2C, 2F- together, various subtypes are divided (Table 2, Figure 3). 2I). In general, MTS does not appear unusual morphologies The host rock of MTS is typically made up of fine because of differences in location or time of creation, grain carbonates, such as the micrites, dolomites, or but rather these morphologies result from differences in marls (Figure 2); sometimes containing small amount of the strength of the local substrate (Pollock et al., 2006). terrigenous clastic materials (clays and silts). Compared However, in recent years, a new MTS has been found in the with the host rock, the microsparry calcites in the MTS Upper Neoproterozoic Zhangqu Formation in the Suzhou, are clean and bright without contamination and the grain Anhui Province. On this section, MTS is perpendicular to size smaller than that in the host rock (Figure 2F-2I). The the bedding surface and has the same shapes as the other contact relationship between microsparry calcites of MTS MTSs; whereas on the bedding plane, the bulky ribbons of and host rock is typically abrupt, but can show dissolving MTSs make a circular network (Figure 4). edge contact (Kuang et al., 2004a, 2004b, 2004c; Pollock 2.4 Specified sedimentary environment et al., 2006). Under the cathodoluminescence microscope (CL), the microsparry calcites of MTS show homogeneous MTS typically occurs within dynamic sedimen- nuclei in the size of 3-5 μm, non-luminescent or dully tary environments, primarily from subtidal to intertidal luminescent, which are enveloped by the brighter irregular zones of shallow sea (Figure 5). Some scholars consider cement (Figure 2D-2F) (Pollock et al., 2006; Kuang et that MTS was formed in environments of occasional al., 2011a). subaerial exposure (Knoll, 1984). Majority of researchers believe that MTS was formed in shallow water (subtidal 2.3 Morphological diversity to intertidal environments) (Table 3). According to the MTS is often called enigmatic sedimentary structure author's research over the past 10 years (Kuang et al., (Frank and Lyons, 1998; Pollock et al., 2006) because of 2004a, 2004b, 2004c, 2006a, 2006b, 2008, 2009a, 2009b, the complex and diverse shapes. Initially, MTS was a mor- 2011a, 2011b, 2012; Liu et al., 2005, 2010; Peng and phologic term; afterwards, it was assigned the lithologic Kuang, 2010; Peng et al., 2012), the uppermost boundary implication. In brief, morphological descriptions and the for creating MTS is the intertidal zone (with MTS rarely classification of MTS can be divided into two categories reaching the supratidal zone) and the lowermost boundary (Table 2). is near storm wave base. Most commonly, MTS occurred The first category encompasses the origin of shape, in the fine-grained tidal carbonate rocks, in depositional and can be subdivided into the autochthonous MTS and successions characterized by the rhythmic alternaton the allochthonous MTS. The autochthonous MTS can be of micrite, muddy limestone and calcarenite. MTS can, subdivided into ribbons (Smith, 1968; James et al., 1998; alternately develop with or within stromatolite. In the latter Meng and Ge, 2002; Long, 2007; Kuang et al., 2009a), cases, MTS occurs most commonly between the columns the filiform, fusiform, and vermiform morphologies, and of stromatolites, but sometimes coexist. Over all, MTS spheroidal forms (nodule and air bubble) (Ross, 1959; developed primarily on the gentle carbonate slopes during Frank and Lyons, 1998; Furniss et al., 1998; Pollock et al., the Meso-Neoproterozoic, especially on the upper subtidal 366 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

Figure 2 Microfabric of MTS: compositions of MTS and relationship of contact. A-A MTS limestone from the Neoproterozoic Xingmingcun Formation in Dalian; the calcites within MTS are clear and either isometric or anisometric polygons; the contact with the host rock is distinct; the host rock contains clay and organic substances; B and C-MTS from the Neoproterozoic Zhangqu Formation of Anhui Province; B displays sheet calcites that contain dark argillaceous materials; C displays a SEM backscatter image showing cores of individual calcite (potentially originally vaterite; cf. Furniss et al., 1998); C is an enlarged spot of B; D-Under CL, the form of calcite grain from the MTS in the Mesoproterozoic Belt Supergroup, USA (from Pollock et al., 2006) is similar to that in E; E-CL image of calcite from MTS in the Neoproterozoic Nanguanling Formation, Dalian region; individual calcite is isometric polygon with dark color; the calcite cement fills the spaces between the crystals and they illuminate orange-yellow light; F and G-MTS from the Neoproterozoic Wanlong Formation, Jilin Province displays the ptygmatic folds; H-Calcite of MTS from the Neoproterozoic Bitter Spring Formation in Australia; the host rock is made of dolomite; I-MTS from Mesoproterozoic Wumishan Formation, western Liaon- ing; if stained with alizarin red, calcite become red, but dolomite is non-stainable under thin section in H and I. A-B and F-I were taken under polarized microscope. Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 367

Table 2 Category of MTS morphology

Contact relationship with bedding surface Origin Form Perpendicular (PE) Oblique (OB) Parallel (PA) Disordered (DI)

Smooth straight ribbon (SR) PESR OBSR PASR DISR

Curved Ribbon ribbon (CR)

PECR OBCR PACR DICR

Broken ribbon (BR)

PEBR OBBR PABR DIBR

Autochtho- nous MTS Filiform (FF)

PEFF OBFF PAFF DIFF

Fusiform (FS)

PEFS OBFS PAFS DIFS

Vermiform (VF)

Note: The codes in Table 2 mean that, for example, PESR represents straight ribbon Spheroidal form (SF) MTS is perpendicular to the bedding sur- face, followed by the same. Scale bar is 5 cm.

Allochtho- nous Clastic form MTS

368 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

Figure 3 Morphologies of MTS around the world. A-DICR and CF MTS from Mesoproterozoic Belt Supergroup, USA (Photoed by Darrel Long); B-Mainly CR and PSFS MTS from Neoproterozoic Bitter Spring Formation, Australia; C-CR and FF MTS occurred in the Riphean stages, southern Ural (Gao et al., 2007), Russia; D-FS MTS in the limestone from the Mesoproterozoic Gaoyuzhuang For- mation, Jixian, Tianjin; E-FS, VF and SF MTS occurred in the Mesoproterozoic Wumishan Formation in Liaoning Province; F-The coarse OBCR MTS from Neoproterozoic Shiwangzhuang Formation of the Mt. Fulai in Shandong Province; G-CR, FS and VF MTS and H-mainly VF MTS from Mesoproterozoic in Siberia; I-PSER, VF and FS MTS and J-mainly PSER MTS from Neoproterozoic Zhangqu Formation, in the northern Anhui Province (I and J according to Liu et al., 2005); K-DICR MTS of Neoproterozoic Wanlong Formation in Jilin Province; L-Mainly OBCR and PEFS MTS in the Neoproterozoic Xingmincun Formation in Dalian; M-FS MTS from Neoproterozoic in the Tarim Basin, Xingjiang; N-PEFF MTS from Meso-Neoproterozoic Kunyang Group in the Yunnan Prov- ince; O-Mainly PECR and a few of DIFF MTS occurred in the Neoproterozoic in Inner Mongolia; P and Q-DISR and DIBR MTS from Mesoproterozoic Atar Group in Mauritania. Scale bar is 5 cm in A to O and 2 cm in P and Q. Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 369

Figure 4 The circular MTS occurred in the Neoproterozoic Zhangqu Formation in the Suzhou, Anhui Province (D to F, provided by Dr. Zhen-Yu He). zone. These environments were from weak oxidizing to pilations in Ge et al., 2003; Kuang et al., 2006a, 2006b, reducing and the MTC appears to be precipitated from 2011a, 2011b; Long, 2007). Generally, these hypotheses moderate salinity and warm marine waters that were can be divided into three categories: (1) Hypothesis of supersaturated with CaCO3 and received little terrestrial physical origin, i.e., MTS is formed by fissure filling and matters (Kuang et al., 2004b, 2006b, 2007, 2009b, 2011a, liquidation under external mechanical force; (2) Hypoth- 2011b; Peng and Kuang, 2010). esis of biological origin, wherein some scholars think that MTS is derived from actions of bacteria or algae directly; 3 Origins of MTS (3) A synthesized hypothesis, temporarily called “bio- geochemical origin”, which was proposed in recent dec- There are up to 10 hypotheses about the orgin of MTS ade, and it is to analyze the origin of MTS in the terms of since the it was initially discovered and studied (see com- the origin of the cracks, the precipitation of MTC within 370 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

