in Jurassic and Cretaceous Stratigraphy

More documents

Recommendations

Info

Earth Science Frontiers, Vol. 17, Special Issue, Aug. 2010 ISSN 1005-2321 The Lower Jurassic Boreal Bivalve Assemblage from the Higuchi Group, Shimane Prefecture, Southwest Japan 184 K. Nagata 1 , T. Komatsu 2 , T. Sato 3 , Baoyu Jiang 4 1. Mifune Dinosaur Museum, Kumamoto 861-3207, Japan (E-mail: nagata@mifunemuseum.jp) 2. Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan (E-mail: komatsu@sci.kumamoto-u.ac.jp) 3. Fukada Geological Institute, Tokyo 113-0021, Japan (E-mail: sato@fgi.or.jp) 4. School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China (E-mail: byjiang@nju.edu.cn) Lower Jurassic Sinemurian? to Pliensbachian shallow marine fossiliferous deposits are distributed in southwestern and central Japan. The ammonoid and bivalve assemblages are composed of Tethyan and/or Boreal species. Representatives of the Tethyan ammonoid family Hildoceratidae (Fontanelliceras, Cana- varia, and Arieticeras) and the Boreal ammonoid family Amaltheidae (Amaltheus) occur commonly in the Toyora Group in southwestern Japan and the Kuruma Group in central Japan (Sato, 1956; Hirano, 1971, 1973a, b). Tethyan and Boreal species of bivalves are abundant in the Higashinagano Formation, Toyora The Higuchi Group, consisting mainly of silica- clastic sedimentary rocks, is exposed in the Muikaichi area in southwestern Shimane Prefecture and comprises the Orojidani and Higuchidani formations. The Oroji0 dani Formation (180-400 m thick) unconformably over- lies the Permian Nishiki Group and consists of in- creasingly fine repeating units (5-30 m thick), begin- ing with conglomerate and coarse sandstone, passing Group (Hayami, 1962), although benthic marine fossils are rare in the Kuruma Group. The Higuchi Group is distributed in the Toyora and Kuruma areas of southwestern Japan (Naka et al., 1985). Hirano et al. (1978) reported the Tethyan ammonoids Fontanelliceras and Canavaria in this group. We found these Tethyan ammonoids, the Boreal ammonoid Amaltheus, and abundant shallow marine bivalves in the Higuchidani Formation. In this paper, we report on the Boreal bivalves from the Higuchidani Formation and discuss the palaeobiogeographic signi- ficance of the Lower Jurassic benthic fauna. Fig.1 Index map showing study areas through sandstone, and ending with mudstone at the top. This formation commonly contains marine bivalves such as Oxytoma cf. inequivalve and Pleuromya sp. In the Higuchidani Formation (60-120 m thick), which is predominantly dark gray mudstone inter- calated with sandstone, Hirano et al. (1978) reported a Late Pliens- bachian ammonoid assemblage consisting of Fontanel- liceras cf. fontanellense, Arieticeras sp., and Canavaria
Earth Science Frontiers, Vol. 17, Special Issue, Aug. 2010 ISSN 1005-2321 sp. We found some molluscan fossils (the bivalves Kolymonectes mongkensis, Ryderia textulata, Palmoxy- toma cygnipes, Pleuromya sp., and Goniomya sp., and the ammonoids Fontanelliceras sp. and Amaltheus? sp.) in the lower part of the Higuchi- dani Formation. Kolymonectes, Palmoxytoma, Radulonectites, and Agerchlamys were bipolar in distribution during the Early Jurassic, and did not extend to low palaeo- latitudes (Damborenea, 1993, 1998, 2002). Specifically, Kolymonectes was common in the northern polar region (= Boreal region; northeastern Russia and northern Canada), though Kolymonectes weaveri was excep- tionally found in western Argentina (Damborenea, 1998). The Lower Jurassic Sinemurian? to Pliens- bachian Higashinagano Formation, Toyora Group, contains abundant corals (Chomatoseris cyclolitoides, Hispaniastraea cf. ramosa, and Actinastrea sp.) in calcareous sandstone. The bivalve assemblages of this formation contain Tethyan and Boreal species, in- cluding Tutcheria itoi, Prosogyrotrigonia inouyei, Sphaeriola nipponica, Cardinia toriyamai, Plagio- stoma matsumotoi, Chlamys textoria, Oxytoma inequivalve, Entolium cf. calvum, Entolium cf. lunare, Plagiostoma kobayashii, Lopha sazanami, Liostrea toyorensis, Ctenosteron japonicum, and Palmoxytoma cf. cygnipes (Hayami, 