Abstract The Paleogene provenance of the Pearl River Mouth Basin in the northern South China Sea is poorly understood. In this paper, we present the first batch of zircon U-Pb and fission track double-dating ages of the Wenchang, Enping, and Zhuhai Formations in this basin. Together with data from previous provenance studies, the new dataset has been used to document the provenance shift during the Paleogene period. Characterized by a rather limited spectrum of both U-Pb and fission-track ages, the Eocene Wenchang Formation was probably mainly derived from intra-basinal uplifts. Multimodal distribution and large range of zircon ages of the Late Eocene-Early Oligocene Enping Formation is compatible with the age signatures of modern drainage sediments from the Southeastern Cathaysia Block. Age signatures of the Zhuhai Formation (Late Oligocene) and Enping Formation are indistinguishable, suggesting that they may have similar source areas and sediment provenance did not change dramatically during the Oligocene. Although variations in age patterns from the Wenchang Formation to the Enping-Zhuhai Formations imply a dominant provenance shift from local uplifts to the regional Cathaysia Block, it is difficult to exclude the influence of the local uplifts on sediments in the Enping-Zhuhai Formations.

中文翻译：

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南海北部珠江口盆地古近系沉积物物源：锆石U-Pb和裂变径迹双测年的见解

摘要 南海北部珠江口盆地的古近系物源了解甚少。在本文中，我们提出了该盆地文昌组、恩平组和珠海组的第一批锆石U-Pb和裂变径迹双重测年。与先前来源研究的数据一起，新数据集已被用于记录古近纪时期的来源变化。始新世文昌组以 U-Pb 和裂变径迹年龄谱相当有限为特征，可能主要来源于盆地内的隆起。晚始新世-早渐新世恩坪组的多峰分布和大范围的锆石年龄与华夏地块东南部现代排水沉积物的年龄特征相一致。珠海组（晚渐新世）和恩平组的时代特征无法区分，表明它们可能具有相似的源区，并且在渐新世期间沉积物来源没有发生显着变化。虽然文昌组至恩平组—珠海组时代格局的变化意味着主要物源从局部隆起向区域华夏地块转移，但难以排除局部隆起对恩平组—珠海组沉积物的影响。