The present paper focuses on the facies and allogenic controlling factors affecting the eolianite depositional system on a semi-arid carbonate ramp. Facies analysis and stratal architecture are integrated with earlier age-dating data to develop a depositional model of the landmark eolianite ridges in the northwestern Egyptian coast. Nine genetically related eolianite units, separated by eight eolianite-bounding surfaces and paleosol/protosol horizons are recognized. Twelve depositional facies belonging to three main facies associations have been identified. The eolianite facies association comprises cross-stratified oolitic and bioclastic grainstones. The inter-eolianite facies association includes paleosols, protocols and calcretes. The intra-eolianite facies association is represented locally by marine boulders of grainstone and rudstone (possibly reworked and imbricated by storm and tsunami waves) in the Coastal and Maryut eolianite ridges. Depositional development of the carbonate eolianites is strongly controlled by the Quaternary paleoclimate and glacio-eustatic sea-level cycles under mild tectonics on a gentle-slope carbonate ramp. The suggested depositional model matches well with the worldwide age-dating data of the carbonate coastal dunes, which generally indicate contemporaneous periods of eolianite deposition. The studied eolianite units are attributed herein to periods of highstand and stillstand, which can be correlated to the Marine Isotope Stages (MIS) of the middle Pleistocene ‘MIS 9 and 7′, the late Pleistocene ‘MIS 5e’ and ‘MIS 5c-5a’, and finally the Holocene ‘MIS 1′. The paleosols were mostly best developed during periods of lowstand. The Holocene immature paleosol ‘Ps1′ represents an example of the generation of protosol/paleosol during a highstand period. This supports the idea that the Pleistocene paleosols may be initiated during wet periods of the highstand and developed later during subsequent lowstand episodes. Collectively, the results imply that the generated eolianites along the carbonate ramp are strongly controlled by glacio-eustasy and paleoclimate, in addition to other autogenic factors in the depositional system.

本文着眼于影响半干旱碳酸盐岩斜坡上风成岩沉积系统的相和异源控制因素。将相分析和地层构造与较早的年代数据结合起来，以开发埃及西北海岸地标风积岩山脊的沉积模型。九个遗传相关的风成岩单元，被八个风成岩边界表面和古土壤/原生溶胶层隔开。已经确定了属于三个主要相联想的十二个沉积相。绢云母相组成包括交叉分层的橄榄岩和生物碎屑性的花岗岩。风积岩相间的联系包括古土壤，协议和钙质。内部的风积石相协会以沿海和Maryut风积石山脊中的花岗岩和鲁斯通（可能经过风暴和海啸波重新加工和积聚）的海洋巨石为代表。碳酸盐风成岩的沉积发育受第四纪古气候和冰川-欧共体海平面周期的强烈控制，在轻度构造的碳酸盐缓坡上处于缓和构造。建议的沉积模型与碳酸盐岩沿海沙丘的全球年龄记录数据非常吻合，这通常表明风成岩的沉积期与同期相一致。此处研究的风成岩单元归因于高位期和静止期，这可以与中更新世'MIS 9和7'，晚更新世'MIS 5e'和'MIS 5c-5a的海洋同位素阶段（MIS）相关联'，最后是全新世的“ MIS 1”。在低水位时期，古土壤最容易发育。全新世未成熟的古土壤'Ps1'代表在高水准时期原生质/古土壤生成的一个例子。这支持以下观点：更新世古土壤可能在高压期的潮湿时期引发，随后在随后的低压期发作时发育。总的说来，这些结果表明，沿着碳酸盐岩坡道生成的风成岩，除了沉积体系中的其他自生因素外，还受到冰川洋成岩和古气候的强烈控制。这支持以下观点：更新世古土壤可能在高压期的潮湿时期引发，随后在随后的低压期发作时发育。总的说来，这些结果暗示，沿着碳酸盐岩坡道生成的风成岩，除了沉积系统中的其他自生因素外，还受到冰河-Eustasy和古气候的强烈控制。这支持以下观点：更新世古土壤可能在高压期的潮湿时期引发，随后在随后的低压期发作时发育。总的说来，这些结果暗示，沿着碳酸盐岩坡道生成的风成岩，除了沉积系统中的其他自生因素外，还受到冰河-Eustasy和古气候的强烈控制。