Table 3 Depositional environments of MTS

Location Geological time Depositional environment Reference Depositional system of gentle carbonate ramp on the North America, Meso-Neoproterozoic margin of cratonic basin. Africa Shallow water subtidal zone Kah et al., 2012 Mt. Mackenzie Early Neoproterozoic Bylot Su- northern Canada pergroup, Little Dal Formation Late Mesoproterozoic Victor Shallow water and mid-depth water, gentle slope of Baffin Island Bay Formation the subtidal zone James et al., 1998 Early Neoproterozoic Boot inlet Kah et al., 2001 Arctic islands Formation Mesoproterozoic Belt Super- Located inside the photic zone, below the base of North America Pratt, 1998, 1999 group, Helena Formation storm wave 50-100 m. Subtidal zone, extending to near the base of storm South Africa Archaeozoic Bishop et al., 2006 wave Mauritania Atar Group Shallow water carbonate in subtidal zone kah et al., 2012 Ji-Liao-Xu-Huai Neoproterozoic Shallow water platform and inner to mid-ramp Meng et al., 2006 Area, China Shallow water and strong storm environment on the Jilin, Liaoning platform and inner to mid-ramp; on the inner ramp, Provinces, the Neoproterozoic MTS are rare in the coarse grain rock and stromato- Kuang et al., 2004c Xuhuai region in lite, but plentiful in the lower intertidal zone and the China shallow water subtidal zone. Subtidal zone and the peritidal zone above the base of China Meso-Neoproterozoic Liu et al., 2005 storm wave

cracks, and their relationship to the geochemical condition tially lithified sediments on the ocean floor (such as clay in paleocean and potential for biological catalysis. or marl) to dewater, shrink, and fracture; then, these cracks were filled by isogranular calcite that separated from host 3.1 Hypothesis of physical origin rocks. Finally, under pressure and shear forces, the filled Hypothesis of physical origin dates back to the origi- MTS were deformed into folds that were overlapped with nation of the term “molar tooth structure”. Daly (1912) each other either horizontally or vertically, or broken. considered MTS to be similar to the structure of cleav- However, the hypothesis of seismic origin is difficult to age. Eby (1977) was more inclined to imagine that MTS explain the following questions: reflected an originally evaporitic structure filled by calcite. 1) Why does MTS only develop in the Meso-Neopro- Knoll (1984) regarded MTS to be similar to mudcrack; terozoic fine-grained carbonates and marls? conversely, Calver and Baillie (1990) considered MTS to 2) Can earthquake rhythmicity explain the characteristics be subaqueous shrinkage crack. Cowan and James (1992) of distribution and correlation of MTS worldwide? believed that MTS was formed within strata by tensional 3) Why would earthquake activity be limited to a cracking resulting from wave activity. The hypothesis that particular paleoenvironment from the intertidal zone to the best represents the physical origin is the hypothesis of storm wave base? seismic origin (Pratt, 1992, 1998, 1999, 2001; Qiao et al., 4) Can earthquake hypothesis explain the frequent 1994, 2001; Fairchild et al., 1997; Du et al., 2001; Jia et occurrences of MTS in strata with a thickness of a few al., 2003, 2011). In this scenario, there are two theories: dozen meters (Qiao et al., 2001), and the alternating one regards liquefaction of the substrate by earthquake occurrences of MTS and stromatolite (Jia et al., 2011)? (Qiao et al., 2001), followed by dewatering (Qiao and Gao, 5) MTC is mainly composed of microsparry calcite 2000); another one considers the filling of seismic cracks <15 μm diameter. How does the earthquake hypothesis (Pratt, 1998, 1999; Jia et al., 2011). Together, this hypothe- explain liquefaction and segregation of crystal from sis considers that syndepositional earthquakes caused par- sediments with such small grain size? Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 371 of different types of MTS. MTS1: straight ribbon; MTS2: curved ribbon; MTS3: broken ribbon; MTS4: cambiform; MTS5: vermiform; MTS6: Paleoenvironmental positions

filiform; MTS7: spheroidal form (including porphyritic or nodular and/or air bubble); MTS8: clastic (Allochthonous MTS). Scale bar is 5 cm. Figure 5 Figure 372 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

6) Inside MTS, microsparry calcite show clear reaction, which is controlled by specified geochemical characteristic of early diagenesis under the CL (James features of paleoceans during Meso- to Neoproterozoic. et al., 1998; Frank, 1998; Furniss, 1998; Pollock et al., Horodyski (1983) initially proposed that the MTS was 2006; Liu et al., 2010; Kuang et al., 2011b). How does the created by the gaseous bubbles produced by the decaying earthquake hypothesis explain the universal characteristic organisms. Furniss et al. (1998) suggested that this could of MTC? result in occurring of CO2, as well as bacterial sulfate reduction could produce H S. The migration of these gases 3.2 Hypothesis of biological origin 2 would not only create molar tooth (MT) cracks, but CO2

Hypothesis of biological origin came to being since among the gases could also generate calcite (CaCO3) and

MTS was considered to be resulted from either bacterial or H2S could form pyrite, which is sometimes observed in algal activity. Gillson (1929) initially proposed the organic association with MTS. Through laboratory tests, Furniss (algae) origin, and Ross (1959) considered the MTS was and his team obtained cracks similar to MTS. Subsequent directly or indirectly related to living process of primary work by Frank and Lyons (1998) and the team of Gellatly organisms that lived in the original marls. The discovery and Winston (1999) further interpreted MTC as the product of organic filaments in MTS was a great support to this of microsparry calcite rapidly replacing an initial vaterite theory (Plfug, 1968; Smith, 1968; O’Connor, 1972). James precursor. In addition, via the study of carbon isotopic et al. (1998) thought that MTS mostly existing in the Me- compositions, they determined that MTS was created so-Neoproterozoic is related to the depositional condition during the early stage of diagenesis and the forming during this period, especially, to the development of mi- condition must be conducive to the rapid deposit of calcite croorganic mats. The accumulation of SnO2 in carbonates (Frank and Lyons, 1998). Similarly, Marshall and Anglin was related to the activity of organisms (Bao et al, 1996). (2004) presented a hypothesis that the MTS was resulted

A higher abundance of SnO2 in the MTS may indicate that from clathrate (CO2 gas-hydrate) destabilization. Shields organic matter was involved during the forming process of (1999) further suggested that the infilling of MTS was MTC (Kuang, 2003; Kuang et al., 2006b). Meng and oth- related to the changes of marine chemical composition ers (2006) also insisted the possibility of biological origin. and the disappearance of MTS was resulted from decrease 2- Mei (2005) and Mei and others (2009) believed that the of CaCO3 concentration (and/or the increase of SO4 origin of MTS in the carbonate rocks of the Gaoyuzhuang concentration) (Shields, 2002). Formation may be related with the activity of organisms In general, the proposal of Shields (1999) gained the in Jixian. The waxing and waning of MTS was correlated widest support (Ge et al., 2003; Kuang, 2003; Meng et al., with the failing and booming of stromatolite respectively. 2006; Kuang et al., 2007) conducting in-depth analysis Chen (2009) also suggested that MTS might be biologi- of chemical properties of paleocean during the Meso- cal origin. However, the idea and interpretation of a bona Neoproterozoic (Hofmann, 1985; Kah et al., 2001; Chu fide biological origin continues to encounter challenges. et al., 2004; Bartley et al., 2007; Kuang et al., 2008, The lower organic content in MTS than that in the host 2009b, 2011a). At the same time, through analyzing the rocks speaks against a biological origin. Additionally, fila- compositional and geochemical features of MTS, the mentous organism (bacteria or algae) in the MTS also can hypothesis of bio-geochemical origin overcomes the be found in the host rocks. As a result, it is very difficult difficulties and limitations of the former two theories, to prove that the MTS was the direct product of organic specifically whether MTS is partly controlled by the joint activity, i.e., the biological origin can not perfectly repro- influence of unique chemical properties in the paleocean duce the forming process of MTS and the causes of vari- and potential metabolic activities of the microorganic ous complex shapes that occurred. colonies (Shields, 2002; Bishop et al., 2006; Pollock et al., 2006; Bartley et al., 2007). In addition, the studies that 3.3 Hypothesis of bio-geochemical origin carried out by Bishop and others (2006) and Pollock and Hypothesis of bio-geochemical origin is based on others (2006) advanced understanding of origin of MTS evidence that MTS is neither an organism (James et al., to a new level. Pollock and others (2006) detailed how 1998) nor is a biological produced sedimentary structure. deposition of microsparry calcite could directly related However, the creation of MTS is potentially influenced with the gaseous bubbles caused by decomposition of by biological activity. At the same time, the process of organisms in the host rocks, and showed how the grain crystallization of MTS obviously is a typically chemical size and strength of lithological substrates could control Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 373 crack morphology in the host rocks. By contrast, Bishop in the paleocean; also, it is closely related to the environ- and Sumner (2006) utilized a wave-induced fluid flow ment of atmosphere (PCO2 ), paleolatitude (which controls model to explain the formation of MTS. In this scenario, the temperature of seawater), and the biological processes sediments cracks, forming an interconnected network (levels of redox and the circulation between PCO2 and car- of MT cracks; then, storm waves pump sea water into bon in the seawater could accelerate the crystallization of open MT crack networks, causing rapid microcrystalline CaCO3 as well) (Kuang et al., 2006b, 2007, 2008, 2009b, carbonate nucleation, ripening of nuclei, and growth of 2011a, 2011b; Liu et al., 2010). Based on the model of Pol- granular microsparry calcites (cores) that filled cracks. In lock and others (2006), we also propose a model of MTS the view of Bishop and Sumner (2006), filled MTS ribbons origin (Kuang et al., 2011b) (Figure 5), which can explain deform plastically as host sediments are compacted and the origin of most morphologies. As a result, the bio-ge- dewatered, and MTS deforms brittlely under additional ochemical hypothesis maybe is the most parsimonious compaction, so as to create various complicated shapes. method for analyzing the origin of MTS. Even through, it Post-depositional deformation of cracks is also possible in is still difficult to explain the cyclic MTS that was discov- the theory of Pollock and others (2006) (see also Stagner ered in the Zhangqu Formation in Suzhou, Anhui Province et al., 2004), although their work shows the effects of recently (Figure 4). Noticeably, a variety of complicated substrate strength as a critical factor as well. In both cases, shapes of MTS can not be reasonably explained by the ori- deposition of microsparry calcite is independent with the gin theories discussed above. The study of MTS origin still creation of MTS cracks in the host rocks. Microcrystals has a long way to go. grow in the nuclei of MT in these cracks and quickly fill the cracks. Obviously, the hypothesis of bio-geochemical 4 Research significance origin is widely accepted, because it better explains the origin of materials and creation process of MTS. So far, compared to the majority achievements in the depositional environments and the origins of MTS, the 3.4 Summary of origin research studies on microtexture and related geochemistry just be- The mechanism of MTS origin has not yet come to a gin. The creation and occurrence of MTS is not an isolated complete understanding. However, the ranges of MTS re- simple event, its nature of global occurrence in a limited lated subjects (such as lithologic features, morphologies, time interval and specified depositional environment leads environments, geologic periods and geographic distribu- us to recognize that the continual study of MTS should not tions of MTS) have been recognized. The origin of MTS is only focus on the issue of origin. Although some aspects basically undertood that MTS is the collective product of of the MTS origin are still controversial, most researchers evolution of global paleocean, paleoclimate, and paleoen- agree with the two practical functions of MTS, i.e., as a vironment, and could not be simply formed by earthquakes facies indicator (indicating a shallow water subtidal zone) or the “earthquake rhythms”. Some researches link the and as a mark of stratigraphic correlation (used for strati- MTS to the vanishing of stromatolites under seismic ac- graphical correlation of the Proterozoic which is widely tivities (Jia et al., 2011), which obviously deviates from distributed in stable craton in the world). These two practi- the fundamental seismic interpretation. It is a common cal functions are possibly more significant than the ori- knowledge that stromatolite is the byproduct of microbial gin in the Precambrian study. The MTS study provides a growth and lithification (Grotzinger and Knoll, 1999). If new approach to resolve various important Precambrian it is true that seismicity would cause the disappearance of questions, i.e., it provides a better understanding on ocean stromatolites and create the MTS (Jia et al., 2011), then, chemistry (Pollock et al., 2006), depositional palaeogeog- the implication would be that earthquake activity is one of raphy, and stratigraphic correlation, also it may even be external factors affecting the biological activity; however, useful for comprehending the supercontinent reconstruc- MTS is not created by liquefaction stimulated by earth- tion (Gao and Qiao, 2001; Melezhik et al., 2002; Vigner- quake but affected by biological activity. esse, 2005; Qiao et al., 2007). In recent years, our study further proves that the crea- 4.1 Global change in the Precambrian tion of MTS is not a solitary process, but is controlled by physical properties (temperature, and solubility of CaCO3) During different historical periods of the Earth, the li- 2- and chemical properties (concentrations of Fe, SO4 , oxy- thology or mineral composition and diversity are different. gen fugacity, salinity, and isotopic levels of C, O and Sr) For example, the carbonate minerals include many types, 374 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

