Kuma River Research Articles

Range extension and reproduction of introduced Iwana-charr Salvelinus leucomaenis in the upper reaches of the Kuma River in Kyushu Island

Range extension and reproduction of introduced Iwana-charr Salvelinus leucomaenis in the upper reaches of the Kuma River in Kyushu Island

Relationship between Population Density of Land-Locked Masu Salmon, Oncorhynchus masou masou and Form of the River-bed in Mountain Streams of the Kuma River in kyushu

Relationship between Population Density of Land-Locked Masu Salmon, Oncorhynchus masou masou and Form of the River-bed in Mountain Streams of the Kuma River in kyushu

Foraminiferal fauna and lithofacies of Middle Permian limestone blocks in the middle course of Kuma River (Osakama), southern margin of the Chichibu Terrane in west Kyushu, Japan

ABSTRACT Middle Permian (Midian in the Tethyan standard scale) foraminifers of 34 species assignable to 27 genera were identified in erratic limestone blocks collected on the left bank of the middle course of the Kuma River (Osakama), west Kyushu, Japan, where four species of fusulinoideans have been reported. These blocks are thought to have been derived from a small limestone contained in basaltic rocks embedded within uppermost Jurassic mudstone along the southern margin of the Chichibu Terrane (Sambosan Terrane). An Osakama foraminiferal fauna in comparison with contemporaneous faunas known from the Jurassic to Early Cretaceous terranes of Japan and in relation to the limestone lithology are described and discussed in this paper. The Osakama fauna is characterized by dominant occurrence of a newly proposed species Yabeina osakamensis contained in weakly dolomitized gray limestone consisting of fusulinoidean crinoidal bioclastic packstone/grainstone with lithic clasts of limestone. The limestone lithol...

Basic magmatism in the geological history of the Elbrus Neovolcanic area, greater Caucasus: Evidence from K-Ar and Sr-Nd isotope data

The age and genesis of basic rocks in the magmatic evolutionary series are of principal significance for regions with predominant acid, mainly crustal volcanism. The appearance of basic volcanic rocks in the rhyolite‐dacite volcanic sequences is usually a sensitive indicator of a change in the conditions of magma generation, the involvement of different mantle and/or crustal reservoirs, or a change in the geotectonic and geodynamic settings of the volcanic activity. This is evident from the abundance of Neogene‐Quaternary acid and moderately acid volcanism in the Elbrus neovolcanic area, Greater Caucasus. The Neogene‐Quaternary magmatic centers of the Greater Caucasus are localized within three (Kazbek, Central Georgian, and Elbrus) neovolcanic areas. The Elbrus area located in the central part of the northern slope of the Greater Caucasus is bounded by the upper reaches of the Kuban River in the west, the Kuma River in the north, the Cherek River in the east, and the Main Caucasus Range in the south (Fig. 1). Evolution of the young magmatism in the Greater Caucasus is divided into three stages [1] with age boundaries determined by isotope‐geochronological investigations [2‐8]. The first (Late Miocene) stage (9.5‐8.3 Ma) is represented by subalkaline acid intrusive rocks of the Caucasian Mineral’nye Vody area of the Elbrus volcanic area [2, 3]. Products of the second (Pliocene) stage are found in the central sector (Chegem and Tyrnyauz regions). In the Chegem region, the products are represented by acid and moderately acid volcanic rocks of the Upper Chegem caldera and Lower Chegem highland (2.9‐2.7 Ma) [2, 5, 6], andesites of the postcaldera Kumtyube and

Фитоэкологическое картографирование Северного Прикаспия

Фитоэкологическое картографирование Северного Прикаспия

河床れきの状態と底生動物相指標の相関

The interrelationship between some environmental factors and indicator species of bottom fauna phase in the river was investigated and measured in the Kuma River in Kumamoto Pref. during September and November of 1982 and 1983. Among environmental factors, suspended solids in river water are seriously affected by flash floods, and these suspended solids affect matters attached to riverbed gravels. Pollution index, biotic index and diversity index have been used to clarify the degree of water pollution in the river in addition to chemical water quality such as BOD, nitrogen and phosphates. The numbers of individual CHIRONOMIDAE larvae have a good positive correlation (r= 0.824—0.847) with the weight of attached matters. Bottom fauna grew to the critical level of standing crop at 700 dry mg/100 cm2 of attached matters on the riverbed gravels. It was also very clear that numbers of species, numbers of individual and standing crops of bottom fauna have a close correlation with their living space, e. g., ratio of gravel to sampling area (occupation ratio), and flatness of gravels. It was found that biotic indicators should be studied and reported more precisely regarding the riverbed environmental factors such as gravel size, living space, standing crop on the gravel.