基于粒级分离的长江口及邻近陆架沉积物磁性特征及其环境意义

doi:10.3969/j.issn.1000-5641.2021.02.004

摘要/Abstract

摘要：

在粒级分离的基础上, 对长江河口及邻近陆架22个表层沉积物进行了磁学表征, 探讨了磁性特征对物源、输运、沉积动力等环境信息的指示意义. 研究结果表明, 长江入海泥沙、残留砂及废黄河物质是长江口外水下三角洲及邻近陆架沉积物磁性特征的主要物源影响因素, 但3者的空间分布不同. 沉积物磁化率(χ)、饱和等温剩磁(SIRM)、硬剩磁(HIRM)及非磁滞剩磁磁化率(χ_ARM)的空间变化指示了长江入海泥沙出口门后向南及东南方向输运. SIRM与χ及退磁参数(S_–100)与SIRM关系图表明, 大于63 μm粒级沉积物来自残留砂与现代长江粗颗粒, 其分布大致以30 m等深线为界; 小于 16 μm粒级沉积物受长江和废黄河物质的影响, 口内为长江源, 口外北部贴岸以废黄河源为主, 口外其他区域则表现为以长江物质占主导的混合源. 沉积物粒度和磁学特征的空间变化反映了动力的粒度和密度分选作用, 并体现在沉积环境分区磁性特征差异及分粒级组分对全样SIRM贡献的空间变化上. 粒级分离减小了粒度效应对全样磁性特征的干扰, 提高了沉积物物源判别的准确性, 在反映三角洲地貌变化及物源定量识别上具有重要意义.

关键词: 磁性特征, 粒级分离, 物源, 动力分选, 长江口, 东海陆架

Abstract:

Twenty-two surface sediments collected from the Changjiang Estuary and neighboring shelf were subjected to particle-size measurements, with the intent of understanding the implications for provenance, transport, and depositional dynamics. The results showed that Changjiang River-derived sediments, relict sands, and Yellow River-derived sediments were the primary sources controlling the magnetic properties of sediments in the study area. The three areas, however, exhibited different spatial distributions. Spatial variations of magnetic parameters, including magnetic susceptibility (χ), saturation isothermal remanent magnetization (SIRM), hard isothermal remanent magnetization (HIRM), and anhysteretic susceptibility (χ_ARM), suggest that sediments from the Changjiang River are transported towards the south and southeast when they move out of the river mouth. According to bi-plots of SIRM versus χ and S-ratio (S_–100) versus SIRM, the > 63 μm fraction is roughly bounded by the 30 m isobaths that separates the Changjiang River sediment from the relict sands on the shelf. The < 16 μm fraction is derived mainly from the modern fluvial sources of the Changjiang and Yellow Rivers; in particular, the Changjiang River-derived sediment dominates the inner estuary and the Yellow River-derived sediment dominates the northern coast of the shelf. The other areas of the shelf are characterized by mixed sources of the < 16 μm fraction, with a majority being Changjiang River-derived sediment. Spatial variations of particle size compositions and magnetic properties reflect the role of hydrodynamic sorting on particle size as well as mineral density; this results in differences in magnetic properties among the sedimentary units as well as the contribution of different sized fractions to the bulk SIRM values. Particle size separation could reduce the effect of particle size on bulk magnetic properties and lead to more precise provenance discrimination. Our results have great potential in the study of geomorphological changes and quantitative source identification in delta environments.

Key words: magnetic properties, particle size separation, provenance, hydrodynamic sorting, Changjiang Estuary, East China Sea shelf

中图分类号:

P736.21+2

葛灿, 张卫国. 基于粒级分离的长江口及邻近陆架沉积物磁性特征及其环境意义[J]. 华东师范大学学报（自然科学版）, 2021, 2021(2): 30-41.

Can GE, Weiguo ZHANG. Magnetic properties of particle-sized fractions of sediments in the Changjiang Estuary and neighboring shelf, and its environmental implications[J]. Journal of East China Normal University(Natural Science), 2021, 2021(2): 30-41.

