Pub Date : 2024-02-01Epub Date: 2023-04-20DOI: 10.1177/1742271X231164591
Megan Sewell, Samantha Mooney, Erin Cvejic, Kate Stone
Introduction: Adenomyosis is histologically defined by the presence of endometrial glands and stroma in the myometrium. Ultrasound findings of adenomyosis are being redefined to better diagnose adenomyosis pre-operatively.
Methods: A single-centre retrospective study was performed at a regional hospital. The myometrial-cervical ratio was calculated on pre-operative ultrasounds, and histopathology reviewed for each case. Logistic regression was used to estimate the association between the myometrial-cervical ratio and adenomyosis confirmed on histopathology, and the area under the receiver operating characteristic curve was calculated. Comparisons were performed based on the presence of fibroids on ultrasound.
Results: Complete data were available for 136 benign hysterectomies between 1 January 2015 and 31 December 2020. When the myometrial-cervical ratio was treated as a continuous variable in a logistic regression of adenomyosis on histopathology, there was no statistical evidence (χ2(1) < 0.01, p = 0.98) of an association. When cases including fibroids in the myometrial-cervical ratio were excluded, there was a non-significant association between myometrial-cervical ratio and adenomyosis on histopathology (odds ratio = 3.435, 95% confidence interval = 0.964, 12.235; χ2(1) = 3.62, p = 0.057); area under the receiver operating characteristic = 0.637 (95% confidence interval = 0.504, 0.770). The optimal myometrial-cervical ratio cutpoint was 1.875 (95% confidence interval = 1.698, 2.051), which achieved 71.43% sensitivity and 60.00% specificity. There was strong statistical evidence (χ2(1) = 9.02, p = 0.003) that the myometrial-cervical ratio outperformed standard pre-operative ultrasound identification of adenomyosis.
Conclusion: While accuracy remains suboptimal, the myometrial-cervical ratio outperformed standard ultrasound diagnostic features of adenomyosis in a regional setting. The myometrial-cervical ratio may offer a simple imaging measurement for adenomyosis in inexperienced hands when fibroids are absent.
简介子宫腺肌症的组织学定义是子宫内膜腺体和子宫肌层基质的存在。目前正在重新定义子宫腺肌症的超声检查结果,以便在术前更好地诊断子宫腺肌症:方法:在一家地区医院进行了一项单中心回顾性研究。方法:在一家地区医院进行了一项单中心回顾性研究,根据术前超声波检查计算子宫肌层与宫颈的比例,并对每个病例进行组织病理学复查。采用逻辑回归估计子宫肌层-宫颈比率与组织病理学证实的子宫腺肌症之间的关联,并计算接收者操作特征曲线下的面积。根据超声检查是否存在子宫肌瘤进行比较:2015年1月1日至2020年12月31日期间136例良性子宫切除术的完整数据。在对组织病理学上的子宫腺肌症进行逻辑回归时,将子宫肌颈比值作为连续变量处理,没有统计学证据(χ2(1) p = 0.98)表明两者之间存在关联。如果排除子宫肌层-子宫颈比率中包括肌瘤的病例,则子宫肌层-子宫颈比率与组织病理学上的子宫腺肌症之间存在非显著性关联(几率比=3.435,95% 置信区间=0.964, 12.235;χ2(1) = 3.62, p = 0.057);接收者操作特征下面积=0.637(95% 置信区间=0.504, 0.770)。最佳子宫肌层-宫颈比率切点为 1.875(95% 置信区间 = 1.698,2.051),敏感性为 71.43%,特异性为 60.00%。有强有力的统计学证据(χ2(1) = 9.02, p = 0.003)表明,子宫肌层-子宫颈比值优于术前超声鉴定子宫腺肌症的标准值:结论:虽然准确性仍未达到最佳水平,但在地区范围内,子宫肌层与宫颈的比值优于腺肌症的标准超声诊断特征。在没有子宫肌瘤的情况下,子宫肌层与宫颈的比例可为缺乏经验的医生提供子宫腺肌症的简单影像测量方法。
{"title":"The myometrial-cervical ratio: Can a simple sonographic measurement improve diagnosis of adenomyosis in a regional setting?","authors":"Megan Sewell, Samantha Mooney, Erin Cvejic, Kate Stone","doi":"10.1177/1742271X231164591","DOIUrl":"10.1177/1742271X231164591","url":null,"abstract":"<p><strong>Introduction: </strong>Adenomyosis is histologically defined by the presence of endometrial glands and stroma in the myometrium. Ultrasound findings of adenomyosis are being redefined to better diagnose adenomyosis pre-operatively.</p><p><strong>Methods: </strong>A single-centre retrospective study was performed at a regional hospital. The myometrial-cervical ratio was calculated on pre-operative ultrasounds, and histopathology reviewed for each case. Logistic regression was used to estimate the association between the myometrial-cervical ratio and adenomyosis confirmed on histopathology, and the area under the receiver operating characteristic curve was calculated. Comparisons were performed based on the presence of fibroids on ultrasound.</p><p><strong>Results: </strong>Complete data were available for 136 benign hysterectomies between 1 January 2015 and 31 December 2020. When the myometrial-cervical ratio was treated as a continuous variable in a logistic regression of adenomyosis on histopathology, there was no statistical evidence (χ<sup>2</sup>(1) < 0.01, <i>p</i> = 0.98) of an association. When cases including fibroids in the myometrial-cervical ratio were excluded, there was a non-significant association between myometrial-cervical ratio and adenomyosis on histopathology (odds ratio = 3.435, 95% confidence interval = 0.964, 12.235; χ<sup>2</sup>(1) = 3.62, <i>p</i> = 0.057); area under the receiver operating characteristic = 0.637 (95% confidence interval = 0.504, 0.770). The optimal myometrial-cervical ratio cutpoint was 1.875 (95% confidence interval = 1.698, 2.051), which achieved 71.43% sensitivity and 60.00% specificity. There was strong statistical evidence (χ<sup>2</sup>(1) = 9.02, <i>p</i> = 0.003) that the myometrial-cervical ratio outperformed standard pre-operative ultrasound identification of adenomyosis.</p><p><strong>Conclusion: </strong>While accuracy remains suboptimal, the myometrial-cervical ratio outperformed standard ultrasound diagnostic features of adenomyosis in a regional setting. The myometrial-cervical ratio may offer a simple imaging measurement for adenomyosis in inexperienced hands when fibroids are absent.</p>","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"79 1","pages":"19-26"},"PeriodicalIF":4.5,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10836227/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78728826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-25DOI: 10.1017/s0016756824000025
