四川牟尼沟钙华剖面特征及其环境指示意义

何靓雯; 代群威; 徐荣林; 崔杰; 安德军; 杜伟旗; 张婷; 蒋瑞阳; 冉玥

doi:10.11932/karst2024y021

四川牟尼沟钙华剖面特征及其环境指示意义

doi: 10.11932/karst2024y021

1.
西南科技大学环境与资源学院, 四川绵阳 621010
2.
黄龙国家级风景名胜区管理局, 四川松潘 624000

基金项目: 国家自然科学基金—区域创新发展联合基金(U21A2016)；国家自然科学基金(41877288)

详细信息

作者简介:
何靓雯（1998－），女，硕士研究生，研究方向：环境科学与工程。E-mail：1102170441@qq.com

通讯作者:
代群威（1978－），男，博士，教授，研究方向：环境污染调控与生态修复。E-mail：qw_dai@163.com。

中图分类号: P512.2；P532
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- 文章访问数: 75
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- 被引次数: 0
出版历程
- 收稿日期: 2023-06-30
- 网络出版日期: 2024-08-15
- 刊出日期: 2024-06-25

Characteristics of travertine profiles and their environmental indications in Munigou, Sichuan, China

1.
School of Environment and Resource, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China
2.
Huanglong National Scenic Area Administration, Songpan, Sichuan 624000, China

摘要

摘要: 钙华沉积物记录着重要物理、化学和生物信息，被认为是指示环境变化的重要信息载体。文章选择四川牟尼沟钙华剖面为研究对象，测定钙华沉积物中的有机质、总氮（TN）、总磷(TP)和其他化学元素，综合分析牟尼沟钙华剖面特征和环境指示意义。结果表明：有机质、TN、TP含量为294.66~2 366.52 g·kg⁻¹，0~0.89 g·kg⁻¹，0.03~0.25 g·kg⁻¹，在元素含量方面，黑色泥质钙华以SiO₂为主，白色钙华、黄色钙华、灰色钙华均以CaO为主，推测黑色泥质钙华沉积于雨季，降水充沛，气候较湿润，而灰色钙华、白色钙华和黄色钙华形成于旱季，降水较少，气候较干冷。
- 牟尼沟 /
- 钙华剖面 /
- 环境代用指标 /
- 沉积环境 /
- 降水
Abstract: The travertine profiles are located in the Zhaga waterfall in Munigou, Sichuan Province, where the highest altitude ranges from 4,070 m to 2,800 m, and the average annual temperature is 7℃. The study area is situated in the Minjiang fracture zone, with Paleozoic carbonate construction on the east side of the fracture, and shallow metamorphic rocks and slates of the Middle and Upper Triassic Xikang Group on the west side. Travertine is deposited by the stream fed by karst springs, and the mouth of the spring is located on the left bank of the hook upstream of Zhaga waterfall. The travertine deposits are distributed from the mouth of the spring down to the mouth of the gully. Their depositional patterns fall into striated travertine, clastic travertine, etc., and the type of depositional phase is a dam. The overall travertine profile is about 30-meter thick with horizontal sedimentary construction. In this study, the travertine profiles were investigated in terms of mineralogy and isotope geochemistry. UV spectrophotometry and X-ray fluorescence spectroscopy were used to determine the organic matter, total nitrogen, total phosphorus and chemical elements in travertine profile sediments so as to comprehensively analyze the characteristics of the travertine profiles and their significance of environmental indications. The results show that the travertine profiles can be divided into four stages based on sedimentary features such as sediment color, texture and inclusions. Stage 1: 1,080–1130 cm, overall dominated by a black muddy travertine layer interspersed with yellow travertine, grey travertine, and white travertine, containing twigs, leaves, and roots; Stage 2: 1,130–1,230 cm, overall dominated by a grey travertine layer interspersed with yellow travertine and black muddy travertine layers containing tree roots; Stage 3: 1,230–1,353 cm, overall dominated by yellow travertine layers interspersed with black muddy travertine, white travertine and grey travertine; Stage 4: 1,353–1,480 cm, overall dominated by a white travertine layer interspersed with yellow travertine and black muddy travertine layers containing roots and leaves.The testing and analysis of the sediments from the travertine profile in Munigou revealed that the overall organic matter content of travertine sediments ranged from 294.66 g·kg⁻¹ to 2,366.52 g·kg⁻¹ with a mean value of 1,031.93 g·kg⁻¹; the TN content ranged from 0 g·kg⁻¹ to 0.89 g·kg⁻¹ with a mean value of 0.25 g·kg⁻¹; the TP content ranged from 0.03 g·kg⁻¹ to 0.25 g·kg⁻¹ with a mean value of 0.12 g·kg⁻¹. In order to fully understand the relationship between organic matter, TN and TP, and to better reveal the environmental characteristics when the travertine was deposited, we carried out Pearson correlation analyses of organic matter, TN and TP, which showed that the organic matter and TN content exhibited a significant correlation (r=0.822, n=48, P<0.01); the organic matter and TP content were positively correlated (r=0.574, n=48, P<0.01); there was a good correlation between TN and TP contents (r=0.644, n=48, P<0.01). Travertine sediments with four different colors at different depths were selected for elemental analysis, and the results showed that the main chemical compositions of the travertine profile were CaO and SiO₂, followed by Al₂O₃, Fe₂O₃, MgO, Na₂O, and TiO₂. The CaO content ranged from 97.79% to 27.51%, with an average value of 70.25%. The SiO₂ content ranged from 50.10% to 0.76%, with an average value of 19.52%. CaO is chemically active and easy to migrate. The high CaO activity indicates that it is easily lost under warm and humid conditions, making its content relatively low, and under dry and cold conditions, the weak surface chemical action enriches CaO, making its content high. SiO₂ is chemically stable and difficult to migrate; therefore, its high content can indicate much precipitation, warm and wet climate, and its relatively high enrichment, and vice versa.The travertine profiles at 1,080–1,130 cm, 1,250–1,280 cm and 1,460–1,480 cm were dominated by black muddy travertine, with high content of organic matter, TN and TP, and their chemical elements were dominated by SiO₂. The environment at the time of travertine deposition is presumed to be of wet climate during the rainy season with abundant precipitation. The travertine profiles at 1,130–1,250 cm and 1,280–1,460 cm were dominated by grey travertine, white travertine and yellow travertine, with low levels of organic matter, TN, TP, and their chemical elements were dominated by CaO. The environment at the time of deposition is presumed to be of a dry season with little precipitation and dry and cold climate. The above conclusions are intended to reveal the environmental conditions of Munigou at the time when travertine was deposited and to lay the foundation for an in-depth study of the ancient environment of Munigou.
- Munigou /
- travertine profile /
- environmental indicators /
- sedimentary environment /
- precipitation