图/表 9

图1

表1

图2

图3

图4

图5

图6

图7

图8

参考文献 39

1	陈吉余, 沈焕庭, 恽才兴, 等. 长江河口动力过程和地貌演变 [M]. 上海: 上海科学技术出版社, 1988: 48-62.
2	李从先, 汪品先. 长江晚第四纪河口地层学研究 [M]. 北京: 科学出版社, 1998: 114-172.
3	LIU J, XU K, LI A, et al. Flux and fate of Yangtze River sediment delivered to the East China Sea. Geomorphology, 2007, 85 (3/4): 208- 224.
4	WANG J, BASKARAN M, HOU X, et al. Historical changes in ²³⁹Pu and ²⁴⁰Pu sources in sedimentary records in the East China Sea: Implications for provenance and transportation . Earth and Planetary Science Letters, 2017, 466, 32- 42. doi: 10.1016/j.epsl.2017.03.005
5	BAO R, BLATTMANN T, MCLNTYRE C, et al. Relationships between grain size and organic carbon ¹⁴C heterogeneity in continental margin sediments . Earth and Planetary Science Letters, 2019, 505, 76- 85. doi: 10.1016/j.epsl.2018.10.013
6	ZHU M, CHEN K, YANG G, et al. Sulfur and iron diagenesis in temperate unsteady sediments of the East China Sea inner shelf and a comparison with tropical mobile mud belts (MMBs). Journal of Geophysical Research: Biogeosciences, 2016, 121 (11): 2811- 2828. doi: 10.1002/2016JG003391
7	ZHANG W, XING Y, YU L, et al. Distinguishing sediments from the Yangtze and Yellow Rivers, China: A mineral magnetic approach. The Holocene, 2008, 18 (7): 1139- 1145. doi: 10.1177/0959683608095582
8	ZHANG W, MA H, YE L, et al. Magnetic and geochemical evidence of Yellow and Yangtze River influence on tidal flat deposits in northern Jiangsu Plain, China. Marine Geology, 2012, 319-322, 47- 56. doi: 10.1016/j.margeo.2012.07.002
9	ZHANG W, YU L. Magnetic properties of tidal flat sediments of the Yangtze Estuary and its relationship with particle size. Science in China Series D: Earth Sciences, 2003, 46 (9): 954- 966. doi: 10.1007/BF02991341
10	DONG C, ZHANG W, HE Q, et al. Magnetic fingerprinting of hydrodynamic variations and channel erosion across the turbidity maximum zone of the Yangtze Estuary, China. Geomorphology, 2014, 226, 300- 311. doi: 10.1016/j.geomorph.2014.08.008
11	孟庆勇, 李安春. 海洋沉积物的环境磁学研究简述. 海洋环境科学, 2008, 27 (1): 86- 90. doi: 10.3969/j.issn.1007-6336.2008.01.023
12	潘大东, 王张华, 陈艇, 等. 长江口表层沉积物矿物磁性分区特征及其沉积环境指示意义. 海洋学报, 2015, 37 (5): 101- 111. doi: 10.3969/j.issn.0253-4193.2015.05.010
13	张凯棣, 李安春, 卢健, 等. 东海陆架沉积物环境磁学特征及其物源指示意义. 海洋与湖沼, 2017, 48 (2): 246- 257.
14	WANG Y, DONG H, LI G, et al. Magnetic properties of muddy sediments on the northeastern continental shelves of China: Implication for provenance and transportation. Marine Geology, 2010, 274, 107- 119. doi: 10.1016/j.margeo.2010.03.009
15	张卫国, 贾铁飞, 陆敏, 等. 长江口水下三角洲Y7柱样磁性特征及其影响因素. 第四纪研究, 2007, 27 (6): 1063- 1071. doi: 10.3321/j.issn:1001-7410.2007.06.022
16	胡忠行, 张卫国, 董辰寅, 等. 东海内陆架沉积物磁性特征对早期成岩作用的响应. 第四纪研究, 2012, 32 (4): 670- 678. doi: 10.3969/j.issn.1001-7410.2012.04.12
17	马鸿磊, 张卫国, 胡忠行, 等. 长江口外CX21柱样的磁性特征及其影响因素. 华东师范大学学报(自然科学版), 2012, (3): 120- 129. doi: 10.3969/j.issn.1000-5641.2012.03.016
18	GE C, ZHANG W, DONG C, et al. Magnetic mineral diagenesis in the river-dominated inner shelf of the East China Sea, China. Journal of Geophysical Research: Solid Earth, 2015, 120 (7): 4720- 4733. doi: 10.1002/2015JB011952
19	OLDFIELD F, YU L. The influence of particle size variations on the magnetic properties of sediments from the north-eastern Irish Sea. Sedimentology, 1994, 41 (6): 1093- 1108. doi: 10.1111/j.1365-3091.1994.tb01443.x
20	HORNG C, ROBERTS A. Authigenic or detrital origin of pyrrhotite in sediments?: Resolving a paleomagnetic conundrum. Earth and Planetary Science Letters, 2006, 241 (3): 750- 762.
21	FRANKE C, KISSEL C, ROBIN E, et al. Magnetic particle characterization in the Seine river system: Implications for the determination of natural versus anthropogenic input. Geochemistry, Geophysics, Geosystems, 2009, 10, Q08Z05.
