ASSESSMENT OF A REEF COMMUNITY FROM LOWER JURASSIC (PLIENSBACHIAN) STRATA IN THE CENTRAL HIGH ATLAS MOUNTAINS OF MOROCCO
ASSESSMENT OF A REEF COMMUNITY FROM LOWER JURASSIC (PLIENSBACHIAN) STRATA IN THE CENTRAL HIGH ATLAS MOUNTAINS OF MOROCCO
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DOI：
10.2110/palo.2022.010
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发表时间：
2022-11
期刊：
影响因子：
1.6
通讯作者：
T. Stone;R. Martindale;T. Fonville;B. Lathuilière;S. Boivin;Raphäel Vasseur;M. Septfontaine
中科院分区：
文献类型：
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作者：
T. Stone;R. Martindale;T. Fonville;B. Lathuilière;S. Boivin;Raphäel Vasseur;M. Septfontaine
摘要：早侏罗世，随着阿特拉斯裂谷浅海生物礁从三叠纪末期的大灭绝中恢复过来，它们经历了实质性的变化。记录这一变化的极好的下侏罗世生物礁沉积发生在摩洛哥的中部高阿特拉斯地区，在这里我们描述了Owl Olistolith，一种在下Pliensbchia时代(∼1.887亿年前)摩洛哥地层中发现的微绿泥岩。这块岩石记录了生长在阿特拉斯裂谷带内的珊瑚礁的组成，代表了三叠纪末期大规模灭绝后1000万年珊瑚礁恢复∼的快照。猫头鹰橄榄石是从一个礁石中衍生出来的，它最初位于天气良好的波浪基地内的外部平台上；它松动了，被输送到更深的水中，沉积在泥灰岩中。珊瑚和微生物岩构成了珊瑚礁的主要骨架，也存在微问题、有孔虫和其他次要成分。生物礁可分为两个优势相：不含珊瑚的微闪石相(54%-94%)和珊瑚-微闪石相(23%-50%)和珊瑚-微闪石相(14%-72%)。微滑石包含至少15种不同的珊瑚类型。在这项研究中，共鉴定出7个珊瑚属，其中3个代表跨越三叠系/侏罗系界线的分类群，包括CoryPhyllia、Stylophyllopsis和Margarosmilia。这些结果表明，尽管幸存的珊瑚类群起了重要作用，但新演化的珊瑚是摩洛哥早侏罗世珊瑚礁生态系统重建过程中最重要的类群。
Abstract: During the Early Jurassic, reefs in the shallow seas of the Atlas Rift experienced substantial changes as they recovered from the end-Triassic mass extinction. Excellent Lower Jurassic reef deposits documenting this change occur in the Central High Atlas region of Morocco, and herein we describe Owl Olistolith, a micro-olistolith found in lower Pliensbachian-aged (∼ 188.7 million years ago) Moroccan strata. The olistolith records the composition of a reef that grew within the Atlas rift zone and represents a snapshot of reef recovery ∼ 10 million years after the end-Triassic mass extinction. Owl Olistolith is derived from a reef that was originally situated on an outer platform within fair weather wave base; it broke loose and was transported to deeper water and deposited amongst marls. Corals and microbialites formed the primary framework of the reef; microproblematica, foraminifera, and other minor components were also present. The reef can be divided into two dominant facies: a microbialite facies that contains no corals (54%–94% microbialites), and a coral-microbialite facies with substantial proportions of both microbialite (23%–50%) and corals (14%–72%). The micro-olistolith contains at least 15 distinct coral types. In this study, seven coral genera were identified, three of which represent taxa that span the Triassic/Jurassic boundary, including Coryphyllia, Stylophyllopsis, and Margarosmilia. These results indicate that, although surviving taxa played a significant role, newly evolved corals were the most important taxa in the reestablishment of reef ecosystems in the Early Jurassic of Morocco.