Mixed siliciclastic–carbonate sediments in the distal settings of marine systems (i.e., offshore and basin areas) are the result of the complex interaction between production of benthic and pelagic biogenic carbonates and the exportation of terrigenous, and/or carbonate mud from shallow-marine settings. Thus, the origin of mud (particles < 63 mm) of different compositions and the processes responsible for mixing them play a key role in the final distal deposits of mixed systems. Although the understanding of these topics in shallow settings has made significant progress, one of the critical issues is to recognize them in the offshore and basinal settings for understanding the link between shallow-marine and deep-marine areas. In this study, a thick Lower Cretaceous succession (330–650 m) of the Neuquén Basin, composed mostly of mixed (siliciclastic–carbonate) fine-grained marine deposits, was studied through a high-resolution analysis of petrography, SEM analysis, and mineralogy, to define and characterize the origin of carbonate and terrigenous mud as well as to characterize the processes involved in the mixing of terrigenous and carbonate mud on a storm-dominated ramp. Contrary to previous suggestions, most of the carbonate recognized in the basinal setting is composed of silt- to sand-size skeletal remains and micrite (micarbs) and is likely derived from a pelagic biogenic factory combined with carbonate derived from the maceration of benthic organism. Furthermore, micarbs are possibly diagenetic in origin but with a distally produced carbonate precursor. In contrast, the siliciclastic fraction is entirely detrital, being silt-size quartz particles and clay minerals (mainly illite) the most important constituents. Most of the terrigenous mud delivered from shallow areas acts to dilute the distally produced carbonate mud. However, a bloom of carbonate production able to dilute terrigenous supply is recorded, and its origin is likely triggered by the input of waters charged with nutrients from the paleo–Pacific Ocean in addition to nutrients derived from proto-Andes volcanic activity. This demonstrates that the relation between the terrestrially derived siliciclastic components and the biogenically produced carbonates in mixed systems is not linear, but a complex interaction of climate, sea-level, origin of the components, and hydrography of the basin, among others.

中文翻译：

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混合硅质碎屑 - 碳酸盐海洋系统的细粒远端沉积物：泥浆的起源及其对混合过程的影响

海洋系统远端环境（即近海和盆地）的混合硅质碎屑碳酸盐沉积物是底栖和远洋生物碳酸盐的生产与陆源和/或浅海相碳酸盐泥输出之间复杂相互作用的结果设置。因此，不同成分的泥浆（颗粒 < 63 毫米）的来源和混合它们的过程在混合系统的最终远端沉积物中起着关键作用。尽管在浅层环境中对这些主题的理解取得了重大进展，但关键问题之一是在近海和盆地环境中识别它们，以了解浅海和深海区域之间的联系。在这项研究中，内乌肯盆地的下白垩统厚层序（330-650 m），主要由混合（硅质碎屑-碳酸盐）细粒海相沉积物组成，通过岩相学、扫描电镜分析和矿物学的高分辨率分析进行研究，以定义和表征碳酸盐和陆源泥浆的起源以及表征过程参与在风暴主导的斜坡上混合陆源和碳酸盐泥。与先前的建议相反，在盆地环境中发现的大部分碳酸盐是由粉砂到沙子大小的骨骼残骸和泥晶（micarbs）组成的，很可能来自远洋生物成因工厂以及来自底栖生物浸渍的碳酸盐。此外，micarbs 可能起源于成岩作用，但具有远端产生的碳酸盐前体。相反，硅质碎屑部分完全是碎屑，是粉砂大小的石英颗粒和粘土矿物（主要是伊利石）最重要的成分。大多数从浅水区输送的陆源泥浆起到稀释远端产生的碳酸盐泥浆的作用。然而，记录了能够稀释陆源供应的碳酸盐的大量生产，其起源可能是由来自古太平洋的营养物质以及来自原安第斯山脉火山活动的营养物质的输入引发的。这表明混合系统中陆源硅质碎屑成分与生物生成的碳酸盐之间的关系不是线性的，而是气候、海平面、成分来源和盆地水文等的复杂相互作用。大多数从浅水区输送的陆源泥浆起到稀释远端产生的碳酸盐泥浆的作用。然而，记录了能够稀释陆源供应的碳酸盐的大量生产，其起源可能是由来自古太平洋的营养物质以及来自原安第斯山脉火山活动的营养物质的输入引发的。这表明混合系统中陆源硅质碎屑成分与生物生成的碳酸盐之间的关系不是线性的，而是气候、海平面、成分来源和盆地水文等的复杂相互作用。大多数从浅水区输送的陆源泥浆起到稀释远端产生的碳酸盐泥浆的作用。然而，记录了能够稀释陆源供应的碳酸盐的大量生产，其起源可能是由来自古太平洋的营养物质以及来自原安第斯山脉火山活动的营养物质的输入引发的。这表明混合系统中陆源硅质碎屑成分与生物生成的碳酸盐之间的关系不是线性的，而是气候、海平面、成分来源和盆地水文等的复杂相互作用。它的起源很可能是由来自古太平洋的富含营养物质的水的输入触发的，此外还有来自原安第斯山脉火山活动的营养物质。这表明混合系统中陆源硅质碎屑成分与生物生成的碳酸盐之间的关系不是线性的，而是气候、海平面、成分来源和盆地水文等的复杂相互作用。它的起源很可能是由来自古太平洋的富含营养物质的水的输入触发的，此外还有来自原安第斯山脉火山活动的营养物质。这表明混合系统中陆源硅质碎屑成分与生物生成的碳酸盐之间的关系不是线性的，而是气候、海平面、成分来源和盆地水文等的复杂相互作用。