Palaeoworld 16 (2007) 16–30 Research paper The Capitanian (Permian) Kamura cooling event: The beginning of the Paleozoic–Mesozoic transition Yukio Isozaki a,∗ , Hodaka Kawahata b , Kayo Minoshima c b a Department of Earth Science and Astronomy, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan Graduate School of Frontier Sciences and Ocean Research Institute, The University of Tokyo, Minamidai, Nakano, Tokyo 164-8639, Japan c Geological Survey of Japan, AIST, Tsukuba 305-8567, Japan Received 4 January 2007; received in revised form 12 May 2007; accepted 15 May 2007 Available online 25 May 2007 Abstract The Capitanian (late Guadalupian) high positive plateau interval of carbonate carbon isotope ratio (␦13 Ccarb ) was recognized lately in a mid-Panthalassan paleo-atoll limestone in Japan as the Kamura event. This unique episode in the late-middle Permian indicates high productivity in the low-latitude superocean likely coupled with resultant global cooling. This event ended shortly before the Guadalupian–Lopingian (middle-late Permian) boundary (ca. 260 Ma); however, its onset time has not been ascertained previously. Through a further analysis of the Wordian (middle Guadalupian) to lower Capitanian interval in the same limestone at Kamura in Kyushu, we have found that the ␦13 Ccarb values started to rise over +4.5‰ and reached the maximum of +7.0‰ within the Yabeina (fusuline) Zone of the early-middle Capitanian. Thus the total duration of the Kamura event is estimated over 3–4 million years, given the whole Capitanian ranging for 5.4 million years. This 3–4 million years long unique cooling event occurred clearly after the Gondwana glaciation period (late Carboniferous to early Permian) in the middle of the long-term warming trend toward the Mesozoic. This cooling may have been a direct cause of the end-Guadalupian extinction of low-latitude, warm-water adapted fauna including the large fusulines (Verbeekinidae), gigantic bivalves (Alatoconchidae), and rugose corals (Waagenophyllidae). The Kamura event marks the first sharp excursion of ␦13 Ccarb values in the volatile fluctuation interval that lasted for nearly 20 million years from the late-Middle Permian until the early-Middle Triassic. This interval with high volatility in ␦13 Ccarb values represents the transition of major climate mode from the late Paleozoic icehouse to the Mesozoic–Cenozoic greenhouse regime. The endPaleozoic double-phased extinction occurred within this interval and the Capitanian Kamura event is regarded as the prelude to this transition. © 2007 Nanjing Institute of Geology and Palaeontology, CAS. Published by Elsevier Ltd. All rights reserved. Keywords: Guadalupian; C isotope; Panthalassa; Permo-Triassic boundary; Extinction; Productivity 1. Introduction The terminal Paleozoic mass extinction represents the greatest in magnitude throughout the Phanerozoic life ∗ Corresponding author. Tel.: +81 3 5454 6608; fax: +81 3 3465 3925. E-mail address: [email protected] (Y. Isozaki). history (e.g., Erwin, 1993, 2006); however, it was not long time ago when its double-phased nature became widely recognized. Jin et al. (1994) and Stanley and Yang (1994) first pointed out that the Permian biodiversity declined in two steps separated clearly from each other; i.e., first at the Middle-Late Permian boundary (=Guadalupian–Lopingian boundary; G–LB) and second at the Permo-Triassic boundary (P–TB) sensu stricto (or Changhsingian–Induan boundary). 1871-174X/$ – see front matter © 2007 Nanjing Institute of Geology and Palaeontology, CAS. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.palwor.2007.05.011 Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 In contrast to the P–TB issue, not much attention has been paid to the G–LB event; however, the significance of the G–LB event was re-emphasized from a different aspect relevant to the superocean Panthalassa. The timing of the end-Guadalupian extinction apparently coincides with the onset of the superanoxia in Panthalassa, i.e., another global scale geologic phenomenon across the P–TB (Isozaki, 1997a, 2007). In addition to the faunal turnover in mid-oceanic plankton (radiolarians) detected in deep-sea chert, shallow marine sessile benthos (fusulines) also sharply declined in diversity across the G–LB in mid-Panthalassan paleo-atoll complex (Isozaki and Ota, 2001; Ota and Isozaki, 2006). These positively suggest the global nature of the G–LB extinction and causal environmental change. The mid-oceanic paleo-atoll carbonates also recorded secular change in stable carbon isotope composition. Musashi et al. (2001, 2007) and Isozaki et al. (2007) first documented the secular change in carbonate carbon isotopic ratio (␦13 Ccarb ) of mid-Panthalassa across the P–TB and the G–LB, respectively. Besides the boundary negative shifts both at P–TB and G–LB properly predicted from previous studies (e.g., Baud et al., 1989; Holser et al., 1989; Wang et al., 2004), a unique high productivity interval in the Capitanian (late Guadalupian) was newly detected on the basis of the appreciable length of high positive ␦13 Ccarb (between +5 and +6‰) interval (Isozaki et al., 2007; Fig. 1). As such high positive values over +5.0‰ are quite rare in the Phanerozoic record except for several unique events in the Paleozoic (e.g., Veizer et al., 1999; Saltzman, 2005), they named this Capitanian episode the “Kamura event”, emphasizing its significance of global cooling and relevant extinction of large fusulines and gigantic bivalves in low-latitude Panthalassa (Isozaki et al., 2007). In the fusuline-tuned section, the waning history of the Kamura event was clearly documented in high resolution, whereas the earlier history including the onset timing was not yet revealed, owing to the absence of continuous exposure in the previously studied section. This left a big chasm in our understanding of the major environmental change in the late Guadalupian, in particular the cause and processes of the Kamura cooling event. This study aimed to clarify the earlier stage of the Kamura event, particularly focusing on the onset timing, and to bracket the total duration of the event. In the same Kamura area in Kyushu, Japan, we analyzed ␦13 Ccarb chemostratigraphy of two other sections that expose much lower parts of the Guadalupian (Wordian to lower Capitanian) mid-oceanic paleo-atoll carbonates. This article reports the ␦13 Ccarb measurements and discusses their implications to the Capitanian environ- 17 mental change and relevant extinction event. A particular emphasis is given to the Kamura event in the context of a long-term change in environmental regime during the nearly 20 million years of the Paleozoic–Mesozoic transition. 