中国豫西寒武系馒头组叠层石的沉积特征及其古环境意义
摘要: 中国豫西寒武系馒头组一、二段共出露9层叠层石，占寒武纪18层叠层石中的50%，且其特征明显、形态多样，可分为圆柱状、波状、半球状和围绕竹叶状砾屑灰岩生长的叠层石等4大类8小类。本文在逐层分析豫西寒武系馒头组一、二段叠层石相序特征的基础上，通过对不同类型叠层石的宏观、中观形态特征及伴生的其它沉积特征进行详细描述，并以巴哈马Highborne Cays现代海相叠层石的生长环境和前寒武纪叠层石的沉积环境等为佐证，建立了豫西寒武系馒头组8小类11种不同叠层石的沉积环境分布模式，其中潮上带以近水平状叠层石为主，少量为缓波状、小柱状和含水平状薄泥层的叠层石；潮间带上部以缓波状、小柱状和含水平状薄泥层的叠层石为主，少量锥柱状叠层石；潮间带中部以圆柱状叠层石为主，含扁平状核形石和竹叶状砾屑，少量为锥柱状和围绕竹叶状砾屑生长的叠层石；潮间带下部至潮下带以含圆形核形石的圆柱状和半球状叠层石为主，少量含核形石的倒锥状叠层石。海平面的变化即水动力条件是叠层石生长类型变化的决定因素。
Sedimentary Characteristics and Palaeoenvironmental Significance on Stromatolites of Mantou Formation in Cambrian, Western Henan, China
Abstract: From Cambrian in the first and second Member of Mantou Formation, 9 layers stromatolites are exposed, half of the 18 layers' in Cambrian in the western Henan province, China. The morphological characteristics are rich and notable, mainly columnshaped, wavyshaped, hemisphereshaped and surrounding flatpebble conglomerate limestones shaped, and it can be divided into 4 big and 8 small categories. On the basis of analyzing the characteristics of sedimentary facies of every beds of the first and second Member, Mantou Formation in Cambrian, western Henan Province, the distribution model of sedimentary environments has been established as 8 small categories and 11 types stromatolites in Mantou Formation through detailed description on the macro, meso morphological characteristics of different types of stromatolites and accompanying sedimentary structure. At the same time, the paper proved the distribution model of sedimentary environments with the growth environment of modern marine stromatolites and the sedimentary environment of Precambrian. The gently wavyshaped stromatolites are dominated by supratidal, with subordinate wavyshaped, small columnar and having horizontal thin bedded mud stromatolites. The wavyshaped, small columnar and having horizontal thin bedded mud stromatolites are dominated by upper intertidal, with subordinate conicalshaped stromatolites. The teretifolious stramatolites are dominated of middle intertidal having elliptical oncolites and flatpebble conglomerate, with subordinate conicalshaped and surrounding flatpebble conglomerate limestones shaped stromatolites. The teretifolious stramatolites having rounded oncolites and hemisphere shaped stromatolites are dominated of bottom intertidal to subtidal, with subordinate inverted conicalshaped stromatolites having oncolites. Sea level change i.e. hydrodynamic condition is the decisive factor of the stromatolites growth categories.
中国豫西寒武系馒头组叠层石的沉积特征及其古环境意义[J]. 沉积学报, 2013, 31(1): 10-19.
| 引用本文: |
中国豫西寒武系馒头组叠层石的沉积特征及其古环境意义[J]. 沉积学报, 2013, 31(1): 10-19.
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Sedimentary Characteristics and Palaeoenvironmental Significance on Stromatolites of Mantou Formation in Cambrian, Western Henan, China[J]. Acta Sedimentologica Sinica, 2013, 31(1): 10-19.
| Citation: |
Sedimentary Characteristics and Palaeoenvironmental Significance on Stromatolites of Mantou Formation in Cambrian, Western Henan, China[J]. Acta Sedimentologica Sinica, 2013, 31(1): 10-19.
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