This Article Appeared in a Journal Published by Elsevier. the Attached

Home , Central India, Delwara

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights

Author's personal copy

Precambrian Research 238 (2013) 120–128

Contents lists available at ScienceDirect

Precambrian Research

journal homepage: www.elsevier.com/locate/precamres

New age constraints for the Proterozoic Aravalli–Delhi successions of

India and their implications

a,b,∗ b c d

N. Ryan McKenzie , Nigel C. Hughes , Paul M. Myrow , Dhiraj M. Banerjee ,

d e

Mihir Deb , Noah J. Planavsky

Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, TX 78712, USA

Department of Earth Sciences, University of California, Riverside, CA 92521, USA

Department of Geology, Colorado College, Colorado Springs, CO 80903, USA

Department of Geology, Delhi University, Chattra Marg, Delhi 110007, India

Department of Geology and Geophysics, Yale University, New Haven, CT 06520, USA

a r t i c l e i n f o a b s t r a c t

Article history: Proterozoic sedimentary successions of India are important archives of both the tectonic history of the

Received 24 April 2013

Indian subcontinent and the geochemical evolution of Earth surface processes. However, the lack of ﬁrm

Received in revised form

age constraints on many of these stratigraphic units limits their current utility. Here, we present new

19 September 2013

detrital zircon age data from strata of the southern Aravalli–Delhi Orogenic Belt (ADOB) and the Rajasthan

Accepted 2 October 2013

Vindhyan successions. The Alwar Group of the southern Delhi Supergroup yielded a large population of Available online 12 October 2013

∼

1.2 Ga detrital zircon grains, which refutes the 1.9–1.7 Ga age assertion for this unit. Detrital zircon age

distributions from the southern Alwar Group differ strongly from the Alwar Group of the “North Delhi

Keywords:

Proterozoic Belt”, demonstrating miscorrelation between these two regions. The Jhamarkotra Formation of the Lower

Aravalli Aravalli Group contains a large population of 1.9–1.7 Ga detrital zircon grains. Therefore, the unit cannot

∼

Vindhyan be 2.1 Ga as traditionally assumed. Age distributions of the Aravalli and Delhi supergroups are similar

Detrital zircon to those of the lower and upper Vindhyan successions, and we postulate contiguous sediment sources for

Phosphorite both regions, with strata of the tectonically deformed ADOB representing the distal margin equivalents

Boring billion

of the Vindhyan successions. Additionally, a late Paleoproterozoic age for the Jhamarkotra Formation

nulliﬁes the hypothesis that the markedly positive carbonate ␦ C values in this unit are linked to the

2.3–2.0 Ga Lomagundi–Jatuli positive isotope excursion. The potential of a large late Paleoproterozoic

(ca. 1.7 Ga) positive ␦ C excursion contrasts with the long-held view of a prolonged period of carbon

isotope stasis during the so-called ‘boring billion’.

1. Introduction However, there are recently developed chronostratigraphic frame-

works for these various successions (e.g., Patranabis-Deb et al.,

Thick Proterozoic sedimentary successions that cover the Indian 2007; Bengtson et al., 2009; Malone et al., 2008; Pradhan et al.,

shield are considered deposits of discrete isolated basins that are 2010; Bickford et al., 2011; McKenzie et al., 2011; Mukherjee

often referred to as the “Purana Basins” (Purana means ancient) et al., 2012; Pradhan et al., 2012). These are critical to further-

(e.g., Holland, 1909; Valdiya, 1995; Chakraborty, 2006; Chakraborty ing understanding of the tectonic–sedimentary evolution of the

et al., 2010). Modern physiographic features and differences in Indian subcontinent. Additionally, these successions preserve crit-

tectonic deformation typically deﬁne the boundaries of the so- ical information about the Proterozoic evolution of the biosphere

called Purana Basins. The degree of continuity or isolation of these (e.g., Bengtson et al., 2009; Papineau et al., 2009, 2013). The Aravalli

basins from one another during the time of sediment accumulation Supergroup, in particular, contains carbonate rocks with markedly

remains unclear. Interbasinal correlation has largely been hindered positive carbonate ␦ C values that have been linked to the

∼

by a lack of depositional age constraints on the strata within them. 2.3–2.1 Ga Paleoproterozoic Lomagundi–Jatuli carbonate carbon

isotope excursion (Sreenivas et al., 2001; Maheshwari et al., 2002,

2010; Purohit et al., 2010). The Aravalli Supergroup has also been

∗ proposed to contain the oldest phosphorites in the rock record,

Corresponding author at: Department of Geological Sciences, Jackson School of

which along with additional geochemical data, have been used for

Geosciences, University of Texas at Austin, USA.

inferences on biogeochemical cycling following the ∼2.4 Ga Great

E-mail addresses: [email protected], [email protected]

(N.R. McKenzie). Oxidation Event (Papineau et al., 2009, 2013; Papineau, 2010).

Author's personal copy

N.R. McKenzie et al. / Precambrian Research 238 (2013) 120–128 121

In this study we present new U-Pb detrital zircon age data from ARAVALLI-DELHI OROGENIC BELT

major stratigraphic units of the southern Aravalli and Delhi super- Delhi Sgr.

groups and the Vindhyan successions of Rajasthan, India. These Ajabgarh Gr. mixed siliciclastic-carbonate

Alwar Gr. siliciclasitic dominated

data provide new constraints that drastically revise the deposi-

Aravalli Sgr.

tional ages of the Aravalli and Delhi supergroups. Furthermore,

Upper Aravalli Gr. siliciclastic dominated

these new age constraints appear to redeﬁne the signiﬁcance

Middle Aravalli Gr. siliciclastic dominated

of carbonate carbon isotope trends from Proterozoic Aravalli Lower Aravalli Gr. strata. Jhamarkotra Fm. carbonate dominated Delwara Fm. siliiclastic with interspersed

mafic volcanics

2. Geologic setting VINDHYAN SUCCESSIONS

Upper Vindhyan

2.1. Aravalli–Delhi Orogenic Belt Bhander Gr. mixed siliciclastic-carbonate Rewa Gr. siliciclastic dominated

Kaimur Gr. siliciclastic dominated

The roughly north–south trending Aravalli–Delhi Orogenic Belt

Lower Vindhyan

(ADOB) of western India exceeds 700 km in length (Deb et al.,

Semri Gr. mixed siliciclastic-carbonate

1989; Roy and Jakhar, 2002) (Fig. 1). Two major stratigraphic units

are deﬁned in the ADOB: the lower Aravalli Supergroup and the

Fig. 2. Simpliﬁed stratigraphic nomenclature and general lithologies for strata of

upper Delhi Supergroup (Fig. 2). The ADOB is divided into north- the Aravalli–Delhi Orogenic Belt and the Vindhyan successions (units listed in strati-

ern and southern “belts” with strata of both the Aravalli and graphic order). Sgr. = Supergroup; Gr. = Group; Fm. = Formation.

