Makoto Kato

ON THE VOLCANIC ROCKS IN THE JAPANESE PALEOZOIC, FIRST REPORT — GOTLANDIAN AND DEVONIAN

Gotlandian and Devonian deposits are typically developed in a relatively narrow strip around the Sakari and Ichinoseki districts of the Kitakami mountains. In this report, the typical section of pyroclastic sediments found in those deposits are described as to lithic character, thickness and stratigraphical horizon. The volcanic rocks and associated sediments reported from the Gotlandian deposits of Japan outside the Kitakami district are briefly outlined. In short, the volcanic rocks and their associated pyroclastic sediments are especially dominant in the Lower to Middle Devonian (Ohno and Nakazato series), but rather few in the Gotlandian (Kawauchi plus Takainari series) and Upper Devonian (Tobigamori series) in the Kitakami mountains. Of them, keratophyric rocks are prevalent in the Lower Devonian Ohno and Middle Devonian Nakazato series, while diabasic rocks are found in the Lowest Kawauchi series of Middle Gotlandian age, and in the lowest and uppermost parts of the Nakazato series and in the Tobiga...

Phylogenetic and palaeobiological implications of a new Carboniferous rugose coral with unusual trait combinations from the Akiyoshi Terrane of Japan

Morphologically and reproductively constrained colonial Rugosa were recovered from Late Carboniferous (possibly Bashkirian) strata of the Akiyoshi Terrane, south-west Japan. Individual corallites are very small (diameter c.1.7 mm) and exhibit a uniserial fasciculate form with a deep calice. The essential characteristics of the Rugosa, including walls, major and minor septa, tabulae and columellae, are present. However, each morphological component shows an end-member feature (e.g. thick walls for corallites with very small diameter and simple columella), especially consistent with rugose corals considering phylogenetic and structural constraints. Increase is parricidal, occurring only by dichotomous branching in the cardinal–counter plane. The combination of these components results in a somewhat unbalanced morphology, and is the basis for the establishment of Yamatophyllum ultimum gen. et sp. nov. It is likely that the new genus was a terminal lineage, an ephemeral evolutionary experiment within the rugosan clade. Interestingly, morphologically similar but phylogenetically distinct corals commonly appeared in the initial stages of both rugosan and scleractinian diversifications, suggesting restrictions on the available morphospace of corals throughout the Phanerozoic. http://zoobank.org/urn:lsid:zoobank.org:pub:F847EC54-28F3-405B-AC7A-459F60458FF0

ON THE VOLCANIC ROCKS IN THE JAPANESE PALEOZOIC, SECOND REPORT - CARBONIFEROUS

The Carboniferous deposits typically developed in the Kitakami mountains, Japan, have been divided into the following five series in ascending order: Hikoroichi, Arisu, Ohdaira, Onimaru and Nagaiwa series respectively. Of them the Hikoroichi series is divided into the Ikawa and Ohmata stages; the Arisu into the Hinozuchi and jiamonji stages; and the Ohdaira series into the Maide and Kozubo stages. Volcanic rocks and pyroclastic sediments are dominantly found in the lower three formations of the Hikoroichi, Arisu and Ohdaira series, while they seem to be entirely lacking in the Onimaru series, although they are again developed in the Nagaiwa series. Most of those volcanic rocks and their associated sediments are represented by such basic rocks as diabase or schalstein, but porphyrite is frequently found as a tuff or flow (?) in the Ikawa stage, the basal part of the Ohmata stage and also in the basal part of the Hinozuchi stage. Further, similar porphyrite tuff is found in the basal part of the Yornogibata...

ON THE VOLCANIC ROCKS IN THE JAPANESE PALEOZOIC, THIRD REPORT, PERMIAN

Permian deposits widely developing in the southern Kitakami mountains have been divided into the Sakamotosawa series, the Kanokura series and the Toyama subsystem in ascending order. Volcanic rocks and their associated pyroclastic sediments are rather rare in the Permain deposits of those mountains, however, there exist thin liparitic or dacitic tuffs and “schalstein” in the Sakamotosawa series ranging from the Pseudoschwagerina to the lower half of the Parafusulina zone in age. Except for the Sakamotosawa series, volcanics and their pyroclastics have never been found in the Permian systems in that area The Kanokura series is further diyided into, in ascending order, the Kattisawa and Iwaisaki stages. Lepidolina multiseptata horizon of the Iwaisakistage may be possibly correlative to the middle to upper Neoschwagerina zone, while the Lepidolina gigantea horizon of the same stage may be nearly equivalent to the Yabeina globosa zone. Outside the Kitakami mountains, a large amount of volcanic rocks and their...