Petrogenesis of high-K, calc-alkaline and shoshonitic intrusive rocks in the Tongling area, Anhui

25 Pages·2013·4 MB·English

Petrogenesis of high-K, calc-alkaline and shoshonitic
intrusive rocks in the Tongling area, Anhui Province
(eastern China), and their tectonic implications
Cailai Wu1,†, Shuwen Dong2, Paul T. Robinson1, B. Ronald Frost3, Yuanhong Gao1, Min Lei1, Qilong Chen1, and
Haipeng Qin1
1State Key Laboratory of Continental Tectonics and Dynamics, Institute of Geology, Chinese Academy of Geological Sciences,
Beijing 100037, China
2Chinese Academy of Geological Sciences (CAGS), Beijing 100037, China
3Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82072, USA
ABSTRACT ing of differentiated mantle and crustal melts, ing the petro genesis of the two series. Several
followed by assimilation–fraction crystalliza- processes have been proposed for the origin
The Mesozoic intermediate-silicic intru- tion (AFC) processes. The magmatic activity of these rocks: (1) assimilation of country
sive rocks in the Tongling area, Anhui Prov- may have been related to reactivation of the rock by alkaline basaltic magma (Mao, 1990),
ince, eastern China, include a high-K, calc- Tongling-Deijiahui structural zone in re- (2) fractional crystallization of lower-crustal
alkaline series and a shoshonitic series . Rocks sponse to rapid, highly oblique subduction of melts (Wu, 1986), (3) assimilation of lower-
of the calc- alkaline series comprise more the paleo–Pacifi c plate beneath South China. crustal material by alkaline basaltic magma
than 90% of the total and consist chiefl y of followed by fractional crystallization (Xing
gabbro-diorite , granodiorite, quartz monzo- INTRODUCTION and Xu, 1995), (4) partial melting of basaltic
diorite, and porphyritic quartz monzodiorite. lower crust to form tonalitic intrusive rocks
These rocks are associated with important The Tongling district, which is situated in the (Zhang et al., 2001), and (5) mixing of mantle-
skarn-type copper-iron deposits. They con- eastern part of the Yangtze River basin in derived magmas with those formed by partial
tain three types of enclaves: mica-rich vari- Anhui Province, is an ancient copper capital melting of basaltic lower crust (Wang et al.,
eties that appear to be residues of partially of China and one of the most important metal- 2003). In this paper, we reexamine the origin
melted pelitic rock, mafi c quartz monzo- bearing districts in the country (Fig. 1A). The of these granitoids using new sensitive high-
diorite, and microdiorite. The shoshonitic polymetallic district is ~40 km long in an E-W reso lution ion microprobe (SHRIMP) U-Pb
series consists of pyrox ene monzodiorite, direction and 20 km wide, with a total area of ages, whole-rock geochemistry, and the com-
monzonite, and quartz monzonite, which are ~800 km2 (Fig. 1B). Within the district, there positions of the various enclaves hosted in the
commonly asso ciated with skarn-type gold are 76 intermediate-silicic intrusive bodies and gran itoids. We review all of the recent data on
deposits. Enclaves in these rocks are typi- 54 known ore deposits (Wu et al., 2010a). The the ages of the rocks and their enclaves (X.S.
cally pyroxene-rich or amphibole-rich vari- intrusive rocks are mostly intermediate dio- Xu et al., 2004; Du et al., 2004, 2007; Yang
eties or amphibole gabbros. Zircon sensitive rites, monzonites, and quartz monzonites that et al., 2007; Zhang et al., 2006; Wu et al.,
high-resolution ion micro probe (SHRIMP) form an early high-K, calc-alkaline series and a 2001; Wang et al., 2004a, 2004b, 2004c; X.C.
U-Pb age data suggest that the granodiorites, slightly later shoshonitic series. The ore depos- Xu et al., 2008), but the validity of some ages is
quartz monzo diorites, and gabbro-diorites its are predominantly skarn type with copper, uncertain, because different dating techniques
of the calc-alkaline series were generated at iron, and gold mineralization, accompanied by have yielded different ages for the same intru-
ca. 146–142, 143, and 140 Ma, respectively. minor strata-bound types in the host carbon- sive body (Zhou et al., 1987;Wu et al., 1996).
The shoshonitic rocks range in age from 143 ates (Zhao et al., 1999; Zhai et al., 1992). Some For example, 40Ar-39Ar dating of biotite from
to 136 Ma. Although there is some overlap in porphyry-type mineralization is also present, some of the Tongling rocks has yielded ages of
reported ages of the two series, contact rela- but it generally occurs only in the deeper parts 140–137 Ma for granodiorite, 137–136 Ma for
tions indicate that the shoshonitic rocks post- of the intrusions (Pan and Dong, 1999). The quartz monzodiorite, 138–137 Ma for pyroxene
date the calc-alkaline varieties. On the basis total reserves in this district have been esti- monzodiorite, and 134 Ma for gabbro-diorite
of the geochemistry of the two series and the mated to be 500 Mt copper and 150 t gold (Wu (Wu et al., 1996, 2001), but these ages only
character of their enclaves, the shoshonitic et al., 2010a). record the time at which the intrusive bod-
series is thought to have formed primarily by Because of their associated copper and ies cooled through ~300 °C, the Ar-Ar clo-
differentiation of a mantle-derived, weakly gold deposits, the intrusive rocks have been sure temperature of biotite (Cliff, 1985). A
contaminated, alkali basalt magma, whereas studied for many years (e.g., Chang and Liu, few zircon SHRIMP U-Pb ages have recently
the high-K, calc-alkaline series refl ects mix- 1983; Tang et al., 1998; Xing and Xu, 1995, become available (Yang et al., 2008; X.C. Xu
1996; Zhou et al., 1993; Wu et al., 1996, et al., 2008), but these studies all focused on
†E-mail: [email protected] 2000, 2003), but there is no agreement regard- individual bodies . Here, we report new zircon
GSA Bulletin; January/February 2014; v. 126; no. 1/2; p. 78–102; doi: 10.1130/B30613.1; 12 fi gures; 10 tables.
