Island Arc最新文献_第10页

Multistage zircon growth recording polyphase metamorphic evolution caused by pulsed granitoid intrusions into a low-P/T type metamorphic belt: P–T–D–t evolution of migmatites in the Ryoke belt, southwest Japan 记录脉冲花岗岩类侵入低P/T型变质带引起的多相变质演化的多阶段锆石生长：日本西南部Ryoke带混合岩的P–T–D–T演化

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-07-17 DOI: 10.1111/iar.12454

Tetsuo Kawakami, Tomoe Ichino, Keiichi Kazuratachi, Shuhei Sakata, Kota Takatsuka

{"title":"Multistage zircon growth recording polyphase metamorphic evolution caused by pulsed granitoid intrusions into a low-P/T type metamorphic belt: P–T–D–t evolution of migmatites in the Ryoke belt, southwest Japan","authors":"Tetsuo Kawakami, Tomoe Ichino, Keiichi Kazuratachi, Shuhei Sakata, Kota Takatsuka","doi":"10.1111/iar.12454","DOIUrl":"10.1111/iar.12454","url":null,"abstract":"We report contrasting pressure–temperature–time (P–T–t) paths of migmatites developed in the highest-grade metamorphic zone (Grt–Crd zone) and the contact metamorphic zone (Crd–Kfs zone) of the Mikawa area, Ryoke belt, southwest Japan to discuss the complex P–T–D–t evolution of the middle crust that experienced pulsed granitoid intrusions. In the Grt–Crd zone, sillimanite-grade high-T metamorphic condition prevailed from ca. 97 to 87 Ma, followed by cooling to ~500 °C, ~4 kbar. The intrusion of gneissose granitoids below the Grt–Crd zone isobarically reheated the Grt–Crd zone rocks again to the sillimanite-grade high-T condition at ca. 84 Ma. This was followed by ca. 71–70 Ma contact metamorphism. Ductile deformation that formed and folded the foliation of migmatites started before ca. 89 Ma and continued at least until ca. 84 Ma in the Grt–Crd zone. On the other hand, ca. 74 Ma age of the Crd–Kfs zone migmatite developed around the Inagawa Granodiorite in addition to ca. 70 Ma age of a syn-tectonic pegmatite vein revealed that the intrusion of “75–69 Ma granitoids” caused partial melting and locally triggered low-strain ductile deformation in their contact aureoles. Comparison with other areas of the Ryoke belt suggests that plutono-metamorphic evolution of the Mikawa and Aoyama areas are similar with each other in that ca. 80 Ma reheating events (i.e., contact metamorphism) are observed, while absence of separate reheating event postdating peak metamorphism in the Yanai area is a rather uncommon feature in the Ryoke belt.","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":"31 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43734689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Trace-element composition of zircon in Kofu and Tanzawa granitoids, Japan: Quantitative indicator of sediment incorporated in parent magma 日本Kofu和Tanzawa花岗质岩石中锆石的微量元素组成：母岩浆中沉积物的定量指标

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-07-15 DOI: 10.1111/iar.12455

