The transition processes from monogenetic volcanoes to composite volcanoes
are poorly understood. The Late Pleistocene to Holocene intraplate
monogenetic Wulanhada Volcanic Field (WVF) in northern China provides a
snapshot of such a transition. Here we present petrographic observations,
mineral chemistry, bulk rock major and trace element data, thermobarometry,
and a partial melting model for the WVF to evaluate the lithology and partial
melting degree of the mantle source, the crystallization conditions, and
pre-eruptive magmatic processes occurring within the magma plumbing system.
The far-field effect of India–Eurasia collision resulted in a relatively high
degree (10 %–20 %) of partial melting of a carbonate-bearing eclogite
(
Monogenetic eruptions are one of the most widespread forms of volcanism on
Earth, with polygenetic volcanism occurring in intraplate, extensional and
subduction-related settings (e.g., Hildreth, 2007; Cañón-Tapia,
2016). Although the eruption lifespan of a single monogenetic volcano is
usually short and eruptive volumes are small (
The small eruptive volumes and entrainment of mantle xenoliths in monogenetic volcanic fields are generally assumed to have not undergone significant modification during the magmatic evolution processes (such as crustal contamination and fractional crystallization or magma recharge) on ascent from source to surface (e.g., McGee and Smith, 2016; Smith and Németh, 2017; Brenna et al., 2018). This is different from polygenetic volcanism, in which magmatic evolution occurs in interconnected magma reservoirs that are repeatedly replenished and erupt from a stable central conduit system, building a large composite edifice consisting of the products of eruptions with conical morphology (e.g., Cañón-Tapia and Walker, 2004; Devine et al., 2003; Watanabe et al., 2006; Zellmer and Annen, 2008). A consequence of these systematic differences is that monogenetic eruptions produce low cumulative volumes of commonly primitive compositions, whereas polygenetic volcanoes generate large volumes and evolved magmas (e.g., Lynch et al., 1993; Wei et al., 2007; Blondes et al., 2008; Brenna et al., 2012).
Both composite and monogenetic volcanoes are observed to coexist in the same volcanic field (e.g., Lynch et al., 1993; Wei et al., 2007; McLeod et al., 2022) and can be divided into two styles based on their field and genetic relationship. One is that the compositions of monogenetic volcanoes are controlled by composite volcanoes. Monogenetic cones on the flanks of stratovolcanoes are generally regarded as parasitic vents connected to the magma plumbing system of the main volcano (Wilson and Head, 1988; Ablay et al., 1998; Corazzato and Tibaldi, 2006). Another style is that the composite volcanoes and monogenetic volcanoes erupted and evolved independently. For example, Santa Clara, a composite volcano in the Pinacate Volcanic Field, Mexico, is considered to be unrelated to the dispersed monogenetic volcanoes (Lynch et al., 1993). Currently, the evolution processes from monogenetic volcanoes to composite volcanoes with a wide range of compositions are poorly understood (Brenna et al., 2012).
The Late Pleistocene to Holocene monogenetic Wulanhada Volcanic Field (WVF) is one of the Cenozoic monogenetic intraplate volcanic fields in northeast China and is located at the boundary between the northwestern margin of the North China Craton and the southern margin of the Daxing'anling–Mongolia Orogenic Belt (Fig. 1; Fan et al., 2014). The volcanic cones in the WVF are linearly distributed along the NE–SW-striking basement faults and the NW–SE-striking Wulanhada–Gaowusu fault (W–G fault) system. The WVF has been interpreted to be derived from the partial melting of carbonated peridotite in the proportion of 4 %–5 % based on bulk rock trace element and Sr–Nd–Pb–Hf–Mg isotopic compositions (e.g., Fan et al., 2014; Zhao et al., 2019; Sun et al., 2021). However, magma processes (such as fractional crystallization or potential magma mixing) that occurred in the source and magma plumbing system have not been well constrained. In this study, we (1) place constraints upon the lithology of the mantle source, the degree of partial melting and the interaction with the mantle and (2) evaluate the pre-eruptive crystallization conditions and magmatic processes occurring within the magma plumbing system based on comprehensive studies of high-resolution mineralogy, petrography, bulk rock major and trace element geochemistry, and thermobarometric and hygrometric calculation. Our study on the Wulanhada Volcanic Field represents a snapshot of the transition from monogenetic volcanoes to composite volcanoes, which has significance for the evolution of intraplate monogenetic volcanism.