78 For permission to copy, contact [email protected]
© 2013 Geological Society of America
Petrogenesis of intermediate-acid intrusive rocks and zircon SHRIMP U-Pb dating in the Tongling area, Anhui Province (eastern China)
A
B
Figure 1. Geological sketch map of Tongling area, Anhui, China. R—Tertiary system; K , K—Upper and Lower Cretaceous
2 1
system; J —Upper Jurassic system; J —Middle and Lower Jurassic system; T2-T3—Middle Triassic system; D-T1—Upper
3 1–2 2 2 3 2
Devonian system–Middle and Lower Triassic system; S—Silurian system; «—dating sample locations.
Geological Society of America Bulletin, January/February 2014 79
Wu et al.
SHRIMP ages for four plutons and discuss the Paleozoic and Triassic sedimentary rocks form LITHOLOGY OF THE INTRUSIVE
petrogenesis of the intrusive rocks and their a series of complex, NE-trending folds with ROCKS AND THEIR ENCLAVES
enclaves, as well as the tectonic environment thrust faults along their limbs (Zhai et al.,
in which they formed. 1996), many of which are cut by NW-trending The high-K, calc-alkaline series rocks range
brittle faults (Fig. 1B). Several possible base- in composition from gabbro-diorite through
GEOLOGICAL SETTING ment faults, including the major Tongling- quartz monzodiorite and granodiorite to aplitic
Deijiahui structural zone, have been identifi ed granite. Most of these rocks have hypidiomor-
The continental core of China is composed from geophysical data, and their intersections phic granular textures, except for the gabbro-
of the South China block and the North China are thought to partially control the location diorites, which have gabbroic-diabasic textures,
craton, which were welded together along the of the Mesozoic intrusions (Ren et al., 1992; and some granodiorites with porphyritic tex-
Dabie-Sulu orogenic belt between ca. 250 and Zhai et al., 1996; Chang et al., 1996; Tang tures. The rock-forming minerals are plagio-
220 Ma. The South China block was formed et al., 2004). clase, quartz, amphibole, biotite, and potassium
by collision and amalgamation of the Yangtze Seventy-six individual intrusions have been feldspar, most of which range from 1.2 mm to
and Cathaysian blocks at ca. 880 Ma. The identifi ed in the Tongling area (Fig. 1B). Most 2.2 mm in size. Some porphyritic granodiorites
Tongling area lies in the Yangtze polymetal- of these are small stocks and dikes, gener- have plagioclase phenocrysts up to ~6 mm.
lic belt located in the northeastern part of ally with outcrop areas of 0.05–3 km2, locally Many of the plagioclase grains have diffuse
the Yangtze block (Chang et al., 1991; S. Xu accompanied by small sills, apophyses, and cores crowded with opaque inclusions; others
et al., 1992; Pan and Dong, 1999) (Fig. 1A). veins. They are hosted mostly in Silurian to contain inclusions of apatite. Some alkali feld-
It is nearly perpendicular to the Tan-Lu fault, a Triassic carbonates and quartz sandstones, and spar phenocrysts are rimmed by plagioclase,
major left-lateral, strike-slip fault that offsets less commonly in siliceous rocks. The intrusive suggesting magma mixing (cf. Hibbard, 1991).
the Dabie ultrahigh-pressure (UHP) metamor- rocks are divided into a high-K, calc-alkaline These rocks contain three types of enclaves,
phic belt several hundred kilometers to the series and a shoshonitic series on the basis of which are different from those in the shoshonitic
northeast (Fig. 1A). The exact age of initiation their petrochemistry. series. Their main features are:
of the Tan-Lu fault is uncertain, but 40Ar-39Ar The high-K, calc-alkaline rocks occur as (1) Mica-rich enclaves: These enclaves occur
dating of amphibole in ductile shear zones in NE-trending stocks in Carboniferous dolomitic mainly in the granodiorites. They are black,
the southern part of the fault suggests it was limestone and Permian to Triassic carbon- elliptical bodies that range from 4 to 8 cm in
activated no later than 143 Ma, in response to ate rocks. Mineralized skarns hosting copper their long direction, and they consist chiefl y of
rapid, highly oblique subduction of the paleo– deposits are well developed in the carbonates biotite (>80 modal%) and plagioclase (15%),
Pacifi c plate beneath southeast China (Zhu (Chang and Liu, 1983), and these may represent with minor cordierite and almandine garnet.
et al., 2005). Gravity and aeromagnetic data remobilization of stratiform sulfi de deposits (Xu Accessory minerals include magnetite, pyrite,
suggest that the Tongling district is underlain and Zhou, 2001). Many of the stocks lie along, chalcopyrite, and sphalerite. Texturally, the
by a regional, deep-seated, structural feature, or near, the axes of anticlines, but some irregu- enclaves consist of plagioclase phenocrysts
the Tongling-Deijiahui structural zone (E-W lar bodies appear to have been emplaced at fault imbedded in a granular mosaic of biotite. These
dashed line in Fig. 1B; Chang et al., 1991, intersections. The calc-alkaline bodies contain enclaves are interpreted as partially melted resi-
1996; Lu et al., 2003). This feature is consid- abundant enclaves, chiefl y composed of micro- dues of metamorphic country rock.
ered by Wang and Cong (1998) to be an east- diorite, mafi c quartz monzodiorite, and mica- (2) Mafic quartz monzodiorite enclaves:
ward extension of the Xiaotian-Mozitan deep ceous material. Based on fi eld relationships, These enclaves occur in granodiorites and
fault, which separates the Huaiyang arc fl ysch these rocks predate the shoshonitic bodies and quartz monzodiorites. They are light gray in
belt from the Dabie arc complex west of the have 40Ar-39Ar cooling ages ranging from 140 to color, angular in shape, and 8–30 cm across.