Takeshi Imayama, Dripta Dutta, Keewook Yi
The origins and age distribution of the Himalayan high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic rocks are critical for understanding the pre-Himalayan history. Although the protoliths to the UHP Tso Morari eclogites in Ladakh, NW Himalaya are believed to be the Permian Panjal volcanics, the geochronological evidence is absent. Here, we demonstrate that the protoliths of the UHP Tso Morari Complex formed in a continental rift setting at the Indian margin associated with the northern East Gondwana during the Early Paleozoic. Zircon U–Pb dates from eight gneisses and one garnet amphibolite indicate the Early Paleozoic bimodal magmatism of 493–476 Ma, which could be associated with the separation of South China from North India. Except for arc-related eclogites found in the Nidar ophiolite, the eclogites and amphibolites are rift-related, exhibiting enriched light rare earth elements and high concentrations of incompatible elements, along with evidence for crustal contamination. Our findings support the previously reported diversity in the sources and ages of the protoliths of the Himalayan HP–UHP metamorphic rocks along the orogen.
{"title":"The origin of the ultrahigh-pressure Tso Morari complex, NW Himalaya: implication for early Paleozoic rifting","authors":"Takeshi Imayama, Dripta Dutta, Keewook Yi","doi":"10.1017/s0016756824000025","DOIUrl":"https://doi.org/10.1017/s0016756824000025","url":null,"abstract":"<p>The origins and age distribution of the Himalayan high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic rocks are critical for understanding the pre-Himalayan history. Although the protoliths to the UHP Tso Morari eclogites in Ladakh, NW Himalaya are believed to be the Permian Panjal volcanics, the geochronological evidence is absent. Here, we demonstrate that the protoliths of the UHP Tso Morari Complex formed in a continental rift setting at the Indian margin associated with the northern East Gondwana during the Early Paleozoic. Zircon U–Pb dates from eight gneisses and one garnet amphibolite indicate the Early Paleozoic bimodal magmatism of 493–476 Ma, which could be associated with the separation of South China from North India. Except for arc-related eclogites found in the Nidar ophiolite, the eclogites and amphibolites are rift-related, exhibiting enriched light rare earth elements and high concentrations of incompatible elements, along with evidence for crustal contamination. Our findings support the previously reported diversity in the sources and ages of the protoliths of the Himalayan HP–UHP metamorphic rocks along the orogen.</p>","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"3 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139554338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.1017/s0016756823000833
Kai Wei, Hansheng Cao, Fajin Chen, Zaiyun Wang, Zhihui An, Hanli Huang, Chunqing Chen
The Ediacaran–Cambrian (E-C) transition (∼542–517 Ma) witnessed the rapid evolution of Cambrian animals, which was accompanied by carbon cycling anomalies and a significant increase in the concentration of oxygen in Earth’s atmosphere. The mechanisms stimulating the evolution of complex eukaryotes, however, remain problematic, especially concerning the link between biological evolution and contemporaneous changes in the oceanic environment. In this study, integrated δ13Ccarb–δ13Corg–δ15N compositions were analysed from the YD-4 core samples to understand redox fluctuations and nitrogen cycling of the middle Yangtze Block across the E-C transition. Two negative δ13Ccarb excursions (N1 and N2) and a positive δ13Ccarb excursion (P1) are identified from the studied samples and are supposedly of primary origin. Constrained by of the U-Pb age, biolithology and pattern of isotopic variation, N1, P1 and N2 are comparable to the Basal Cambrian Carbon Isotope Excursion (BACE), Zhujiaqing Carbon Isotope Excursion (ZHUCE) and Shiyantou Carbon Isotope Excursion (SHICE). We interpreted the decreased δ15N values in this study as resulting from intensified atmospheric nitrogen fixation driven by enhanced denitrification associated with expanded marine anoxia, as well as partial ammonium assimilation, while increased δ15N values suggest weakened denitrification associated with an amplified oxic water mass. The temporal coincidence of N1 and N2, with two episodes of negative δ15N excursions, and of P1, with a positive δ15N excursion, suggests that variable oceanic redox conditions and nitrogen bioavailability may have influenced the evolution of the Cambrian eukaryote-dominated community.