Yusuke Sawaki, Hisashi Asanuma, Shuhei Sakata, Mariko Abe, Takeshi Ohno

{"title":"Trace-element composition of zircon in Kofu and Tanzawa granitoids, Japan: Quantitative indicator of sediment incorporated in parent magma","authors":"Yusuke Sawaki, Hisashi Asanuma, Shuhei Sakata, Mariko Abe, Takeshi Ohno","doi":"10.1111/iar.12455","DOIUrl":"10.1111/iar.12455","url":null,"abstract":"Zircon is one of the most important minerals in geochronologic research. Isotopic ratios and trace elements in zircons are expected to reflect those of their parent magmas. Many geochemical researchers have proposed various discrimination diagrams for zircon to indicate tectonic setting and to identify source rock. Because most detrital zircons accumulated at river mouths are derived primarily from granitoids, the classification of zircon within granitoids is potentially meaningful. In our research, we focused on sediment involvement during granitoid formation and tried to identify trace-element compositions in zircon that are sensitive to variation in sediment incorporation. To accomplish this, we examined trace-element compositions of both the granitoids and the included zircons in the Kofu granitic complex and the Tanzawa tonalitic plutons in Japan. Among the high-field-strength elements (Th, U, Ta, Nb, Hf, and rare earth elements), only Nb and Ta concentrations in the granitoids increased as the rate of sediment contribution increased. However, the zircon did not show such trends in Nb and Ta content. Zircon Y and P contents exhibited a positive correlation, indicating that xenotime substitution occurs to some extent. Because P exists as pentavalent ions in igneous systems, its presence likely affects the concentrations of pentads in zircon. When we divided the Nb and Ta contents by the P content, it became clear that zircon Nb/P and Ta/P ratios increase depending on sediment involvement. While some exceptions exist, we found that zircon Yb/Gd ratios also respond to sediment involvement. Our data further demonstrated that zircons in granitoids with significant sediment incorporation are characterized by low Ce/P contents, which is partly attributable to monazite crystallization before zircon saturation. This study demonstrates that combining these element ratios is useful for indicating sediment incorporation.","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":"31 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43120692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Sanbe volcano: Long-term evolution of an arc magmatic system 桑贝火山：弧岩浆系统的长期演化

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-07-08 DOI: 10.1111/iar.12453

Andreas Auer, Atsushi Kamei, Daisuke Endo

{"title":"Sanbe volcano: Long-term evolution of an arc magmatic system","authors":"Andreas Auer, Atsushi Kamei, Daisuke Endo","doi":"10.1111/iar.12453","DOIUrl":"10.1111/iar.12453","url":null,"abstract":"A suite of samples was studied that represents the major explosive eruptions of Sanbe volcano, SW Japan. We demonstrate how rate of magma flux into the Trans-Crustal Magmatic System (TCMS) presents a major control on the type and style of the subsequently forthcoming eruptions. Erupted products can be separated into two distinct groups. An older group is characterized by highly evolved, high-K, LILE-rich rhyolitic magmas, showing a supressed adakitic trace element signature (otherwise characteristic for the young stratovolcanoes in the SW Japan arc) with low Ca, Sr concentrations and a negative Eu anomaly. In contrast, the younger group (dominantly of andesitic—dacitic composition) displays a strong adakitic trace element signature with characteristic steep REE profiles and high Sr concentrations. An Eu anomaly is generally lacking here. The two groups are also distinct in their petrographic features, with the early group being almost aphyric showing simple log linear crystal size distributions and homogeneous, uniform mineral chemistries. In contrast, products of the younger group show complex crystal size distributions with diverse mineral compositions and abundant disequilibrium features. Our study shows that an initial high melt-production rate allowed dehydration melting of lower crustal rocks leading to the formation of highly evolved K-rich magmas. These magmas intruded into the shallow crust and produced two large Plinian rhyolitic, caldera forming eruptions. Subsequently the primary magma production rate decreased and the lower crust became too refractory for additional dehydration melting by these lower volume magma batches, causing the conventional adakitic magmatism to produced several additional eruptions of smaller magnitude, mainly of Sub-Plinian or Pelean styles.","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":"31 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49616017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Middle Holocene relative sea-level changes and vertical tectonic crustal movements on Shikoku Island near the Nankai Trough, Japan 日本南开海槽附近四国岛中全新世相对海平面变化与垂直构造地壳运动

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-06-29 DOI: 10.1111/iar.12452

Tatsuhiko Yamaguchi, Futoshi Nanayama, Toshimichi Nakanishi, Tomohiro Tsuji, Michiharu Ikeda, Yasuo Kondo, Michiko Miwa, Yohei Hamada

