Paleokarst observed in Upper Paleozoic Limestone inn the japanese Islands

阐明了北上山下二叠统坂本泽组Sd段基底内嵌的含铁星岩的成因。这些沉积物是由古岩溶作用、碳酸盐岩古土壤和Hikami花岗岩等深部岩体风化分解的产物沉积而成。Monodiexodina matubaishi是fusulinoidea的一种，表明来自Kanokura组的标本是经过加工的。这些标本的生物层组学研究间接显示了坂本泽碳酸盐岩的古岩溶作用。石尾山库族地区出露的长上组为二叠系纳拜山灰岩组古岩溶作用的标志。古岩溶作用的产物为细粒至中粒碳酸盐碎屑、泥岩、残余角化碳酸盐碎屑及其他粗粒碎屑的夹层。石炭系一野谷组中嵌有含铁高铝页岩、尖砾岩（角砾岩）和其他残余岩石。古岩溶作用侵蚀了早石炭世晚期至早泥盆世的碳酸盐岩层序。米诺地块赤坂灰岩中嵌有源自灰岩和深成岩古土壤的赤铁矿床。由于大部分矿体已被采出，这一古岩溶作用有待进一步研究。

The present study clarifies the genesis of iron-bearing starata intercalated in the basal part of the Sd Member of the Lower Permian Sakamotozawa Formation in the Kitakami Mountains. These sediments was deposited from the products of paleokarstification, paleosol of the carbonate rocks and weathering decoposition of plutonic rocks, such as the Hikami Granite. A Fusulinoidean species, Monodiexodina matubaishi indicates that the specimens came from the Kanokura Formation are reworked ones. Biostratinomic study of these specimens indirectly shows paleokarstification of carbonate rocks of the Sakamotozawa.The Nagaami Formation exposed in the Kuzu area, Ashio Mountains indicates paleokarstification of the Permian Nabeyama Limestone Formation. Products of the paleokarstification represent the intercalation of fine-to medium-grained carbonate clasts, muddy rocks, residual brecciated carbonate rocks, and others ruubly clasts.The Ichinotani Formation (Carboniferous) intercalates iron-bearing high-aluminous shale, sharpstone (breccia) conglomerate, and other residual rocks. This paleokarstification eroded the carbonate sequence ranging from late Early Carboniferous to Early Devonian.The Akasaka Limestone of the Mino Terrane intercalates hematite ore deposits that derived from paleosol of limestone and plutonic rocks. Further study is necessary to elucidate this paleokarstification, because most of the ore body was quarried out.