1962). Therefore, the bivalve assemblage of the Higuchi Group is typical of the Boreal biotic realm, and the benthic assemblages of the Toyora Group are probably a transitional fauna be- tween the Tethyan and Boreal biotic realms. Key words: Bivalves; Boreal fauna; Southwest Japan; Lower Jurassic References: Damborenea S.E. Early Jurassic South American Pectinaceans and circum Pacific palaeobiogeo- graphy. Palaeogeography, Palaeoclimatology, Palaeoecology, 1993, 100: 109-123. Damborenea S.E. The bipolar bivalve Kolymonectes in South America and the diversity of propeau- mussiidae in Mesozoic Time. In: Johnston P.A., Haggart J.W. (ed). Bivalves: An Eon of Evolu- tion. Paleobiological Studies Honoring Norman D. Calgry: University of Calgry Press, 1998: 143- 155. Damborenea S.E. Jurassic evolution of southern Hemisphere marine palaeobiogeographic units based on benthonic bivalves. Geobios, 2002, 35: 51-71. Hirano H. Biostratigraphic study of the Jurassic Toyora Group Part 1. Memoirs of the Faculty of Science Kyushu University, Series D, Geology, 1971, 21: 93-128. Hirano H. Biostratigraphic study of the Jurassic Toyora Group Part 2. Transactions and Proceedings of the Palaeontological Society of Japan, New Series, 1973a, 89: 1-14. Hirano H. Biostratigraphic study of the Jurassic Toyora Group Part 2. Transactions and Proceedings of the Palaeontological Society of Japan, New Series, 1973b, 90: 45-71. Hirano H., Mikami T., Miyagawa H. Lower Jurassic Ammonites from the Higuchi Group, Southwest Japan. Transactions and Proceedings of the Palaeontological Society of Japan, New Series, 1978, 112: 410-416. Hayami I. Jurassic pelecypod faunas in Japan with special reference to their stratigraphical distribution and biogeographical provinces. The Journal of the Geological Society of Japan, 1962, 68: 96-108 (in Japanese with English abstract). Naka T., Tokuoka S., Sato S., et al. Stratigraphy and structure of the Higuchi Group (Lower Jurassic), Muikaichicho, Shimane Prefecture. Geological Reports of Shimane University, 1985, 4: 91-104 (in Japanese with English abstract) Sato T. Correlation du Jurassique inferieur japonais en basant sur les Ammonites fossils. The Journal of the Geological Society of Japan, 1956, 62: 490- 503 (in Japanese with French abstract). 185
Page 4 and 5:
THE 8 TH INTERNATIONAL CONGRESS ON
Page 6 and 7:
EARTH SCIENCE FRONTIERS Short paper
Page 8 and 9:
Earth Science Frontiers, Vol. 17, S
Page 10 and 11:
Page 12 and 13:
Page 14 and 15:
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141: Earth Science Frontiers, Vol. 17, S
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Page 274 and 275:
Page 276 and 277:
Page 278 and 279:
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
Page 286 and 287:
Page 288 and 289:
Page 290 and 291:
Page 292 and 293:
Page 294 and 295:
Page 296 and 297:
Page 298 and 299:
Page 300 and 301:
Page 302 and 303:
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
Page 310 and 311:
Page 312 and 313:
Page 314 and 315:
Page 316 and 317:
Page 318 and 319:
Page 320 and 321:
Page 322 and 323:
Page 324 and 325:
Page 326 and 327:
Page 328 and 329:
Page 330 and 331:
Page 332 and 333:
Page 334 and 335:
Page 336 and 337:
Page 338 and 339:
Page 340 and 341:
Page 342 and 343:
Page 344 and 345:
Page 346 and 347:
Page 348 and 349:
Page 350 and 351:
Page 352 and 353:
Page 354 and 355:
Page 356 and 357:
Page 358 and 359:
Page 360 and 361:
Page 362 and 363:
Page 364 and 365:
Page 366 and 367:
Page 368 and 369:
Page 370 and 371:
Page 372 and 373:
Page 374 and 375:
Page 376 and 377:
Page 378 and 379:
Page 380 and 381:
Page 382 and 383:
Page 384 and 385:
Page 386 and 387:
Page 388 and 389:
Page 390 and 391:
Page 392 and 393:
Page 394 and 395:
Page 396 and 397:
Page 398 and 399:
Page 400 and 401:
Page 402 and 403:
Page 404 and 405:
Page 406 and 407:
Page 408 and 409:
Page 410 and 411:
Page 412 and 413:
Page 414 and 415:
Page 416 and 417:
410 EARTH SCIENCE FRONTIERS Short P
Page 418 and 419:
P.A. Selden 191 V.I. Katkova 309 P.
show all

in Jurassic and Cretaceous Stratigraphy

Create successful ePaper yourself

Delete template?

Save as template?