{"title":"Middle Holocene relative sea-level changes and vertical tectonic crustal movements on Shikoku Island near the Nankai Trough, Japan","authors":"Tatsuhiko Yamaguchi, Futoshi Nanayama, Toshimichi Nakanishi, Tomohiro Tsuji, Michiharu Ikeda, Yasuo Kondo, Michiko Miwa, Yohei Hamada","doi":"10.1111/iar.12452","DOIUrl":"10.1111/iar.12452","url":null,"abstract":"The Philippine Sea plate subducts beneath the Eurasia plate at the Nankai Trough, northwestern Pacific, causing crustal deformation, mega-thrust earthquakes, and tsunami events. Shikoku Island, 150 km northwest of the trough, experiences both coseismic and interseismic deformation. Coastal sediments potentially record vertical crustal movements as relative sea level (RSL) changes. We studied sedimentary facies and microfossil ostracodes in core SKM from southwestern Shikoku Island for evidence of middle Holocene tsunami events and deformation. The core sediments included nine event layers corresponding to storm or tsunami events. Using modern analog techniques, we estimated RSLs from the ostracode assemblages of core SKM and 13 other cores from Shikoku Island and the surrounding region. Then, we subtracted RSL changes due to glacio-hydro isostatic adjustment from the estimated RSLs to estimate vertical tectonic movement rates in these cores between 8.6 and 4.7 ka. The inferred RSL changes suggest that the Sukumo site has experienced both uplift and subsidence since 8.6 ka. Before 6.6 ka, rates of tectonic crustal movement were higher than the modern-day rate, and its spatial distribution also differed. After 6.6 ka, tectonic crustal movement showed a similar spatial pattern and occurred at rates close to the modern day interseismic rate. The spatial pattern and rates of tectonic crustal movement could be caused by changes in rupture areas between the Eurasia and the Philippine Sea plates beneath the Shikoku Island and in stress condition of the asthenosphere. Some of the vertical displacements can be explained by the movements of local active faults.","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":"31 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49277730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

An obelisk-shaped granitoid tower at Mt. Jizogadake in the Southern Alps of Japan: A 3-D morphological study 在日本南阿尔卑斯的志佐加达克山的方尖碑状花岗岩塔:三维形态研究

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-06-10 DOI: 10.1111/iar.12449

Masahiro Chigira

{"title":"An obelisk-shaped granitoid tower at Mt. Jizogadake in the Southern Alps of Japan: A 3-D morphological study","authors":"Masahiro Chigira","doi":"10.1111/iar.12449","DOIUrl":"10.1111/iar.12449","url":null,"abstract":"Well-developed tors and associated boulder fields are present in exposed granitoid pluton, but their geomorphological origins have not been fully addressed. Although the tor-like features are commonly attributed to the orthogonal joint system along which weathering proceeds and the weathering materials are removed, the majority of previous studies lack three-dimensional (3-D) morphological observations. One of the well-known granitoid rock towers in Japan, namely, the obelisk at Mt. Jizogadake in the Japanese Southern Alps, was investigated using unmanned air vehicles (UAVs). A 3-D observation of the granitoid obelisk found that it is shaped by columnar joints with an undulation along a long axis and irregularly shaped cross-sections. Because of these features and intersection angles between the rock columns and exposure surfaces, the obelisk exhibits a peculiar morphology appearing as a heap of rock blocks when observed from the ground. The columnar jointing might have occurred in a marginal zone of the granitoid pluton due to faster cooling rates. The 3-D observations also confirmed the columnar joints formation was predated by high-angle, planar joints. The columnar joints divide the rock mass between those planar joints. This may imply that the high-angle joints would have formed probably during cooling under the presence of tectonic and thermal stresses.","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":"31 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62641144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Microbial influences on manganese deposit formation at Yunotaki Fall, Japan 微生物对日本Yunotaki瀑布锰矿形成的影响

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-05-27 DOI: 10.1111/iar.12448