2. Geologic setting The Permian and Triassic limestone at Kamura (Takachiho town, Miyazaki prefecture; Fig. 2) in Kyushu forms a part of an ancient mid-oceanic atoll complex primarily developed on a mid-oceanic paleo-seamount (Sano and Nakashima, 1997; Isozaki and Ota, 2001; Ota and Isozaki, 2006). This limestone, like many other Permian limestones in Japan, occurs as an allochthonous block incorporated in the Middle-Upper Jurassic disorganized mudstone/sandstone of the Jurassic accretionary complex in the Chichibu belt (the tectonic outlier of the Mino-Tanba belt; Isozaki, 1997b). The limestone blocks in the Kamura area retain parts of the primary midoceanic stratigraphy that ranges in age from the Wordian (middle Guadalupian) to Norian (Late Triassic) with several sedimentary breaks in the Triassic part (Kambe, 1963; Kanmera and Nakazawa, 1973; Watanabe et al., 1979; Koike, 1996; Ota and Isozaki, 2006). The Permian part consists of bioclastic limestone with a typical Tethyan shallow marine fauna that includes various fusulines, smaller foraminifera, large-shelled bivalves, gastropods, brachiopods, rugose corals, and calcareous algae. The Permian rocks are stratigraphically divided into the Guadalupian Iwato Formation (ca. 70 m thick) and the overlying Lopingian Mitai Formation (ca. 30 m thick). Fusulines are the most abundant, and they provide a basis for subdividing the Iwato Formation into four biostratigraphic units; i.e., the Neoschwagerina Zone, Yabeina Zone, Lepidolina Zone, and a barren interval, in ascending order (Ota and Isozaki, 2006; Isozaki and Igo, in preparation). The overlying Lopingian Mitai Formation is subdivided into two fusuline zones, i.e., the Codonofusiella-Reichelina Zone and Palaeofusulina Zone (Kanmera and Nakazawa, 1973; Ota and Isozaki, 2006). All these fusuline assemblages and associated fossils (rugose corals and large-shelled bivalves of Family Alatoconchidae; Isozaki, 2006) indicate that the seamount was located in a low-latitude warm-water domain in the superocean Panthalassa under a tropical climate. The Neoschwagerina Zone is correlated with the Wordian (middle Guadalupian) of Texas and with the Murgabian in Transcaucasia (Leven, 1996; Wilde et al., 1999), while the Yabeina Zone, Lepidolina Zone, and most of the barren interval are correlated with the Capi- 18 Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 Fig. 1. Schematic diagram showing the late Guadalupian Kamura event documented by high positive ␦13 Ccarb values at Kamura in Japan (modified from Isozaki et al., 2007) (A), and the composite Permian secular curve of ␦13 Ccarb values modified from Korte et al. (2005) (B). Road: Roadian, Wor: Wordian. Note that the Guadalupian large fusuline and bivalve fauna became extinct in the middle of the Kamura cooling event, whereas the post-extinction radiation of the Lopingian small fusulines started during the subsequent warming period. In contrast to the waning history of the Kamura event, its onset timing and processes were unknown previously. In (B), two possible paths (broken lines) for the Guadalupian secular change of ␦13 Ccarb values were shown by Korte et al. (2005); the lower for the Tethyan domain, the upper for the Delaware basin in Texas. The Capitanian Kamura event recorded much higher positive ␦13 Ccarb values between +5.0 and +7.0‰ in Kamura, suggesting the positive excursion of global context in the late Guadalupian. See text and Figs. 4 and 5 for details. Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 19 Fig. 2. Index map and stratigraphic columns of the three studied sections in the Kamura area, Kyushu. Not to scale. The present chemostratigraphic research focused on the Wordian and lower Capitanian parts of the Iwato Formation exposed in Sections 1 and 3. Refer to Ota and Isozaki (2006) and Isozaki et al. (2007) for more details of the area and Section 2. Loping.: Lopingian; Wuch.: Wuchiapingian; C-R: Codonofusiella-Reichelina. 20 Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 tanian (upper Guadalupian) of Texas and with Midian in Transcaucasia (Ota and Isozaki, 2006). The stratigraphic relationship between the Yabeina Zone and the Lepidolina Zone has long been controversial (e.g., Toriyama, 1967; Ishii, 1990), however, our recent study clarified that the former stratigraphically underlies the latter within the Iwato Formation (Isozaki and Igo, in preparation). The Codonofusiella-Reichelina Zone corresponds to the Wuchiapingian (Lower Lopingian) in South China. For details of fusuline biostratigraphy and age assignment, see Ota and Isozaki (2006) and Isozaki (2006). The Iwato Formation is exposed in three sections in Kamura; i.e., Sections 1–3 from the east to the west (Fig. 2). Section 2 (32◦ 44 58 N, 131◦ 20 02 E; Fig. 2) at south of Shioinouso displays a continuous outcrop of the upper Iwato Formation and the lower Mitai Formation that spans across the G–LB (Ota and Isozaki, 2006). In this section, a unique high positive plateau in the Lepidolina Zone/barren interval and the following sharp negative shift in ␦13 Ccarb were documented (Isozaki et al., 2007). In the present study, we analyzed two additional sections in the Kamura area that expose the lower part of the Iwato Formation; i.e., Sections 1 and 3 (Kambe, 1963; Murata et al., 2003; Isozaki, 2006; Fig. 2). Section 1 (32◦ 45 12 N, 131◦ 20 55 E) to the southeast of Saraito village is composed of 57 m-thick limestone that belongs to the Neoschwagerina Zone and Yabeina Zone, whereas Section 3 (32◦ 45 05 N, 131◦ 19 52 E) to the northeast of Hijirikawa is 8 m thick and entirely belongs to the Yabeina Zone (Fig. 2). Detailed biostratigraphy of these two sections is under scrutiny and results will be published elsewhere (Isozaki and Igo, in preparation). Among the three sections in Kamura, Section 1 represents the stratigraphical lowest, whereas Section 2 the highest (Fig. 2). A slight stratigraphic gap may exist between Sections 2 and 3; however, the similarity in lithofacies suggests that the possible gaps are considerably small, if at all. The same fauna and lithofacies in Sections 1 and 3 likewise indicate that a possible gap is much smaller or even absent. 