22	HORNG C, HUH C. Magnetic properties as tracers for source-to-sink dispersal of sediments: A case study in the Taiwan Strait. Earth and Planetary Science Letters, 2011, 39 (1/2): 141- 152.
23	强萧萧, 韩宗珠, 王永红, 等. 中国东部海域表层沉积物磁化率空间分布特征. 中国海洋大学学报, 2018, 48 (4): 94- 103.
24	LIU Q, BANERJEE S, JACKSON M, et al. An integrated study of the grain-size-dependent magnetic mineralogy of the Chinese loess/paleosol and its environmental significance. Journal of Geophysical Research: Solid Earth, 2003, 108 (B9): 2437.
25	HATFIELD R, MAHER B. Fingerprinting upland sediment sources: Particle size-specific magnetic linkages between soils, lake sediments and suspended sediments. Earth Surface Processes and Landforms, 2009, 34 (10): 1359- 1373. doi: 10.1002/esp.1824
26	HATFIELD R, STONER J, REILLY B, et al. Grain size dependent magnetic discrimination of Iceland and South Greenland terrestrial sediments in the northern North Atlantic sediment record. Earth and Planetary Science Letters, 2017, 474, 474- 489. doi: 10.1016/j.epsl.2017.06.042
27	LIU S, ZHANG W, HE Q, et al. Magnetic properties of East China Sea shelf sediments off the Yangtze Estuary: Influence of provenance and particle size. Geomorphology, 2010, 119 (3/4): 212- 220.
28	LI P, LI P, ZHANG X, et al. Magnetic properties of different grain-sized particles of sediments from the Okinawa Trough and their relationships to sedimentary environment. Chinese Science Bulletin, 2005, 50 (7): 696- 703. doi: 10.1360/04wd0167
29	ZAN J, FANG X, YAN M, et al. Comparison of hysteresis, thermomagnetic and low-temperature magnetic properties of particle-size fractions from loess and palaeosol samples in Central Asia and the Chinese Loess Plateau. Geophysical Journal International, 2018, 214 (3): 1608- 1622. doi: 10.1093/gji/ggy209
30	HAO Q, OLDFIELD F, BLOEMENDAL J, et al. Particle size separation and evidence for pedogenesis in samples from the Chinese Loess Plateau spanning the past 22 m.y. Geology, 2008, 36 (9): 727- 730. doi: 10.1130/G24940A.1
31	葛灿. 长江口—东海内陆架沉积物磁性特征及其指示意义 [D]. 上海: 华东师范大学, 2017.
32	BLOEMENDAL J, KING J, HALL F, et al. Rock magnetism of Late Neogene and Pleistocene deep-sea sediments: Relationship to sediment source, diagenetic processes, and sediment lithology. Journal of Geophysical Research: Solid Earth, 1992, 97 (B4): 4361- 4375. doi: 10.1029/91JB03068
33	THOMPSON R, OLDFIELD F. Environmental Magnetism [M]. London: Allen & Unwin, 1986.
34	WANG F, ZHANG W, NIAN X, et al. Magnetic evidence for Yellow River sediment in the late Holocene deposit of the Yangtze River Delta, China. Marine Geology, 2020, 427, 106274. doi: 10.1016/j.margeo.2020.106274
35	JIA J, GAO J, CAI T, et al. Sediment accumulation and retention of the Changjiang (Yangtze River) subaqueous delta and its distal muds over the last century. Marine Geology, 2018, 401, 2- 16. doi: 10.1016/j.margeo.2018.04.005
36	NGUYEN, T, ZHANG, W, LI Z, et al. Magnetic properties of sediments of the Red River: Effect of sorting on the source-to-sink pathway and its implications for environmental reconstruction. Geochemistry, Geophysics, Geosystems, 2016, 17, 270- 281. doi: 10.1002/2015GC006089
37	DEMASTER, J, MCKEE, A, NITTROUER, C, et al. Rates of sediment accumulation and particle reworking based on radiochemical measurements from continental shelf deposits in the East China Sea. Continental Shelf Research, 1985, 4 (1): 143- 158.
38	黎兵, 严学新, 何中发, 等. 长江口水下地形演变对三峡水库蓄水的响应. 科学通报, 2015, 60 (18): 1736- 1745.
39	CHENG Q, WANG F, CHEN J, et al. Combined chronological and mineral magnetic approaches to reveal age variations and stratigraphic heterogeneity in the Yangtze River subaqueous delta. Geomorphology, 2020, 359, 107163. doi: 10.1016/j.geomorph.2020.107163