Delhi supergroups recognized in the southern belt, whereas all

strata of the northern belt are classiﬁed as Delhi Supergroup, and

thus it is commonly termed the “North Delhi Belt”. At least two

major tectonothermal events are recorded in the ADOB that can Jhamarkotra Formation, which contains localized phosphorite

be broadly deﬁned as late Paleoproterozoic (1.9–1.6 Ga) and late (Banerjee, 1971; Banerjee et al., 1986). It has been suggested that

Mesoproterozoic–early Neoproterozoic (1.1–0.8 Ga) in age (Deb the Aravalli Supergroup was deposited in a series of “sub-basins”

et al., 1989, 2001; Buick et al., 2006; Bhowmik et al., 2010; Meert along an active rift margin (Roy and Paliwal, 1981; Roy and Jakhar,

et al., 2010). 2002) but, just as with the deﬁnition of the Purana Basins, the

The Aravalli Supergroup overlies the ∼2.5 Ga Banded Gneiss so-called “sub-basins” of the Aravalli Supergroup are deﬁned by

Complex-I (BGC-I) Deb and Sarkar, 1990 (Deb et al., 1989; modern day outcrop limits and lithological facies variations, pri-

Wiedenbeck et al., 1996; Buick et al., 2006; Meert et al., 2010; marily the presence or absence of phosphatic stromatolites. As

Pradhan et al., 2010) and is divided into lower, middle and a result, these sub-basins have been subsequently divided into

upper groups. The Lower Aravalli Group includes the basal Del- “phosphatic” and “non-phosphatic” domains (Papineau et al., 2009,

wara Formation, which consists mostly of siliciclastic strata with 2013; Purohit et al., 2010). Their status as isolated basins dur-

interspersed volcanics, and the overlying carbonate-dominated ing deposition has yet to be adequately veriﬁed, as there are no

Fig. 1. (a) Small-scale map illustrating locations of major Purana Basins of India (ADOB = Aravalli–Delhi Orogenic Belt; RV = Rajasthan Vindhyan; SV = Son Valley Vindhyan;

Ch = Chhattisgarh Basin, IB = Indravati Basin; Cu = Cuddapah Basin; CITZ = Central Indian Tectonic Zone). (b)Simpliﬁed Geologic map of Vindhyan and Aravalli successions

(modiﬁed after Buick et al., 2006; Malone et al., 2008). Published data: NAQ = Northern Alwar Quartzite (Kaur et al., 2011); RVB = Rajasthan Vindhyan Bhander Group (Malone

et al., 2008); SVS, SVK, SVR, and SVB = Son Valley Semri, Kaimur, Rewa, and Bhander groups, respectively (McKenzie et al., 2011). GPS coordinates for sample localities:

◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦

RSV1 = 24 50.513 N, 74 35.458 E; RSK1 = 24 53.750 N, 74 38.586 E; RA05 = 24 27.492 N, 73 52.372 E; RA10 = 24 49.971 N, 73 46.029 E; RA11 = 24 36.002 N, 73

◦ ◦

40.688 E; RD4 = 24 45.173 N, 73 21.510 E.

Author's personal copy

122 N.R. McKenzie et al. / Precambrian Research 238 (2013) 120–128

well-constrained synsedimentary faults or evidence for basement 3. Methods

onlap of strata between the sub-basins. This, combined with lithos-

tratigraphic similarities between “sub-basin” deposits throughout Detrital zircon geochronology has proven useful for establish-

the region, supports arguments against the suggestion that these ing depositional age constraints on siliciclastic strata and resolving

sedimentary units were originally laterally discontinuous or that correlation problems across the Indian craton (e.g., Malone et al.,

each “sub-basin” was a separate depositional system. Furthermore, 2008; McKenzie et al., 2011). In this study, new detrital zircon U–Pb

regardless of the validity of the sub-basin model, Papineau et al. age data were generated from siliciclastic rocks of the Aravalli and

(2013) used integrative data to argue for contemporaneous depo- Delhi supergroups of the southern ADOB and Vindhyan successions

sition of the Jhamarkotra Formation strata throughout the region. of Rajasthan (Figs. 3 and 4). Individual zircon grains were separated

The Lower Aravalli Group is considered to have depositional using standard heavy mineral separation procedures and analyzed

ages from 2.1 to 1.9 Ga, although geochronologic constraints for by means of laser ablation multicollector inductively coupled mass

this age range are contentious. A minimum age constraint is often spectroscopy (LA-MC-ICPMS) at the University of Arizona Laser-

inferred from a ∼1.9 Ga Rb–Sr isochron for the Darwal granite Chron Center (see supplementary materials for analytical details

that is believed to intrude the base of the Lower Aravalli Group and data tables). Back-scattered electron (BSE) images of polished

(Choudhary et al., 1984). However, Deb and Thorpe (2004) noted grain mounts were used to help target portions of zircon grains with

a complicated contact relationship between the Darwal intrusion clear growth zoning for spot analysis and to avoid inherited cores,

and basal Aravalli strata, and questioned its usefulness for provid- un-zoned rims, and fractures. Sandstone samples analyzed from the

ing a minimum age constraint. Ahmad et al. (2008) presented a Aravalli Supergroup include the basal Delwara Formation (RA10),

series of whole-rock Sm–Nd model ages for ultramaﬁc–maﬁc vol- the Jhamarkotra Formation (RA5), and the Middle Aravalli Group

canic rocks in the basal Delwara Formation that ranged from 2.3 (RA11). A Delhi Supergroup sample was analyzed from the Alwar

to 1.8 Ga. The wide range of calculated ages for this series of vol- Group (RD4). Vindhyan samples collected near Chittorgarh include

canic ﬂows (a ∼0.5 billion year interval) illustrates a problem with the Semri (RSV1) and Kaimur groups (RVK1). Unfortunately, sam-

using these data for reliable age constraints. Sparse Pb–Pb model ples collected from the Upper Aravalli Group and the Ajabgarh

ages from galena extracted from barite veins in Delwara volcanics Group of the upper Delhi Supergroup did not yield zircon grains.