3. Samples and analytical methods We collected dark gray to black limestone specimens of the Guadalupian Iwato Formation for stable carbon and oxygen isotope measurements at 34 horizons; i.e., 21 from Section 1 and 13 from Section 3. Rocks of the two sections are unmetamorphosed and mostly fresh, and those with strong weathering and with many calcite veins were screened out in the field and in the labora- tory under the microscope. The black limestone of the Iwato Formation has TOC around 0.1 wt% (Isozaki et al., 2007). The micritic part of wackestone from each horizon was milled by microdrill after examining under the microscope. Approximately 100 m of the aliquot samples were reacted with 100% H3 PO4 at 90 ◦ C in an automated carbonate device (Multiprep) coupled with a Micromass Optima mass spectrometer at the Geological Survey of Japan, AIST. Here, ␦13 C = [((13 C/12 Csample )/(13 C/12 Cstandard )) − 1] × 1000, and ␦18 O = [((18 O/16 Osample )/(18 O/16 Ostandard )) − 1] × 1000. All isotopic data are reported as per mil (‰) relative to Vienna Pee Dee belemnite (V-PDB) standard. The internal precision was 0.03‰ and 0.04‰ (1) for ␦13 C and ␦18 O, respectively, based on replicate measurements of 23 consecutive samples of the NBS-19 calcite standard (Suzuki et al., 2000). 4. Results Table 1 lists all the measurements of ␦13 Ccarb and carb of 47 samples from 34 horizons from Sections 1 and 3 in Kamura. Figs. 3 and 4 show secular changes in ␦13 Ccarb values plotted on the stratigraphic columns of Sections 1 and 3, respectively. All ␦13 Ccarb values showed a wide range from +3.55 to +6.97‰, whereas ␦18 Ocarb values fluctuated between −7.58 to −12.36‰, which might be partly due to a slight diagenetic alteration, however, the correlation between ␦13 Ccarb and ␦18 Ocarb indicates that they behaved independently. Thus we consider that the ␦13 Ccarb values were not likely affected by secondary alteration but reflect the primary isotopic composition of the inorganic carbon reservoir in ancient seawater, in which the carbonates were deposited. At Section 1, the ␦13 Ccarb values range between +3.5 and +5.2‰. This section is divided into two parts in terms of ␦13 Ccarb values; i.e., segment Sr-1 (Neoschwagerina Zone; 32 m) and the overlying segment Sr-2 (Yabeina Zone; 3.5 m) (Fig. 3). In the segment Sr-1, the ␦13 Ccarb values gradually and steadily increased from +3.5 to +4.3‰. On the other hand in the segment Sr-2, the ␦13 Ccarb values fluctuated between +4.4 and +5.2‰. Although the boundary between the segments Sr-1 and Sr-2 is covered, a general trend of increasing ␦13 Ccarb values can be recognized in Section 1. The sample SrB35 in the segment Sr-2 marked the lowest horizon of high positive ␦13 Ccarb values over +5.0‰ in the Iwato Formation. At Section 3, the ␦13 Ccarb values range between +5.0 and +7.0‰. This section is chemostratigraphi␦18 O Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 Table 1 Analytical results of ␦13 Ccarb and ␦18 Ocarb normalized to the Vienna Pee Dee belemnite of the Guadalupian Iwato Formation in the Kamura area, Kyushu ␦13 Ccarb (‰) ␦18 Ocarb (‰) Section 3 (Hijirikawa) Yabeina Zone (13 horizons) Hj-0.5 7.50 Hj0 6.75 Hj1 6.15 Hj1.5 5.90 Hj2-1 5.45 Hj2-2 5.45 Hj3 5.15 Hj4 4.55 Hj5 4.15 Hj5.5 3.75 Hj6.1 3.35 Hj7.1-1 2.40 Hj7.1-2 2.40 Hj10 0.70 Hj11 0.20 5.332 5.817 5.425 5.936 6.872 6.970 5.791 5.681 5.191 5.502 5.005 5.046 5.008 4.776 4.857 −10.001 −8.480 −8.366 −11.370 −10.052 −8.559 −7.578 −9.013 −9.941 −8.697 −8.616 −10.414 −10.085 −11.163 −10.913 Section 1 (Saraito) Yabeina Zone (8 horizons) B41 56.8 B40 56.4 B39-1 56.1 B39-2 56.1 B38 55.3 B38Y1 55.3 B38Y2 55.3 B37 55.0 B37Y2 55.0 B37Y3 55.0 B36 54.7 B35 54.1 B34 53.8 4.575 4.478 5.051 5.235 5.013 5.056 4.941 4.932 4.774 4.917 4.704 5.050 4.430 −10.049 −8.744 −10.426 −10.824 −10.893 −10.789 −11.677 −11.356 −11.978 −11.891 −8.933 −9.350 −8.081 Neoschwagerina Zone (13 horizons) B12-1 33.9 4.213 B12-2 33.9 4.384 B9 31.0 4.314 B6-1 28.0 4.042 B6-2 28.0 4.267 B5-1 27.7 4.128 B5-2 27.7 4.173 B4-1 27.0 4.123 B4-2 27.0 4.177 B3 26.0 4.201 51 25.5 3.935 B2 24.0 4.072 B1-1 21.0 3.550 B1-2 21.0 3.648 X-1 15.0 3.714 X-2 15.0 3.969 07-05 4.5 3.959 07-03 3.4 3.546 Z4 0.0 3.536 −10.435 −10.715 −11.773 −10.775 −9.899 −11.003 −11.245 −11.414 −12.362 −7.970 −10.139 −8.329 −10.890 −10.570 −10.602 −7.753 −9.192 −8.841 −9.747 Sample Horizon (m) 21 cally divided into two parts; i.e., segment Hi-1 (3.5 m+) and the overlying segment Hi-2 (2.2 m+) (Fig. 4). The segment Hi-1 is characterized by a gradual increase in ␦13 Ccarb values, whereas the Hi-2 by a reversed decrease. The sample Hj-2 with +7.0‰ marked the highest ␦13 Ccarb value in the Iwato Formation. In summary, the current C isotope analysis clarified the following two facts: (1) the ␦13 Ccarb values keep increasing from the Neoschwagerina Zone (segment Sr1; Wordian) to the Yabeina Zone (segments Sr-2 and Hi-1; lower Capitanian) except for the upper part of the Yabeina Zone (segment Hi-2); (2) all the ␦13 Ccarb values of the Capitanian Iwato Formation range above +4.4‰ up to the highest value of +7.0‰ in the upper Yabeina Zone. 5. Discussion This study confirms the development of the Kamura event in the late Guadalupian, and suggests that the interval of this unique event has ranged stratigraphically further downward. We will discuss here the geological implications of the new dataset, focusing on the onset timing and total duration of the Kamura event with respect to the end-Guadalupian environmental changes and mass extinction, and particularly to the transition of climatic regime from the late Paleozoic icehouse (Gondwana glaciation) to Mesozoic greenhouse. 