Tan-Lu fault. We suggest that the magmatism 137 Ma for granodiorite, 137–136 Ma for quartz They have sharp contacts with the host rocks
and mineralization in the Tongling district monzodiorite, and 134 Ma for gabbro-diorite and are generally concentrated along intrusive
may have been initiated during reactivation (Wu et al., 2000). contacts, suggesting that they represent a chilled
of this feature by transtensional movement on The shoshonitic intrusive bodies are pyrox- border phase. The mineralogy of these enclaves
the Tan-Lu fault. Such reactivation may have ene monzodiorites that occur as NW- to NE- is similar to that of the host rocks, i.e., plagio-
caused crustal thinning and mantle upwelling, trending dikes or stocks. They typically have clase + amphibole + alkali feldspar + quartz
leading to partial melting of the upper mantle sharp contacts with the host Triassic carbonates + biotite, but they contain a higher percentage
and lower crust, ultimately producing exten- and exhibit a preferred orientation of tabular of dark minerals, such as amphibole and bio-
sive intermediate-silicic magmatism in the plagioclase grains aligned parallel to the intru- tite. Typical specimens have hypidiomorphic-
region. Subduction of the paleo–Pacifi c plate sive contacts. The host carbonates have locally granular textures and consist of 50–60 modal%
also triggered extensive Jurassic and Creta- been converted to marble, scapolite, and skarn. plagioclase, 15%–20% euhedral amphibole, and
ceous magmatic activity elsewhere in south- All of these intrusive bodies contain abundant 5%–10% quartz, accompanied by minor potas-
east China and reactivated many preexisting enclaves, including spinel pyroxenite, horn- sium feldspar and biotite.
faults and fracture zones (Wong et al., 2009). blendite, hornfels, marble, and skarn. Some (3) Microdiorite enclaves: These enclaves
Very few basement outcrops occur in the of the shoshonitic bodies were intruded along occur chiefl y in granodiorites but are also pres-
Yangtze block, and the Tongling area is domi- contacts between the high-K, calc-alkaline ent in some quartz monzodiorites and porphy-
nated by a sequence of Paleozoic and Trias- bodies and the host country rocks. The shosho- ritic granodiorites. They are dark gray in color
sic marine carbonate, clastic, and siliceous nitic rocks are commonly associated with gold, and vary in shape from ellipsoidal or spherical
sedimentary rocks, locally overlain by Cre- silver, lead, and zinc deposits. Their 40Ar/39Ar to irregular, fl ame-like forms. These enclaves
taceous to Middle Tertiary continental clastic cooling ages range from 137 to 136 Ma (Wu generally range from 20 to 50 cm in diameter,
and volcanic rocks (Xu and Zhou, 2001). The et al., 2000). with the largest up to 140 cm. They are typically
80 Geological Society of America Bulletin, January/February 2014
Petrogenesis of intermediate-acid intrusive rocks and zircon SHRIMP U-Pb dating in the Tongling area, Anhui Province (eastern China)
distributed in the middle of the intrusive bodies, composition. All have sharp contacts with the Whole-Rock Chemical Analysis
locally occurring in swarms or belts, and they host rock. We interpret these to be accumula-
Thirty-six relatively fresh whole-rock and
have gradational contacts with the host rocks. tions of early-formed pyroxene crystals that
six enclave samples were selected for complete
These enclaves mostly contain the same miner- solidifi ed before they were dispersed by a new
whole-rock chemical analysis at the Chinese
als as the host rocks, and some of the crystals pulse of similar magma.
Geological Experiment and Testing Center,
have reaction rims, suggesting possible min- (2) Amphibole-rich enclaves: These occur in
Academy of Geological Sciences, Beijing.
gling of magmas. Some enclaves are compos- the monzonites and pyroxene monzodiorites.
Major oxides and Sr, Ba, Zn, Rb, Nb, Zr, and Ga
ite features with dark central zones and lighter They are black, spherical or ellipsoidal, and
were determined by X-ray fl uorescence spec-
rims, probably also refl ecting magma mix- 20–30 cm across. They consist chiefl y of amphi-
trometry (XRF) on glass discs using National
ing events. The minerals in these enclaves are bole (90–95 modal%) accompanied by minor
Standard GB/T 14506-1919. Total iron as FeO
plagio clase (40–50 modal%), amphibole (20%– clinopyroxene, biotite, and pyrite. Most of these 2 3
was determined by XRF, and FeO contents
30%), biotite (5%–8%), potassium feldspar enclaves have textures and grain sizes similar to
were determined by titration. Rare earth ele-
(3%–7%), and quartz (3%–5%), with accessory those of pyroxene-rich varieties. Likewise, they
ments (REE) and other trace elements, includ-
apatite, titanite, zircon, magnetite, pyrite, and all have sharp contacts with the host rocks, and
ing Cu, Pb, Th, U, Hf, Ta, Sc, Cs, V, Co, Cr, and
chalcopyrite. They have typical microgranular they are typically marked by thin reaction rims
Ni, were determined by inductively coupled
textures and locally contain plagioclase pheno- of very fi ne-grained diopside. In some samples,
plasma–mass spectrometry (ICP-MS) with an
crysts with compositions similar to those of the tabular plagioclase in the host rock is oriented
Agilent 7500a system using National Standard
groundmass grains. Some of the phenocrysts parallel to the enclave boundary. These enclaves
LY/T 1253-1999. The analytical precision for
straddle the boundary between the enclave and are also interpreted as accumulations of amphi-
the major oxides is better than 1%, whereas that
host rock, and some have distinct, ellipsoidal bole dispersed by intrusion of a more mafi c
for most trace elements is 5%.
