Origin of Paleo-Tokyo Bay Sands

古东京湾晚更新世松散砂体记录了沉积环境和物源等重要变量对骨架组成的影响。河流相砂岩包括许多岩屑，与浅层海相砂岩相比，石英砂和长石砂岩较少。近岸砂岩以最稳定的单晶石英颗粒为特征，但与滨海砂岩相比，长石质较少。持续的近岸动力作用可能造成了不稳定的岩屑和长石的磨损和破坏，这些不稳定的岩屑和长石被旧东京湾沉积物的再循环所覆盖，这些沉积物被海岸露头侵蚀掉了。滨海和离岸砂岩是由风暴波间歇性地形成近岸和/或河口环境，伴随着洪水的涌入，以河流和近岸砂岩的中间成分为特征。来自火山和沉积岩来源的沉积物的相对量主要由各省古代和现代河流河道砂岩的组组成来表示，这进一步表现为古水流、古东京湾沉积物的独特组合，以及总岩屑和单晶石英颗粒的相对丰度，与火山岩碎屑的相对丰度相对应。参考流经各省的现代河流体系的流域地质组成。与长石颗粒对应的石英颗粒上海滩沙的成分变化也很好地证明了深成岩源区的邻近。这两个组分向花岗岩源区附近省份逐渐增加。

Unconsolidated loose sands of the Late Pleistocene Paleo-Tokyo Bay document the effects of important variables of depositional environment and provenance on framework composition. Fluvial sands include many lithic fragments, and are less quartzose and less feldspathic than shallow marine sands. Near shore sands are characterized by the most stable monocrystalline quartz grains but are less feldspathic than shoreface to offshore sands. Continual nearshore dyrnamic action may have caused abrasion and destruction of unstable lithic fragments and feldspar, overprinted by recydling of the older Paleo-Tokyo Bay sediments which were eroded away grom the coastal outcrops. shoreface and off shore sands are derived intermittently grom nearshore and/or river mouth environments by storm waves, accompanied by the influx of flood water, and are characterized by the intermediate composition between that of fluvial and nearshore sands.The relative amounts of contributed sediments from volvanic and sedimentary rock sources are largely represented by group compositions of ancient and recent fluvial channel sands in each province, which is further represented by unique combination of paleocurrents, topography and architecture of the Paleo-Tokyo Bay sediments, on the relative abundance of total lithic fragments to monocrystalline quartz grains, plotted against the relative abundance of volcanic rock fragments, refering to the geological composition of drainage areas of the recent fluvial systems which have been runing through the each province. The proximity of plutonic rock surce areas are also well documented by compositional variation of beach sands on the quartz grains plotted against the feldspar grains. The two components gradually increase towards the proximal provinces to the granitic rock sources.