5.1. Onset of the Kamura event The present study has clarified that the lower part of the Iwato Formation (Wordian Neoschwagerina Zone and lower Capitanian Yabeina Zone) is thoroughly characterized by positive values of ␦13 Ccarb over +3.5‰ (Figs. 3 and 4). In particular, all the ␦13 Ccarb values of the Yabeina Zone both in Sections 1 and 3 exceed +4.4‰, and they range mostly in a high positive domain between +5.0 to +6.0‰. The Yabeina Zone of the Iwato Formation in general has more or less the same isotopic signature as the overlying Lepidolina Zone and barren interval in which the Kamura event was originally recognized (Isozaki et al., 2007). Thus the interval of the Kamura event with ␦13 Ccarb values over +5.0‰ ranges stratigraphically downward to the Yabeina Zone. On the other hand, the Wordian Neoschwagerina Zone recorded relatively lower ␦13 Ccarb values between +3.5 and +4.2‰, thus the Kamura event had not yet started in the Wordian. However, the ␦13 Ccarb record of the Neoschwagerina Zone clearly demonstrates a steadily upward-increasing pattern, suggesting that 22 Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 Fig. 3. Chemostratigraphy of stable carbon isotope of carbonates of Section 1 near Saraito in Kamura. Legends for columnar section are the same as those for Fig. 2. This section is divided into two chemostratigraphic segments: Sr-1 and Sr-2. Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 23 Fig. 4. Chemostratigraphy of stable carbon isotope of carbonates of Section 3 near Hijirikawa in Kamura. Legends for columnar section are the same as those for Fig. 2. This section is divided into two chemostratigraphic segments: Hi-1 and Hi-2. the oceanographic condition started to shift gradually already in the Wordian toward the extreme state of the Capitanian with unusual enrichment of 13 C in seawater. The sample SrB35 in the Yabeina Zone in Section 1 marks the lowest horizon with ␦13 Ccarb values over +5.0‰, suggesting the lower limit of the interval of the Kamura event. Unfortunately much lower horizon of the Yabeina Zone is covered and the boundary between the Neoschwagerina Zone and Yabeina Zone has not been observed in Kamura. Nonetheless, the general secular trend of the ␦13 Ccarb record positively indicates that the Kamura event has first emerged around the Wordian/Capitanian boundary (265.8 Ma according to the latest geological timescale by Gradstein et al., 2004; Fig. 5). It is noteworthy that a strange condition has appeared in the middle of the superocean around the Wordian/Capitanian boundary because the Kamura event may mark the first episode of large isotopic excursion in the Permian (Fig. 1B). Although the trigger for this oceanographic change is unknown at present, the 24 Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 Fig. 5. Schematic summary of the ␦13 Ccarb chemostratigraphy of the Guadalupian Iwato Formation and Early Lopingian Mitai Formation in Kamura, showing the total range of the Kamura event. Not to scale. Note the main extinction occurred in the middle of the high positive plateau interval of ␦13 Ccarb values. C-R: Codonofusiella-Reichelina. onset timing of the Kamura event should be checked further carefully in continuous sections elsewhere in order to examine whether or not this event started synchronously throughout the world. 5.2. Duration of the Kamura event As discussed above, the Kamura event apparently ranged through three successive fusuline zones of the Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 Capitanian; i.e., the Yabeina Zone, Lepidolina Zone, and barren interval in ascending order (Fig. 5). The basal part of the Yabeina Zone in Kamura is missing, whereas the uppermost part of the barren interval is free from high positive ␦13 Ccarb values. Thus the Kamura event likely spanned throughout almost the entire Capitanian, except for the uppermost and possibly the lowest parts. This is supported by the data from the GSSP of the G–LB at Penglaitan and Tieqiao, South China, as there is no high positive plateau recognized in the uppermost Capitanian immediately below the conodont-defined G–LB (Wang et al., 2004; Jin et al., 2006). Although detailed chronology of the three fusuline zones of the Capitanian has not yet been established, given the whole Capitanian ranging for 5.4 million years from 265.8 Ma to 260.4 Ma (according to the timescale by Gradstein et al., 2004), the total duration of the Kamura event is estimated to be more than a half of the Capitanian, probably 3–4 million years. Such a remarkable period characterized by an unusual positive ␦13 Ccarb excursion has never been recognized in the Permian. It is also noteworthy that the highest ␦13 Ccarb value 7.0‰ was detected in the sample Hj-2 in the upper part of the Yabeina Zone, as no-such high positive value has ever been reported from the Permian rocks (e.g., Grossman, 1994; Scholle, 1995; Korte et al., 2005). Thus the maximum ␦13 Ccarb value in the Yabeina Zone suggests that the Kamura event may have culminated in the early-middle Capitanian, held the similar condition for a while, and finally collapsed quickly in the late Capitanian. In general, extremely high positive ␦13 Ccarb values indicate extraordinarily high productivity in the ocean. As oceanic productivity is strongly controlled by nutrient availability, constant supply particularly of limiting elements such as P and N is necessary to maintain longlasting high productivity. Saltzman (2005) compiled all available ␦13 Ccarb measurements from the Paleozoic (middle Cambrian to Carboniferous) rocks in the Great Basin of western USA, and demonstrated a composite Paleozoic secular curve that is punctuated by nine unique events of remarkable positive excursions by over +3.0‰ lasted for more than a few million years. He concluded that these nine events, detected also in different continents, represent intermediate cool climate intervals between typical greenhouse and icehouse periods. By lowering the sea surface temperature, oceanic circulation can be accelerated to bring sufficient nutrients from the deep ocean to the surface and this will result in high primary productivity by blooming of phytoplankton/cyanobacteria. As to the nutrient condi- 25 tion, however, the high productivity will not hold for a long time because of negative feedback mechanism, if world oceans are nitrogen-limited. In contrast, under a phosphorous-limited condition, high primary productivity coupled with preferential organic carbon burial will continue to keep seawater ␦13 C in high positive values for certain duration until effective recycling of P stops (Saltzman, 2005). Although the Silurian (Ireviken) event remains still controversial (Cramer and Saltzman, 2007), other eight Paleozoic cases with