cores with more calcic compositions than the magma as indicated by the pyroxene rims.
rims. Plagioclase in the groundmass is typically (3) Amphibole gabbro enclaves: These mainly
Mineral Analysis
reversely zoned and contains many inclusions occur in the monzonites and quartz monzonites.
of apatite. Some quartz contains abundant inclu- They are black, spherical clots ranging from 5 The compositions of plagioclase, potassium
sions of fi brous amphibole. Such textures sug- to 15 cm in diameter, composed of amphibole feldspar, amphibole, biotite, and pyroxene were
gest that the enclave magma cooled rapidly in (60–70 modal%) with subordinate plagioclase determined on a Superprobe 733 at the Mineral-
the host magma (Di et al., 2003). (15%–27%), minor biotite (1%–3%), and traces ogy Laboratory of the China University of Geo-
The shoshonitic series includes pyroxene of pyroxene and apatite. These enclaves have sciences, Beijing, with an acceleration voltage
monzodiorite, monzonite, and quartz monzo- allotriomorphic to hypidiomorphic textures. of 15 kV and a beam current of 0.02 mA using
nite, all of which have idiomorphic-hypidiomor- On the basis of their textures and mineralogies, natural and synthetic minerals for standards
phic granular textures. The main rock-forming these enclaves most likely formed by mixing of (Tables 3–7). The accuracy of the reported val-
minerals (which range from 1.5 to 2.2 mm in mafi c and felsic magmas. ues is 1%–5%, depending on the absolute ele-
size) are clinopyroxene, plagioclase, potassium ment concentrations. Oxygen abundances in the
feldspar, and quartz, accompanied by subor- ANALYTICAL METHODS silicate minerals are based upon stoichiometry
dinate biotite and amphibole. In addition, the (Deer et al., 1992).
rocks contain abundant, fi ne-grained (0.01– Zircon SHRIMP U-Pb Dating
0.5 mm) accessory minerals such as magnetite, ANALYTICAL RESULTS
zircon, titanite, and apatite. Sulfi de minerals, Four samples, HCJZK1, SYSZK3, FHS2,
Zircon SHRIMP U-Pb Dating
including chalcopyrite, pyrite, sphalerite, and and YSZ3, each ~2 kg, were collected for zircon
bornite, are also common. separation. The samples were crushed to 60–100
Each dated sample is described in this sec-
Three types of enclaves also occur in these mesh, rinsed, and air-dried. Magnetic minerals
tion, and the analytical results are presented
rocks: pyroxene-rich, amphibole-rich, and were removed with a hand magnet, and the dense
in Table 1.
amphibole gabbro enclaves. The pyroxene- and minerals were separated with heavy liquids. Zir-
amphibole-rich enclaves are coarser grained con grains were then handpicked under a binoc- Sample HCJZK1
than the host rocks, but the minerals in the ular microscope, mounted in epoxy along with Sample HCJZK1 is from a drill core (hole
enclaves and host rock have the same compo- zircon standard R33 (Black et al., 2004), and ZK1) of the Huchengjian gabbro-diorite of the
sitions. The amphibole gabbro enclaves are ground to about half their thickness. The zircon high-K, calc-alkaline series. The rock is dark
medium grained and have typical allotriomor- grains were photographed in refl ected light and gray in color and is characterized by abundant
phic and hypidiomorphic textures, suggesting imaged in cathodoluminescence mode (CL) to pyroxene and plagioclase phenocrysts of simi-
that they may have formed by mixing of mafi c determine their internal structures and to select lar size. The matrix has a diabasic texture and
and felsic magmas. points for analysis. All of the analyses were consists of tabular plagioclase with fi ne-grained
(1) Pyroxene-rich enclaves: These mainly carried out using the Stanford/U.S. Geological interstitial pyroxene and magnetite (see Table 2
occur in the pyroxene monzodiorites. They form Survey (USGS) SHRIMP-RG (sensitive high- for a chemical analysis of this rock).
black, irregular clots, 4–7 cm across, composed resolution ion microprobe, reverse geometry) Zircon grains from this sample are prismatic,
chiefl y of clinopyroxene (90–95 modal%), with facility. Age uncertainties are cited at the 95% with length:width ratios generally between 1:1
subordinate spinel (2%–3%), amphibole (1%– confi dence level for the selected populations, and 2:1. CL images are uniformly gray with no
2%), and accessory biotite, apatite, magnetite, and the internal precision for single analyses in evidence of zoning (Fig. 2A). Their U contents
and pyrite. Most of the enclaves have abundant, tables and fi gures is 1σ. The age calculations range from 524 to 1545 ppm, and Th ranges
relatively large (3–5 mm), euhedral to rounded were performed using the software Isoplot and from 661 to 2752 ppm, yielding Th/U ratios of
crystals of pyroxene in a matrix of the same Squid (Ludwig, 2001, 2003). 1.3–2.7, indicating an igneous origin (Table 1).
Geological Society of America Bulletin, January/February 2014 81
Wu et al.