{"title":"Fluctuation in redox conditions and the evolution of early Cambrian life constrained by nitrogen isotopes in the middle Yangtze Block, South China","authors":"Kai Wei, Hansheng Cao, Fajin Chen, Zaiyun Wang, Zhihui An, Hanli Huang, Chunqing Chen","doi":"10.1017/s0016756823000833","DOIUrl":"https://doi.org/10.1017/s0016756823000833","url":null,"abstract":"The Ediacaran–Cambrian (E-C) transition (∼542–517 Ma) witnessed the rapid evolution of Cambrian animals, which was accompanied by carbon cycling anomalies and a significant increase in the concentration of oxygen in Earth’s atmosphere. The mechanisms stimulating the evolution of complex eukaryotes, however, remain problematic, especially concerning the link between biological evolution and contemporaneous changes in the oceanic environment. In this study, integrated δ<jats:sup>13</jats:sup>C<jats:sub>carb</jats:sub>–δ<jats:sup>13</jats:sup>C<jats:sub>org</jats:sub>–δ<jats:sup>15</jats:sup>N compositions were analysed from the YD-4 core samples to understand redox fluctuations and nitrogen cycling of the middle Yangtze Block across the E-C transition. Two negative δ<jats:sup>13</jats:sup>C<jats:sub>carb</jats:sub> excursions (N1 and N2) and a positive δ<jats:sup>13</jats:sup>C<jats:sub>carb</jats:sub> excursion (P1) are identified from the studied samples and are supposedly of primary origin. Constrained by of the U-Pb age, biolithology and pattern of isotopic variation, N1, P1 and N2 are comparable to the Basal Cambrian Carbon Isotope Excursion (BACE), Zhujiaqing Carbon Isotope Excursion (ZHUCE) and Shiyantou Carbon Isotope Excursion (SHICE). We interpreted the decreased δ<jats:sup>15</jats:sup>N values in this study as resulting from intensified atmospheric nitrogen fixation driven by enhanced denitrification associated with expanded marine anoxia, as well as partial ammonium assimilation, while increased δ<jats:sup>15</jats:sup>N values suggest weakened denitrification associated with an amplified oxic water mass. The temporal coincidence of N1 and N2, with two episodes of negative δ<jats:sup>15</jats:sup>N excursions, and of P1, with a positive δ<jats:sup>15</jats:sup>N excursion, suggests that variable oceanic redox conditions and nitrogen bioavailability may have influenced the evolution of the Cambrian eukaryote-dominated community.","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"6 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139495977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-10DOI: 10.1017/s001675682300078x
Nuo Zhang, Zhenghong Liu, Zhongyuan Xu, Gang Li, Xiaojie Dong, Jin Liu, Wenqing Li
Various magmatisms during the subduction-collision process are crucial to reveal the long-term tectonic evolution of the eastern Central Asian Orogenic Belt. In this paper, we present major and trace elements of whole-rock, zircon U-Pb dating and Hf isotope of the Shanmen pluton. Results imply that the Shanmen pluton consists of quartz diorite and mylonitic granite, with zircon U-Pb ages of 263.7–259.6 Ma. The studied quartz diorite contains high Sr/Y (51.19–90.87) and (La/Yb)N (7.82–13.62) ratios, and belongs to adakitic rocks. Coupled with the positive εHf(t) values of +5.71 to +12.8 with no obvious Eu anomaly, we propose that quartz diorite is the product of the interaction between different degrees of slab melt and the overlying mantle wedge. In contrast, the mylonitic granite has lower MgO (0.28 wt% – 0.47 wt%) contents and positive εHf(t) values of +7.79 to +10.15, indicating an affinity with I-type granite originated by partial melting of the intermediate-basic lower crust. The geochemical characteristics and lithological assemblages, along with the Permian magmatic rocks in the Changchun-Kaiyuan area displaying arc rocks affinity, propose their formation is related to the southward subduction of the Paleo-Asian Ocean (PAO). Based on this study and previous evidence, we lean towards adopting a middle-late Permian slab break-off model, wherein the PAO did not close until the late Permian.