yielded ages around 2.1–2.0 Ga, whereas the majority of Pb–Pb

galena model ages from various units within the Lower Aravalli

Group consistently yielded ages around 1.8–1.7 Ga (Deb et al., 1989; 4. Results and discussion

Deb and Thorpe, 2004). A 2.2–2.0 Ga depositional age has also been

suggested for the Jhamarkotra Formation based on correlation of 4.1. Revised ages for the Aravalli Supergroup

anomalously C-enriched carbonate in the Jhamarkotra Forma-

tion with the Lomagundi–Jatuli isotope excursion (Sreenivas et al., The basal Delwara Formation sample (RA10) contains a range of

2001; Maheshwari et al., 2002, 2010; Purohit et al., 2010; Papineau Archean zircon grains with only a single concordant zircon younger

207 206

et al., 2009, 2013), as this global event is roughly constrained to than ∼2.5 Ga, which yielded a Pb/ Pb age of 1709 ± 8 Ma. The

between 2.3 and 2.05 Ga (Melezhik et al., 2007). Jhamarkotra Formation sample (RA05) contains a large population

The Delhi Supergroup is divided into the lower Alwar and of 1.9–1.7 Ga detrital zircon (∼1772 Ma age peak) and the youngest

207 206

upper Ajabgarh groups with depositional ages suggested to range single grain yielded a Pb/ Pb age of 1762 ± 9 Ma. A sample

between 1.7 and 1.5 Ga (Choudhary et al., 1984). However, recent from the middle Aravalli group (RA11) contained a broad popula-

age data for the Delhi Supergroup are conﬂicting. Strata of the North tion of 1.8–1.6 Ga detrital zircon with abundant ∼2.5 Ga grains and

207 206

Delhi Belt are well constrained to 1.8–1.7 Ga with minimum and the single youngest zircon yielded a Pb/ Pb age of 1576 ± 7 Ma

maximum age depositional ages provided by cutting relationship (Fig. 4).

of intrusive igneous rocks and detrital zircon age data, respectively The single 1709 ± 8 Ma grain provides a problematic age con-

(Biju-Sekhar et al., 2003; Kaur et al., 2011), whereas rocks associ- straint for the Delwara Formation. The Delwara sample was

ated with the upper Delhi Supergroup in the southern belt may be as collected less than 10 m above the depositional contact with the

young as ∼1.0 Ga (Deb et al., 2001). It is also noteworthy that Delhi BGC-I basement. The large population of Archean grains was likely

Supergroup rocks of the southern belt lack ∼1.7 Ga intrusive rocks derived directly from proximal BGC-I rocks, and the near-absence

known from the North Delhi Belt, and these strata have not yielded of ∼1.7 Ga grains might be the result of dilution from locally derived

Pb–Pb model ages older than ∼1.0 Ga (Deb and Thorpe, 2004). detritus. A similar dilution problem may exist with a sample from

the Semri Group of the lower Vindhyan succession (discussed

below). The possibility that the single ‘young’ 1709 ± 8 Ma grain

2.2. Vindhyan successions

resulted from contamination during sample processing must also

be considered, although this is unlikely as grains around this par-

The Great Boundary Fault marks the eastern limits of the ADOB

ticular age are not common in any sample. Alternatively, the single

and is the present structural boundary with the Vindhyan basin. The

‘young’ grain may represent an inaccurate age from erroneous

Vindhyan basin is regionally divided into the western Rajasthan and

measurement or later alteration of the grain through Pb loss or

eastern Son Valley sectors (Fig. 1). Vindhyan strata are divided into

metamorphic overprinting during a ∼1.7 Ga tectonothermal event

lower and upper successions by a prominent unconformity, with

(see Buick et al., 2006). Therefore, the single ∼1.7 Ga grain only

the lower Vindhyan succession consisting of the Semri Group and

provides a tentative age constraint for the Delwara Formation and

the upper Vindhyan succession consisting of the Kaimur, Rewa, and

further investigation of this unit is required.

Bhander groups, in ascending order (Fig. 2). The upper part of the

The presence of a large population of 1.9–1.7 Ga zircon grains in

Semri Group is well dated at ∼1.6 Ga (Rasmussen et al., 2002; Ray

the Jhamarkotra Formation nullify assertions of 2.2–2.0 Ga depo-

et al., 2002; Ray, 2006; Bengtson et al., 2009), and strata of the upper

sitional ages for the formation and for all overlying strata of the

Vindhyan succession are constrained to between ∼1.1 and 1.0 Ga

Aravalli Supergroup. The detrital zircon data presented here con-

(Gregory et al., 2006; Malone et al., 2008; McKenzie et al., 2011;

strain only the maximum depositional age. However, Deb et al.

Pradhan et al., 2012; Gopalan et al., 2013). Thus, the unconformity

(1989) reported numerous ∼1.7 Ga Pb–Pb model ages for syn-

between the upper and lower Vindhyan successions represents an

genetic ore deposits associated with the Jhamarkotra Formation

approximate 500 million year interval.

that provide tentative minimum depositional age constraints for

Author's personal copy

N.R. McKenzie et al. / Precambrian Research 238 (2013) 120–128 123

Fig. 3. (a) Semri Group sample locality (RSV1): ﬂuvial feldspathic pebble to very coarse grained sandstone/conglomerate overlying cross-bedded coarse-medium grained

sandstone; (b) Kaimur Group sample locality (RVK1): wave ripple imprints on sole of bed; (c) Delwara Formation sample locality (RA10): massive quartzite above BGC-I

contact; (d) Jhamarkotra Formation locality (RA05): fresh surface of white massive, medium-grained sandstone of the Jhamarkotra Formation; (e) cut and polished section

of Delwara Formation sample (RA10); (f) cut and polished section of Jhamarkotra Formation sample (RA05).

the unit. Therefore, the Jhamarkotra Formation is interpreted to subduction and arc magmatism postulated along the margin

have a ∼1.7 Ga depositional age. This age is further supported by a (Kaur et al., 2009, 2013). A similar contemporaneous tectonic

lack of younger ∼1.6 Ga zircon grains that are present in the overly- setting existed along the north Indian margin as well (Kohn et al.,

ing Middle Aravalli Group and a lack of Mesoproterozoic grains that 2010). The abundance of relatively young 1.9–1.7 Ga zircon grains

are common in younger strata of the ADOB and other Indian cra- in the Jhamarkotra Formation may result from syntectonic deposi-

tonic successions (e.g., Malone et al., 2008; McKenzie et al., 2011) tion along the active convergent margin, which is common along

(Fig. 4). The Aravalli region experienced considerable magmatic similar tectonic settings (e.g., Cawood et al., 2012). The introduc-

activity between 1.9 and 1.7 Ga (Deb et al., 2002; Biju-Sekhar et al., tion of younger ∼1.6 Ga zircon grains into the Middle Aravalli group

2003; Buick et al., 2006; Kaur et al., 2007, 2009), with Andean-type is consistent with a younger depositional age for this unit.