σ err111111111111111111111131411111112112112*113*1111
1
e
g
a
HINA 238Pb/U (Ma)14014214214414614314314114014414514114314513914213814213914014614453114369114114014514214314214223514414614814523301562104149147145147
VINCE, C 206 % err2.62.22.42.01.62.02.03.13.22.02.14.41.81.74.22.83.77.42.04.65.02.51.44.61.62.37.04.32.75.14.86.84.56.08.34.24.90.42.90.73.36.54.92.6
O
R
P U
G, ANHUI 207206Pb/0.04810.04740.04690.04830.04840.04870.04790.04940.04840.04820.04820.04900.04890.04980.04840.04800.04930.04630.04890.05100.04720.04650.06450.04470.06650.05080.04830.04630.04670.04610.04920.04810.05870.04510.04630.04750.04750.16150.05080.16120.04930.04700.04680.0513
N
NGLI % err0.50.50.50.40.40.50.40.60.70.50.51.00.40.50.70.50.70.90.61.00.90.50.50.70.60.71.00.60.60.70.81.00.80.81.01.10.90.50.80.60.80.90.80.7
O
T
ROCKS OF 206238Pb/U0.02190.02220.02230.02260.02300.02240.02250.02210.02200.02260.02270.02220.02240.02280.02170.02230.02170.02220.02170.02200.02280.02250.08660.02240.11370.02220.02190.02260.02220.02240.02220.02220.03750.02240.02280.02310.02280.44340.02450.40280.02330.02300.02270.0231
E
USIV % err1.91.81.61.51.41.51.53.12.21.81.83.41.51.72.21.72.52.92.03.52.91.81.32.41.32.33.32.12.12.22.73.32.42.63.13.22.90.42.90.72.82.92.72.6
R
T
N
R I Pb
PIC DATA FO 207206Total Pb/0.05000.04860.04880.04970.04910.05010.04920.04940.05060.04900.04920.05100.04990.04980.05250.05080.05180.05230.04890.05310.05080.04820.06480.04950.06770.05080.05410.05070.04830.04930.05190.05350.06300.05130.05520.04990.05210.16170.05080.16140.05050.05240.05090.0513
O
T
b ISO % err0.50.50.50.40.40.50.40.60.60.50.51.00.40.50.60.50.70.90.61.00.80.50.50.60.60.71.00.60.60.60.81.00.80.70.91.10.80.50.80.60.80.80.80.7
P
U-
P) b
M P
HRI 206U/6500771153644719382195986890777600710224623854487814249805518170552542116825854878248233
E (S 238al 45.45.44.44.43.44.44.45.45.44.43.44.44.43.45.44.46.44.46.45.43.44.11.44.8.45.45.43.45.44.44.44.26.44.43.43.43.2.40.2.42.43.43.43.
OB Tot
R
P
O
MICR Disc.(%)−25−50−69−20−17−7−3420−14−24−266027−13−3017−92470−58−8342−1511965−20−91−75−9811−27134−134−91−50−48449138−65−7472
HIGH-RESOLUTION ION 206PbR232238Th/(ppm)U1.8514.71.3415.52.6620.21.6920.41.8430.51.8423.21.5821.11.4110.11.309.91.7117.21.5616.60.794.11.0620.90.8318.81.099.41.8418.31.827.81.025.41.0412.30.733.61.307.21.7416.20.2722.60.8510.00.9421.50.929.00.944.30.6910.60.8710.90.919.90.766.60.524.40.497.50.086.90.104.80.115.00.065.80.3199.00.117.00.5362.90.076.70.096.10.117.00.127.6nic portions, respectively.
NSITIVE Th(ppm)140110552705171627522151167372566114711288163111876752917057402796611334611416794292014222043614814522551151102924261877369323283745d radioge
ON SE m)32265723471369359499794803503561372040126876mon an
TABLE 1. ZIRC 206PbUC(%)(pppot nameCJZK1-10.2378CJZK1-20.0381CJZK1-30.01105CJZK1-40.10104CJZK1-50.01154CJZK1-60.15120CJZK1-70.03109CJZK1-80.0753CJZK1-90.2252CJZK1-100.0188CJZK1-110.0385YSZK03-10.2721YSZK03-20.13108YSZK03-30.1195YSZK03-40.4750YSZK03-50.2495YSZK03-60.3841YSZK03-70.4328YSZK03-80.0165YSZK03-90.5318YSZK03-100.2436YSZK03-110.0983HS2-10.8330HS2-20.0751HS2-30.6422HS2-40.2547HS2-50.6622HS2-60.2254HS2-70.0757HS2-80.0551HS2-90.3934HS2-100.5823HS2-111.5223SZ3-10.3035SZ3-20.7924SZ3-30.1125SZ3-40.3929SZ3-51.3826SZ3-61.2133SZ3-73.3818SZ3-80.1833SZ3-90.4230SZ3-100.2435SZ3-110.2938206206Note: and PbPb are comCR206207Pb/Pb age.*
SHHHHHHHHHHHSSSSSSSSSSSFFFFFFFFFFFYYYYYYYYYYY
82 Geological Society of America Bulletin, January/February 2014
Petrogenesis of intermediate-acid intrusive rocks and zircon SHRIMP U-Pb dating in the Tongling area, Anhui Province (eastern China)
d)
TGS1QMD62.620.5616.821.321.950.071.475.864.972.940.270.480.010.1499.48 8.01.70.680.572.070.780.1226.236.913.4597.87409913.8184160455.60.72ontinue
1 1 c
(
D2D726752078313771513793068072003 057668798813429 9 197
BM1.0.6.2.3.0.1.5.4.2.0.0.0.0.0. 7.1.0.0.1.0.0.4.1.0.8308916.46.0.
EQ6 1 0 37171771811
T 1 7 1 9
D1D296544724613736696382984025613 426967326913819 3 7 1 677
BM0.0.6.0.3.0.1.7.3.3.0.0.0.0.0. 7.1.0.0.0.0.0.3.9.0.39.269.67.15.0.