Cenozoic volcanism in North China, including hundreds of individual
volcanoes, is spread over an area of
The basement of the WVF is primarily composed of Proterozoic quartzite,
marble schist and gneiss in the north of the province, whereas granites of
same age dominate the central and southern area (Bai et al., 2008).
The WVF hosts 30 small monogenetic volcanic edifices including scoria cones,
lava shields, spatter cones and lavas covering an area of 180 km
The WVF volcanic rocks are considered to have been formed from the Late Pleistocene to Holocene based on field relationships of the well-preserved volcanic edifices and supported by thermoluminescence dating on lavas overlaying the loess, which provide minimum ages of 21.05–30.56 ka (Bai et al., 2008). Recent K–Ar ages on WVF lavas representing the entire volcanic activity range between 10.8 and 0.22 Ma, indicating a slightly longer timing with a supposedly west-to-east progression of the volcanic activity (Zhao et al., 2019). There are, however, no high-precision age determinations available, and therefore the temporal evolution of volcanism in the region is not well constrained and should be the subject of future studies. We focus here on six of the 0.50 to 0.22 Ma old and well-preserved volcanic centers: Beiliandanlu (BLDL), Zhongliandanlu (ZLDL), Nanliandanlu (NLDL), Heinaobao (HNB), Huoshaoshan (HSS) and Hongshan (HS). These monogenetic volcanoes of the WVF encompass similar magmatic styles and the compositional range of the field, and the following characterization is a brief description of these volcanoes.
The Beiliandanlu volcano is a scoria cone
The Zhongliandanlu volcano is the largest scoria cone of the WVF at
The Nanliandanlu volcano reaches heights of
The Heinaobao volcano is located between BLDL and ZLDL and is composed of
one large cone (51 m in height, 430 m in diameter) and three smaller
satellite cones. The southeast flank of HNB displays volcaniclastic
sequences consisting of bedded ash, lapilli layers and scoria due to
artificial destruction. Their volcaniclastic sequences unconformably
overlie the basement Variscan granodiorite in the WVF (Fig. 2b). In detail,
there is 1–2 cm thick soil formation between eruptive units, indicating that
events were non-continuous with short periods of quiescence. The lava flow
extends 300 m to the northwest, covering an area of 3 km
The Hongshan volcano, located in the southeast part of the WVF, is a relatively
low scoria cone reaching heights of
The Huoshaoshan volcano is located to the northwest of HS, and their center vents
are only 200 m apart, parallel to the W–G fault. HSS hosts two calderas
comprising coarse spatter bombs and variably sized lapilli and lava
Field photographs of the Wulanhada Volcanic Field.
Thirty-one lava and scoria samples of six representative volcanic edifices from the WVF were collected in July 2018, including (1) the Beiliandanlu volcano (lava – BLDL1-2, BLDL1-4, BLDL1-8, BLDL1-11; scoria – BLDL1-7, BLDL1-10), (2) the Zhongliandanlu volcano (lava – ZLDL3-1, ZLDL3-2, ZLDL3-3; scoria – ZLDL1-3, ZLDL1-6), (3) the Nanliandanlu volcano (lava – NLDL1-1, NLDL1-2, NLDL2-1; scoria –NLDL2-6, NLDL2-9), (4) the Heinanbao volcano (lava – HNB1-5, HNB-ZM; scoria – HNB1-1, HNB1-2), (5) the Huoshaoshan volcano (lava – HSS07, HSS08; scoria – HSS01, HSS02, HSS05, HSS06) and (6) the Hongshan volcano (lava – HS01-2, HS04; scoria – HS01-1, HS03, HS05). Information on sample composition and locations is shown in Table S1 in the Supplement.