俯冲碰撞过程中的各种岩浆活动对揭示中亚造山带东部的长期构造演化至关重要。本文介绍了山门岩浆岩的全岩主要元素和痕量元素、锆石U-Pb定年和Hf同位素。结果表明,山门岩浆岩由石英闪长岩和麦饭石花岗岩组成,锆石U-Pb年龄为263.7-259.6 Ma。所研究的石英闪长岩含有较高的Sr/Y(51.19-90.87)和(La/Yb)N(7.82-13.62)比值,属于闪长岩。再加上εHf(t)值为+5.71至+12.8的正值,且无明显的Eu异常,我们认为石英闪长岩是不同程度的板块熔融与上覆地幔楔相互作用的产物。相比之下,麦饭石花岗岩的氧化镁含量较低(0.28 wt% - 0.47 wt%),εHf(t)值为+7.79至+10.15的正值,表明其与中基性下地壳部分熔融而成的I型花岗岩有亲缘关系。长春-开原地区的地球化学特征和岩性组合,以及二叠纪岩浆岩与弧岩的亲缘关系,表明其形成与古亚洲洋(PAO)向南俯冲有关。根据这项研究和以往的证据,我们倾向于采用二叠纪中晚期板块断裂的模式,即 PAO 直到二叠纪晚期才关闭。
{"title":"Tectonic evolution of the Middle-Late Permian orogenic belt in the eastern part of the CAOB: Implications from the magmatism in the Changchun-Kaiyuan area","authors":"Nuo Zhang, Zhenghong Liu, Zhongyuan Xu, Gang Li, Xiaojie Dong, Jin Liu, Wenqing Li","doi":"10.1017/s001675682300078x","DOIUrl":"https://doi.org/10.1017/s001675682300078x","url":null,"abstract":"<p>Various magmatisms during the subduction-collision process are crucial to reveal the long-term tectonic evolution of the eastern Central Asian Orogenic Belt. In this paper, we present major and trace elements of whole-rock, zircon U-Pb dating and Hf isotope of the Shanmen pluton. Results imply that the Shanmen pluton consists of quartz diorite and mylonitic granite, with zircon U-Pb ages of 263.7–259.6 Ma. The studied quartz diorite contains high Sr/Y (51.19–90.87) and (La/Yb)<span>N</span> (7.82–13.62) ratios, and belongs to adakitic rocks. Coupled with the positive ε<span>Hf</span>(t) values of +5.71 to +12.8 with no obvious Eu anomaly, we propose that quartz diorite is the product of the interaction between different degrees of slab melt and the overlying mantle wedge. In contrast, the mylonitic granite has lower MgO (0.28 wt% – 0.47 wt%) contents and positive ε<span>Hf</span>(t) values of +7.79 to +10.15, indicating an affinity with I-type granite originated by partial melting of the intermediate-basic lower crust. The geochemical characteristics and lithological assemblages, along with the Permian magmatic rocks in the Changchun-Kaiyuan area displaying arc rocks affinity, propose their formation is related to the southward subduction of the Paleo-Asian Ocean (PAO). Based on this study and previous evidence, we lean towards adopting a middle-late Permian slab break-off model, wherein the PAO did not close until the late Permian.</p>","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"224 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139413263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-10DOI: 10.1017/s0016756823000791
Srinjoy Datta, Amiya K. Samal, Sayandeep Banerjee, Rajesh K. Srivastava
Mafic dykes are typically emplaced through primary hydraulic fracturing of undeformed crust or may make use of pre-existing crustal inhomogeneities, representing the plumbing systems of a large igneous province. The Eastern Dharwar Craton has dense exposures of several generations of Paleoproterozoic mafic dyke swarms ranging from ca. 2.37 Ga to ca. 1.79 Ga. Herein, using anisotropy of magnetic susceptibility fabric data of mafic dykes and associated host granites, the emplacement systematics of the NW- to W-trending ca. 2.21 Ga Anantapur–Kunigal dyke swarm, displaying a radiating geometry, have been studied to understand magma flow dynamics. A low-angle relationship between the silicate and opaque fabrics and good correlation with magnetic lineation, identified via petrographic studies and shape preferred orientation analyses of multiple oriented thin sections, suggest a primary flow-related magnetic anisotropy for the studied dyke samples. The classic subparallel relationship between the trend of the dyke planes and magnetic fabric of the associated host granites suggests that the radiating geometry of the ca. 2.21 Ga dyke swarm was supported by a favourable pre-existing structural grain of the country rock. We interpret the magma for the studied dyke swarm was fed laterally from a distant plume. It was emplaced as laterally propagating primary dyke fractures as well as injected into the pre-existing subparallel crustal inhomogeneities. Corroborating all these inferences, a detailed emplacement model for ca. 2.21 Ga Anantapur–Kunigal dyke swarm is also proposed.
岩浆岩堤通常是通过未变形地壳的原生水力断裂而形成的,也可能是利用了预先存在的地壳不均匀性,代表了一个大型火成岩矿带的管道系统。东达尔瓦克拉通密集出露了从约 2.37 Ga 到约 1.79 Ga 的几代古新生代岩浆岩堤群。在此,利用岩浆岩堤和相关主花岗岩的磁感应强度各向异性结构数据,研究了约2.21 Ga的Anantapur-Kunigal岩浆岩堤群的NW-W走向的置换系统学,该岩浆岩堤群显示出放射状的几何形状,以了解岩浆流动动力学。硅酸盐和不透明结构之间的低角度关系以及与磁力线的良好相关性(通过岩石学研究和多个定向薄切片的形状优选取向分析确定)表明,所研究的堤坝样本存在与流动相关的主要磁各向异性。堤坝平面的趋势与相关主花岗岩的磁性结构之间典型的近平行关系表明,约 2.21 Ga 的堤坝群的辐射几何形状是由其磁性结构决定的。2.21Ga的堤坝群的放射状几何形状是由原生岩的有利结构纹理支撑的。我们的解释是,所研究的堤坝群的岩浆是从一个遥远的羽流中横向注入的。岩浆以横向扩展的原生堤裂缝形式喷出,并注入到预先存在的次平行地壳不均匀性中。与所有这些推论相印证的是,约 2.21 Ga 的阿南塔普尔-金伯利岩的详细成岩模式。2.21Ga的阿南塔普尔-库尼加尔堤坝群的详细成岩模型。
{"title":"Contextual relationship between mechanical heterogeneity and dyking: constraints from magma emplacement dynamics of the ca. 2.21 Ga Anantapur–Kunigal mafic dyke swarm, Dharwar Craton, India","authors":"Srinjoy Datta, Amiya K. Samal, Sayandeep Banerjee, Rajesh K. Srivastava","doi":"10.1017/s0016756823000791","DOIUrl":"https://doi.org/10.1017/s0016756823000791","url":null,"abstract":"<p>Mafic dykes are typically emplaced through primary hydraulic fracturing of undeformed crust or may make use of pre-existing crustal inhomogeneities, representing the plumbing systems of a large igneous province. The Eastern Dharwar Craton has dense exposures of several generations of Paleoproterozoic mafic dyke swarms ranging from ca. 2.37 Ga to ca. 1.79 Ga. Herein, using anisotropy of magnetic susceptibility fabric data of mafic dykes and associated host granites, the emplacement systematics of the NW- to W-trending ca. 2.21 Ga Anantapur–Kunigal dyke swarm, displaying a radiating geometry, have been studied to understand magma flow dynamics. A low-angle relationship between the silicate and opaque fabrics and good correlation with magnetic lineation, identified via petrographic studies and shape preferred orientation analyses of multiple oriented thin sections, suggest a primary flow-related magnetic anisotropy for the studied dyke samples. The classic subparallel relationship between the trend of the dyke planes and magnetic fabric of the associated host granites suggests that the radiating geometry of the ca. 2.21 Ga dyke swarm was supported by a favourable pre-existing structural grain of the country rock. We interpret the magma for the studied dyke swarm was fed laterally from a distant plume. It was emplaced as laterally propagating primary dyke fractures as well as injected into the pre-existing subparallel crustal inhomogeneities. Corroborating all these inferences, a detailed emplacement model for ca. 2.21 Ga Anantapur–Kunigal dyke swarm is also proposed.