EQ6 1 0 − 3217 931810
T 1 1 8 1 9
T
C
DISTRI DBZ1QMD59.150.7516.502.232.190.062.536.365.481.960.281.130.270.9099.79 7.62.80.620.461.110.740.12445.711.0909.43175217.825615.57884.160.85
G
N
LI
G
E TON DBZ3QMD59.950.7516.262.742.750.062.696.425.002.700.310.850.270.50101.25 7.71.90.660.511.280.720.1124.886.713.9112104178016.922614.70454.820.91
H 1
T
F
O
AVES JT4QMD60.100.6416.153.132.840.061.344.924.242.990.251.290.521.0899.55 7.51.40.810.682.390.860.1331.153.88.88210.2955720.57815.8813.780.67
L 7 1 8
C
N
D E es
CKS AN aline seri DGS1QMD60.860.7715.752.163.440.122.125.814.382.820.330.690.160.3499.75 7.31.60.710.621.420.770.1228.867.410.38615.36298119.817115.59234.840.86
O k
R al
USIVE K, calc- SJ1MD9.010.726.492.543.120.112.405.694.183.010.451.840.670.560.79 7.41.40.690.571.540.830.1331.23.281.4887.825.985.280.97
NTR High- QQ5 1 10 361517119126192
F I
O
SES TS2MD3.660.575.691.824.070.121.434.064.033.010.230.760.210.550.21 7.11.30.790.743.020.920.121.780.962.3734.556.965.031.05
LY DQ6 1 10 39161876124103
A 1
N
A
L
A
CHEMIC JGS9QMD61.880.5516.282.322.620.071.364.634.253.230.240.980.021.0299.45 7.71.30.770.662.930.870.1330.562.110.3689.58690212.913216.311315.170.79
O
E
G
ROCK JGS2QMD60.210.5816.111.502.500.071.295.584.073.390.241.540.102.2999.47 7.81.20.740.661.970.80.1331.364.111.3709.98789312.519215.99144.120.71
E-
L
O
H
W P923182958073197 44274 28
LE 2. MJ1QMD54.30.815.53.82.40.12.06.73.22.80.33.20.04.9100.6 6.61.20.70.5–0.70.70.141.12011.712415.99556618.37317.76084.10.6
B
A
T
ML3BD4.530.907.702.725.730.183.066.723.772.180.391.060.090.389.41 6.11.70.720.650.790.870.143.98.30.401738.463.313.50.36
SG5 1 9 – 431162672115165
CJZK1GBD52.641.1517.323.595.360.183.458.093.672.170.410.570.120.2298.94 6.01.70.710.61–2.260.770.1443.948.612.69123.8660326.41219.2395.210.92
H 1 7 2 6
O
es K2
SamplRocksSiO2TiO2AlO23FeO23FeOMnOMgOCaONaO2KO2OP52LOISCO2Total ALKO/Na2Fe*Fe#MALIASIAIAnCrNiVCoRbSrYZrNbBaHfTa
Geological Society of America Bulletin, January/February 2014 83
Wu et al.
d)
TGS1QMD8.931.352405710.85.560.32.50.20.2022.2132.281.539.176.28.831.406.051.544.040.672.920.511.150.271.710.271750.910.0714.279.6ontinue
c
(
D2D8260 36613342461907871006533876836805237211 870919
BM9.2.245.7.0.3.0.0.8.6.2.1.0.6.8.1.6.1.4.0.3.0.2.0.0.0.80.0.3.0.
EQ 192 11 47 3 7 14
T 1
D1D6660 13536974283950219034626172957584341619 881184
BM1.2.577.7.0.4.0.0.9.3.2.2.1.0.9.1.6.1.4.0.3.0.1.0.1.0.40.0.9.2.
EQ1 182 11 48 3 8 4
d) T 1
e
u
n
nti
T (co BZ1MD0.222.87306.69.20.12.90.70.745.79.21.961.07.85.18.91.906.211.584.310.743.650.681.790.391.690.2750.890.045.42.2
RIC DQ1 41 1 37 3 17 24
T
S
DI
NGLING DBZ3QMD9.412.3543311.69.630.22.70.80.80179.71.880.834.565.47.527.205.441.453.930.613.410.611.710.361.750.271540.920.0525.546.2
O
T
E
H
OF T JT4QMD8.502.40216241.56.120.327.81.70.2120.58.71.92.239.772.28.930.706.451.434.480.843.990.802.310.390.810.12730.780.139.336.9
S 2 1
E
V
S AND ENCLA alkaline series DGS1QMD8.722.481227621.88.340.27.80.90.8416.713.62.181.239.478.38.633.406.331.695.250.693.800.701.950.271.910.281830.880.0614.849.5
USIVE ROCK High-K, calc- QSJ1QMD9.442.83906834.35.360.25.60.40.3818.29.12.261.638.479.29.331.406.242.118.240.994.560.942.450.312.090.271870.910.0611.967.3
R
T
S OF IN DTS2QMD11.142.023695195.890.14.30.80.5222.616.82.132.534.464.77.326.405.021.323.420.632.960.531.330.291.500.251500.930.1112.052.6
E
S
Y
L
A
CAL AN JGS9QMD10.172.70635514.85.140.120.20.3019.610.72.181.234.765.57.425.905.001.273.410.612.640.471.110.211.860.301500.900.0913.269.9
MI
E
H
K GEOC JGS2QMD9.732.30734421.15.230.13.60.30.30199.52.151.435.165.07.325.704.861.253.330.532.610.441.100.262.100.321500.910.1010.571.4
C
O
R
WHOLE- MJ1QMDP12.062.1028862490.12.80.20.2418.625.42.511.045.385.39.633.606.481.584.500.663.680.691.810.372.670.411970.860.176.430.9
2.
