进入新世纪,科技的发展造就了大数据的爆发式增长,这为基于深度学习方法来研究地质学问题奠定了基础。卷积神经网络已被用于地质填图,但卷积操作关注的是数据空间维度的特征信息,无法建模不同通道维度之间的依赖关系。为了发掘不同通道...进入新世纪,科技的发展造就了大数据的爆发式增长,这为基于深度学习方法来研究地质学问题奠定了基础。卷积神经网络已被用于地质填图,但卷积操作关注的是数据空间维度的特征信息,无法建模不同通道维度之间的依赖关系。为了发掘不同通道的输入数据和特征图之间的关联性,提升智能地质填图的效果,本文在全卷积神经网络Unet中引入通道注意力模块--挤压-激励模块(Squeeze and Excitation Block,SE Block),提出了一种新网络SE-Unet,并将该网络应用于湖南省鲤鱼塘地区的1∶5万智能地质填图。实验结果表明,相比于Unet,SE-Unet智能地质填图的总体精确度由81.58%提高到了83.72%,可视化结果显示,两种原来难以识别的地质单元被大致识别出来。这验证了通道注意力机制能够提升网络的学习和表征能力,也说明了本方法对于提升智能地质填图效果的可行性与有效性。展开更多
The carbonate-hosted Pb–Zn deposits in the Sanjiang metallogenic belt on the Tibetan Plateau are typical of MVT Pb–Zn deposits that form in thrust-fold belts. The Jiamoshan Pb–Zn deposit is located in the Changdu a...The carbonate-hosted Pb–Zn deposits in the Sanjiang metallogenic belt on the Tibetan Plateau are typical of MVT Pb–Zn deposits that form in thrust-fold belts. The Jiamoshan Pb–Zn deposit is located in the Changdu area in the middle part of the Sanjiang belt, and it represents a new style of MVT deposit that was controlled by karst structures in a thrust–fold system. Such a karst-controlled MVT Pb–Zn deposit in thrust settings has not previously been described in detail, and we therefore mapped the geology of the deposit and undertook a detailed study of its genesis. The karst structures that host the Jiamoshan deposit were formed in Triassic limestones along secondary reverse faults, and the orebodies have irregular tubular shapes. The main sulfide minerals are galena, sphalerite, and pyrite that occur in massive and lamellar form. The ore-forming fluids belonged to a Mg2+–Na+–K+–SO2-4–Cl-–F-–NO-3–H2 O system at low temperatures(120–130°C) but with high salinities(19–22% NaCl eq.). We have recognized basinal brine as the source of the ore-forming fluids on the basis of their H–O isotopic compositions(-145‰ to-93‰ for δDV-SMOW and-2.22‰ to 13.00‰ for δ18 Ofluid), the ratios of Cl/Br(14–1196) and Na/Br(16–586) in the hydrothermal fluids, and the C–O isotopic compositions of calcite(-5.0‰ to 3.7‰ for δ13 CV-PDB and 15.1‰ to 22.3‰ for δ18 OV-SMOW). These fluids may have been derived from evaporated seawater trapped in marine strata at depth or from Paleogene–Neogene basins on the surface. The δ34 S values are low in the galena(-3.2‰ to 0.6‰) but high in the barite(27.1‰), indicating that the reduced sulfur came from gypsum in the regional Cenozoic basins and from sulfates in trapped paleo-seawater by bacterial sulfate reduction. The Pb isotopic compositions of the galena samples(18.3270–18.3482 for 206 Pb/204 Pb, 15.6345–15.6390 for 207 Pb/204 Pb, and 38.5503–38.5582 for 208 Pb/204 Pb) are similar to those of the regional Triassic volcanic-arc rocks that formed during the closure of the Paleo-Tethys, indicating these arc rocks were the source of the metals in the deposit. Taking into account our new observations and data, as well as regional Pb–Zn metallogenic processes, we present here a new model for MVT deposits controlled by karst structures in thrust–fold systems.展开更多
Objective Most scholars agreed that the tectonic setting of South China block（SBC）changed from Tethys during the Indosinian to Pacific tectonic regime in the Yanshanian.However,the specific change time for the trans...Objective Most scholars agreed that the tectonic setting of South China block（SBC）changed from Tethys during the Indosinian to Pacific tectonic regime in the Yanshanian.However,the specific change time for the transition is still in debate and the Triassic to Jurassic magmatic activity will provide a clue to better understanding the transition.展开更多