Fumito Shiraishi, Ryoji Chihara, Risa Tanimoto, Kazuya Tanaka, Yoshio Takahashi

{"title":"Microbial influences on manganese deposit formation at Yunotaki Fall, Japan","authors":"Fumito Shiraishi, Ryoji Chihara, Risa Tanimoto, Kazuya Tanaka, Yoshio Takahashi","doi":"10.1111/iar.12448","DOIUrl":"10.1111/iar.12448","url":null,"abstract":"Microorganisms are considered to play an important role in the formation of manganese oxide in natural environments. At Yunotaki Fall in north Japan, manganese-oxidizing bacteria were previously assumed to have oxidized manganese to precipitate birnessite, which relied on oxygen released from algae (i.e., indirect oxidation sensu lato). However, it remained unclear whether larger-scale manganese oxide precipitation was actually occurring under light conditions. This study therefore evaluated the contribution of indirect oxidation using microelectrodes to analyze local water chemistry, in addition to bulk water chemistry and DNA analyses. With the downward flow of hot spring water, pH increases because of CO2 degassing and causes the saturation index of birnessite to increase downstream. Manganese concentrations in the hot spring water decrease downstream even if it was undersaturated in birnessite, suggesting the dominance of manganese oxide deposition by microorganisms. Indeed, the deposit surface was covered by thick microbial mats, and microscopic observations and DNA analysis of the mats indicate the presence of cyanobacteria, eukaryotic algae (green algae), and manganese-oxidizing bacteria. Microelectrode measurements at the surface of a deposit covered with eukaryotic algae showed that pH and O2 concentration profiles are characteristic of oxygenic photosynthesis and aerobic respiration. On the other hand, the light and dark conditions show nearly identical Mn(II) concentration profiles decreasing within the algal mats. These results demonstrate that low bulk pH values in the hot spring water hindered indirect oxidation despite the occurrence of active oxygenic photosynthesis and that direct oxidation by manganese-oxidizing bacteria is considered to dominate in the investigated sample.","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":"31 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41942177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Zircon U–Pb ages of the Higo plutonic complex: Implication for migration of Cretaceous igneous activity in Kyushu, southwest Japan 东古深部杂岩体锆石U-Pb年龄:日本西南部九州地区白垩纪火成岩活动的迁移意义

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-04-20 DOI: 10.1111/iar.12446

Yukiyasu Tsutsumi

引用次数: 1

Relationship among paleosol types, depositional settings, and paleoclimates in Tetori group (Lower Cretaceous, central Japan) 日本中部下白垩统鸟取群古土壤类型、沉积环境与古气候的关系

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-04-11 DOI: 10.1111/iar.12445

Kensuke Kuroshima, Masato Fujita, Yoshihiro Kakizaki, Fumito Shiraishi

{"title":"Relationship among paleosol types, depositional settings, and paleoclimates in Tetori group (Lower Cretaceous, central Japan)","authors":"Kensuke Kuroshima, Masato Fujita, Yoshihiro Kakizaki, Fumito Shiraishi","doi":"10.1111/iar.12445","DOIUrl":"10.1111/iar.12445","url":null,"abstract":"One of the key areas and periods for dinosaur evolution is considered to be Early Cretaceous East Asia, of which paleoclimate, that affected dinosaur diversity, needs to be accurately estimated. This study reconstructed paleoenvironmental information from two paleosol sections of the Lower Cretaceous Tetori Group in Hokuriku province, Japan. Elemental and isotopic compositions indicate that the two sections (Sections K5 and T1) formed under similar mean annual temperature (MAT) and mean annual precipitation (MAP) but exhibit significantly different paleosol colors (red in the Section K5, and gray in the Section T1) and mineralogy of carbonate nodules (dolomite–siderite in the Section K5, and dolomite–calcite in the Section T1). In addition, the oxygen isotopic ratio of carbonate minerals in the Section K5 was significantly low. The differences in sedimentary features and isotopic composition were considered to reflect the differences of seasonal climatic factors (e.g., monsoon) and local settings (e.g., drainage condition) despite the two sections exhibiting similar MAT and MAP. The results of this study suggest that the northeastern margin of East Asia, where the Tetori Group was deposited, had temperate and humid climate with monsoonal contrast in humidity during Aptian to Albian.","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":"31 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46707247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pressure effect on cathodoluminescence emission intensity recorded in metamorphosed detrital zircons of the Sanbagawa schists 压力对三八川片岩变质碎屑锆石阴极发光发射强度的影响