prominent positive ␦13 Ccarb excursion all suggest the appearance of cool climate. Accordingly, the late Guadalupian Kamura event was nominated as the 10th case in the Paleozoic characterized by a remarkable positive ␦13 Ccarb excursion, and the Kamura event likewise represents a transient cool interval that appeared in the late Guadalupian (Isozaki et al., 2007). The unique lithofacies of the Iwato Formation dominated by black to dark gray, organic-rich (TOC ∼0.1 wt%) wackestone probably reflects the high productivity in surface waters, as most of the Permian paleo-atoll limestone in Japan has much lower TOC less than 0.01 wt%. It is worth noting that this event marks the first cooling episode, after the Gondwana glaciation ended in the Artinskian (late Cisuralian; Jones and Fielding, 2004), in the middle of the long-term warming trend toward the generally warm Mesozoic era. In good accordance with the above interpretation, the lately compiled Permian sea-level fluctuation curve demonstrates that the Permian lowest-stand occurred around the G–LB (Hallam and Wignall, 1999; Tong et al., 1999). A major hiatus on the top of the Guadalupian Maokou Formation has been recognized extensively in South China, and the top of the well-known Permian Reef complex in west Texas is unconformably covered by the Lopingian evaporites (e.g., Mei and Wardlaw, 1996). The “Permian chert event” in high latitudes (Beauchamp and Baud, 2002) likely supports the appearance of a cool period in the Guadalupian, too. 5.3. Critical cooling The end-Guadalupian is regarded as a timing of one of the two major extinction events of the terminal Paleozoic era (Jin et al., 1994; Stanley and Yang, 1994). Isozaki (1997a, 2007) emphasized the geological significance of the G–LB event from a viewpoint of the timing coincidence between two global geological phenomena; i.e., the biotic extinction and the onset of the P–TB superanoxia in the superocean. As to the cause of the G–LB 26 Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 event, a global environmental change triggered by the large-scale volcanism of the Emeishan Trap in South China is currently favored by many workers (e.g., Chung et al., 1998; Ali et al., 2002; Wignall, 2001); however, details including possible direct kill mechanisms are not yet fully clarified. In this regard, the extinction of the Guadalupian fauna in the middle of the Capitanian Kamura event appears critical. The clear extinction pattern of large fusulines (Verbeekinidae) and bivalves (Alatoconchidae) in the Capitanian part of the Iwato Formation (Isozaki, 2006; Ota and Isozaki, 2006) suggests that the claimed cooling of the Kamura event might have played the key role in the kill scenario, in particular for the creatures well adapted to a warm tropical climate in low-latitude areas (Isozaki et al., 2007). The occurrence/distribution of the middle Permian Verbeekinidae, Alatoconchidae, and Waagenophyllidae (rugose coral) families was restricted in low-latitude shallow seas in Tethys and Panthalassa, and the gigantism in fusulines and Alatoconchidae bivalves was probably due to the symbiosis with photosynthetic algae/bacteria in such oligotrophic environment in mid-ocean in general (Isozaki, 2006). In the late Capitanian, large fusulines were screened out by size (Wilde, 2002; Yang et al., 2004; Ota and Isozaki, 2006), aberrant Alatoconchidae bivalves became totally extinct (Isozaki, 2006), and the diversity of rugose corals declined remarkably (Wang and Sugiyama, 2000). The possible drop in sea surface temperature in low latitudes may have caused a total malfunction of photosymbiosis factory shared by the above-mentioned “tropical trio” that were too much adapted to warm-water environments to survive the change. At Tieqiao, the last occurrence of large fusuline Metadoliolina (Verbeekinidae) was confirmed in the Jinogondolella xuanhanensis Zone with ␦13 Ccarb values of +3 to +4‰ (Jin et al., 2006), suggesting that the extinction of large fusulines slightly delayed in South China probably owing to the local variability in water temperature. 27 In addition, some gastropods and brachiopods behaved similarly as the trio. For example, the occurrence of extraordinarily large gastropods, such as Bellerophon (13 cm in diameter), Pleurotomaria (18 cm × 16 cm), and Murchisonia (40 cm in height), were reported from the Capitanian limestone in Akasaka (Hayasaka and Hayasaka, 1953), whereas all the gastropods from the overlying Lopingian are no more than 1 cm in diameter. It is also noteworthy that some early-middle Permian brachiopods originated in middlehigh paleolatitude domains (Attenuatella, Waagenites, Strophalosiina, Comuqia) migrated to low-latitudes and made their first appearance in the paleoequatorial zone at the end of the Capitanian (Shen and Shi, 2002). Although the Permian gastropods and brachiopods as a whole did not experienced a remarkable diversity loss at the G–LB (e.g., Pan and Erwin, 1994; Shen and Shi, 2002), these observations likewise support the appearance of a cool interval in the Capitanian Tethys and Panthalassa. The G–LB is placed not at the extinction level of the Guadalupian fauna but at the first appearance datum (FAD) of the Wuchiapingian index conodont Clarkina postbitteri postbitteri as defined at the stratotype section (GSSP) at Penglaitan in South China (Jin et al., 1998; Henderson et al., 2002). Owing to the absence of conodonts, the G–LB in Kamura is set at the horizon ca. 11 m above the main extinction level in the upper part of the barren interval on the basis of the first appearance of the Lopingian fusulines and ␦13 Ccarb chemostratigraphical correlation (Ota and Isozaki, 2006; Isozaki et al., 2007). The main extinction occurred not at the G–LB per se but in a much lower horizon in the midst of the positive ␦13 Ccarb excursion interval. Thus an appreciable time has elapsed between the end-Guadalupian extinction and the following radiation of the Lopingian fauna in shallow mid-Panthalassa (Fig. 1A). The present study demonstrated that the oceanic carbon cycle started to change in mid-Panthalassa around 265 Ma, at least by 4–5 million years earlier than the G–LB (ca. 260 Ma). Should the claimed cooling have been responsible for the extinction of the Guadalupian Fig. 6. Secular change of ␦13 Ccarb in the Paleozoic