</p>","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"39 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139413264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The traces left by earthquakes in the unlithified sediments, recorded as soft-sediment deformation structures (SSDS), are well reconstructed as palaeo-seismic signals, while the origin of SSDS, seismic vs. Aseismic, is challenging. The present study discusses the origin of SSDS and its implications on palaeoceanography and sediment architecture. In the Middle Jurassic succession of Spiti Himalayan region in India, the topmost part of the Ferruginous Oolitic Formation (FOF) consists of four layers of SSDS and is underlain by the lower member of the Spiti Formation (SF). The sedimentary facies analysis documents the palaeogeographic shift from the middle shelf (carbonate-shale repository: FOF) to the outer shelf (black shale: lower member of SF). The SSDS layers, exhibiting load casts, ball and pillow structures, indicate gravitational instability, while syn-sedimentary faults and insitu breccia are the results of brittle deformation. The dominance of storms in depositional sites often argues for a possible triggering agent for SSDS. Therefore, it was necessary to distinguish between seismic vs. aseismic triggering agents. The lateral continuity, vertical repetition, confinement of SSDS at the top part of FOF and sharp change of facies assemblage indicate seismicity-induced syn-sediment deformation, i.e. seismite. The transition from middle shelf to outer shelf at the onset of seismite indicates that seismic impact possibly caused the rapid subsidence, resulting in the palaeogeographic shift. The rapid transgression is recorded as carbonate-shale repository to anoxic black shale. This study highlights the importance of sedimentological analysis to distinguish the seismite and its implications on palaeogeographic evolution and sedimentary architecture.
{"title":"Linking the impact of seismicity on palaeogeographic evolution and sedimentary architecture: A case study from Middle Jurassic succession of Spiti Himalaya","authors":"Sabyasachi Mandal, Abha Singh, Santanu Banerjee, Premraj Uddandam, Ranveer Singh Negi","doi":"10.1017/s0016756823000778","DOIUrl":"https://doi.org/10.1017/s0016756823000778","url":null,"abstract":"<p>The traces left by earthquakes in the unlithified sediments, recorded as soft-sediment deformation structures (SSDS), are well reconstructed as palaeo-seismic signals, while the origin of SSDS, seismic vs. Aseismic, is challenging. The present study discusses the origin of SSDS and its implications on palaeoceanography and sediment architecture. In the Middle Jurassic succession of Spiti Himalayan region in India, the topmost part of the Ferruginous Oolitic Formation (FOF) consists of four layers of SSDS and is underlain by the lower member of the Spiti Formation (SF). The sedimentary facies analysis documents the palaeogeographic shift from the middle shelf (carbonate-shale repository: FOF) to the outer shelf (black shale: lower member of SF). The SSDS layers, exhibiting load casts, ball and pillow structures, indicate gravitational instability, while syn-sedimentary faults and insitu breccia are the results of brittle deformation. The dominance of storms in depositional sites often argues for a possible triggering agent for SSDS. Therefore, it was necessary to distinguish between seismic vs. aseismic triggering agents. The lateral continuity, vertical repetition, confinement of SSDS at the top part of FOF and sharp change of facies assemblage indicate seismicity-induced syn-sediment deformation, i.e. seismite. The transition from middle shelf to outer shelf at the onset of seismite indicates that seismic impact possibly caused the rapid subsidence, resulting in the palaeogeographic shift. The rapid transgression is recorded as carbonate-shale repository to anoxic black shale. This study highlights the importance of sedimentological analysis to distinguish the seismite and its implications on palaeogeographic evolution and sedimentary architecture.</p>","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"4 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139083271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-02DOI: 10.1017/s0016756823000808
Daniel Kwayisi, Emmanuel Nyavor, Elikplim Abla Dzikunoo, Iris Ekua Mensimah Fynn, Jacob Kutu, Prosper M Nude
The study presents detailed petrographical, geophysical, structural and geochemical data of the internal nappes zone to establish the deformational history, origin and tectonic setting and constrain the crustal growth and evolution of the active margin of the Dahomeyide belt. Two main lithological units, (i) deformed meta-granitoids (migmatites and gneisses) and (ii) undeformed granitoids, dominate the internal nappes zone. The granitoids are generally I-type, metaluminous to weakly peraluminous, low-K tholeiite to high-K calc-alkaline and of tonalite, granodiorite and granite affinity. The overall trace element patterns of the studied granitoids characterized by the enriched LILE and depleted HFS, with negative peaks of Nb-Ta, Sr, P and Ti, are indications of arc-related magmatism. Structural analysis reveals four deformation phases (D1-D4). D1 represents Northwest-Southeast (NW-SE) Pan African shortening associated with a continent-continent collision, resulting in westward nappe stacking. Progressive NW-SE shortening resulted in D2 and D3 top-to-the-NW dextral and sinistral thrusting events during the Pan-African orogeny. D4 is an extensional event likely associated with the orogenic collapse phase. The gneisses and migmatites, with dominant axial planar foliations, point to their formation in a collisional setting or influence by the Pan-African collisional processes. Continental-arc signatures in these rocks imply continental subduction during their protolith formation. The intrusive granitoid and pegmatite are undeformed, meaning late- to post-orogenic emplacement. These findings suggest that the internal nappes zone archived the subduction-collision and post-collisional phase of the Pan-African orogeny and recorded large-scale migmatization and granitoid emplacement due to partial melting of thickened lower crust between Mid-Cryogenian and late Ediacaran.