Author's personal copy

124 N.R. McKenzie et al. / Precambrian Research 238 (2013) 120–128

Southern Aravalli-Delhi Belt Rajasthan Vindhyan Son Valley Vindhyan RD4-040512 Bhander Gr. 1187 1713 Bhander Gr. Alwar Gr. n = 196 1554 n = 52 n = 98 1589 (Malone et al.,2008) 1729 McKenzie et al., (2011) 1212 1174 1586 1022

Late Mesoproterozoic- Early Neoproterozoic RVK1-032712 Rewa Gr. 1175 1586 Kaimur Gr. 1596 1772 n = 83 n = 81 1003 McKenzie et al., (2011) RA11-040112 Middle Aravalli Gr. n = 77 Relative Probability

1646 1772 1586 Kaimur Gr. n = 94 1713 McKenzie et al., (2011) RA5-033112 REGIONAL Jhamarkotra Fm. 1772 UNCONFORMITY 1851 n = 73 1172 Late Paleoproterozoic

RVS1-032712 Semri Gr.?

n = 50 ? ? ?

RA10-040112 Semri Gr. Delwara Fm. 1870 (n = 2) ? 1729 n = 84

n = 96 1647 McKenzie et al., (2011)

0.5 1.0 1.5 2.0 2.5 3.0 3.5 Age (Ga) ? 1709 (n = 1)

Earlier Paleoproterozoic?

0.5 1.0 1.5 2.0 2.5 3.0 3.5 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Age (Ga) Age (Ga)

Fig. 4. Detrital zircon age distributions and suggested correlation of strata from the southern Aravalli–Delhi Orogenic Belt and the Vindhyan successions.

4.1.1. Late Paleoproterozoic phosphatic stromatolites in north columnar stromatolites that are only a few centimeters in

India diameter (Fig. 5). In the Jhamarkotra deposits the stromatolitic

The Jhamarkotra Formation sample analyzed for detrital zircon columns are phosphatic, with the intercolumnar space consisting

grains was collected stratigraphically below the phosphatic carbon- primarily of massive dolostone. Therefore, there are some differ-

ate in the Jhamarkotra mine. The ∼1.7 Ga maximum depositional ences in mode of carbonate-ﬂuorapatite deposition between the

age for the Jhamarkotra Formation nulliﬁes the interpretation Himalayan–Vindhyan and Jhamarkotra phosphatic stromatolites,

that this unit was deposited during a ∼2.0 Ga global phospho- despite both being shallow water, stromatolitic phosphorites. The

genic event following the Great Oxidation Event (Papineau et al., similar age among all of these phosphatic deposits suggests there

2009, 2013; Papineau, 2010). Phosphatic stromatolites are known may have been similar over-arching controls on carbonate ﬂuo-

in ca. 1.6 Ga late Paleoproterozoic rocks in both the upper Semri rapatite precipitation across the north Indian margin during the

Group of the lower Vindhyan succession and the Gangolihat late Paleoproterozoic. Whatever the cause, various stromatolite

Dolomite of the Lesser Himalaya (e.g., Valdiya, 1969; Banerjee bioherms created local environments that permitted phosphogen-

et al., 1986; McKenzie et al., 2011). The Himalayan–Vindhyan esis in northern India during this discrete interval of time. This is

phosphatic deposits consist of branching columnar stromatolitic noteworthy given the general dearth of Precambrian phosphorites.

bioherms with columns exceeding 10 cm in diameter. The phos-

phatic horizons in those deposits are restricted to within only a

few meters of the bioherm with the phosphate occurring in the 13

4.1.2. A mid-Proterozoic ı C excursion?

inter-columnar spaces as phosphatic grainstone, as coatings on

The revised age determination for the Lower Aravalli Group also

terrigenous material, and as crusts on the stromatolite columns, 13

brings into question claims that ␦ C enrichments in the Jhamarko-

whereas the stromatolite build-ups themselves are mostly dolo-

tra Formation are related to the ∼2.1 Ga Lomagundi–Jatuli event.

stone (Banerjee et al., 1986; Bengtson et al., 2009; McKenzie et al., 13

The Jhamarkotra Formation has yielded variable ␦ C values. Phos-

2011). In both the Vindhyan and Himalayan deposits the phos- 13

phatic horizons yield ␦ C values around 0‰ whereas thick sections

phate does not occur throughout the stromatolitic lamination, and 13

of massive dolostone yield variable ␦ C values that range up to

the phosphatic crusts around the individual columns appear to

+11‰ (Sreenivas et al., 2001; Maheshwari et al., 2002, 2010; Purohit

pinch-out along the stromatolitic heads in a discrete interval of the

et al., 2010). Nitrogen and organic carbon isotopic values are sim-

bioherms (e.g., McKenzie et al., 2011). These speciﬁc similarities

ilar for both phosphatic and non-phosphatic sections (Papineau

may suggest a common mode of phosphogenesis in both regions.

et al., 2013). The dolostone with isotopically heavy carbon val-

The phosphate-bearing Jhamarkotra stromatolitic bioherms are

ues is considered to sit stratigraphically below the phoshpatic

up to 10’s of meters in stratigraphic thickness (e.g., Banerjee,

horizons (e.g., Sreenivas et al., 2001). Following the arguments

1971) and are dominated by infrequently branching, elongate

of Papineau et al. (2013) for contemporaneous deposition of all

Author's personal copy

N.R. McKenzie et al. / Precambrian Research 238 (2013) 120–128 125

Fig. 5. Phosphatic stromatolites of the Jhamarkotra Formation from the Jhamarkotra mine. (a) Out-of-place block with cross-sectional view of stromatolitic columns. Arrow

points in “up” direction as inferred from stromatolitic laminae. (b) Polished cross-section of stromatolitic column. Note white phosphatic stromatolitic column and dark gray

dolostone ﬁlling intercolumnar space. (c) Quasi-planar view of stromatolitic bioherm. (d) Polished quasi-planar section of stromatolitic bioherm. Scale bars = 2 cm.