分区样品		各粒级百分含量/%				SIRM/ (×10^–6Am²·kg^–1)					对全样SIRM贡献/%
分区样品		< 16 μm	16 ~ 32 μm	32 ~ 63 μm	> 63 μm	< 16 μm	16 ~ 32 μm	32 ~ 63 μm	> 63 μm	全样	< 16 μm	16 ~ 32 μm	32 ~ 63 μm	> 63 μm
A	S1	1	3	14	82	6398	7566	12715	2714	4369	1.6	5.9	40.7	51.8
	S2	19	32	8	41	7750	6411	8790	4055	5994	25.5	34.4	12	28.2
	S6	6	3	9	82	12829	14552	28929	6578	9711	7.9	4.8	28.7	58.5
	S7	1	1	1	97	10888	9729	30083	6692	6884	1.4	0.9	3.4	94.4
	S9	0	1	4	95	11541	63166	36218	4350	6559	0.8	7.4	25.1	66.7
B	S3	29	36	8	27	6691	6030	8030	4978	5809	32.1	36.1	9.6	22.2
	S4	23	41	10	26	9817	7179	6936	7543	7814	28.8	37.2	8.7	25.3
	S5	29	35	17	19	6531	5894	5800	6469	5948	30.8	33.7	15.7	19.8
	S8	51	11	4	34	6412	7799	16194	14555	7622	33.4	8.9	6.4	51.3
	S10	50	36	9	5	9033	5827	6803	10949	7872	57.7	26.9	8.1	7.3
	S17	83	12	3	2	5829	3862	3085	4212	5415	88.2	8.5	1.9	1.4
	S20	74	15	9	2	6068	3335	2342	3047	5147	85.6	8.8	4.2	1.4
C	S11	53	7	4	36	3844	2397	4829	4394	3635	51.6	4.5	4.3	39.6
	S12	8	2	1	89	4808	4601	5932	4400	4263	8.4	2.3	1.5	87.7
	S14	57	17	7	19	3947	3636	3673	2600	3594	62.2	17.2	6.8	13.8
	S15	0	0	0	100	0	0	0	4462	4100	0	0	0	100
	S18	34	6	6	54	5302	4653	7374	3025	3851	42.7	6.5	11.3	39.5
	S21	25	5	5	65	5548	6375	8710	3332	4101	31.8	7.5	9.3	51.4
	S13	54	10	3	33	4761	4001	4804	5219	4440	53.3	8.3	3.1	35.3
	S16	13	4	3	80	4141	3618	5530	3763	3554	14.4	3.8	4.1	77.6
D	S19	9	3	2	86	4021	3202	6322	2800	2756	12.3	3.2	4.7	79.8
D	S22	15	7	9	69	3921	3192	3129	1510	1977	27.0	10.6	13.7	48.8