该研究提供了内页岩带的详细岩相学、地球物理、结构和地球化学数据,以确定其变形历史、起源和构造环境,并对达霍迈德带活动边缘的地壳增长和演化进行约束。内页岩带主要有两个岩性单元:(i) 变形元花岗岩(偏闪长岩和片麻岩);(ii) 未变形花岗岩。这些花岗岩一般为 I 型,含金属铝至弱过铝,从低 K 托来岩到高 K 钙碱性岩,与英安岩、花岗闪长岩和花岗岩有亲缘关系。所研究花岗岩的总体微量元素形态特征为富集的 LILE 和贫化的 HFS,以及 Nb-Ta、Sr、P 和 Ti 的负峰值,这些都是与弧有关的岩浆活动的迹象。结构分析显示了四个变形阶段(D1-D4)。D1 代表西北-东南(NW-SE)泛非缩短,与大陆-大陆碰撞有关,导致向西的岩层堆积。在泛非造山运动中,西北-东南逐渐缩短导致了 D2 和 D3 自上而下向西北的右旋和正弦推力事件。D4 是一个延伸事件,很可能与造山运动的塌陷阶段有关。片麻岩和偏闪长岩具有主要的轴向平面叶理,表明它们是在碰撞环境中形成的,或受到泛非碰撞过程的影响。这些岩石中的大陆弧特征意味着在其原岩形成过程中发生了大陆俯冲。侵入的花岗岩和伟晶岩没有变形,这意味着是晚期到成因后形成的。这些发现表明,内部褶皱带记录了泛非造山运动的俯冲-碰撞和后碰撞阶段,并记录了在中白垩世至晚埃迪加拉纪期间,由于增厚的下地壳部分熔化而导致的大规模岩浆移行和花岗岩喷出。
{"title":"Cryogenian-Ediacaran crustal growth and evolution of the active margin of the Dahomeyide belt, Ghana","authors":"Daniel Kwayisi, Emmanuel Nyavor, Elikplim Abla Dzikunoo, Iris Ekua Mensimah Fynn, Jacob Kutu, Prosper M Nude","doi":"10.1017/s0016756823000808","DOIUrl":"https://doi.org/10.1017/s0016756823000808","url":null,"abstract":"<p>The study presents detailed petrographical, geophysical, structural and geochemical data of the internal nappes zone to establish the deformational history, origin and tectonic setting and constrain the crustal growth and evolution of the active margin of the Dahomeyide belt. Two main lithological units, (i) deformed meta-granitoids (migmatites and gneisses) and (ii) undeformed granitoids, dominate the internal nappes zone. The granitoids are generally I-type, metaluminous to weakly peraluminous, low-K tholeiite to high-K calc-alkaline and of tonalite, granodiorite and granite affinity. The overall trace element patterns of the studied granitoids characterized by the enriched LILE and depleted HFS, with negative peaks of Nb-Ta, Sr, P and Ti, are indications of arc-related magmatism. Structural analysis reveals four deformation phases (D<span>1</span>-D<span>4</span>). D<span>1</span> represents Northwest-Southeast (NW-SE) Pan African shortening associated with a continent-continent collision, resulting in westward nappe stacking. Progressive NW-SE shortening resulted in D<span>2</span> and D<span>3</span> top-to-the-NW dextral and sinistral thrusting events during the Pan-African orogeny. D<span>4</span> is an extensional event likely associated with the orogenic collapse phase. The gneisses and migmatites, with dominant axial planar foliations, point to their formation in a collisional setting or influence by the Pan-African collisional processes. Continental-arc signatures in these rocks imply continental subduction during their protolith formation. The intrusive granitoid and pegmatite are undeformed, meaning late- to post-orogenic emplacement. These findings suggest that the internal nappes zone archived the subduction-collision and post-collisional phase of the Pan-African orogeny and recorded large-scale migmatization and granitoid emplacement due to partial melting of thickened lower crust between Mid-Cryogenian and late Ediacaran.</p>","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"203 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139078668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Blackcurrant is available as a traditional medicine in Europe. However, the detailed effects of blackcurrant on the human gut microbiota remain unknown. In this study, we investigated the prebiotic effects of a blackcurrant extract using a human fecal culture model in six healthy subjects. Feces were individually inoculated into a medium with or without the blackcurrant extract and then fermented for 48 hr under anaerobic conditions. The results obtained from analysis of samples from the fermented medium demonstrated that after 48 hr of fermentation, the pH of the medium with the blackcurrant extract was significantly decreased (control, 6.62 ± 0.20; blackcurrant extract, 6.41 ± 0.33; p=0.0312). A 16S rRNA gene sequencing analysis of the microbiota of the fermented medium showed a significant increase in the relative abundance of Bifidobacteriaceae. In measuring the concentrations of putrefactive components in the fermented medium, we found that the blackcurrant extract significantly reduced ammonia levels and displayed a tendency toward reduced indole levels. Our results suggest that blackcurrant extract could be a potential ingredient for relief of putrefactive components in the gut.