Jhamarkotra strata, the C-rich Jhamarkotra deposits would have Phaner. Proterozoic Archean

Neo- Meso- Paleo- Neo- Meso- Paleo-

been deposited around ∼1.7 Ga.

16 Lomagundi Excursion

The positive values in the Jhamarkotra Formation are likely 12 a Great Oxidation

13 8 Event

to record depositional ␦ C signatures. Foremost, the carbonates ‘Boring Billion’

are found in a relatively pure, organic-lean carbonate succession C (‰, V-PDB) 0 13

δ -4

(rather than a carbonate-cemented siliciclastic unit) and most dia-

13 16 Aravalli

genetic processes drive the ␦ C values negative. The fact that the

12 b Excursion

isotope excursion is found in a thick (>55 m stratigraphic inter- 8

13 4

val) unit with ␦ C values exceeding +7‰ (Maheshwari et al., 2002,

C (‰, V-PDB) 0 13

2010) also points toward a depositional, rather than diagenetic, -4

13 13 00.51.0 1.5 2.0 2.5 3.0 3.5

␦ ␦

origin for the anomalous C values; typical methanic-zone C Age (Ga)

enrichment in carbonate constitutes a relatively minor aspect of

sedimentary successions (e.g., Irwin et al., 1977). Although the Fig. 6. (a) A generalized carbonate carbon isotope curve through time and (b) a

revised curve assuming a ca. 1.7 Ga depositional age for the Jhamarkotra Formation

Jhamarkotra Formation has been metamorphosed to greenschist

based on a new maximum age constraints presented here (modiﬁed from Planavsky

facies (Papineau et al., 2009, 2013), a metamorphic origin of the

et al. (2012)).

anomalously high positive carbonate ␦ C values is highly unlikely.

Therefore, all available evidence suggests that the Jhamarkotra For-

mation may host a previously unidentiﬁed late Paleoproterozoic dramatically affect views of the evolution of the carbon cycle during

positive ␦ C excursion (Fig. 6). the Precambrian. Given the potential for the Jhamarkotra Forma-

The prevailing view is that the mid-Proterozoic (1.8–0.8 Ga) tion to fundamentally reshape our view of biogeochemical cycling

was characterized by carbonate isotope and general biogeochem- for a billion years of Earth’s history, additional work to rigorously

ical stasis (Brasier and Lindsay, 1998), which has given rise to test the validity of a ca. 1.7 Ga positive carbonate carbon isotope

the moniker the ‘boring billon’ (e.g., Holland, 2006). The potential excursion is certainly warranted.

implications of a billion years of carbon isotope stasis have been

far reaching. For example, this framework has shaped models of 4.2. Revised ages of the Delhi Supergroup and miscorrelation of

eukaryotic diversiﬁcation (e.g., Anbar and Knoll, 2002), and played the North and South Delhi belts

a central role in models of environmental change and carbon iso-

tope chemistry bracketing the Proterozoic (e.g., Swanson-Hysell A sample from the Alwar Group (RD4) of the southern Delhi

et al., 2010; Bekker and Holland, 2012). If both the age and pri- Supergroup possesses a large population of 1.2–1.1 Ga detrital

mary nature of this isotope excursion are corroborated, and if it in zircons (∼1187 Ma age peak) (Fig. 7). Therefore, the southern

fact reﬂects global-scale marine processes, the presence of a signiﬁ- Delhi Supergroup cannot be 1.9–1.7 Ga as previously asserted. The

cant late Paleoproterozoic positive carbon isotope excursion would ∼1.2 Ga depositional age constraint together with reports of 987 ± 6

Author's personal copy

126 N.R. McKenzie et al. / Precambrian Research 238 (2013) 120–128

Alwar Group here. Kaimur Group sandstone (RVK1) contains large populations

South Delhi Belt of ∼1.2 Ga (∼1175 age peak) and ∼1.6 Ga zircon grains. This is simi-

n = 98

lar to both a published age distribution from the Son Valley Kaimur

Group, which also produced a youngest age peak of ∼1172 Ma, and

age distributions from both the Rajasthan and Son Valley Bhander

groups (McKenzie et al., 2011) (Fig. 4). Together, these similarities

support correlation of upper Vindhyan successions between the

Rajasthan and Son Valley sectors.

Alwar Group

While the abundance of grains from distinct age populations

North Delhi Belt

n = 144 within each distribution is variable, the Kaimur Group distribu-

(Kaur et al., 2011) tions are strikingly similar to the age distribution of the southern

Delhi Group. Most notable are the similar age peaks around ∼1.2

and ∼1.6 Ga in the Rajasthan Kaimur Group and Delhi Group, with

both samples lacking ∼2.5 Ga grains, which are common in all other

age distributions (Fig. 4). Overall, strata of the ADOB have similar

0.5 1.0 1.5 2.0 2.5 3.0 3.5 age-relationships to lower and upper Vindhyan successions, and

Age (Ga)

it is suggested here that the Aravalli–Delhi supergroups represent

the tectonically deformed equivalents of the Vindhyan successions,

Fig. 7. Comparison of detrital zircon age distributions from the so-called Alwar

with the Aravalli–Delhi supergroups separated by the same ∼500

Group from the northern and southern ADOB.

million year unconformity present in the Vindhyan successions

(Fig. 4). The similarity of detrital zircon age distributions in the

Vindhyan successions and strata of the ADOB likely resulted from

and 986 2 Ma rhyolites associated with the uppermost part of the shared sediment sources, and thus these strata were deposited as

Delhi Supergroup (Deb et al., 2001) brackets the depositional ages part of a contiguous margin with Vindhyan strata deposited in

∼ ∼

of the southern Delhi Supergroup between 1.2 and 1.0 Ga. The epicontinental settings and the Aravalli deposited along the con-

age distribution from the southern sample differs from published tinental margin, rather than in discrete isolated basins as generally

age data from the Alwar Group of the North Delhi Belt (Kaur et al., assumed.