and early Mesozoic, compiled from Saltzman (2005) for the Cambrian to Carboniferous, from Korte et al. (2005) and this study for the Permian, from Payne et al. (2004) and Gradstein et al. (2004) for the Triassic, and from Palfy et al. (2001) and Katz et al. (2005) for the Jurassic. Note the four distinct intervals of volatility with high positive ␦13 Ccarb excursion; i.e., Late Cambrian, Late Ordovician–Silurian, Late Devonian–Early Carboniferous, and the Middle Permian–Middle Triassic (=Paleozoic–Mesozoic transitional interval; PMT-interval). The PMT-interval from the Capitanian (Late Middle Permian) to Anisian (Early Middle Triassic) ranged for ca. 20–25 million years, representing the transition from the late Paleozoic icehouse, centered by the Pennsylvanian to Early Permian Gondwana glaciation, to the Mesozoic/Cenozoic greenhouse. The PMT-interval recorded a period of a transient cool climate with a P-limited oceanographic condition between icehouse and greenhouse modes, and the Kamura event marks the beginning of the mode change from the Paleozoic icehouse to the Mesozoic greenhouse. It is noteworthy that the two major mass extinctions (at the G–LB and P–TB) occurred during the PMT-interval, and that the PMT-interval chronologically overlaps the P–TB superanoxic period (Isozaki, 1997a). 28 Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 fauna, the ultimate cause of the environmental change must have appeared by the early Capitanian time. The Emeishan Trap volacanism in South China was recently dated 256–259 Ma (Zhou et al., 2002). This early Lopingian age is obviously too young for the trap to be responsible for the environmental change in the early Capitanian (ca. 265 Ma). In general, large-scale basaltic volcanism likely drives the opposite consequence; i.e., global warming, rather than 3–4 million year-long cooling. Thus the superficial correlation between the end-Guadalupian extinction and the trap volcanism needs re-consideration. Refer to Isozaki and Ota (2007) for more details of relative timing between the G–LB extinction and the Emeishan Trap volcanism. 5.4. δ13 Ccarb volatility in the Paleozoic–Mesozoic transition interval The Guadalupian major environmental change of global context has appeared around 265 Ma (early Capitanian) several million years earlier than the endGuadalupian mass extinction at the latest Capitanian. In a long-term viewpoint, the Capitanian Kamura event is particularly significant because it marks not only the onset of wild ␦13 Ccarb fluctuations across the P–TB into the early Anisian, middle Triassic, but also the first remarkable positive ␦13 Ccarb excursion after a nearly 85 million years of relative quiescence (Fig. 6). In addition to the well-known sharp negative shift across the P–TB (Baud et al., 1989; Holser et al., 1989; Musashi et al., 2001), more positive and negative excursions of greater magnitude occurred particularly in the early Triassic (Payne et al., 2004). As to the Lopingian, similar ␦13 Ccarb fluctuations are likely expected from the preliminary results (Baud et al., 1996; Shao et al., 2000; Korte et al., 2005); however, the dataset is too immature to document detailed secular change particularly for the Wuchiapingian (lower Lopingian). In sharp contrast to the Paleozoic–Mesozoic transition (PMT)-interval, such a wild fluctuation varying from +8 to −3‰ has not been recognized in the Cisuralian to early Guadalupian nor in the middle Triassic and later part of the Mesozoic (Fig. 6). In fact, ␦13 Ccarb value over +5.0‰ has never been recorded throughout the Mesozoic and Cenozoic (e.g., Veizer et al., 1999; Katz et al., 2005). Thus a volatile change in global carbon cycle relevant to oceanography is restricted solely to the ∼20 million year-long PMT-interval from the Capitanian (ca. 265 Ma) to early Anisian (ca. 245 Ma). As pointed out by Saltzman (2005), there are three other intervals in the Paleozoic that are characterized by volatile fluctuations of ␦13 Ccarb values; i.e., the Late Cambrian, Late Ordovician to Silurian, and Late Devonian to Early Carboniferous (Fig. 6). The first two intervals was described as a transient cool interval between two greenhouse periods when the globe was almost running into an icehouse but did not. Unlike these, the rest two correspond to bona fide transient cool periods between an icehouse and a greenhouse period. The late Paleozoic (Carboniferous to Early Permian) was dominated by the icehouse climate centered by the Gondwana glaciation, while the Mesozoic in total was governed by warm greenhouse climate (e.g., Frakes et al., 1992). It is noteworthy that this PMT-interval with high ␦13 Ccarb volatility approximately overlaps the superanoxic period in the superocean (Isozaki, 1997a). Regardless of climatic modes, the deep-sea cherts both of the Pennsylvanian–Guadalupian (icehouse interval) and the Middle Triassic to Jurassic (greenhouse interval) were well oxygenated. This indicates that the growth and retreat of superanoxia have been controlled not solely by the climate-dependent, global oceanic circulation but also by other factors. At any rate, a major re-organization of global oceanography, including the global carbon cycle, occurred during the PMT-interval, and this clearly separated the ancient regime of the Paleozoic and the new one of the Mesozoic. The causes and processes of the two major mass extinction events, at the G–LB and at P–TB, should better be explained in the scope of such long-term geological context. After all, the late Guadalupian Kamura event preludes all these drastic change in the PMT-interval from the Paleozoic to post-Paleozoic world, and the ultimate trigger(s) of this major mode change in environment can be found neither in the strict G–LB nor P–TB intervals but likely in the upper Guadalupian rock records. 6. Summary The present study on the mid-Panthalassan paleo-atoll complex clarified the following new aspects of the late Guadalupian environmental change relevant to the mass extinction: (1) The Kamura event with high positive ␦13 Ccarb values ranged for nearly 3–4 million years in the Capitanian (ca. 265–260 Ma), late Guadalupian. (2) The end-Guadalupian extinction occurred in the middle of the Kamura cooling event. (3) The Kamura event marks the beginning of the major mode change of global climate and oceanography from the Paleozoic to post-Paleozoic regime. Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 Acknowledgements This article is dedicated to late Lao Jin (Prof. Jin Yugan) for honoring his great contributions to the Permian study. We thank Shen Shuzhong, Chen Siwei and an anonymous reviewer for their constructive reviews, Hisayoshi Igo for identification of fusulines, Teruhisa Kasuya for drafting in part, plus Susumu Nohda and Tomomi Kani for their help in fieldwork. This research was supported by the Grant-in-Aid of Japan Society of Promoting Science (no. 16204040 to YI and no. 17253006 to HK). References Ali, J.R., Thompson, G.M., Song, X.Y., Wang, Y.L., 2002. Emeishan basalts (SW China) and the ‘end-Guadalupian’ crisis: magnetobiostratigraphic constraints. J. Geol. Soc. Lond. 159, 21–29. Baud, A., Magaritz, M., Holser, W.T., 1989. Permian-Triassic of the Tethys: carbon isotope studies. Geol. Rund. 78, 649–677. Baud, A., Atudorei, V., Sharp, Z., 1996. Late Permian and early Triassic evolution of the Northern Indian margin: carbon isotope and sequence stratigraphy. Geod. Acta (Paris) 9, 57–77. Beauchamp, B., Baud, A., 2002. Growth and demise of Permian biogenic chert along northwest Pangea: evidence for end-Permian collapse of thermohaline circulation. Palaeogeogr. Palaeoclimatol. Palaeoecol. 187, 37–63. Chung, S.L., Jahn, B.M., Wu, G.Y., Lo, C.H., Cong, B.L., 1998. The Emeishan flood basalt in SW China: a mantle plume initiation model and its connection with continental breakup and mass extinction at the Permian–Triassic boundary. Am. Geophys. Union Geodyn. Ser. 27, 47–58. Cramer, B.D., Saltzman, M.R., 2007. Fluctuations in epeiric sea carbonate production during Silurian positive carbon isotope excursions: a review of proposed paleoceanographic models. Palaeogeogr. Palaeoclimatol. Palaeoecol. 245, 37–45. Erwin, D.H., 1993. The Great Paleozoic Crisis. Columbia University Press, New York, 327 pp. Erwin, D.H., 2006. Extinction. Princeton University Press, Princeton, 296 pp. Frakes, L.A., Francis, J.E., Syktus, J.I., 1992. Climate Modes of the Phanerozoic. Cambridge University Press, Cambridge, 286 pp. Gradstein, F.M., Ogg, J.G., Smith, A.G., 2004. Geologic Timescale 2004. Cambridge University Press, Cambridge, 589 pp. Grossman, E.L., 1994. The carbon and oxygen isotope record during the evolution of Pangea: Carboniferous to Triassic. Geol. Soc. Am. Special Paper 288, 207–228. Hallam, A., Wignall, P.B., 1999. Mass extinctions and sea-level changes. Earth-Sci. Rev. 48, 217–250. Hayasaka, I., Hayasaka, S., 1953. Fossil assemblages of mollusks and brachiopods of unusually large sizes from the Permian of Japan. Trans. Proc. Palaeontol. Soc. Jpn. New Ser. 30, 37–44. Henderson, C.M., Mei, S.L., Wardlaw, B.R., 2002. New conodont definition at the Guadalupian–Lopingian boundary. In: Hills, L.V., Henderson, C.M., Bamber, E.W. (Eds.), Carboniferous and Permian of the World, vol. 19. Canadian Society of Petroleum Geologists Memoir, pp. 725–735. Holser, W.T., Schöenlaub, H.P., Attrep Jr., M., Boeckelmann, K., Klein, P., Margaritz, M., Orth, C.J., Fenninger, A., Jenny, C., Kralik, M., 29 Mauritsch, H., Pak, E., Schramm, J.M., Stattegger, K., Schmöeller, R., 1989. A unique geochemical record at the Permian/Triassic boundary. Nature 337, 39–44. Ishii, K., 1990. Provinciality of some fusulinacean faunas in Japan. In: Ichikawa, K., Mizutani, S., Hara, I., Hada, S., Yao, A. (Eds.), PreCretaceous Terranes of Japan. Nihon Insatsu, Osaka, pp. 297–305. Isozaki, Y., 1997a. Permo-Triassic boundary superanoxia and stratified superocean: records from lost deep-sea. Science 276, 235–238. Isozaki, Y., 1997b. Jurassic accretion tectonics of Japan. Island Arc 6, 25–51. Isozaki, Y., 2006. Guadalupian (middle Permian) giant bivalve Alatoconchidae from a mid-Panthalassan paleo-atoll complex in Kyushu, Japan: a unique community associated with Tethyan fusulines and corals. Proc. Japan Acad. 82 (B), 25–32. Isozaki, Y., 2007. Guadalupian–Lopingian boundary event in mid-Panthalassa: correlation of accreted deep-sea chert and midoceanic atoll carbonates. In: Wong, T.E. (Ed.), Proceedings of the XVth International Congress on Carboniferous and Permian Stratigraphy 2003. Royal Netherlands Academy of Arts and Sciences, Special Publication, Amsterdam, pp. 111–124. Isozaki, Y., Ota, A., 2001. Middle/Upper Permian (Maokouan/Wuchiapingian) boundary in mid-oceanic paleo-atoll limestone in Kamura and Akasaka, Japan. Proc. Japan Acad. 77 (B), 104–109. Isozaki, Y., Ota, A., 2007. Reply to discussion by Ali, J. and Wignall, P.B. (Fusuline biotic turnover across the Guadalupian–Lopimgian (Middle-Upper Permian) boundary in mid-oceanic carbonate buildups: biostratigraphy of accreted limestone in Japan, Journal of Asian Earth Sciences 26, 353–368.). J. Asian Earth Sci. 30, 201–203. Isozaki, Y., Kawahata, H., Ota, A., 2007. A unique carbon isotope record across the Guadalupian–Lopingian (Middle-Upper Permian) boundary in mid-oceanic paleoatoll carbonates: the highproductivity “Kamura event” and its collapse in Panthalassa. Global Planet. Change 55, 21–38. Jin, Y.G., Zhang, J., Shang, Q.H., 1994. Two phases of the endPermian mass extinction. In: Embry, A.F., Beauchamp, B., Glass, D.J. (Eds.), Global Environments and Resources, vol. 17. Canadian Society of Petroleum Geologists Memoir, Pangea, pp. 813–822. Jin, Y.G., Mei, S.L., Wang, W., Wang, X.D., Shen, S.Z., Shang, Q.H., Chen, Z.Q., 1998. On the Lopingian Series of the Permian System. Palaeoworld 9, 1–18. Jin, Y.G., Shen, S.Z., Henderson, C.M., Wang, X.D., Wang, W., Wang, Y., Cao, C.G., Shag, Q.H., 2006. The global stratotype section and point (GSSP) for the base-Wuchiapingian stage and baseLopingian (upper Permian) series. Episodes 29, 253–262. Jones, A.T., Fielding, C.R., 2004. Sedimentological record of the late Paleozoic glaciation in Queensland, Australia. Geology 32, 153–156. Kambe, N., 1963. On the boundary between the Permian and Triassic Systems in Japan with the description of the Permo-Triassic formations at Takachiho-cho, Miyazaki Prefecture in Kyushu and the Skytic fossils contained. Geological Survey of Japan, Report 198, pp. 1–68. Kanmera, K., Nakazawa, K., 1973. Permian-Triassic relationships and faunal changes in the eastern Tethys. In: Logan, A., Hills, L.V. (Eds.), The Permian and Triassic Systems and their Mutual Boundary, vol. 2. Canadian Society of Petroleum Geologists Memoir, pp. 100–119. Katz, M.E., Wright, J.D., Miller, K.G., Cramer, B.S., Fennel, K., Falkowski, P.G., 2005. Biological overprint of the geological carbon cycle. Marine Geol. 217, 323–338. 