[1]	宋云平, 朱建荣. 长江口余水位时空变化的数值模拟和分析[J]. 华东师范大学学报（自然科学版）, 2021, 2021(4): 121-133.
[2]	朱宜平. 长江口青草沙水域外海正面盐水入侵特点分析[J]. 华东师范大学学报（自然科学版）, 2021, 2021(2): 21-29.
[3]	杨正东, 朱建荣, 宋云平, 顾靖华. 长江口余水位时空变化及其成因[J]. 华东师范大学学报（自然科学版）, 2021, 2021(2): 12-20.
[4]	张梦霞, 郑艳玲, 尹国宇, 董宏坡, 韩平, 高娟, 刘程, 常永凯, 刘敏, 侯立军. 纳米银对河口潮滩硝酸盐异化还原成铵过程的影响[J]. 华东师范大学学报（自然科学版）, 2020, 2020(3): 68-77.
[5]	王浩斌, 杨世伦, 杨海飞. 台风对长江口表层悬沙浓度的影响[J]. 华东师范大学学报(自然科学版), 2019, 2019(2): 195-208.
[6]	朱平, 吴辉. 夏季长江口与苏北海域之间的水体运动及其对动力因子的响应[J]. 华东师范大学学报(自然科学版), 2018, 2018(4): 171-183.
[7]	白玫, 吴辉. 利用SOM神经网络研究长江口邻近海域海表温度特征[J]. 华东师范大学学报(自然科学版), 2018, 2018(4): 184-194.
[8]	杨万伦, 道付海, 栾华龙, 葛建忠, 丁平兴. 长江口洪季南北槽落潮分流分沙比观测研究[J]. 华东师范大学学报(自然科学版), 2018, 2018(2): 170-180.
[9]	李远, 李占海, 张钊, 王智罡, 姚弘毅. 长江口北槽下游河道悬沙浓度垂向分布特征研究[J]. 华东师范大学学报(自然科学版), 2017, 2017(6): 114-125.
[10]	杨天, 杨世伦, 杨海飞, 朱琴, 张文祥, 张朝阳, 王如生. 悬浮絮凝体特征及其影响因子的综合作用——以长江口内河槽和口门最大浑浊带为例[J]. 华东师范大学学报(自然科学版), 2017, (4): 149-159.
[11]	陶英佳, 葛建忠, 丁平兴. 长江口咸潮入侵预报系统的设计与应用[J]. 华东师范大学学报(自然科学版), 2016, 2016(2): 128-143.
[12]	顾圣华，李琪. 长江口水文监测站网布局研究[J]. 华东师范大学学报(自然科学版), 2015, 2015(4): 1-6.
[13]	戴苒，朱建荣. 长江口崇明东滩风况统计分析[J]. 华东师范大学学报(自然科学版), 2015, 2015(4): 17-25.
[14]	王如生，杨世伦，罗向欣，陆叶峰，苗丽敏. 近30年长江北支口门附近的冲淤演变及其对人类活动的响应[J]. 华东师范大学学报(自然科学版), 2015, 2015(4): 34-41.
[15]	王一鹤，吴辉，朱建荣，沈健. 长江口及闽浙海域浮游植物动力学模型研究[J]. 华东师范大学学报(自然科学版), 2015, 2015(4): 97-109.