2011) as the northern sample contains a large population of ∼1.7 Ga

zircon grains with nothing younger (Fig. 7). A potential age discrep-

5. Conclusions

ancy between the northern and southern Delhi groups has been

previously recognized (Biju-Sekhar et al., 2003), although this dis-

We provide new age constraints on the sedimentary succes-

crepancy was attributed to differences in tectonic history of each

sion of the ADOB. The Aravalli Supergroup is constrained to be late

“basin”. On the basis of data presented here, we suggest that the

Paleoproterozoic in age. The Jhamarkotra Formation has an esti-

discrepancy results from a longstanding miscorrelation of strata

mated depositional age of ∼1.7 Ga. Based on these revised ages, it is

between the two regions.

doubtful that the positive carbonate ␦ C values measured in this

The age distribution from the ∼1.7 Ga northern Alwar Group is

unit are linked to the 2.2–2.0 Ga Lomagundi–Jatuli event. There-

similar to the Jhamarkotra Formation, which we have estimated

fore, this presents the intriguing possibility of an unrecognized late

to have a depositional age of ∼1.7 Ga. Based on the similar depo-

Paleoproterozoic positive ␦ C excursion. If veriﬁed, this would call

sitional ages and detrital zircon age distributions, strata of the

into question the idea of mid-Precambrian carbon isotope stasis,

so-called North Delhi Belt likely represent the northern equiv-

which has become a key facet of current models on the evolution

alents of the Aravalli Supergroup. Kaur et al. (2013) suggest

of biogeochemical cycling in the Precambrian.

syntectonic deposition for strata of the North Delhi Belt along

The Delhi Supergroup of the southern ADOB has a depositional

an active continental arc system and based on data presented

age range of 1.2–1.0 Ga and is not correlative with the Delhi Super-

herein, we suggested a similar depositional environment for the

group of the North Delhi Belt. Strata of the northern belt are

Aravlli Supergroup. Deposition along a convergent margin con-

likely correlative with the Aravalli Supergroup. These late Paleo-

trasts the long-standing hypothesis that the Aravalli Supergroup

proterozoic strata were deposited syntectonically along an active

was deposited along an active rift margin.

convergent margin, rather than an active rift margin. Age rela-

tionships of the Aravalli–Delhi supergroups reﬂect those of the

4.3. The Rajasthan Vindhyan successions and correlation across

lower–upper Vindhyan successions and similar age distributions

the north Indian margin

of detrital zircon grains from all regions are used to suggest that

these strata were deposited across a contiguous margin, with Vin-

Forty-eight of the ﬁfty zircon grains analyzed from the Semri

207 206 dhyan strata representing epicontinental deposits and strata of the

Group sample (RVS1) yielded Pb/ Pb ages between 2515 ± 4

ADOB representing the distal continental margin equivalents.

and 2588 ± 41 Ma and the two other grains yielded ages of 1877 ± 7

and 1885 ± 17 Ma. This sample was acquired from coarse-grained

feldspathic sandstone (Fig. 3a) and the abundance of ∼2.5 Ga zircon Acknowledgements

grains likely reﬂects almost exclusive derivation of detritus from

a proximal ∼2.5 Ga felsic igneous source. The two ∼1.8 Ga grains We thank Dr. N.K. Chauhan for local support in Udaipur, G.

are close in age to the 1854 ± 7 Ma volcanic Hindoli rocks located Gehrels, M. Pecha, and N. Giesler for analytical assistance at

∼

150 km northeast of the Semri Group locality (Deb et al., 2002), the Arizona LaserChron Center, JS. Lackey for providing facilities

as well as ∼1.9–1.7 Ga plutons of the North Delhi Belt (e.g., Biju- and assistance for sample processing, and C. Lee for analytical

Sekhar et al., 2003; Kaur et al., 2009, 2013), and the BGC-II of the assistance. Comments from M. Bickford, S. Long, J. Meert, H. Frim-

southern ADOB (Buick et al., 2006). The Semri Group age distribu- mel, and anonymous reviewers greatly improved the manuscript.

tion from Rajasthan is considerably different from a Semri Group This work was supported by National Science Foundation Grants

age distribution from the Son Valley (Fig. 3) and direct correla- EAR-1124303 to N. Hughes and EAR-1124518 to P. Myrow. McKen-

tion between these regions is not possible based on data presented zie acknowledges the UT Austin Jackson Postdoctoral Fellowship

Author's personal copy

N.R. McKenzie et al. / Precambrian Research 238 (2013) 120–128 127

Program and N. Planavsky acknowledges the NSF-EAR-Postdoctoral Holland, H.D., 2006. The oxygenation of the atmosphere and oceans. Philosophical

Transactions of the Royal Society B 361, 903–915.

Fellowship Program. The Arizona LaserChron Center is supported

Irwin, H., Curtis, C., Coleman, M., 1977. Isotopic evidence for source of diagenetic car-

by NSF-EAR-0732436.

bonates formed during burial of organic-rich sediments. Nature 269, 209–213.

Kaur, P., Chaudhri, N., Raczek, I., Kroner, A., Hofmann, A.W., 2007. Geochemistry,

zircon ages and whole-rock Nd isotopic systematics for Palaeoproterozoic A-

Appendix A. Supplementary data

type granitoids in the northern part of the Delhi belt, Rajasthan, NW India:

implications for late Palaeoproterozoic crustal evolution of the Aravalli craton.

Geological Magazine 144, 361–378.

Supplementary data associated with this article can be

Kaur, P., Chaudhri, N., Raczek, I., Kroner, A., Hofmann, A.W., 2009. Record of 1.82 Ga

found, in the online version, at http://dx.doi.org/10.1016/

Andean-type continental arc magmatism in NE Rajasthan, India: insights from

j.precamres.2013.10.006. zircon and Sm–Nd ages, combined with Nd–Sr isotope geochemistry. Gondwana

Research 16, 56–71.

Kaur, P., Zeh, A., Chaudri, N., Gerdes, A., Okrusch, M., 2011. Archaean to Palaeo-

References proterozoic crustal evolution of the Aravalli mountain range, NW India, and

its hinterland: the U–Pb and Hf isotope record of detrital zircon. Precambrian

Research 187, 155–164.

Ahmad, T., Dragusanu, C., Tanaka, T., 2008. Provenance of Proterozoic Basal Aravalli

Kaur, P., Zeh, A., Chaudhri, N., Gerdes, A., Okrusch, M., 2013. Nature of magmatism

maﬁc volcanic rocks from Rajasthan, Northwestern India: Nd isotopes evidence

and sedimentation at a Columbia active margin: insights from combined U–Pb

for enriched mantle reservoirs. Precambrian Research 162, 150–159.

and Lu–Hf isotope data of detrital zircons from NW India. Gondwana Research,

Anbar, A.D., Knoll, A.H., 2002. Proterozoic ocean chemistry and evolution: a bioinor-

23.

ganic bridge? Science 297, 1137–1142.