Figure 6 Origin model for MTS. A-Location of the contact zone (the yellow rectangle) discussed in B-E; B-Gases are produced by decayed organic matters inside sediments at the contact zone with pore fluids, and cracks are created in the matrix; C-Due to the lower rate of diagenesis in matrix along with the increase of gaseous concentration, the pressure increases as well; finally, in a well- sealed system, the continual gas supply resulted in the development of cracks of various sizes, diverse magnitudes, and mixed patterns (Pollock et al., 2006); the activities of exterior forces, such as the storm wave or the sliding on the slope, also could create cracks and further enlarge or deform them; D-Mineralogically pure calcites within cracks precipitated from the interstitial water of matrix, which helps the rapid crystallization and diagenesis; the organic or argillaceous catalysis accelerates the nucleate formation of microsparry calcite in the MTS (Naka and Chujo, 2001); E-MTS from the cracks produced by the gaseous activity is often in a banded or spotty shape; alternatively, MTS from the cracks deformed or expanded by the exterior forces are not only in divergent shapes, but also are mixed with the matrix (the microsparry calcites of MTS as the cement are scattered in the matrix). such as the seafloor crusts of fibrous crystals, micrites, ygen (Kuang et al., 2011b), and warm sea water. Over all, aragonite fans, and stromatolites (Kah and Knoll, 1996; the thermal field of the Earth inclined to a relatively high James et al., 1998; Bartley et al., 2000). The global change end, which might be influenced by relatively higher partial of palaeogeography, paleocean and palaeoclimate controls pressure of carbon dioxide (PCO2 ) of the Precambrian (Bar- the formation, evolution, distribution and disappearance of tley and Kah, 2007; Kah and Riding, 2007) or be affected MTS. The time interval from the earliest record of MTS by volcanic events. Furthermore, from the view of the pal- (the Paleoproterozoic, 2.6 Ga, in South Africa) to the latest aeogeographic location of tectonic plates, the developmen- occurrence (750 Ma, in Australia), is a crucial period for tal region of MTS locates around the mid-low latitude area the prokaryotic organisms evolving into eukaryotic organ- (Zhang et al., 2000; Zhao et al., 2004; Jaffrés et al., 2007; isms and for evolution of multicellular organisms. Li et al., 2008) in the continental margins (Figure 7) and the During this special period, the major occurrence of MTS salinity of seawater was in the normal range all the time. globally is correlated to the occurrence of banded magnet- However, before major appearance and after disappearance ite, high value of isotopic carbon, low value of isotopic ox- of MTS, the characteristic of marine carbonate geochemistry Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 375 displayed relatively high salinity, especially the content of characteristics in the lithology, morphology, depositional sulfate was increased (Shields, 2002). The disappearance of environment, microtexture, and geochemical feature, but MTS has been used as one of the markers concerning with they also are limited within specified time and space. the beginning of the Cryogenian in the pre-glacial period The MTS in the Neoproterozoic carbonates in the North (Shields-Zhou et al., 2012). China can be broadly correlated with the one from other The origin of MTS thereby appears to have been closely continents. The geological age of MTS is in the range of related to the Proterozoic palaeoenvironment, paleocean, ca. 1700-750 Ma (may be earlier than 720 Ma, see Mac- and palaeoclimate. After searching microtexture and geo- donald et al., 2010) before the Sturtian glaciation. MTS chemical characteristic of MTS, it is proved that the crea- completely disappeared before the Marinoan glaciation tion and vanishing of MTS not only was controlled by the (630 Ma) (Meng et al., 2006; Shields et al., 2012). Clearly, alteration of chemical properties in paleocean, but also before the glaciation, during the Late Mesoproterozoic to jointly influenced by atmosphere, climate, and organic the Early Neoproterozoic convergence of Rodinia super- activity. The visible characteristic of MTS is the organic continent, the warm oceanic environment was beneficial assemblage of internal composition and the external con- to the creation of MTS. Their reliable global distribution figuration. Therefore, based on the aspects above, the es- and excellent correlation indicates that MTS was widely tablished origin model can favorably explain the source of created on the entire Rodinia supercontinent (Figure 7), materials for the microsparry calcite, the process of crea- which further implies that the North China Plate and the tion, and the control factors (Figure 6, and Kuang et al., Rodinia supercontinent may be associated in some degree. 2011b, 2012). It requires more researches to clarify whether the MTS As a special type of carbonates with an enigmatic and the supercontinent cycle have a kind of relationship feature worldwide, MTS only occurs in the paleocean in or not. However, MTS occurred in the geological records the transitional period between the lifeless Archean and by means of episodic deposit is an indisputable fact. the Phanerozoic represented by the Cambrian bio-radiation There are at least three episodic deposits (Table 1): the and the shell fragment carbonates (James et al., 1998). first is during the Neoarchean (South Africa, 2.6 Ga)to Thus, the MTC is the responsive deposit and the record of the Early Paleoproterozoic (Canada, 1.9-1.75 Ga), and the Precambrian alteration around the world. In return, we then respectively, about 1.6-1.4 Ga (represented by North can learn the global alteration of the Precambrian in term America, North China and Siberia), and 1.0-0.8 Ga (North of studying the characteristics of MTS. China, Europe and Australia). According to the new testing data, the final convergence of the Colombia supercontinent 4.2 Stratigraphic correlation of the Precambrian occurred in 1.4 Ga approximately (Zhao et al., 2004), The study of either intra-basinal or inter-basinal cor- while the convergence of the Rodinia supercontinent relation of the Proterozoic sedimentary strata is a chal- took place around 1.2-1.0 Ga (Sun et al., 2012) or 1.2- lenge due to the lack of suitable organisms for detailed bi- 0.9 Ga (Qiao et al., 2007; Li et al., 2008). The coupling ostratigraphy and the shortage of geochronological data, in relationship between peaks of MTS occurrence and the addition to the complicated litho-stratigraphy (Kah et al., final convergence time of the supercontinent imply that 2012). On the other hand, the occurrence and vanishing of there may be some connections. Whether these connec- MTC was not only related with depositional environment tions are clearly to supercontinents, or perhaps to sea level and marine chemical conditions of that time, but also co- and the distribution of environments that result from su- ordinated with the biological evolution on the Earth. MTC percontinent formation, needs more evidence to be estab- is a particular type of the Meso-Neoproterozoic carbonate lished (Figure 7) in the future. with special texture and structure and it is controlled by the conditions of marine physics and chemistry. Furthermore, 5 Advanced research for the future MTC is also precisely limited by the depositional environ- ment and lithologic facies. The characteristics of global MTS has important implications for researches in distribution of MTS will be a good index to solve the prob- paleocean and palaeogeography. It will be helpful for ex- lems of mute stratigraphic correlation in the Precambrian. ploring the relationship between paleocean environment, sedimentary geochemical condition, palaeogeography and 4.3 Reconstruction on global palaeogeography microbial activity, and to systematically study and discuss All of the MTSs around the world not only have similar the origin mechanism of MTS. Therefore, the advanced 376 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