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-04-06 DOI: 10.1111/iar.12444

Yuta Tsuchiya, Kazumasa Aoki, Tetsu Kogiso, Yoshiki Seo, Shogo Aoki, Hirotsugu Nishido

{"title":"Pressure effect on cathodoluminescence emission intensity recorded in metamorphosed detrital zircons of the Sanbagawa schists","authors":"Yuta Tsuchiya, Kazumasa Aoki, Tetsu Kogiso, Yoshiki Seo, Shogo Aoki, Hirotsugu Nishido","doi":"10.1111/iar.12444","DOIUrl":"10.1111/iar.12444","url":null,"abstract":"The cathodoluminescence (CL) emission and spectra analyses were conducted on detrital zircons in the Cretaceous Sanbagawa schists to describe changes in CL properties of zircons associated with metamorphism. In addition, high-pressure (HP) and high-temperature (HT) experiments were conducted on the non-metamorphosed Miocene Ashizuri igneous zircons, and the CL emission intensities obtained from them were compared with those of the Sanbagawa zircons. As a result, as compared to low-grade Sanbagawa zircons, the emission intensities of the high-grade Sanbagawa zircons reduced. The emission intensities produced from the HP-treated Ashizuri zircons, on the other hand, were twice as high as those generated from untreated zircons, but less than half of those generated from HT-treated zircons. Combining our results with previous studies on the temperature influence on zircon CL properties, it indicates that increasing metamorphic pressure decreases the increase in the CL emission intensity of metamorphosed detrital zircons resulting from the increasing temperature. The pressure effect on the emission intensity of zircon during metamorphism might be larger than the temperature effect.","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":"31 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42440920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Santonian-Campanian dinoflagellate cyst biostratigraphy and paleoenvironment of the Krishna-Godavari Basin, India 印度Krishna‐Godavari盆地Santonian‐Campanian甲藻囊生物地层学和古环境

IF 1.5 4区地球科学

Island Arc Pub Date : 2022-03-30 DOI: 10.1111/iar.12443

Ashish K. Mishra, Arun Deo Singh, Vandana Prasad

{"title":"Santonian-Campanian dinoflagellate cyst biostratigraphy and paleoenvironment of the Krishna-Godavari Basin, India","authors":"Ashish K. Mishra, Arun Deo Singh, Vandana Prasad","doi":"10.1111/iar.12443","DOIUrl":"10.1111/iar.12443","url":null,"abstract":"The present study deals with the biostratigraphic framework of Late Cretaceous sediments of the subsurface Well (DNG) “A” (2085–1840 m depth) from the Raghavapuram/Chintalapalli Shale of the Krishna-Godavari Basin and analyzed the palynological assemblage. The recorded palynological assemblage is dominated by marker dinoflagellate cyst viz. Areoligera coronata, Areoligera senonensis, Heterosphaeridium spinaconjunctum, Nelsoniella aceras, Nelsoniella semireticulata, Odontochitina porifera, Xenascus ceratioides, and Xenascus gochtii species. The last occurrence (LO) of significant species of dinoflagellate cysts is considered for the biostratigraphic establishment. On the basis of dinoflagellate cyst biostratigraphy, the examined sequences correspond to the Santonian-Campanian age. The dominance of gonyaulacoid dinoflagellate cysts is interpreted in terms of sea-level fluctuation and other paleoenvironmental signals through this biostratigraphic establishment. The recorded dinoflagellate cysts indicate the outer neritic, cool depositional environment. The sea-level rise, recorded in our study is linked with the transgressive phase during the Late Cretaceous (Santonian-Campanian) period.","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":"31 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41451841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0