Abstract The development of an estuary and the accumulation of organic matter in it are strongly influenced by variations in sea level and river discharge related to climate changes. We examined the relationship between development of a Holocene estuary and the sedimentation of organic matter. The study estuary, on the Niigata Plain, central Honshu, Japan, is wave-dominated and microtidal, with a barrier island and bay-head delta. We took two 50-m-long cores, one from an area adjacent to major river discharge and another from the basin margin. Estuarine environmental and sea-level changes were reconstructed using facies analysis. Bottom conditions, which affect the preservation of organic matter, were also examined by means of facies and geochemical analyses, including the TS (total sulfur) content and C/S (carbon to sulfur) ratio. Organic constituents of the estuarine sediments were examined with reflected-light fluorescent microscopy and geochemical analyses, including TOC (total organic carbon), C/N (carbon to nitrogen) and stable carbon isotope ratio (δ 13 C) of organic matter. Late transgressive and highstand estuaries are especially suitable for the preservation of organic matter, because they are enclosed by a barrier island that promotes anoxic bottom conditions. Nearly all of the organic matter preserved in this estuary is terrestrial origin, and a part of it is preserved as NFA (nonfluorescent amorphous organic matter), which forms under anoxic conditions. The NFA formed during the highstand stage in the basin-margin area, whereas an even greater abundance of coarsegrained organic matter accumulated during the late transgressive stage in the area with major river input. During the late highstand stage, coarse-grained terrigenous organic matter, including vitrinite and cutinite, was deposited in both the marginal area and the river -mouth area. Industrial minerals and rocks are Earth materials utilized because of their characteristic physical and/or chemical properties and not because of their metal content and which are not energy sources. According to this definition they cover a broad spectrum of minerals and rocks which form at all geological environments. The relative importance of industrial minerals to the economy of the various countries reflects the economic maturity of that country and today they constitute the most important raw materials exploited in the developed industrialized countries. The unit value of many industrial minerals is small compared to that of metals and depends on the geographic site from which they are extracted, i.e . they have a large place value. The small unit value also dictates the extent of processing and beneficiation. As they are used by the industry because of their physical and chemical properties, different industrial minerals may often compete for the same applications. In some cases the industrial practice requires production of synthetic industrial minerals, such as zeolites and diamonds, with tailored properties and therefore high added value. Due to increasing environmental awareness, there is need for utilization of waste materials from mining activities, which are also in the mineral form and can thus be considered as industrial minerals. The economic significance of industrial minerals is expected to increase further in the future.