–720 Ma, Rodina rifting finished –825 Ma, Rodina rifting started

East Ant. Greater India Kalahari Australia Arabia Nubia South Rio de South Tarim la Plata Tarim China Sahara Laurentia China Congo- Siberia Greater North San Francisco India China Seychelles Australia Siberia E. Madagascar Amazonia East Ant. Laurentia West Kalahari Africa North China Arabia Baltica Rio de Nubia la Plata Sahara Congo- San Francisco Amazonia Baltica West Africa

–900 Ma, Rodina assembling finished –1100 Ma, Assembling Rodina

Yangtze Cathaysia Siberia Greater Tarim Tarim India Laurentia

Rodinia Rio de Australia la Plata North North Australia China China East Siberia Kalahari Greater Ant. India East South Ant. China Amazonia Baltica Arabia Kalahari Laurentia Nubia

Sahara Rio de la Plata Congo- San Francisco Congo- West San Francisco Africa Amazonia Baltica West Africa

MTS Continental rift Spreading ridge Orogen Active margin Superplume

Figure 7 Occurrence of MTS in the Rodinia Supercontinent. MTS usually developed in the margin of Supercontinent. The base map of assembly and breakup and their chronology of Rodinia are cited from Li et al. (2008); and locations and time outline of MTS are according to Table 1. research in the future, on the one hand is to continuously sparry calcites, which are important to reveal the creation discuss the relationship among paleocean environment, process, material resources and factors affecting crystal- geochemical condition and MTS types to improve the lization. The crystallization process of microsparry calcite theory of origin; on the other hand, is to further confirm is described or analyzed very occationally on the micro- the possibility whether MTS can be used as a marker for scopic level. In addition, the scientific information of tem- stratigraphic correlation and for sedimentary facies identi- perature, pressure and external conditions and the crys- fication or not. As a result, it can be applied to the research- tallization process of MTS formation are hard to obtain, es on paleocean and palaeogeographic reconstruction and even if some simulation experiments were accomplished will make contribution to solve some significant scientific (Goodman and Kah, 2007; Hazen et al., 2013). The above problems. mentioned researches should be promoted in the future. 1) Geochemistry and microfabric studies 2) Further studies of the relationships among the mor- Geologists have conducted substantial researches on phology of MTS, depositional environment and the geo- the morphology and development of MTS previously. chemical composition However, studies regarding characteristics of microtexture Although the complicated morphology led to the enig- and geochemistry of MTC are still insufficient. Up to now, ma of MTS origin, the relationship between morphology technological measures including polarizing microscope of MTS and depositional environment is evident. With the (PM), scanning electron microscope (SEM), cathodolumi- further study and more morphologies being discovered, nescence microscope (CL), backscattered-electron diffrac- the microtexture of different morphologies and geochem- tion (BSED) and electron probe microanalysis (EPMA) istry characteristics of MTS will reveal the origin of MTS have been used to reveal the shape of MT microsparry on a new level. Although the relationship between mor- calcites and the relationship between them. Geologists, phology of MTS and sedimentary environment revealed whereas can not clearly display the interior structure and by geochemical characteristics were emphasized and dis- the distribution relationship of cements between micro- cussed previously, comparative study on the geochemical Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 377 properties and sedimentary facies of different MTS are still sociated with the breakup of Rodinia. MTC possibly had necessary. Not only to compare the geochemical properties a potential connect with the formation and evolution of of different MTS in the same sedimentary environment, supercontinent. It is also of global correlation significance but also to compare the same types of MTS in different and can be used as a marker of global change. As a special sedimentary environments, will be helpful to indicate the product existed only in the Precambrian, MTS certainly is relationship among morphology of MTS, sedimentary related to geochemical conditions of the unique Precam- environments and geochemical properties of paleocean. brian Ocean and the sedimentary background. So it surely 3) Origin of dolomitic MTS will reveal the geochemical conditions and is useful in re- The researches of the past one hundred years constructing paleocean environment in the Precambrian. indicated that MTS of different geologic periods around As above mentioned, these are the urgent tasks of MTS the world consists primarily of microsparry calcite. studies, in order to demonstrate the viability of using MTS From the Mesoproterozoic Belt Supergroup in North as an index for the Precambrian stratigraphic correlation America, Riphean stage in the southern Ural, Russia to and sedimentary environment identification, and to prove the Gaoyuzhuang and the Wumishan Formations in the its scientific values as early as possible. Yanshan region of China, MTS consist of microsparry calcite. Among the Neoproterozoic, although host rocks Acknowledgements of MTS consist of dolomite, MTS is still composed of microsparry calcite, e.g., MTS from the Bitter Spring This paper is sponsored by the National Natural Sci- Formation in Australia (Figure 2H) and from the Wangshan ence Foundation of China (40772078, 41472082). During Formation in northern Anhui Province of China. In the the writing process of this paper, I would like to express meantime, a new problem appears: a large quantity of our sincere gratitude to Prof. Yong-Qing Liu, who offered dolomitic MTS developed in the dolomitic strata in the useful comments and suggestions and some fantastic pho- lower part of the Yingchengzi Formation on the Zhaokanzi tos; Ms. Dechin Wang is so kind to translate the manu- section in eastern Liaoning Province. These MTS-like script into English; thanks to the graduate student Ming- structures developed inside the primary dolomite consist Wei Wang, Dr. Nan Peng and Qi-Chao Zhang, who made of dolosiltite with indistinct trait of filling and are lack of contributions to organizing references, figures and tables cementing lineage. The testing results of isotopic carbon of this paper. I also express my thanks to Prof. Zeng-Zhao and isotopic oxygen indicate the features of syngenesis Feng and the editing team of Journal of Palaeogeography or penecontemporaneous dolomite (unpublished data). In for their much effort to polish this paper. At meantime, I the previous studies, MTS is consisted of microsparry cal- give my respectably thanks to four reviewers: Dr. Linda cite. Is the dolomitic MTS-like mineral originally MTC? Kah, Dr. Graham Shields-Zhou, Dr. Liu-Qin Chen and How is it formed? We need to understand the creation of Prof. Lin-Zhi Gao for their appropriated opinions and ben- dolomitic MTS‑ like, structures, especially, the diagenesis efited suggestions, and especially thanks to Dr. Linda Kah, process. she is so kind to streamline the whole paper. 4) Practical value to the Precambrian study MTC is a type of carbonates with special origin and References commonly develops during the Meso-Neoproterozoic around the world. MTC appears to have initiated in the Aitken, J. D., 1981. Stratigraphy and sedimentology of the upper Neoarchean-Early Paleoproterozoic, peaked its devel- Proterozoic Little Dal Group, Mackenzie Mountains, Northwest opment during the 1000-900 Ma (Table1 and Figure 7) Territories. In: Campbell, F. H. A., (ed). Proterozoic Basins of on the continents around the world, and disappeared be- Canada. Geological Society of Canada, Paper, 81(10): 47-71. fore the Sturtian glaciation (750 Ma or 720 Ma) (Shields, Bartley, J. K., Kah, L. C., 2007. Unusual carbonate microspar associ- ated with “fluidized” beds: A geologic snapshot of spontaneous 2002; Macdonald et al., 2010). As we know, the regional- water-column nucleation and formation of a viscous colloid. Ge- scale magmatic events at 1460 Ma, 1380 Ma, and 1280 ological Sosiety of America Abstracts with Programs, 39(6): 420. Ma can be associated with the breakup of the proposed Bartley, J. K., Kah, L. C., McWilliams, J. L., Stagner, A. F., 2007. Late Paleoproterozoic supercontinent, Nuna (Columbia); Carbon isotope chemostratigraphy of the Middle Riphean type the events at 1300-900 Ma overlapped with the assembly section (Avzyan Formation, Southern Urals, Russia): Signal re- of Rodinia; and the events at 825 Ma, 800 Ma, 780 Ma, covery in a fold-and-thrust belt. Chemical Geology, 237(1-2): 755 Ma, and possibly 720 Ma (Li et al., 2008), were as- 211-232. 378 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