{"title":"Effects of blackcurrant extract on indole and ammonia productions in an <i>in vitro</i> human fecal culture model.","authors":"Nanami Ishiguro, Takayuki Hayashi, Miho Okayama, Taiki Yamaguchi, Mamiko Kohno, Hirosato Kawakami, Tohru Mitsunaga, Kohei Nakamura, Mizuho Inagaki","doi":"10.12938/bmfh.2022-094","DOIUrl":"10.12938/bmfh.2022-094","url":null,"abstract":"<p><p>Blackcurrant is available as a traditional medicine in Europe. However, the detailed effects of blackcurrant on the human gut microbiota remain unknown. In this study, we investigated the prebiotic effects of a blackcurrant extract using a human fecal culture model in six healthy subjects. Feces were individually inoculated into a medium with or without the blackcurrant extract and then fermented for 48 hr under anaerobic conditions. The results obtained from analysis of samples from the fermented medium demonstrated that after 48 hr of fermentation, the pH of the medium with the blackcurrant extract was significantly decreased (control, 6.62 ± 0.20; blackcurrant extract, 6.41 ± 0.33; p=0.0312). A 16S rRNA gene sequencing analysis of the microbiota of the fermented medium showed a significant increase in the relative abundance of <i>Bifidobacteriacea</i>e. In measuring the concentrations of putrefactive components in the fermented medium, we found that the blackcurrant extract significantly reduced ammonia levels and displayed a tendency toward reduced indole levels. Our results suggest that blackcurrant extract could be a potential ingredient for relief of putrefactive components in the gut.</p>","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"117 1","pages":"23-28"},"PeriodicalIF":3.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10767324/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78560846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-21DOI: 10.1101/2023.06.23.546264
Jessica N Wilson, Kristina A Kigerl, Michael D Sunshine, Chase E Taylor, Sydney L Speed, Breanna C Rose, Chris M Calulot, Brittany E Dong, Tara R Hawkinson, Harrison A Clarke, Adam D Bachstetter, Christopher M Waters, Ramon C Sun, Phillip G Popovich, Warren J Alilain
Spinal cord injury (SCI) is a devastating condition characterized by impaired motor and sensory function, as well as internal organ pathology and dysfunction. This internal organ dysfunction, particularly gastrointestinal (GI) complications, and neurogenic bowel, can reduce the quality of life of individuals with an SCI and potentially hinder their recovery. The gut microbiome impacts various central nervous system functions and has been linked to a number of health and disease states. An imbalance of the gut microbiome, i.e., gut dysbiosis, contributes to neurological disease and may influence recovery and repair processes after SCI. Here we examine the impact of high cervical SCI on the gut microbiome and find that transient gut dysbiosis with persistent gut pathology develops after SCI. Importantly, probiotic treatment improves gut health and respiratory motor function measured through whole-body plethysmography. Concurrent with these improvements was a systemic decrease in the cytokine tumor necrosis factor-alpha and an increase in neurite sprouting and regenerative potential of neurons. Collectively, these data reveal the gut microbiome as an important therapeutic target to improve visceral organ health and respiratory motor recovery after SCI.
Research highlights: Cervical spinal cord injury (SCI) causes transient gut dysbiosis and persistent gastrointestinal (GI) pathology.Treatment with probiotics after SCI leads to a healthier GI tract and improved respiratory motor recovery.Probiotic treatment decreases systemic tumor necrosis factor-alpha and increases the potential for sprouting and regeneration of neurons after SCI.The gut microbiome is a valid target to improve motor function and secondary visceral health after SCI.