Mineral chemistry was analyzed at the Key Laboratory of Submarine
Geosciences, State Oceanic Administration, Second Institute of Oceanography,
Ministry of Natural Resources, China, using an electron microprobe analyzer
(JXA-8100, JEOL) equipped with wavelength-dispersive X-ray spectrometers and
one energy-dispersive X-ray spectrometer analyzer. For phenocrysts crystals
and fine-grained matrices, the instrument was operated at 15 nA, 15 kV, and a
focused 1 or 5
A total of 31 lava and scoria samples free from obvious or with only
slight signs of alteration were selected and prepared for analysis. Where
present, signs of alteration (slight discoloring) were removed with a saw
before jaw crushing of hand specimens and the subsequent grounding of the
millimeter-sized rock chips in agate mills to fine powders. Bulk rock major
compositions were obtained on fusion beads by X-ray fluorescence (XRF)
analysis using a PW4400 at the laboratory of Nanjing Hongchuang Geological
Exploration Technology Service Co., Ltd. (NHETS), in Nanjing, China. Total
loss on ignition (LOI) was measured on pre-dried powders after ignition at
950
Trace elements were measured by inductively coupled plasma mass spectrometry
(ICP-MS; PerkinElmer ELAN 300D) at NHETS. A total of 25 mg of crushed sample powders
was dissolved using a 1 mL HF and 0.5 mL HNO
The proportions of phenocrysts, vesicles and groundmass were determined by
point counting with a PELCON Automatic Point Counter for 30 representative
samples at the China University of Geosciences (Beijing). We manually operated
a mechanical slide along the
Raw point-counting data and mass fractions for samples of the WVF.
Abbreviations: Plg, plagioclase; Cpx, clinopyroxene; Ol, olivine; Gm, groundmass; Ves, vesicles.
All samples from different cones of the WVF show porphyritic textures with phenocrysts of plagioclase (3 vol %–18 vol %, 0.75 to 2.5 mm long), clinopyroxene (1 vol %–5 vol %, 0.5–1.5 mm long), olivine (1 vol %–3 vol %, 0.3–1 mm long) and Fe–Ti oxides (0.5 vol %–1 vol %, 0.3–0.75 mm long) embedded in a microcrystalline groundmass consisting of the same mineral phases. Phenocrysts occur as single crystals and as glomerocrysts that are nearly ubiquitous and are commonly dominated by euhedral crystals. These phenocryst phases will be described below. Selected microphotographs are displayed in Fig. 3.
Representative photomicrographs of volcanic rocks in the WVF under
cross-polarized light.
Olivine within samples from the WVF occurs as euhedral to subhedral crystals
in the glomerocrysts and phenocrysts as well as groundmass, which were
generally analyzed in both the core and the rim. The compositions of olivine
minerals are listed in Table S2. The Fo content
(forsterite content, molar
Backscattered electron (BSE) images of the olivine crystals from the samples
in the WVF generally display normal and reverse as well as oscillatory zoning
patterns. A representative of a reverse mineral profile is shown in Fig. 5h,
i.e., the core of the reverse-zoned olivine span from Fo
Major element composition of main mineral phases observed in the
WVF.
Clinopyroxene is pervasively present, occurring as individual phenocrysts,
glomerocrysts and groundmass. The compositions of clinopyroxene are listed
in Table S3. According to the classification scheme of
Morimoto (1988), clinopyroxene phenocrysts and groundmass are classified as
diopside–augite (En Type 1 clinopyroxene (Cpx-1) is the common type in all studied samples,
generally homogeneous or normally zoned with slightly decreasing Mg# to
the rim (Fig. 5a). Mg# of Type 1 ranges from 66–84 with a peak of 75. The
normally zoned clinopyroxenes are euhedral in shape in general and
compositionally varied from Mg# Type 2 clinopyroxene (Cpx-2) is also observed in all the studied samples.