Bartley, J. K., Knoll, A. H., Grotzinger, J. P., Sergeev, V. N., 2000. 611. Lithification and fabric genesis in precipitated stromatolites Chen, L. Q., 2009. Origin models of molar tooth structures and their and associated peritidal carbonates, Mesoproterozoic Billyakh temporal spatial distribution significances. Journal of Earth Sci- Group, Siberia. SEPM Special Publication, 67: 59-73. ences and Environment, 31(3): 245-253 (in Chinese with Eng- Bartley, J. K., Pope, M. C., Knoll, A. H., Petrov, P. Y., 1997. Mo- lish abstract). lar-tooth nodules, Burovaya Formation (Early Neoproterozoic), Chu, X. L., Zhang, T. G., Zhang, Q. R., Feng, L. J., Zhang, F. S., Turukhansk Uplift, Siberia. Geological Sosiety of America Ab- 2004. Carbon isotopic variations of Proterozoic carbonates in stracts with Programs, 29(6): 192. Jixian, Tianjin, China. Science in China Series D: Earth Sciences, Bauerman, H., 1885. Report on the geology of the country near the 47(2): 160-170 forth-ninth parallel of north latitude west of the Rocky Moun- Cowan, C. A., James, N. P., 1992. Diastasis cracks: Mechanically tains. Canada Geological Survey of Report Progress 1882-1884. generated synaeresis-like cracks in Upper Cambrian shallow wa- Part B: 1-42. ter oolite and ribbon carbonates. Sedimentology, 39(6): 1101- Bertrand-Sarfati, J., Caby, R., 1976. Carbonates et stromatolites 1118. du sommet du Grouped’ Eleanore Bay (PreCambrien terminal) Crawford, J. C., Goodman, E. E., Kah, L. C., 2006. Origin of Pre- au Canning Land (Groenland oriental). Grølands Geologiske cambrian molar-tooth microspar: A new look at an old problem. Undersøgelse Bulletin, 119: 1-51 (in French). Geological Sosiety of America Abstracts with Programs, 38(3): Bertrand-Sarfati, J., Moussine-Pouchkine, A., 1988. Is cratonic sedi- 24. mentation consistent with available models? An example from Crawford, J. C., Kah, L. C., 2004. Investigating the origin of Precam- the Upper Proterozoic of the West African craton. Sedimentary brian molar-tooth carbonate morphology. Geological Sosiety of Geology, 58(2-4): 255-276. America Abstracts with Programs, 36(5): 251. Bishop, J. W., Sumner, D. Y., 2006. Molar tooth structures of the Daly, R. A., 1912. Geology of the North American Cordillera at the Neoarchean Monteville Formation, Transvaal Supergroup, South Forty-Ninth Parallel. GSC Memoir, 38(1-3): 1-857. Africa. I: Constraints on microcrystalline CaCO3 precipitation. Delaney, G. D., 1981. The Mid-Proterozoic Wernecke Supergroup, Sedimentology, 53(5): 1049-1068. Wernecke Mountains, Yukon Territory. In: Campbell, F. H. A., Bishop, J. W., Sumner, D. Y., Huerta, N. J., 2006. Molar tooth struc- (ed). Proterozoic Basins of Canada. GSC Paper, 81(10): 1-23. tures of the Neoarchean Monteville Formation, Transvaal Super- Donaldson, J. A., 1973. Possible correlation between Proterozoic group, South Africa. II: A wave-induced fluid flow model. Sedi- strata of the Canadian Shield and North American Cordillera. mentology, 53(5): 1069-1082. University of Idaho and Idaho Bureau of Mines and Geology, Bose, P. K., Eriksson, P. G., Sarkar, S., Wright, D. T., Samanta, P., Belt Symposium, 61-75. Mukhopadhyay, S., Mandal, S., Banerjee, S., Altermann, W., Du, Y. S., Han, X., Gu, S. Z., Lin, W. J., Zhang, C. H., 2001. Earth- 2012. Sedimentation patterns during the Precambrian: A unique quake event deposits in Mesoproterozoic Kunyang Group in record? Marine and Petroleum Geology, 33(1): 34-68. central Yunnan Province and its geological implications. Science Braga, J. C., Martin, J. M., Riding, R., 1995. Controls on microbial in China (Series D), 31(4): 283-289 (in Chinese with English dome fabric development along a carbonate-siliciclastic shelf- abstract). basin transect, Miocene, SE Spain. Palaios, 10(4): 347-361. Eby, D. E., 1977. Sedimentation and early diagenesis within eastern Cai, X. F., Tian, W. M., Zhang, X. H., Wu, L. Y., 2013. Formation portions of the “Middle Belt carbonate interval” (Helena Forma- symbols and significance of Mesoproterozoic carbonate platform tion), Belt Supergroup (Precambrian), western Montana [Ph. D. in the area of Kavabulake, Xinjiang. Resources Survey and Envi- thesis]. State University of New York, Stony Brook, NY, 1-504. ronment, 34(1): 8-15 (in Chinese with English abstract). Fairchild, I. J., Einsel, G., Song, T. R., 1997. Possible seismic origin Calver, C. R., Baillie, P. W., 1990. Early diagenetic concretions asso- of molar tooth structures in Neoproterozoic carbonate ramp de- ciated with intrastratal shrinkage cracks in an Upper Proterozoic posits, North China. Sedimentology, 44(4): 611-636. dolomite, Tasmania, Australia. Journal of Sedimentary Petrology, Fairchild, I. J., Spiro, B., 1987. Petrological and isotopic implica- 60(2): 293-305. tions of some contrasting Late Precambrian carbonates, NE Campbell, F. H. A., Cecile, M. P., 1976. Geology of the Kilohigok Spitsbergen. Sedimentology, 34(6): 973-989. Basin, Goulburn Group, Bathurst Inlet, District of Mackenzie. Fairchild, I. J., Spiro, B., Herrington, P. M., Song, T., 2000. Con- Geological Society of Canada, Paper, 76(1A): 369-377. trols on Sr and C isotope compositions of Neoproterozoic Sr-rich Campbell, F. H. A., Cecile, M. P., 1981. Evolution of the Early Prote- limestones of East Greenland and North China. SEPM Special rozoic Kilohigok Basin, Bathurst Inlet Victoria Island, Northwest Publication, 67: 297-313. Territories. In: Campbell, F. H. A., (ed). Proterozoic Basins of Fenton, C. L., Fenton, M. A., 1937. Belt series of the north: Stra- Canada. Geological Society of Canada, Paper, 81(10): 103-132. tigraphy, sedimentation, paleontology. GSA Bulletin, 48(12): Chaudhuri, A. K., 2003. Stratigraphy and palaeogeography of the 1873-1970. Godavari Supergroup in the south-central Pranhita-Godavari Val- Frank, T. D., Lyons, T. W., 1998. “Molar-tooth” structures: A geo- ley, South India. Journal of Asian Earth Sciences, 21(6): 595- chemical perspective on a Proterozoic enigma. Geology, 26(8): Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 379

683-686. mineral evolution. Reviews in Mineralogy and Geochemistry, Furniss, G., Rittel, J. F., Winston, D., 1998. Gas bubble and expan- 75(1): 79-107. sion crack origin of “molar-tooth” calcite structures in the Mid- Herrington, P. M., Fairchild, I. J., 1989. Carbonate shelf and slope dle Proterozoic Belt Supergroup, western Montana. Journal of facies evolution prior to Vendian glaciation, central East Green- Sedimentary Research, 68(1): 104-114. land. In: Gayer, R. A., (ed). The Caledonide Geology of Scandi- Gao, L. Z., Ding, X. Z., Yin, C. Y., Ren, L. D., Li, T. D., Chen, T. Y., navia. London: Graham and Trotman, 263-273. Chen, B. W., Li, G. S., Lu, S. N., 2007. Meso-and Neoproterozoic Hoffman, P. F., Halverson, G. P., Domack, E. W., Maloof, A. C., stratigraphic sequences in the southern Ural area and discovery Swanson-Hysell, N. L., Cox, G. M., 2012. Cryogenian gla- of molar-tooth structures in carbonate and clastic rocks of the ciations on the southern tropical paleomargin of Laurentia (NE sequences and their geological significance. Geology in China, Svalbard and East Greenland), and a primary origin for the up- 34(6): 962-973 (in Chinese with English abstract). per Russøya (Islay) carbon isotope excursion. Precambrian Re- Gao, L. Z., Liu, Y. Q., 2005. Microspar veins in the Neoproterozo- search, 206-207: 137-158. ic Hejiayao Formation in the Songshan area, Henan Province. Hofmann, H. J., 1985. The Mid-Proterozoic Little Dal macrobiota, Geological Review, 51(4): 373-381 (in Chinese with English Mackkenzie Mountains, North-West Canada. Palaeontology, abstract). 28(2): 331-354. Gao, L. Z., Qiao, X. F., 2001. Events stratigraphy in Neoproterozoic Horodyski, R. J., 1976. Stromatolites of the upper Siyeh Limestone and Early Paleozoic and its relationship with supercontinent Ro- (Middle Proterozoic), Belt Supergroup, Glacier National Park, dinia in North China. Gondwana Research, 4(4): 617. Montana. Precambrian Research, 3(6): 517-536. Gao, L. Z., Zhang, C. H., Liu, P. J., Tang, F., Song, B., Ding, X. Z., Horodyski, R. J., 1983. Sedimentary geology and stromatolites of 2009. Reclassification of the Meso- and Neoproterozoic chron- the Middle Proterozoic Belt Supergroup, Glacier National Park, ostratigraphy of North China by SHRIMP zircon ages. Acta Geo- Montana. Precambrian Research, 20(2-4): 391-425. logica Sinica (English Edition), 83(6): 1074-1084. Jackson, G. D., 1986. Notes on the Proterozoic Thule Group, north- Ge, M., Meng, X. H., Kuang, H. W., Cai, G. Y., Liu, Y. X., Liu, W. ern Baffin Bay. Geological Society of Canada, Paper, 86(1A): F., 2003. Molar-tooth carboantes: Carbonate research highlight 541-552. of the world in the 21st century. Acta Sedimentologica Sinica, Jackson, G. D., Ianelli, T. R., 1981. Rift-related cyclic sedimenta- 21(1): 81-89 (in Chinese with English abstract). tion in the Neohelikian Borden Basin, northern Baffin Island. In: Gellatly, A. M., Winston, D., 1999. Were “molar-tooth” gas expan- Campbell, F. H. A., (ed). Proterozoic Basins of Canada. Geologi- sion voids in the Helena Formation (Middle Proterozoic Belt Su- cal Society of Canada, Paper, 81(10): 269-302. pergroup, Montana) initially filled by vaterite? Geological Sosi- Jaffrés, J. B. D., Shields, G. A., Wallmann, K., 2007. The oxygen iso- ety of America Abstracts with Programs, 31(4): 13. tope evolution of seawater: A critical review of a long-standing Gilleaudeau, G. J., Kah, L. C., 2010. Molar-tooth crack formation controversy and an improved geological water cycle model for and the Proterozoic marine substrate: Insights from the Belt Su- the past 3.4 billion years. Earth-Science Reviews, 83(1-2): 83- pergroup, Montana and the Atar Group, Mauritania. Geological 122. Sosiety of America Abstracts with Programs, 42(5): 137. James, N. P., Narbonne, G. M., Sherman, A. G., 1998. Molar-tooth Gillson, J. L., 1929. Contact metamorphism of the rocks in the carbonates: Shallow subtidal facies of the Mid- to Late Protero- Pend Oreille district, northern Idaho. USGS Professional Paper, zoic. Journal of Sedimentary Research, 68(5): 716-722. 158(F): 111-121. Jia, Z. H., 2004. A research on the depositional environments chang- Goodman, E. E., Kah, L. C., 2007. Reassessing formation of Precam- ing and its’ biological responsing during the sedimentation of brian molar-tooth microspar: Constraints from carbonate pre- the Neoproterozoic Jiuliqiao Formation, Huainan Region, Anhui cipitation experiments. Geological Sosiety of America Abstracts Province, China [Doctoral thesis]. Hefei University of Technol- with Programs, 39(6): 420. ogy (in Chinese with English abstract). Gorokhov, I. M., Semikhatov, M. A., Baskakov, A. V., Kutyavin, E. Jia, Z. H., Hong, T. Q., Zheng, W. W., Li, S. Y., 2003. The characters P., Melnikov, N. N., Sochava, A. V., Turchenko, T. L., 1995. Sr and environments of the seismites of the Neoproterzoic Wang- isotopic composition in Riphean, Vendian, and Lower Cambrian shan Formation in North Anhui. Journal of Stratigraphy, 27(2): carbonates from Siberia. Stratigraphy and Geological Correla- 146-149, 158 (in Chinese with English abstract). tion, 3: 1-28. Jia, Z. H., Ning, X. F., Hong, T. Q., Zheng, W. W., 2011. The Neo- Grotzinger, J. P., Knoll, A. H., 1999. Stromatolites in Precambrian proterozoic molar-tooth carbonate rock veins in northern Anhui carbonates: Evolutionary mileposts or environmental dipsticks? and Jiangsu Provinces and their forming mechanism. Journal of Annual Review of Earth and Planetary Sciences, 27: 313-358. Palaeogeography (Chinese Edition), 13(6): 627-634 (in Chinese Höy, T., 1993. Geology of the Purcell Supergroup in the Fernie West- with English abstract). half map area, southeastern British Columbia. Geological Survey Jiangsu Geology and Mineral Exploration Bureau, 1984. Regional of Canada Bulletin, 84: 1-157. Geology of Jiangsu Province. Beijing: Geological Publishing Hazen, R. M., Downs, R. T., Kah, L., Sverjensky, D., 2013. Carbon House, 45-57 (in Chinese). 380 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