文摘进入新世纪,科技的发展造就了大数据的爆发式增长,这为基于深度学习方法来研究地质学问题奠定了基础。卷积神经网络已被用于地质填图,但卷积操作关注的是数据空间维度的特征信息,无法建模不同通道维度之间的依赖关系。为了发掘不同通道的输入数据和特征图之间的关联性,提升智能地质填图的效果,本文在全卷积神经网络Unet中引入通道注意力模块--挤压-激励模块(Squeeze and Excitation Block,SE Block),提出了一种新网络SE-Unet,并将该网络应用于湖南省鲤鱼塘地区的1∶5万智能地质填图。实验结果表明,相比于Unet,SE-Unet智能地质填图的总体精确度由81.58%提高到了83.72%,可视化结果显示,两种原来难以识别的地质单元被大致识别出来。这验证了通道注意力机制能够提升网络的学习和表征能力,也说明了本方法对于提升智能地质填图效果的可行性与有效性。
基金supported by the National Key Research and Development Program of China(Grant No.2016YFC0600306)the National Natural Science Foundation of China(Grant Nos 41773042,41922022,41773043,41772088,91962105 and 41702082)+1 种基金the independent research project from Key Laboratory of DeepEarth Dynamics of the Ministry of Natural Resources(Grant No.J1901-6)the IGCP-662 program。
文摘The carbonate-hosted Pb–Zn deposits in the Sanjiang metallogenic belt on the Tibetan Plateau are typical of MVT Pb–Zn deposits that form in thrust-fold belts. The Jiamoshan Pb–Zn deposit is located in the Changdu area in the middle part of the Sanjiang belt, and it represents a new style of MVT deposit that was controlled by karst structures in a thrust–fold system. Such a karst-controlled MVT Pb–Zn deposit in thrust settings has not previously been described in detail, and we therefore mapped the geology of the deposit and undertook a detailed study of its genesis. The karst structures that host the Jiamoshan deposit were formed in Triassic limestones along secondary reverse faults, and the orebodies have irregular tubular shapes. The main sulfide minerals are galena, sphalerite, and pyrite that occur in massive and lamellar form. The ore-forming fluids belonged to a Mg2+–Na+–K+–SO2-4–Cl-–F-–NO-3–H2 O system at low temperatures(120–130°C) but with high salinities(19–22% NaCl eq.). We have recognized basinal brine as the source of the ore-forming fluids on the basis of their H–O isotopic compositions(-145‰ to-93‰ for δDV-SMOW and-2.22‰ to 13.00‰ for δ18 Ofluid), the ratios of Cl/Br(14–1196) and Na/Br(16–586) in the hydrothermal fluids, and the C–O isotopic compositions of calcite(-5.0‰ to 3.7‰ for δ13 CV-PDB and 15.1‰ to 22.3‰ for δ18 OV-SMOW). These fluids may have been derived from evaporated seawater trapped in marine strata at depth or from Paleogene–Neogene basins on the surface. The δ34 S values are low in the galena(-3.2‰ to 0.6‰) but high in the barite(27.1‰), indicating that the reduced sulfur came from gypsum in the regional Cenozoic basins and from sulfates in trapped paleo-seawater by bacterial sulfate reduction. The Pb isotopic compositions of the galena samples(18.3270–18.3482 for 206 Pb/204 Pb, 15.6345–15.6390 for 207 Pb/204 Pb, and 38.5503–38.5582 for 208 Pb/204 Pb) are similar to those of the regional Triassic volcanic-arc rocks that formed during the closure of the Paleo-Tethys, indicating these arc rocks were the source of the metals in the deposit. Taking into account our new observations and data, as well as regional Pb–Zn metallogenic processes, we present here a new model for MVT deposits controlled by karst structures in thrust–fold systems.
基金supported by the National Key Research and Development Program of China(grant No.2016YFC0600205)the Geological Survey program of China Geological Survey(grant No.DD20160134,DD20160033)
文摘Objective Most scholars agreed that the tectonic setting of South China block（SBC）changed from Tethys during the Indosinian to Pacific tectonic regime in the Yanshanian.However,the specific change time for the transition is still in debate and the Triassic to Jurassic magmatic activity will provide a clue to better understanding the transition.