30 Y. Isozaki et al. / Palaeoworld 16 (2007) 16–30 Koike, T., 1996. The first occurrence of Griesbachian conodonts in Japan. Trans. Proc. Palaeontol. Soc. Jpn. New Ser. 181, 337–346. Korte, C., Jasper, T., Kozur, H.W., Veizer, J., 2005. ␦18 O and ␦13 Ccarb of Permian brachiopods: a record of seawater evolution and continental glaciation. Palaeogeogr. Palaeoclimatol. Palaeoecol. 224, 333–351. Leven, E.J., 1996. The Midian stage of the Permian and its boundary. Stratigr. Geol. Correlat. 4, 540–551. Mei, S.L., Wardlaw, B.R., 1996. On the Permian conodont lianshanensis-bitteri Zone and related problems. In: Wang, H.Z., Wang, X.L. (Eds.), Centennal Memorial Volume of Prof. Sun Yunzhu: Palaeontology and Stratigraphy. China University of Geoscience Press, Wuhan, pp. 130–140. Murata, K., Goto, H., Hada, S., 2003. Late Permian fusulinids yielded in limestone blocks in the Jurassic accretionary complex of the Sambosan Terrane in the Kamura area, Southwest Japan. Bull. Kobe Women’s Univ. 36, 49–62 (in Japanese, with English abstract). Musashi, M., Isozaki, Y., Koike, T., Kreulen, R., 2001. Stable carbon isotope signature in mid-Panthalassa shallow-water carbonates across the Permo-Triassic boundary: evidence for 13 C-depleted ocean. Earth Planet. Sci. Lett. 196, 9–20. Musashi, M., Isozaki, Y., Koike, T., Kreulen, R., 2007. Carbon isotope study on mid-Panthalassa shallow-water limestone across the Permo-Triassic boundary: reassessment. In: Wong, T.E. (Ed.), Proceedings of the XVth International Congress on Carboniferous and Permian Stratigraphy 2003. Royal Netherlands Academy of Arts and Sciences, Special Publication, Amsterdam, pp. 131–138. Ota, A., Isozaki, Y., 2006. Fusuline biotic turnover across the Guadalupian–Lopingian (Middle-Upper Permian) boundary in mid-oceanic carbonate buildups: biostratigraphy of accreted limestone in Japan. J. Asian Earth Sci. 26, 353–368. Palfy, J., Demeny, A., Haas, J., Hetenyi, M., Orchard, M.J., Veto, I., 2001. Carbon isotope anomaly and other geochemical changes at the Triassic–Jurassic boundary from a marine section in Hungary. Geology 29, 1047–1050. Pan, H.Z., Erwin, D.H., 1994. Gastropod diversity patterns in South China during the Chihsia–Ladinian and their mass extinction. In: Jin, Y.G., Utting, J., Wardlaw, B.R., (Eds.), Permian Stratigraphy, Environments and Resources, vol. 1, Palaeontology and Stratigraphy. Palaeoworld 4, 249–262. Payne, J.L., Lehrmann, D.J., Wei, J., Orchard, M.J., Schrag, D.P., Knoll, A.H., 2004. Large perturbations of the carbon cycle during recovery from the end-Permian mass extinction. Science 305, 506–509. Saltzman, M.R., 2005. Phosphorous, nitrogen, and redox evolution of the Paleozoic oceans. Geology 33, 573–576. Sano, H., Nakashima, K., 1997. Lowermost Triassic (Griesbachian) microbial bindstone–cementstone facies, Southwest Japan. Facies 36, 1–24. Scholle, P.A., 1995. Carbon and sulfur isotope stratigraphy of the Permian and adjacent intervals. In: Scholle, P.A., Peryt, T.M., Ulmer-Scholle, D.S. (Eds.), The Permian of Northern Pangea, 1: Paleogeography, Paleoclimates, Stratigraphy. Springer-Verlag, New York, pp. 167–185. Shao, L., Zhang, P., Dou, J., Shen, S., 2000. Carbon isotope compositions of the Late Permian carbonate rocks in southern China; their variations between the Wujiaping and Changxing formations. Palaeogeogr. Palaeoclimatol. Palaeoecol. 161, 179–192. Shen, S.Z., Shi, G.R., 2002. Paleobiogeographical extinction patterns of Permian brachiopods in the Asian-western Pacific region. Paleobiology 28, 449–463. Stanley, S.M., Yang, X., 1994. A double mass extinction at the end of the Paleozoic Era. Science 266, 1340–1344. Suzuki, A., Kawahata, H., Tanimoto, Y., Tsukamoto, H., Gupta, L.P., Yukino, I., 2000. Skeletal isotopic record of a Porites coral during the 1998 mass bleaching event. Geochem. J. 34, 321–329. Tong, J.N., Yin, H.F., Zhang, K.X., 1999. Permian and Triassic sequence stratigraphy and sea level changes of eastern Yangtze Platform. J. China Univ. Geosci. 10, 161–169. Toriyama, R., 1967. Fusulinacean zones of Japan. Memoir of the Faculty of Science, Kyushu University, Ser. D 18, 35–260. Veizer, J., Ala, D., Azmy, K., Bruckschen, P., Buhl, D., Bruhm, F., Carden, G.A.F., Diener, A., Ebneth, S., Godderis, Y., Jasper, T., Korte, C., Pawellek, F., Podlaha, O.G., Strauss, H., 1999. 87 Sr/86 Sr, ␦13 Ccarb and ␦18 Ocarb evolution of Phanerozoic seawater. Chem. Geol. 161, 59–88. Watanabe, K., Kanmera, K., Nakashima, K., 1979. Conodont biostratigraphy in the Kamura limestone (Triassic), Takachiho-cho, Nishiusuki-gun, Miyazaki prefecture. In: Koike, T., Igo, H. (Eds.), Biostratigraphy of Permian and Triassic Conodonts and Holothurian Sclerites in Japan. Publ. Commit. Prof. M. Kanuma’s Retir, Tokyo, pp. 127–137 (in Japanense). Wang, X.D., Sugiyama, T., 2000. Diversity and extinction patterns of Permian coral faunas of China. Lethaia 33, 285–294. Wang, W., Cao, C.Q., Wang, Y., 2004. The carbon isotope excursion on GSSP candidate section of Lopingian–Guadalupian boundary. Earth Planet. Sci. Lett. 220, 57–67. Wignall, P.B., 2001. Large igneous provinces and mass extinctions. Earth-Sci. Rev. 53, 1–33. Wilde, G.L., 2002. End Permian; end fusulinaceans. In: Hills, L.V., Henderson, C.M., Bamber, E.W. (Eds.), Carboniferous and Permian of the World. Canadian Society of Petroleum Geologists Memoir 19, pp. 616–629. Wilde, G.L., Rudine, S.F., Lambert, L.L., 1999. Formal designation: Reef Trail Member, Bell Canyon Formation, and its significance for recognition of the Guadalupian–Lopingian boundary. Soc. Econ. Geol. Paleontol. Mineral. Spec. Publicat. 65, 63–83. Yang, X.N., Liu, J.R., Shi, G.J., 2004. Extinction process and patterns of Middle Permian fusulinaceans in southwest China. Lethaia 37, 139–147. Zhou, M.F., Malpas, J., Song, X.Y., Robinson, P.T., Sun, M., Kennedy, A.K., Lesher, C.M., Keays, R.R., 2002. A temporal link between the Emeishan large igneous province (SW China) and the end-Guadalupian mass extinction. Earth Planet. Sci. Lett. 196, 113–122.
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