Jilin Geology and Mineral Exploration Bureau, 1988. Regional Ge- Kuang, H. W., Liu, Y. X., Meng, X. H., Ge, M., 2006a. Molar-tooth ology of Jilin Province. Beijing: Geological Publishing House, structure and sedimentary characteristics of the Wanlong Forma- 73-74 (in Chinese). tion of Neoproterozoic at Erdaojiang section of Tonghua County Kah, L. C., Bartley, J. K., Teal, D. A., 2012. Chemostratigraphy of in southern Jilin Province. Journal of Palaeogeography (Chinese the Late Mesoproterozoic Atar Group, Taoudeni Basin, Mauri- Edition), 8(4): 457-466 (in Chinese with English abstract). tania: Muted isotopic variability, facies correlation, and global Kuang, H. W., Meng, X. H., Ge, M., 2006b. Discussion on origin for isotopic trends. Precambrian Research, 200-203: 82-103. Molar Tooth carbonate rocks: An example From the Neoprote- Kah, L. C., Crawford, D. C., Bartley, J. K., Kozlov, V. I., Sergeeva, rozoic in Jilin-Liaoning Area. Journal of Palaeogeography, 8(1): N. D., Puchkov, V. N., 2007. C- and Sr-isotope chemostratigra- 63-73 (in Chinese with English abstract). phy as a tool for verifying age of Riphean deposits in the Kama- Kuang, H. W., Liu, Y. X., Meng, X. H., Ge, M., 2007. A study on the Belaya aulacogen, the east European platform. Stratigraphy and environmental conditions of the microsparite (Molar-Tooth) car- Geological Correlation, 15(1): 12-29. bonates. Chinese Journal of Geochemistry, 26(1): 28-34. Kah, L. C., Knoll, A. H., 1996. Microbenthic distribution of Prote- Kuang, H. W., Jin, G. C., Liu, Y. X., 2009a. Genesis types of the rozoic tidal flats: Environmental and taphonomic considerations. Neoproterozoic molar tooth structures in the southeastern Jilin Geology, 24(1): 79-82. and eastern Liaoning Provinces and its research significances. Kah, L. C., Lyons, T. W., Chesley, J. T., 2001. Geochemistry of a Science in China Series D: Earth Sciences, 52(1 Supplement): 1.2 Ga carbonate-evaporite succession, northern Baffin and By- 135-142. lot Islands: Implications for Mesoproterozoic marine evolution. Kuang, H. W., Peng, N., Luo, S. S., Cen, C., Li, J. H., Chen, M. P., Precambrian Research, 111(1-4): 203-234. 2009b. Discovery of MT structure and its geological features and Kah, L. C., Riding, R., 2007. Mesoproterozoic carbon dioxide levels studying significance in the eastern Yanshan in Lingyuan, Liaon- inferred from calcified cyanobacteria. Geology, 35(9): 799-802. ing Province. Progress in Natural Science, 19(12): 1308-1318 Keller, B. M., Chumakov, N. M. E., 1983. Stratotype of the Riphean (in Chinese with English abstract). Stratigraphy, Geochronology. USSR Academy of Sciences, Geo- Kuang, H. W., Liu, Y. Q., Peng, N., Liu, L. J., 2011a. Geochemistry logical Institute, Trudy, 377: 1-184 (in Russian). of the Neoproterozoic molar-tooth carbonates in Dalian, eastern Knoll, A. H., 1984. Microbiotas of the Late Precambrian Hunnberg Liaoning, China, and its geological implications. Earth Science Formation, Nordaustlandet, Svalbard. Journal of Paleontology, Frontiers, 18(4): 25-40 (in Chinese with English abstract). 58(1): 131-162. Kuang, H. W., Liu, Y. Q., Peng, N., Liu, Y. X., Li, J. H., 2011b. On Knoll, A. H., Kaufman, A. J., Semikhatov, M. A., 1995. The carbon- origin of molar tooth carbonate rocks. Journal of Palaeogeogra- isotopic composition of Proterozoic carbonates: Riphean succes- phy (Chinese Edition), 13(3): 253-261 (in Chinese with English sions from northwestern Siberia (Anabar Massif, Turukhansk abstract). Uplift). American Journal of Science, 295(7): 823-850. Kuang, H. W., Liu, Y. Q., Peng, N., Luo, S. S., Li, J. H., Cen, C., Knoll, A. H., Swett, K., 1990. Carbonate deposition during the Late Chen, M. P., 2012. Molar-tooth structure from the Mesoprotero- Proterozoic Era: An example from Spitsbergen: American Jour- zoic Wumishan Formation in Lingyuan, Yanshan Region, North nal of Science, 290(A): 104-132. China, and geological implications. Acta Geologica Sinica (Eng- Kuang, H. W., 2003. Neoproterozoic molar tooth (microspar) car- lish Edition), 86(1): 85-95. bonate sedimentology and its significance in Jilin and Liaoning Li, H. K., Zhu, S. X., Xiang, Z. Q., Su, W. B., Lu, S. N., Zhou, H. Y., region [Doctoral thesis]. China University of Geosciences (Bei- Geng, J. Z., Li, S., Yang, F. J., 2010. Zircon U-Pb dating on tuff jing) (in Chinese with English abstract). bed from Gaoyuzhuang Formation in Yanqing, Beijing: Further Kuang, H. W., Jin, G. C., Liu, Y. X., Meng, X. H., Ge, M., 2004a. constraints on the new subdivision of the Mesoproterozoic stra- The environmental conditions of the microsparite (molar tooth) tigraphy in the northern North China. Acta Petrologica Sinica, 26 carbonates opened out by geochemistry: An example from the (7): 2131-2140 (in Chinese with English abstract). microsparite carbonates of Neoproterozoic in Ji-Liao region, Li, Z. X., Bogdanova, S. V., Collins, A. S., Davidson, A., De Waele, China. Natural Gas Geoscience, 15(2): 150-155 (in Chinese B., Ernst, R. E., Fitzsimons, I. C. W., Fuck, R. A., Gladkochub, with English abstract). D. P., Jacobs, J., Karlstrom, K. E., Lu, S., Natapov, L. M., Pease, Kuang, H. W., Li, Y. X., Zeng, Y. T., Meng, X. H., Ge, M., 2004b. V., Pisarevsky, S. A., Thrane, K., Vernikovsky, V., 2008. Assem- Biomarkers in the molar tooth (MT)-bearing limestones in the bly, configuration, and break-up history of Rodinia: A synthesis. Jilin-Liaoning area of China. Chinese Journal of Geochemistry, Precambrian Research, 160(1-2): 179-210. 23(4): 334-341. Liaoning Geology and Mineral Exploration Bureau, 1989. Regional Kuang, H. W., Liu, Y. X., Meng, X. H., Ge, M., Cai, G. Y., 2004c. Geology of Liaoning Province. Beijing: Geological Publishing Sedimentary lithofacies and petrological features of Neoprote- House, 82-123 (in Chinese). rozoic MT structures-bearing carbonates in Jilin-Liaoning area. Liu, W. F., Meng, X. H., Ge, M., Kuang, H. W., Liu, Y. X., 2004. Ori- Acta Geoscientica Sinica, 25(6): 647-652 (in Chinese with Eng- gin of the Neoproterozoic molar-tooth carbonates in the Xuzhou- lish abstract). Huainan area. Geological Review, 50(5): 454-463 (in Chinese Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 381