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图 1 牟尼沟地理位置及采样点图（a）和牟尼沟钙华剖面图（b、c）

Figure 1. Geographic location of Munigou, map of sampling sites (a) and Munigou travertine profile (b, c)

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图 2 Ca²⁺和${\rm{HCO}}_3^{-}$浓度图（a）和水样Piper图（b）

Figure 2. Ca²⁺ and ${\rm{HCO}}_3^{-}$ concentrations (a) and Piper diagram of water samples (b)

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图 3 钙华剖面特征图

Figure 3. Characteristics of travertine profiles

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图 4 钙华剖面沉积物有机质、TN、TP随深度变化趋势图

Figure 4. Variations of organic matter, TN and TP with the increase of depth in the sediments of travertine profiles

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图 5 钙华剖面沉积物有机质与TN、TP关系图（a.有机质与TN，b.有机质与TP，c.TN与TP）

Figure 5. Relationship between organic matter, TN and TP in the sediments of travertine profile (a. relationship between organic matter and TN; b. relationship between organic matter and TP; c. relationship between TN and TP)

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表 1 钙华剖面有机质、TN、TP测试结果（g·kg⁻¹）

Table 1. Testing results of organic matter, TN and TP in travertine profiles (g·kg⁻¹)

名称	有机质		TN		TP
名称	范围	平均值	范围	平均值	范围	平均值
黑色泥质钙华	551.67~2 366.52	1 432.37	0.13~0.89	0.43	0.07~0.20	0.15
灰色钙华	306.69~1 782.51	1 047.66	0.08~0.48	0.29	0.06~0.25	0.14
黄色钙华	325.57~1 487.85	700.50	0.00~0.03	0.11	0.03~0.18	0.08
白色钙华	294.66~1 858.73	824.06	0.04~0.39	0.12	0.05~0.13	0.09

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表 2 钙华沉积剖面元素测试结果（%）

Table 2. Testing results of elements from travertine deposition profiles (%)

深度/cm	CaO	SiO₂	Al₂O₃	Fe₂O₃	K₂O	MgO	Na₂O	TiO₂	P₂O₅
1 094	27.51	50.10	13.18	3.45	1.79	1.42	1.15	0.84	0.22
1 125	33.60	45.80	11.74	3.48	1.78	1.17	1.07	0.83	0.20
1 130	90.66	4.94	1.84	1.53	0.24	0.25	0.15	0.11	0.04
1 220	81.88	10.17	3.98	2.39	0.32	0.40	0.28	0.26	0.08
1 230	71.25	18.98	5.99	1.72	0.74	0.36	0.19	0.49	0.06
1 390	97.27	1.08	0.46	0.81	0.05	0.11	/	/	0.02
1 420	97.79	0.76	0.35	0.71	0.03	0.12	/	/	0.02
1 440	62.05	24.33	8.06	2.40	1.00	0.61	0.51	0.61	0.11

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深度/cm	SO₃	BaO	MnO	ZrO₂	SrO	ZnO	Rb₂O	Y₂O₃	Cl	烧失量
1 094	0.13	0.08	0.04	0.04	0.03	0.02	0.01	0.01	/	17.78
1 125	0.12	0.08	0.05	0.03	0.02	0.01	0.01	/	/	16.59
1 130	0.12	0.06	/	0.01	/	/	/	/	/	43.47
1 220	0.13	0.04	/	0.01	0.03	/	/	/	0.03	31.77
1 230	0.09	0.05	/	0.02	0.04	0.01	0.01	/	0.01	34.52
1 390	0.11	0.06	/	/	0.04	/	/	/	/	23.45
1 420	0.10	0.06	/	/	0.04	/	/	/	0.01	45.25
1 440	0.13	0.06	0.04	0.02	0.04	0.02	0.01	/	0.02	19.20

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