Mg# of Type 2 ranges from 69–82 with a peak of 75. It is characterized by a
euhedral core with Mg# of Type 3 clinopyroxene (Cpx-3) crystals are characterized by oscillatory zoning
without sieve texture, accounting for Type 4 clinopyroxene (Cpx-4) represents minor proportions (5 %) of the
clinopyroxene crystal population of the samples in the WVF and is characterized
by sieve-textured cores which are commonly enclosed by a compositionally
homogeneous mantle/rim, occasionally displaying oscillatory zoning at the
outermost rim (Fig. 5g).
Summary of the mineral assemblage of the WVF.
Rim-to-core compositional profiles of representative olivine,
clinopyroxene and plagioclase crystals from the WVF. Yellow lines in BSE images
mark measured line profiles.
Plagioclase is the most abundant mineral and appears as euhedral to
sub-euhedral phenocrysts, glomerocrysts and groundmass. The compositions of
plagioclase are listed in Table S4. Phenocrysts show a range
of compositions from An
Comparable with the clinopyroxene, plagioclase typically displays complex
zoning patterns, including normal, reverse and oscillatory zoning as
well as sieve and resorption/embayed textures. Plagioclase crystals in
glomerocrysts are also predominantly homogeneous and/or slightly zoned, in
some cases, representing the dominant mineral phase within the glomerocryst
(Fig. 3b). Based upon textural investigation and core-to-rim compositional
profiles of plagioclase crystals, the plagioclase phenocrysts are divided
into four groups which are consistent with those of the clinopyroxene.
Type 1 plagioclase (Pl-1) is the ubiquitous phase in the plagioclase population,
which is characterized by absence of zonation or normally zoned with
slightly decreasing An content ranging from 58 to 54 along the core-to-rim
profile (Fig. 5b). An content of Type 1 ranges from 47–63 with a peak of 57. Type 2 plagioclase (Pl-2) constitutes 10 % of the studied plagioclase of
the samples in the WVF. An content of Type 2 ranges from 51–62 with a peak of 56. It is characterized by a low An Type 3 plagioclase (Pl-3) with oscillatory zoning is characterized by faint
oscillations and extensive oscillations of the An content in the
compositional interval An Type 4 plagioclase (Pl-4) with resorbed/embayed crystals is characterized by
the resorption of all the crystals or of most of their cores and is
encircled by a narrow euhedral rim (Fig. 3h), accounting for
Fe–Ti oxides occur as subhedral phenocryst and groundmass distributed in the groundmass and as inclusions in the phenocryst mineral like olivine or clinopyroxene. No exsolution lamellas were observed among the oxides.
Bulk rock major and trace element concentrations are reported in
Table S1. The studied samples fall into the trachybasalt,
basaltic trachyandesite, and boundary between phonotephrite and tephrite
fields on the silica-vs.-total alkali classification diagram (TAS
diagram; Le Bas et al., 1986; Fig. 6a). Moreover, on the K
In this study, we use the pressure-sensitive thermometer of
Putirka (2008, Eq. 33) with the temperature-sensitive barometer of Neave and Putirka (2017) based on the jadeite and diopside–hedenbergite exchange equilibria
between clinopyroxene and coexisting melt iteratively to determine the
Tests for equilibrium between clinopyroxene or olivine and nominal
melts.
The clinopyroxene–melt thermobarometric estimation results are displayed in
Table 3, and the relative probability density curves of the thermobarometry
data are highlighted by kernel density estimate (KDE) plots (Fig. 9). The
temperature estimates derived from the Type 1, 2 and 3 clinopyroxene–melt pairs show a
distribution peak value of 1115–1130
Geothermobarometry and hygrometry estimations derived for samples from the WVF based on various olivine, clinopyroxene and plagioclase models.