with English abstract). 2143 (in Chinese with English abstract). Liu, Y. Q., Gao, L. Z., Liu, Y. X., 2005. Neoproterozoic molar-tooth Meng, X. H., Ge, M., Ren, G. X., Liu, Z. L., Li, X. G., Liu, H. J., structure and constraint of depositional facies and environment in 2011. The example of Cosmos-Earth System responses: The su- the North China Platform in Jiangsu, Anhui and Liaoning, eastern percyclic sequence and rhythms of the Wumishan Sub-system of China. Acta Geologica Sinica (English Edition), 79(4): 533-539. Jixian System. Earth Science Frontiers, 18(4): 107-122 (in Chi- Liu, Y. Q., Kuang, H. W., Peng, N., Liu, Y. X., Jiang, X. J., Xu, H., nese with English abstract). 2010. Proterozoic microspar and constraint of sedimentary envi- Miller, N. R., Stern, R. J., Avigad, D., Beyth, M., Schilman, B., 2009. ronment in China. Acta Petrologica Sinica, 26(7): 2122-2130 (in Cryogenian slate-carbonate sequences of the Tambien Group, Chinese with English abstract). Northern Ethiopia (I): Pre-“Sturtian” chemostratigraphy and re- Liu, Y. X., Kuang, H. W., Cai, G. Y., Meng, X. H., Ge, M., 2003. gional correlations. Precambrian Research, 170(3-4): 129-156. Depositional environments of molar-tooth limestones of the Moussine-Pouchkine, A., Bertrand-Sarfati, J., 1997. Tectonosedi- Neoproterozoic Yingchengzi Formation in southern Liaoning. mentary subdivisions in the Neoproterozoic to Early Cambrian Geological Bulletin of China, 22(6): 419-425 (in Chinese with cover of the Taoudenni Basin (Algeria-Mauritania-Mali). Journal English abstract). of African Earth Sciences, 24(4): 425-443. Long, D. G. F., 2007. Tomographic study of Paleoproterozoic car- Naka, K., Chujo, Y., 2001. Control of crystal nucleation and growth bonates as key to understanding the formation of molar-tooth of calcium carbonate by synthetic substrates. Chemistry of Mate- structure. Gondwana Research, 12(4): 566-570. rials, 13(10): 3245-3259. Macdonald, F. A., Schmitz, M. D., Crowley, J. L., Roots, C. F., Jones, O’Connor, M. P., 1972. Classification and environmental interpre- D. S., Maloof, A. C., Strauss, J. V., Cohen, P. A., Johnston, D. tation of cryptalgal organosedimentary “molar-tooth” structure T., Schrag, D. P., 2010. Calibrating the Cryogenian. Science, from Late Precambrian Belt-Purcell Supergroup. Journal of Ge- 327(5970): 1241-1243. ology, 80(5): 592-610. Marshall, D., Anglin, C. D., 2004. CO2-clathrate destabilization: A Ovchinnikova, G. V., Semikhatov, M. A., Gorokhov, I. M., 1995. new model of formation for molar tooth structures. Precambrian U-Pb systematization of the Precambrian carbonates: Riphean Research, 129(3-4): 325-341. Sukhaya Tunguska Formation, Turukhansk Uplift, Siberia. Li- Maslov, A. V., Krupenin, M. T., 1991. Riphean Sections of the thology and Mineral Resources, 30(5): 525-536. Baskiriya Anticlinorium (Western Slope of the South Urals), Peng, N., Kuang, H. W., 2010. Morphology of molar-tooth structures Sverdlovsk. Institute of Geology and Geochemistry, Uralian in Neoproterozoic and its indication significance for the deposi- Branch of USSR Academy of Sciences, 1-172 (in Russian). tional environment of Jinshitan area in Dalian, eastern Liaoning Mei, M. X., 2005. Preliminary study on sequence-stratigraphic po- Province. Acta Petrologica et Mineralogica, 29(2): 189-198 (in sition and origin for molar-tooth structure of the Gaoyuzhuang Chinese with English abstract). Formation of Mesoproterozoic at Jixian section in Tianjin. Jour- Peng, N., Kuang, H. W., Liu, Y. Q., Li, J. H., 2010. Lithologic charac- nal of Palaeogeography (Chinese Edition), 7(4): 437-447 (in teristics and sedimentary environment of molar-tooth carbonates Chinese with English abstract). in the Xingmincun Formation, Golden Pebble Beach Region, Da- Mei, M. X., 2007. Implications of the Precambrian non-stromatolitic lian. Bulletin of Mineralogy, Petrology and Geochemistry, 29(2): carbonate succession making up the third member of Mesoprote- 127-133 (in Chinese with English abstract). rozoic Gaoyuzhuang Formation in Yanshan area of North China. Peng, N., Liu, Y., Kuang, H., 2012. Relationship between deposi- Journal of China University of Geosciences, 18(3): 191-209. tional environment and morphology of molar tooth: Taking the Mei, M. X., Gao, J. H., Meng, Q. F., 2009. MISS in Mesoproterozoic Neoproterozoic molar-tooth in Dalian, China as an example. non-stromatolitic limestones: A case study from the third mem- Geological Journal of China Universities, 18(1): 180-188 (in ber of Gaoyuzhuang Formation at Qiangon section in Beijing. Chinese with English abstract). Earth Science Frontiers, 16(5): 207-218 (in Chinese with Eng- Petrov, P. Y., 1993. Depositional environments of the lower forma- lish abstract). tions of the Riphean sequence, northern part of the Turukhansk Melezhik, V. A., Roberts, D., Gorokhov, I. M., Fallick, A. E., Zwaan, uplift, Siberia. Stratigraphy and Geological Correlation, 1: 182- K. B., Kuznetsov, A. B., Pokrovsky, B. G., 2002. Isotopic evi- 191. dence for a complex Neoproterozoic to Silurian rock assemblage Petrov, P. Y., 2011. Molar tooth structures: Formation and specificity in the North-Central Norwegian Caledonides. Precambrian Re- of carbonate diagenesis in the Late Precambrian, Middle Riphean search, 114 (1-2): 55-86. Sukhaya Tunguska Formation of the Turukhansk Uplift, Siberia. Meng, X. H., Ge, M., 2002. The sedimentary features of Proterozoic Stratigraphy and Geological Correlation, 19(3): 247-267. microspar (molar-tooth) carbonates in China and their signifi- Petrov, P. Y., Semikhatov, M. A., 1997. Structure and environmen- cance. Episodes, 25(3): 185-195. tal conditions of a transgressive Upper Riphean complex: Mi- Meng, X. H., Ge, M., Kuang, H. W., Nielsen, J. K., 2006. Origin of roedikha Formation of the Turukhansk Uplift, Siberia. Lithology microsparite carbonates and the significance in the evolution of and Mineral Resources, 32: 11-29. the Earth in Proterozoic. Acta Petrologica Sinica, 22(8): 2133- Petrov, P. Y., Semikhatov, M. A., 1998. The Upper Riphean stroma- 382 JOURNAL OF PALAEOGEOGRAPHY Oct. 2014