E
L
TAB ML3BD7.562.26153.52.230.290.30.30.7170.81.941.68.65.76.65.205.251.443.970.633.710.671.830.291.800.2860.940.099.79.3
SG 41151 1 12 25 2 13 3
CJZK1GBD6.601.32753152.20.280.233.21.60.2028.431.71.92.437.973.09.834.707.931.865.931.155.331.073.140.482.300.35850.800.099.826.6
H 1 1
s
SampleRocksThUCuZnPbScAgAsBiSbGaLiBeMoLaCePrNdSmEuGdTbDyHoErTmYbLuΣREEEu*/EuRb/SrBa/RbSr/Y
84 Geological Society of America Bulletin, January/February 2014
Petrogenesis of intermediate-acid intrusive rocks and zircon SHRIMP U-Pb dating in the Tongling area, Anhui Province (eastern China)
HAC) TEBDB6MQME54.500.9015.093.195.140.204.697.423.822.330.240.760.820.5799.67 6.31.60.620.52−1.30.690.1147.9283.917.9207247659313.71845829n.d.n.d.continued)
s ( (
e
v
a
Encl HSB4MDE59.580.9316.354.133.290.092.653.443.852.510.431.770.960.1000.08 6.51.50.730.5531.110.1321.6716.26.23215.1159027.6361497n.d.n.d.
F 1 1 16 1 7
GS3GV5.370.112.690.510.970.040.161.643.873.960.030.240.040.169.79 7.91.00.90.866.230.930.17.45.29.176.6527.212.653.90.67
d) T 7 1 9 12 1 629 12169
e
u
n
nti
coRICT ( YSZ3GDP58.190.4715.142.112.760.111.386.461.462.710.223.520.035.69100.25 4.60.50.770.67−2.520.90.1767.5219.26.9548.710544816.54313.54895.40.61
T
S
DI
NGLING XQT4GDP63.590.3214.491.052.180.100.894.361.413.880.173.100.334.27100.14 5.70.40.770.711.011.020.1763.2623.15.8356.31672041316118.27265.10.82
O
T
E
S OF TH SJDLC1GDP63.770.4915.532.232.940.071.334.144.113.100.220.920.330.82100.00 7.41.30.790.693.130.890.1229.8374.310.16310.611269714.716216.88984.70.76
E
V
A
L
ND ENC QTY2GDP61.720.4216.080.552.090.050.734.485.123.410.182.160.213.08100.28 9.01.50.770.744.270.80.122051.612.15413857038.611815.38035.270.81
RUSIVE ROCKS A aline series (HAC) QTY1GDP61.160.5216.341.252.680.031.063.964.562.780.232.860.652.20100.28 7.81.60.780.723.570.940.1229.2174.514.86510.4787058.212216.16814.210.75
LYSES OF INT High-K, calc-alk STJ5GD64.330.4816.401.532.740.071.233.945.092.700.210.660.360.95100.69 7.91.90.760.693.90.90.1124.45104.112.05410.770101911.817217.99514.50.56
A
CAL AN STJ3GD64.230.5016.381.872.580.081.223.605.062.530.210.750.090.95100.05 7.72.00.770.684.060.940.1125.33129.413.0599.872118811.917518.8105650.67
MI
E
H
K GEOC NHC1GD62.850.6016.131.721.550.071.445.034.683.330.232.200.340.26100.43 8.21.40.680.523.050.80.122579.312.65711.37596113.2196139413.980.82
C
O
R
WHOLE- FHS1GD63.580.5716.262.122.900.091.464.184.753.010.250.620.020.36100.17 7.81.60.760.673.610.880.1226.15810.0728.411480917.418717.78986.781.26
2.
E
L
TAB FHS2GD63.120.5615.482.123.060.081.223.943.933.230.251.310.161.81100.27 7.41.20.80.713.320.920.1331.2122.29.9669.413469916.118717.58196.130.88
TGS2QMD62.740.5516.732.522.420.111.444.724.812.720.280.580.010.2799.90 7.61.80.770.632.840.880.1228.357.311.161117204015.518916.90985.90.85
1 1
O
es K2
SamplRocksSiO2TiO2AlO23OFe23FeOMnOMgOCaONaO2OK2OP25LOISCO2Total ALKO/Na2Fe*Fe#MALIASIAIAnCrNiVCoRbSrYZrNbBaHfTa
Geological Society of America Bulletin, January/February 2014 85
Wu et al.
HAC) TEBDB6MQME9.00n.d.20214812.7n.d.0.565.20.10.6115.937.20.963.626.347.25.220.704.301.204.900.603.500.601.400.261.200.201180.800.1310.943.3continued)
s ( (
e
v
a
Encl HSB4MDE15.00n.d.047112.5n.d.0.631.80.30.4019.720.51.52.157.013.912.846.408.201.607.601.206.001.202.900.482.700.40620.610.176.925.0
F 6 1 2
GS3GV6.082.427891.510.237.83.10.505.20.93.071.27.07.83.09.501.900.541.410.211.210.240.670.111.340.2250.980.220.70.6
d) T 1 12910 4 121 12 6 14
e
u
n
nti
RICT (co YSZ3GDP8.411.5077360.86.410.1311.70.10.5417261.840.626.351.76.223.004.531.253.360.523.220.581.650.291.950.301250.950.234.727.2
T
S
DI
NGLING XQT4GDP16.441.3855919.42.210.122.80.30.4318.59.82.581.836.462.66.621.103.750.902.430.402.370.471.350.321.740.271410.860.824.315.7
O
T
E
S OF TH SJDLC1GDP11.692.5683815.76.120.124.40.40.5319.710.12.21.633.864.27.425.904.941.203.340.602.930.531.380.191.300.211480.860.168.047.4
E
V
A
L
D ENC QTY2GDP10.262.80446424.14.860.196.21.10.4722.515.81.981.329.558.26.623.204.321.022.710.471.860.310.690.111.300.21300.860.129.581.7
N 1
RUSIVE ROCKS A aline series (HAC) QTY1GDP9.592.609317731.15.650.4511.41.2020.818.52.143.132.462.27.024.604.501.092.780.471.810.300.620.151.160.251390.880.118.886.0
S OF INT K, calc-alk STJ5GD11.422.19684316.34.580.112.70.40.302214.82.272.243.384.59.633.605.981.413.550.492.530.400.990.111.000.161880.870.0713.786.4
LYSE High-
A
CAL AN STJ3GD11.692.152571177.34.70.092.90.31.3023.216.72.431.441.480.99.332.705.901.383.510.492.570.411.060.131.450.231810.860.0614.799.8
MI
E
H
K GEOC NHC1GD7.812.57386731.24.210.12.50.41.3821.115.22.231.237.368.27.425.904.441.394.200.492.530.491.350.191.150.141550.980.0812.572.8
C
O
R
WHOLE- FHS1GD9.952.251405818.16.40.33.60.40.4020.98.42.462.139.975.78.630.705.841.393.870.633.500.631.670.331.610.261750.850.147.946.5
2.