{"title":"Targeting the Microbiome to Improve Gut Health and Breathing Function After Spinal Cord Injury.","authors":"Jessica N Wilson, Kristina A Kigerl, Michael D Sunshine, Chase E Taylor, Sydney L Speed, Breanna C Rose, Chris M Calulot, Brittany E Dong, Tara R Hawkinson, Harrison A Clarke, Adam D Bachstetter, Christopher M Waters, Ramon C Sun, Phillip G Popovich, Warren J Alilain","doi":"10.1101/2023.06.23.546264","DOIUrl":"10.1101/2023.06.23.546264","url":null,"abstract":"<p><p>Spinal cord injury (SCI) is a devastating condition characterized by impaired motor and sensory function, as well as internal organ pathology and dysfunction. This internal organ dysfunction, particularly gastrointestinal (GI) complications, and neurogenic bowel, can reduce the quality of life of individuals with an SCI and potentially hinder their recovery. The gut microbiome impacts various central nervous system functions and has been linked to a number of health and disease states. An imbalance of the gut microbiome, i.e., gut dysbiosis, contributes to neurological disease and may influence recovery and repair processes after SCI. Here we examine the impact of high cervical SCI on the gut microbiome and find that transient gut dysbiosis with persistent gut pathology develops after SCI. Importantly, probiotic treatment improves gut health and respiratory motor function measured through whole-body plethysmography. Concurrent with these improvements was a systemic decrease in the cytokine tumor necrosis factor-alpha and an increase in neurite sprouting and regenerative potential of neurons. Collectively, these data reveal the gut microbiome as an important therapeutic target to improve visceral organ health and respiratory motor recovery after SCI.</p><p><strong>Research highlights: </strong>Cervical spinal cord injury (SCI) causes transient gut dysbiosis and persistent gastrointestinal (GI) pathology.Treatment with probiotics after SCI leads to a healthier GI tract and improved respiratory motor recovery.Probiotic treatment decreases systemic tumor necrosis factor-alpha and increases the potential for sprouting and regeneration of neurons after SCI.The gut microbiome is a valid target to improve motor function and secondary visceral health after SCI.</p>","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10769193/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79188538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-14DOI: 10.1017/s0016756823000754
David J. Went
Field evidence from the northern Cotentin Peninsula and regional data are used to construct a tectono-stratigraphic model for the Ordovician which characterizes basin development in the North Armorican Massif. In La Hague, 15 m of transgressive marine sandstone belongs to the Dapingian age Grès Armoricain Formation which onlaps lower Cambrian, rift-fill deposits via an unconformity. Approximately 450 m of overlying Darriwilian strata are dominated by shallow marine sandstone showing hummocky cross-stratification with subordinate shales containing trace and body fossils. Together, these facies support an interpretation of offshore shallow marine strata overlying a break-up unconformity. Regional analysis indicates the time gap at the unconformity is 20–40 Ma and formed from crustal upwarping, which was greatest in the north of the Armorican Massif. Dapingian strata (Grès Armoricain) thins irregularly to the north (0–94 m), interpreted to reflect passive onlap onto residual relief associated with the uplift and the initiation of thermal subsidence on the margin. The succeeding Darriwilian strata (Schistes de Beaumont to Grès de May) conversely display a steady thickening (161–623 m) to the north, the stratal patterns suggesting that from the Darriwilian onwards, the ocean basin to the north was firmly established as the main locus of subsidence on the continental margin.
利用科坦丁半岛北部的野外证据和区域资料,建立了北北美洲地块奥陶系盆地发育的构造-地层模型。在La Hague, 15 m海侵海相砂岩属于大坪期gr Armoricain组,该组通过不整合叠加下寒武统裂谷充填矿床。上覆约450 m的达里威廉地层以浅海相砂岩为主,呈丘状交叉层状,下部页岩含有微量化石和体化石。总之,这些相支持了一种近海浅海地层上覆破碎不整合的解释。区域分析表明,不整合的时间间隔为20 ~ 40 Ma,是由地壳隆升形成的,在美洲地块北部隆升幅度最大。大平纪地层(gr s Armoricain)向北(0-94 m)不规则变薄,反映了与隆升和边缘热沉降开始相关的残余隆起的被动上覆。随后的Darriwilian地层(Schistes de Beaumont至gr de May)相反地向北加厚(161-623 m),地层格局表明,从Darriwilian开始,北部的海洋盆地被牢固地确立为大陆边缘的主要沉降点。
{"title":"Ordovician sedimentation and basin development in the North Armorican Massif, NW France: Field evidence from the northern Cotentin Peninsula","authors":"David J. Went","doi":"10.1017/s0016756823000754","DOIUrl":"https://doi.org/10.1017/s0016756823000754","url":null,"abstract":"<p>Field evidence from the northern Cotentin Peninsula and regional data are used to construct a tectono-stratigraphic model for the Ordovician which characterizes basin development in the North Armorican Massif. In La Hague, 15 m of transgressive marine sandstone belongs to the Dapingian age Grès Armoricain Formation which onlaps lower Cambrian, rift-fill deposits via an unconformity. Approximately 450 m of overlying Darriwilian strata are dominated by shallow marine sandstone showing hummocky cross-stratification with subordinate shales containing trace and body fossils. Together, these facies support an interpretation of offshore shallow marine strata overlying a break-up unconformity. Regional analysis indicates the time gap at the unconformity is 20–40 Ma and formed from crustal upwarping, which was greatest in the north of the Armorican Massif. Dapingian strata (Grès Armoricain) thins irregularly to the north (0–94 m), interpreted to reflect passive onlap onto residual relief associated with the uplift and the initiation of thermal subsidence on the margin. The succeeding Darriwilian strata (Schistes de Beaumont to Grès de May) conversely display a steady thickening (161–623 m) to the north, the stratal patterns suggesting that from the Darriwilian onwards, the ocean basin to the north was firmly established as the main locus of subsidence on the continental margin.</p>","PeriodicalId":12612,"journal":{"name":"Geological Magazine","volume":"22 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138628985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}