Kernel density estimates (KDEs) of thermobarometric and
hygrometric calculation results for the Type 1
Further constraints on magma storage conditions and differentiation
processes can be obtained through the combination of other mineral–melt
thermobarometers. We apply Eq. (24a) (SEE of
Plagioclase and bulk rock composition yield anorthite (An)–albite (Ab)
partitioning coefficient
Kernel density estimates (KDEs) of thermometric calculation
results for plagioclase
The olivine–melt equilibrium thermometer, i.e., Eq. (22) of Putirka (2008) with SEE of
Melt water contents of our samples from the WVF were estimated by the
plagioclase–melt hygrometer of Putirka (2008, Eq. 25b) which was
calibrated based on anorthite–albite exchange reaction between crystal and
melt with a relatively high SEE of
The results are listed in Table 3, and KDE plots are displayed in Figs. 9 and
10. The results show that all types of minerals have a similar H
Based on the above thermobarometers and melt water content estimation, it is
postulated that there are two distinct magma storage zones at depths with
similar temperature and water content, with a deeper region at the lower
crustal levels or near the crust–mantle boundary (
Particularly, in this study, the Type 1 of clinopyroxene and plagioclase is
characterized by normal zoning as shown in Fig. 5a–b, suggesting that they
crystallized in magma reservoirs involving fractional crystallization
processes. In contrast, the Type 2 of clinopyroxene and plagioclase comprises typical
reverse-zoned crystals (Fig. 5c–d) where relatively Mg- and An-rich rims
are observed. Combined with the presence of some reverse-zoned olivine
phenocrysts, it is reasonable to believe that primitive magma recharge and
mixing occurred during the evolution of the magmatic plumbing system for the
WVF (e.g., Streck, 2008; Longpré et al., 2014; Neill et al., 2015;
Gernon et al., 2016; Ubide and Kamber, 2018). In addition, oscillatory
compositional zonation is also observed in the Type 3 of clinopyroxene and
plagioclase (Fig. 5e–f), which could be interpreted either by small-scale
crystallization kinetic effects at the crystal–melt interface or by repeated
changes in the physicochemical conditions controlled by external parameters
(e.g., Shore and Fowler, 1996; Ginibre et al., 2002). Nevertheless, the
small-scale crystallization kinetics model is more suitable for the small-scale and low-amplitude fine banding rather than relatively large zonation
width and composition variation (Elardo and Shearer, 2014). Therefore,
repeated and periodic magma replenishment and magma convection could account
for the oscillatory bands with relatively large Mg# or An variation
(
Based on the bulk rock trace elements and the Sr–Nd–Pb–Hf–Mg isotopic
compositions, previous studies have suggested that the Wulanhada alkaline basalts
with low MgO contents formed by fractional crystallization of primary melt
produced by relatively low degree partial melting of carbonated peridotite
(e.g., Fan et al., 2014; Zhao et al., 2019; Sun et al., 2021). To further
constrain the mantle source of the WVF, we evaluated the inverse fractional
crystallization processes by adding proportions of olivine, clinopyroxene
and plagioclase as observed in our samples (Table 1; see Armienti et al.,
2013, for the details of calculations), obtaining the primary melt
compositions in equilibrium with the most primitive clinopyroxene and
olivine (Fig. 6; Table S5). The Wulanhada primitive melt composition shows
low MgO (4.4 wt %–6.6 wt %), Mg# (44–52) and
For comprehensive evaluations of the mantle source lithology in the WVF, we use
various discrimination parameters as follows. Pyroxene has high Ca but low
Geochemical compositional indicators of mantle source lithology
and crustal contamination.