E
L
TAB FHS2GD11.352.672754219.76.130.53.37.30.4620.910.92.393.338.271.38.228.905.441.343.650.553.220.581.540.311.400.221650.880.196.143.4
GS2MD9.371.12310.85.40.11.40.20.244.44.92.390.90.58.89.12.706.371.624.310.683.280.591.370.211.210.2010.900.075.37.1
TQ 192 22 47 3 18 16
s
SampleRocksThUCuZnPbScAgAsBiSbGaLiBeMoLaCePrNdSmEuGdTbDyHoErTmYbLuΣREEEu*/EuRb/SrBa/RbSr/Y
86 Geological Society of America Bulletin, January/February 2014
Petrogenesis of intermediate-acid intrusive rocks and zircon SHRIMP U-Pb dating in the Tongling area, Anhui Province (eastern China)
d)
CSB1HGE40.942.4511.989.208.340.206.8610.882.512.051.900.841.090.8400.08 4.71.20.710.55−6.490.50.149.0318.28.53546.7778228.577673n.d.n.d.ntinue
1 5 6 3 o
c
(
)O
H
S(seva BMS2HCE34.822.4513.147.159.160.188.5713.481.910.951.722.870.522.5599.47 3.12.00.640.52−11.40.490.1268.322.29.25712.66277320.6698322n.d.n.d.
lc
n
E
MBS6PCE41.960.4012.132.793.970.2811.4718.411.881.161.852.680.370.4999.84 1.70.70.360.2617.30.360.127224.49.0628.250007.624680n.d.n.d.
d) − 3 2
e
u
n
contiCT ( SMLQM62.300.4816.021.002.800.100.992.210.9710.120.191.691.080.80100.75 11.40.10.780.749.140.980.2653.647.57.1528.82.7963816.918216.90555.50.86
RI 1
T
S
DI
GLING SA1QM57.460.7015.993.423.020.121.056.004.463.190.291.320.212.6299.85 8.01.40.850.741.720.750.1227.355.111.910610.110290320201189434.90.86
N
O
T
F THE SJC1QM59.350.7915.682.253.910.112.495.664.273.770.310.990.200.3800.16 8.21.10.70.612.410.750.1325.746.613.20016.68731217817.5164.20.54
O 1 1 0 1 9
S 1
E
V
A
CL 5D586883369309246576722213455014 786457918115 24 5 1 683
EN XSQM61.0.15.1.2.0.2.4.3.4.0.1.0.0.00. 8.0.0.0.3.0.0.2863.12.8214.301915.7217725.0.
D 1 1 17 1 9
N
A
SIVE ROCKS )OHS(seires XS1QM58.850.7116.161.972.470.101.896.474.354.750.310.700.860.2099.79 9.30.90.690.572.680.680.1422.3115.111.48511.210494017.619018.99445.20.75
U c
OF INTR itinohsoh DS4QM61.690.6515.590.823.980.082.093.903.905.100.211.061.020.23100.32 9.20.80.680.665.20.830.1523.2209.614.37314.716266513.815917.19665.741.21
S S
E
S
Y
L ANAL DS8QM56.320.9916.412.965.070.162.555.844.412.930.341.010.830.0599.87 7.51.50.750.671.530.80.1230.593.813.414321.28772018.515917.97894.710.95
A
C
MI
OCHE CS1Mz57.321.0516.670.974.540.081.736.274.703.360.350.500.842.5500.93 8.31.40.750.721.840.750.1326.718.412.5289.8605220.90115.7885.190.88
E 1 1 9 2 7
G
K
C
O
E-R QT3MD5.520.876.603.843.320.181.916.894.493.110.451.100.041.519.83 7.81.40.780.630.730.730.139.61.89.983.6793.348.645.70.72
HOL XP5 1 9 23 12110110219194
W
2.
BLE G6MD0.811.217.162.715.550.143.269.633.733.100.560.761.300.340.26 7.01.20.70.632.860.650.149.94.54.489.4364.991.126.230.94
TA JP5 1 10 − 3211729111226275
)A
C
sv(Healc FHSB7MRE42.071.8820.445.919.470.246.043.902.595.060.161.310.030.1499.24 7.80.50.70.613.841.230.2240.83180.779.530737.532166925.9202231684n.d.n.d.
n
E
O
es K2
SamplRocksSiO2TiO2AlO23OFe23FeOMnOMgOCaONaO2OK2OP25LOISCO2Total ALKO/Na2Fe*Fe#MALIASIAIAnCrNiVCoRbSrYZrNbBaHfTa
Geological Society of America Bulletin, January/February 2014 87