Kohn, M.J., Paul, S.K., Corrie, S.L., 2010. The lower Lesser Himalayan sequence: a Pale-

Banerjee, D.M., 1971. Precambrian Stromatolitic Phosphorites of Udaipur, Rajasthan,

oproterozoic arc on the northern margin of the Indian plate. Geological Society

India. Geological Society of America Bulletin 82, 2319.

of America Bulletin 122, 323–335.

Banerjee, D.M., Schidlowski, M., Arneth, J.D., 1986. Genesis of upper Proterozoic-

Maheshwari, A., Sial, A.N., Chittora, V.K., Bhu, H., 2002. A positive delta C-13 carb

Cambrian phosphorite deposits of India: isotopic inferences from carbonate

anomaly in Paleoproterozoic carbonates of the Aravalli Craton, Western India:

ﬂuorapatite, carbonate and organic carbon. Precambrian Research 33, 239–253.

support for a global isotopic excursion. Journal of Asian Earth Sciences 21, 59–67.

Bekker, A., Holland, H.D., 2012. Oxygen overshoot and recovery during the early

Maheshwari, A., Sial, A.N., Gaucher, C., Bossi, J., Bekker, A., Ferreira, V.P., Romano,

Paleoproterozoic. Earth and Planetary Science Letters 317, 295–304.

A.W., 2010. Global nature of the Paleoproterozoic Lomagundi carbon isotope

Bengtson, S., Belivanova, V., Rasmussen, B., Whitehouse, M., 2009. The controversial

excursion: a review of occurrences in Brazil, India, and Uruguay. Precambrian

“Cambrian” fossils of the Vindhyan are real but more than a billion years older.

Research 182, 274–299.

Proceedings of the National Academy of Sciences 106, 7729–7734.

Malone, S.J., Meert, J.G., Banerjee, D.M., Pandit, M.K., Tamrat, E., Kamenov, G.D., Prad-

Bhowmik, S.K., Bernhardt, H.-J., Dasgupta, S., 2010. Grenvillian age high-pressure

han, V.R., Sohl, L.E., 2008. Paleomagnetism and detrital zircon geochronology of

upper amphibolite-granulite metamorphism in the Aravalli–Delhi Mobile Belt,

the upper Vindhyan sequence, Son Valley and Rajasthan, India: a ca. 1000 Ma

Northwestern India: new evidence from monazite chemical age and its impli-

closure age for the Purana basins? Precambrian Research 164, 137–159.

cation. Precambrian Research 178, 168–184.

McKenzie, N.R., Hughes, N.C., Myrow, P.M., Sharma, M., 2011. Correlation of

Bickford, M.E., Basu, A., Mukherjee, A., Hietpas, J., Schieber, J., Patranabis-Deb, S., Ray,

Precambrian–Cambrian sedimentary successions across northern India and the

R.K., Guhey, R., Bhattacharya, P., Dhang, P.C., 2011. New U–Pb SHRIMP Zircon

utility of isotopic signatures of Himalayan lithotectonic zones. Earth and Plane-

Ages of the Dhamda Tuff in the Mesoproterozoic Chhattisgarh Basin, Peninsular

tary Science Letters 312, 471–483.

India: Stratigraphic Implications and Signiﬁcance of a 1-Ga Thermal-Magmatic

Meert, J.G., Pandit, M.K., Pradhan, V.R., Banks, J., Sirianni, R., Stroud, M., Newstead, B.,

Event. Journal of Geology 119, 535–548.

Gifford, J., 2010. Precambrian crustal evolution of Peninsular India: a 3.0 billion

Biju-Sekhar, S., Yokoyama, K., Pandit, M.K., Okudaira, T., Yoshida, M., Santosh, M.,

year odyssey. Journal of Asian Earth Sciences 39, 483–515.

2003. Late Paleoproterozoic magmatism in Delhi Fold Belt, NW India and its

Melezhik, V.A., Huhma, H., Condon, D.J., Fallick, A.E., Whitehouse, M.J., 2007. Tempo-

implication: evidence from EPMA chemical ages of zircons. Journal of Asian Earth

ral constraints on the Paleoproterozoic Lomagundi-Jatuli carbon isotopic event.

Sciences 22, 189–207.

Geology 35, 655–658.

Brasier, M.D., Lindsay, J.F., 1998. A billion years of environmental stability and

Mukherjee, A., Bickford, M.E., Hietpas, J., Schieber, J., Basu, A., 2012. Implications of

the emergence of eukaryotes: new data from northern Australia. Geology 26,

555–558. a newly dated ca. 1000-Ma Rhyolitic Tuff in the Indravati Basin, Bastar Craton,

India. Journal of Geology 120, 477–485.

Buick, I.S., Allen, C., Pandit, M., Rubatto, D., Hermann, J., 2006. The Proterozoic

Papineau, D., 2010. Global biogeochemical changes at both ends of the Proterozoic:

magmatic and metamorphic history of the Banded Gneiss Complex, central

insights from phosphorites. Astrobiology 10, 165–181.

Rajasthan, India: LA-ICP-MS U–Pb zircon constraints. Precambrian Research 151,

119–142. Papineau, D., Purohit, R., Fogel, M.L., Shields-Zhou, G., 2013. High phosphate avail-

ability as a possible cause for massive cyanobacterial production of oxygen in the

Cawood, P.A., Hawkesworth, C.J., Dhuime, B., 2012. Detrital zircon record and tec-

Paleoproterozoic atmosphere. Earth and Planetary Science Letters 362, 225–236.

tonic setting. Geology 40, 875–878.

Papineau, D., Purohit, R., Goldberg, T., Pi, D., Shields, G.A., Bhu, H., Steele, A., Fogel,

Chakraborty, C., 2006. Proterozoic intracontinental basin: the Vindhyan example.