tolitic reefal complex: Burovaya Formation of the Turukhansk stract). Region, Siberia. Lithology and Mineral Resource, 33: 539-560. Qiao, X. F., Song, T. R., Gao, L. Z., Peng, Y., Li, H. B., Gao, M., Petrov, P. Y., Semikhatov, M. A., 2001. Sequence organization and Song, B., Zhang, Q. D., 1994. Seismic sequence in carbonate growth patterns of Late Mesoproterozoic stromatolite reefs: An rocks by vibrational liquefaction. Acta Geologica Sinica (English example from the Burovaya Formation, Turukhansk Uplift, Sibe- Edition), 68(3): 243-265. ria. Precambrian Research, 111(1-4): 257-281. Qiao, X., Gao, L., Peng, Y., 2007. Mesoproterozoic earthquake Petrov, P. Y., Semikhatov, M. A., 2009. Platforms: Shorikha Forma- events and breakup of the Sino-Korean Plate. Acta Geologica tion of the Turukhansk Uplift, Siberia. Stratigraphy and Geologi- Sinica (English Edition), 81(3): 385-397. cal Correlation, 17(5): 461-475. Rezak, R., 1957. Stromatolites of the Belt Series in Glacier National Pflug, H. D., 1968. Gesteinsbildende organismen aus dem molar Park and Vicinity, Montana. USGS Professional Paper, 294(D): tooth limestone der Beltserie (Präkambrium). Palaeontographica 127-154. Abteilung B: Paläophytologie, 121(4-6): 134-141 (in German). Ricketts, B. D., Donaldson, J. A., 1981. Sedimentary history of the Pollock, M. D., Kah, L. C., Bartley, J. K., 2006. Morphology of Belcher Group of Hudson Bay. In: Campbell, F. H. A., (ed). Pro- molar-tooth structures in Precambrian carbonates: Influence of terozoic Basins of Canada. Geological Society of Canada, Paper, substrate rheology and implications for genesis. Journal of Sedi- 81(10): 235-254. mentary Research, 76(2): 310-323. Ross, C. P., 1959. Geology of Glacier National Park and the Flathead Pope, M. C., Bartley, J. K., Knoll, A. H., Petrov, P. Y., 2003. Mo- region, northwestern Montana. USGS Professional Paper, 296: lar tooth structures in calcareous nodules, Early Neoproterozoic 1-125. Burovaya Formation, Turukhansk Region, Siberia. Sedimentary Ross, G. M., Villeneuve, M. E., Theriault, R. J., 2001. Isotopic prov- Geology, 158(3-4): 235-248. enance of the lower Muskwa assemblage (Mesoproterozoic, Pratt, B. R., 1992. Shrinkage feature (molar tooth structure) in Pro- Rocky Mountains, British Columbia): New clues to correlation terozoic limestone: New model for their origin through synsedi- and source areas. Precambrian Research, 111(1-4): 57-77. mentary earthquate-induced dewatering. Geological Sosiety of Sarkar, S., Bose, P. K., 1992. Variations in Late Proterozoic stromato- America Abstracts with Programs, 24(7): 53. lites over a transition from basin plain to nearshore subtidal zone. Pratt, B. R., 1998. Molar-tooth structure in Proterozoic carbonate Precambrian Research, 56(1-2): 139-157. rocks: Origin from synsedimentary earthquakes, and implica- Schieber, J., 1992. Facies and deposition of a mixed terrigenous-car- tions for the nature and evolution of basins and marine sediment. bonate suite in a Mid-Proterozoic epicratonic sea: The Newland GSA Bulletin, 110(8): 1028-1045. Formation, Belt Supergroup, Montana, U. S. A. Neues Jahrbuch Pratt, B. R., 2001. Oceanography, bathymetry and syndepositional für Geologie und Paläontologie - Abhandlungen, 184: 155-180. tectonics of a Precambrian intracratonic basin: Integrating sedi- Semikhatov, M. A., 1962. The Riphean and Lower Cambrian of the ments, storms, earthquakes and tsunamis in the Belt Supergroup Yenisei Ridge. Moscow: USSR Academyof Sciences, Geological (Helena Formation, ca. 1.45 Ga), western North America. Sedi- Institute, Trudy, 68(a): 1-242 (in Russian). mentary Geology, 141-142: 371-394. Semikhatov, M. A., Serebryakov, S. N., 1983. The Siberian Hypos- Pratt, B. R., Winston, D., Rittel, J. F., Furniss, G., 1999. Gas bub- tratotype of the Riphean. Moscow: USSR Academy of Sciences, ble and expansion crack origin of molar-tooth calcite structures Geological Institute, Trudy, 367: 1-224 (in Russian). in the Middle Proterozoic Belt Supergroup, western Montana: Shields, G. A., 1999. Working towards a new stratigraphic calibra- Discussion and reply. Journal of Sedimentary Research, 69(5): tion scheme for the Neoproterozoic-Cambrian. Eclogae Geologi- 1136-1145. cae Helvetiae, 92: 221-233. Qiao, X. F., Gao, L. Z., 1999. Earthquake events in Neoproterozoic Shields, G. A., 2002. ‘Molar-tooth microspar’: A chemical explana- and Early Paleozoic and its relationship with supercontinen- tion for its disappearance ~ 750 Ma. Terra Nova, 14(2): 108-113. tal Rodinia in North China. Chinese Science Bulletin, 44(16): Shields-Zhou, G. A., Hill, A. C., Macgabhann, B. A., 2012. Chapter 1753-1757 (in Chinese). 17 — The Cryogenian Period. In: Gradstein, F. M., Ogg, J. G., Qiao, X. F., Gao, L. Z., 2000. Earthquake events in Neoproterozoic Schmitz, M. D., Ogg, G. M., (eds). The Geologic Time Scale. and Early Paleozoic and its relationship with supercontinental Boston: Elsevier, 393-411. Rodinia in North China. Chinese Science Bulletin, 45(10): 931- Siedlecka, A., 1978. Late Precambrian tidal-flat deposits and algal 935. stromatolites in the Båtsfjord Formation, East Finnmark, North Qiao, X. F., Gao, L. Z., Peng, Y., 2001. Neoproterozoic of Ancient Norway. Sedimentary Geology, 21(4): 277-310. Tanlu Fault Zone: Cataclysm, Sequence and Biology. Beijing: Smith, A. G., 1968. Origin and deformation of some molar-tooth Geological Publishing House, 1-128 (in Chinese). structures in Precambrian Belt-Purcell Supergroup. Journal of Qiao, X. F., Gao, L. Z., Peng, Y., Zhang, Y. X., 1997. Composite Geology, 76(4): 426-443. stratigraphy of the Sailinhuodong Group and ore-bearing micrite Southgate, P. N., 1991. A sedimentological model for the Loves mound in the Bayan Obo Deposit, Inner Mongolia, China. Acta Creek Member of the Bitter Springs Formation, northern Ama- Geologica Sinica, 71(3): 202-211 (in Chinese with English ab- deus Basin. Australia Bureau of Mineral Resources Bulletin, 236: Vol. 3 No. 4 Hong-Wei Kuang: Review of molar tooth structure research 383

113-126. aoning Provinces, China: Implications for the Late Precambrian Stagner, A. F., Bartley, J. K., Kah, L. C., 2004. Variation in deforma- evolution of the southeastern North China Craton. Precambrian tion style of molar-tooth structure during fluidization: Tawaz For- Research, 216-219: 162-176. mation, Atar Group, Mauritania. Geological Sosiety of America Young, G. M., 1981. The Amundsen embayment, Northwest Terri- Abstracts with Programs, 36(2): 88. tories: Relevance to the Upper Proterozoic evolution of North Sumner, D. Y., Grotzinger, J. P., 1996, Herringbone calcite: Petrog- America. In: Campbell, F. H. A., (ed). Proterozoic Basins of raphy and environmental significance: Journal of Sedimentary Canada. Geological Society of Canada, Paper, 81(10): 203-218. Research, 66(3): 419-429. Young, G. M., 1982. The Late Proterozoic Tindir Group, east-central Sun, L. H., Gui, H. R., Chen, S., 2012. Geochemistry of sandstones Alaska: Evolution of a continental margin. GSA Bulletin, 93(8): from the Neoproterozoic Shijia Formation, northern Anhui Prov- 759-783. ince, China: Implications for provenance, weathering and tec- Young, G. M., Long, D. G. F., 1977. Carbonate sedimentation in a tonic setting. Chemie der Erde - Geochemistry, 72(3): 253-260. Late Precambrian shelf sea, Victoria Island, Canadian Arctic Ar- Taylor, G. C., Stott, D. F., 1973. Tuchodi Lakes Map-Area, British chipelago. Journal of Sedimentary Petrology, 47(3): 943-955. Columbia. GSC Memoir, 373: 1-37. Zhang, C. H., Gao, L. Z., Wu, Z. J., Shi, X. Y., Yan, Q. R., Li, D. J., Tosca, N. J., Macdonald, F. A., Strauss, J. V., Johnston, D. T., Knoll, 2007. Zircon SHRIMP U-Pb ages of tuff in the Kunyang Group A. H., 2011. Sedimentary talc in Neoproterozoic carbonate suc- in central Yunnan Province: Orogenic evidence for Grenville Pe- cessions. Earth and Planetary Science Letters, 306(1-2): 11-22. riod in South China. Chinese Science Bullitin, 52(7): 818-824 Vigneresse, J. L., 2005. The specific case of the Mid-Proterozoic ra- (in Chinese with English abstract). pakivi granites and associated suite within the context of the Co- Zhang, S. H., Li, Z. X., Wu, H. C., Wang, H. Z., 2000. The new lumbia supercontinent. Precambrian Research, 137(1-2): 1-34. achievements and palaeogeographic significance of research on Walter, M. R., Veevers, J. J., Calver, C. R., Gorjan, P., Hill, A. C., paleomagnetic in Neoproterozoic of North China Platform. Sci- 2000. Dating the 840-544 Ma Neoproterozoic interval by iso- ence in China Series D: Earth Sciences, 30(S1): 138-147 (in topes of strontium, carbon, and sulfur in seawater, and some in- Chinese with English abstract). terpretative models. Precambrian Research, 100(1-3): 371-433. Zhang, S. H., Zhao, Y., Yang, Z. Y., He, Z. F., Wu, H., 2009. The 1.35 Wang, B. S., Zhang, X. Y., Li, J. B., 2007. Seismites sequence of Shi- Ga diabase sills from the northern North China Craton: Implica- wangzhuang Formation of Neoproterozoic in South Shandong tions for breakup of the Columbia (Nuna) supercontinent. Earth sector of Tancheng-Lujiang fault zone. Journal of Shandong Uni- and Planetary Science Letters, 288 (3-4): 588-600. versity of Science and Technology (Natural Science), 26(4): 4-9, Zhao, G. C., Sun, M., Wilde, S. A., Li, S. Z., 2004. A Paleo-Mesopro- 22 (in Chinese with English abstract). terozoic supercontinent: Assembly, growth and breakup. Earth- Yang, D. B., Xu, W. L., Xu, Y. G., Wang, Q. H., Pei, F. P., Wang, F., Science Reviews, 67(1-2): 91-123. 2012. U-Pb ages and Hf isotope data from detrital zircons in the Neoproterozoic sandstones of northern Jiangsu and southern Li- (Edited by Xiu‑Fang Hu)