In order to further constrain the mantle source characteristics of Wulanhada
alkaline basalts, a non-modal batch melting model is employed to simulate
the partial melting of carbonate-bearing eclogite (Fig. 12; Shaw, 1970; see
Zou et al., 2022, for the details of the calculations). A quantitative
calculation of the mineral assemblages of carbonate-bearing eclogite can be
achieved by using diagnostic ratios such as
The Wulanhada region experienced the southward subduction of the Paleo-Asian plate beneath the North China Craton and collision to form the Central Asian Orogenic Belt from the late Paleozoic to the early Mesozoic (Yang et al., 2006; Zhang et al., 2009). It has also been affected by the westward subduction of the Paleo-Pacific plate since the Cretaceous (Niu, 2005; Wu et al., 2005). Based on the low bulk rock Mg isotopic composition of the Wulanhada basalts, Sun et al. (2021) speculated that these rocks may be related to the subduction of the ancient Pacific plate, through the eastward retreat of slab or detachment into the lower mantle. However, according to the carbonate xenoliths exposed in Cenozoic Hannuoba basalts in eastern China, Chen et al. (2016) suggested that the carbonates originated from subduction of the Paleo-Asian plate rather than the Paleo-Pacific plate. A precise date of the carbonate xenoliths exposed in the Wulanhada region is required to determine the subduction event. However, it is possible that the subducted slab carried a large volume of carbon into the mantle, which remained in the deep mantle as carbonated eclogite (Hammouda, 2003; Dasgupta et al., 2004). In addition, the fluids released from the subducted slab infiltrated the lithospheric mantle, resulting in the development of amphibolite and pyroxenite veins with signatures of subduction (Niu and O'Hara, 2003; Pilet et al., 2008; Shea and Foley, 2019; Brenna et al., 2021). The carbonate-bearing eclogite-derived melts assimilated the metasomatic veins during ascent to the surface, resulting in the subduction-related signature with Nb–Ta negative anomalies and Rb–Ba enrichment as displayed by the sample from Nanliandanlu (Fig. 7).
In addition to the uplift of the Tibetan Plateau and adjacent regions, the
collision of the Indian and Eurasian plates also has an effect on volcanic
activities thousands of kilometers away. For instance, Zhang et al. (2021)
suggested that the far-field effect of the Indian–Eurasian collision plays
an essential role in controlling the eruption of basalts in central
Mongolia. Based on tectonic features, Zhao et al. (2019) suggested that
the Wulanhada Volcanic Field was also influenced by the Indian–Eurasian
collision. The asthenosphere flowed eastward due to the collision, causing
the mantle potential temperature beneath the WVF to exceed the solidus of the
mantle source lithology and promote partial melting (Liu et al., 2004). Due
to the solidus of carbonated eclogite being lower than the anhydrous garnet
peridotite (Hirose, 1997; Hammouda, 2003; Dasgupta et al., 2007), a
relatively high degree (10 %–20 %) of partial melting occurred in the
carbonate-bearing eclogite (
The primitive magma of Nanliandanlu underwent more complex processes in
comparison with those of the other five volcanoes. It interacted with the
lithospheric mantle during ascent, which increased the MgO contents but
decreased the alkaline contents in the melt. Additionally, the modified
magma did not stagnate at the Moho but ascended along a secondary fault and
was stored at the middle crust (Fig. 13;
Schematic diagram of the magma plumbing systems beneath the
Wulanhada Volcanic Field. Melt with a slightly higher degree of partial
melting (
Elucidating the link between the monogenetic and the polygenetic volcanism has played an important role in understanding the evolution of magma and assessing the volcanic hazard (Brenna et al., 2010; Németh and Kereszturi, 2015; Cañón-Tapia, 2016; Smith and Németh, 2017). A sensu stricto monogenetic volcano is characterized by a single eruptive vent through which only a small and temporal magma supply of single composition or various compositions erupts once in a brief period of time (Németh and Kereszturi, 2015; Tchamabe et al., 2016). However, studies on monogenetic volcanoes of Rangitoto Island in the Auckland Volcanic Field, New Zealand, and Udo off Jeju Island, South Korea, have shown that the magma underwent fractional crystallization and magma mixing during ascent to the surface, which generated complex magma composition (Brenna et al., 2010; McGee et al., 2011). The Rangitoto and Udo monogenetic volcanoes represent a transition towards polygenetic volcanic systems. Primitive basaltic magma that underwent fractional crystallization, magma mixing and crustal contamination in the crustal magma reservoirs could generate polygenetic volcanoes with high magma supply and evolved composition (Smith and Németh, 2017), such as the polygenetic Ruapehu volcano in the Auckland Volcanic Field, New Zealand (Gamble et al., 2003; Lindsay et al., 2011).