M.L., 2009. High primary productivity and nitrogen cycling after the Paleopro-

Journal of Earth System Science 115, 3–22.

terozoic phosphogenic event in the Aravalli Supergroup, India. Precambrian

Chakraborty, P.P., Dey, S., Mohanty, S.P., 2010. Proterozoic platform sequences

Research 171, 37–56.

of Peninsular India: implications towards basin evolution and supercontinent

Patranabis-Deb, S., Bickford, M.E., Hill, B., Chaudhuri, A.K., Basu, A., 2007. SHRIMP

assembly. Journal of Asian Earth Sciences 39, 589–607.

ages of zircon in the uppermost tuff in Chattisgarh Basin in central India require

Choudhary, A.K., Gopalan, K., Sastry, C.A., 1984. Present status of the geochronology

similar to 500-Ma adjustment in Indian Proterozoic stratigraphy. Journal of

of the Precambrian rocks of Rajasthan. Tectonophysics 105, 131–140.

Geology 115, 407–415.

Deb, M., Sarkar, S.C., 1990. Proterozoic Tectonic Evolution and Metallogenesis in the

Planavsky, N.J., Bekker, A., Hofmann, A., Lyons, T.W., 2012. Sulfur record of ris-

Aravalli Delhi Orogenic Complex, Northwestern India. Precambrian Research 46,

115–137. ing and falling marine oxygen and sulfate levels during the Lomagundi event.

Proceedings of the National Academy of Sciences 45, 18300–18305.

Deb, M., Thorpe, R., Krstic, D., 2002. Hindoli group of rocks in the eastern fringe of the

Pradhan, V.R., Meert, J.G., Pandit, M.K., Kamenov, G., Gregory, L.C., Malone, S.J.,

Aravalli–Delhi Orogenic Belt-Archean secondary greenstone belt or Proterozoic

2010. India’s changing place in global Proterozoic reconstructions: a review of

supracrustals? Gondwana Research 5, 879–883.

geochronologic constraints and paleomagnetic poles from the Dharwar, Bun-

Deb, M., Thorpe, R.I., 2004. Geochronological constraints in the Precambrian Geology

delkhand and Marwar cratons. Journal of Geodynamics 50, 224–242.

of Rajasthan and their Metallogenic implications. In: Deb, M., Goodfellow, W.D.

Pradhan, V.R., Meert, J.G., Pandit, M.K., Kamenov, G., Mondal, M.E.A., 2012. Paleomag-

(Eds.), Sediment-hosted Lead–Zinc Sulphide Deposits. Narosa Publishing House,

netic and geochronological studies of the maﬁc dyke swarms of Bundelkhand

New Delhi, pp. 246–263.

craton, central India: implications for the tectonic evolution and paleogeo-

Deb, M., Thorpe, R.I., Cumming, G.L., Wagner, P.A., 1989. Age, source and Strati-

graphic reconstructions. Precambrian Research 198, 51–76.

graphic implications of Pb isotope data for conformable, sediment-hosted,

Purohit, R., Sanyal, P., Roy, A.B., Bhattacharya, S.K., 2010. 13C enrichment in

base-metal deposits in the Proterozoic Aravalli–Delhi Orogenic Belt, Northwest-

the Palaeoproterozoic carbonate rocks of the Aravalli Supergroup, north-

ern India. Precambrian Research 43, 1–22.

west India: inﬂuence of depositional environment. Gondwana Research 18,

Deb, M., Thorpe, R.I., Krstic, D., Corfu, F., Davis, D.W., 2001. Zircon U–Pb and galena

538–546.

Pb isotope evidence for an approximate 1.0 Ga terrane constituting the western

Rasmussen, B., Bose, P.K., Sarkar, S., Banerjee, S., Fletcher, I.R., McNaughton, N.J.,

margin of the Aravalli–Delhi Orogenic Belt, northwestern India. Precambrian

2002. 6 Ga U–Pb zircon age for the Chorhat Sandstone, lower Vindhyan, India:

Research 108, 195–213.

possible implications for early evolution of animals. Geology 30, 103–106.

Gopalan, K., Kumar, A., Kumar, S., Vijayagopal, B., 2013. Depositional history of the

Ray, J., Martin, M.W., Veizer, J., Bowring, S.A., 2002. U–Pb zircon dating and

Upper Vindhyan succession, central India: time constraints from Pb–Pb isochron

Sr isotope systematics of the Vindhyan Suergroup, India. Geology 30,

ages of its carbonate components. Precambrian Research 233, 108–117.

131–134.

Gregory, L.C., Meert, J.G., Pradhan, V., Pandit, M.K., Tamrat, E., Malone, S.J., 2006. A

Ray, J.S., 2006. Age of the Vindhyan Supergroup: a review of recent ﬁndings. Journal

paleomagnetic and geochronologic study of the Majhgawan kimberlite, India:

of Earth Systems Science 115, 149–160.

implications for the age of the Upper Vindhyan Supergroup. Precambrian

Roy, A.B., Jakhar, S.R., 2002. Geology of Rajasthan (Northwest India): Precambrian

Research 149, 65–75.

to Recent. Scientiﬁc Publishers (India), Jodhpur.

Holland, T.H., 1909. Imperial Gazetteer of India., pp. 50–103.

Author's personal copy

128 N.R. McKenzie et al. / Precambrian Research 238 (2013) 120–128

Roy, A.B., Paliwal, B.S., 1981. Evolution of lower Proterozoic Epicontinental deposits Valdiya, K.S., 1969. Stromatolites of the Lesser Himalayan carbonate forma-

– Stromatolite-bearing Aravalli rocks of Udaipur, Rajasthan, India. Precambrian tion and the Vindhyans. Journal of the Geological Society of India 10,

Research 14, 49–74. 1–25.

Sreenivas, B., Das Sharma, S., Kumar, B., Patil, D.J., Roy, A.B., Srinivasan, R., 2001. Valdiya, K.S., 1995. Proterozoic sedimentation and Pan-African geodynamic devel-

Positive d13C excursion in carbonate and organic fractions from the Paleopro- opment in the Himalaya. Precambrian Research 74, 35–55.

terozoic Aravalli Supergroup, Northwestern India. Precambrian Research 106, Wiedenbeck, M., Goswami, J.N., Roy, A.B., 1996. Stabilization of the Aravalli Craton of

277–290. northwestern India at 2.5 Ga: an ion microprobe zircon study. Chemical Geology

Swanson-Hysell, N.L., Rose, C.V., Calmet, C.C., Halverson, G.P., Hurtgen, M.T., Maloof, 129, 325–340.

A.C., 2010. Cryogenian Glaciation and the onset of carbon-isotope decoupling.

Science 328, 608–611.