A change in the local or regional stress field leads to the transition from polygenetic to monogenetic volcanism occurring in the Higashi-Izu region of Japan (Hasebe et al., 2001) and back-arc volcanism in southeast Guatemala (Walker et al., 2011). The increase in the crustal extension rate promotes the development of monogenetic volcanism (Takada, 1994; Bucchi et al., 2015). The tectonic setting and the local stress field control the genesis of some volcanic fields, such as in the San Francisco Volcanic Field (Arizona) where volcanism is thought to migrate with the westward movement of the North American Plate (Tanaka et al., 1986). The WVF could be the result of a far-field effect of the Indian–Eurasian collision (Zhao et al., 2019). On a local scale, the distribution of volcanic cones within a field can reveal the orientation of faults (Muffler et al., 2011). There are volcanic fields in which vents show a marked alignment normally associated with faults such as the Chaîne des Puys in France (Boivin and Thouret, 2014). The volcanic cones in the WVF are linearly distributed along the NE–SW-striking basement faults and the NW–SE-striking Wulanhada–Gaowusu fault (W–G fault) system. The structure of crust also has an effect on the genesis and evolution of the volcanic field (Smith and Németh, 2017). Magma moves upward driven by buoyancy and becomes stagnant at the density variation boundary, such as near the Moho and Conrad discontinuity, to form magma reservoirs (Sparks et al., 2018). Interestingly, the magma reservoirs in the WVF are located near the Moho and Conrad discontinuity, indicating that the structure of crust played an important role in the evolution of the WVF.
In summary, the WVF represents an example of the early stages of the transition from monogenic volcanoes to composite volcanoes. A change in regional tectonic stress resulted in partial melting of the mantle source and supplied the multi-level crustal magma reservoirs, where fractional crystallization, magma mixing and crustal contamination occurred. In this scenario, large volumes of magma in shallow zones of magma storage may evolve for long periods, eventually producing a polygenetic volcano with evolved magmas and large magma fluxes.
The primitive melts of Wulanhada alkaline basalts were produced by
a relatively high degree (10 %–20 %) of partial melting of a carbonate-bearing
eclogite ( The primitive magmas that formed the Hongshan, Huoshaoshan,
Beiliandanlu, Zhongliandanlu and Heinaobao lavas ascended to the Moho
( The Wulanhada intraplate monogenetic volcanism was triggered by the
far-field effect of the Indian–Eurasian collision that caused partial
melting of the mantle and repeated magma replenishment. The Wulanhada
Volcanic Field may represent a snapshot of the transition from monogenetic
volcanoes to composite volcanic eruptions.
The data of Tables S1–S5 can be accessed from a reliable public
data repository:
The supplement related to this article is available online at:
DL, TH, MW, JQ, DY and RP undertook the fieldwork and collected the rock samples. DL and RP carried out the EMPA. All authors discussed and interpreted the results. Acquisition of the financial support for the project was undertaken by TH. The manuscript was written by DL, MKR and TH with contributions from all co-authors: ZZ, XW and MS contributed to the Results and Discussion sections, and FH and RB contributed to the Abstract and Introduction of the paper.
The contact author has declared that none of the authors has any competing interests.
Publisher’s note: Copernicus Publications remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
We greatly appreciate the constructive comments and suggestions from Marco Brenna and the anonymous reviewer, which significantly improved our manuscript. We are also grateful to Elisabetta Rampone and Dewashish Upadhyay for their editorial handling. Thanks to Zongqi Zou and Zaicong Wang of the China University of Geosciences for assistance during the revision of the manuscript.
This research has been supported by the National Key Research & Development Program of China (grant no. 2019YFA0708604-2); the Fundamental Research Funds for the Central Universities (grant nos. 2652018120 and 265QZ201901); the China University of Geosciences, Beijing (grant no. MSFGPMR201804); the Higher Education Discipline Innovation Project (grant no. B18048); an Alexander von Humboldt fellowship (grant no. 1207058); and the National Natural Science Foundation of China (grant no. 41922012).
This paper was edited by Dewashish Upadhyay and reviewed by Marco Brenna and one anonymous referee.