中-晚始新世渭河盆地古气候变化的红河组磁化率记录

始新世暖期可为理解现代增温过程和机制提供历史相似型。广泛分布于渭河盆地的红河组为中始新世到晚始新世的滨浅湖相-冲积扇堆积,剖面出露厚度超过330 m,盆地沉积中心钻探厚度大于1000 m,为一套红色的碎屑沉积间化学沉积序列。盆地边缘的红河组沉积物含碳酸盐岩、泥岩、砂岩和少量砾岩,沉积中心以泥质灰岩、泥岩和粉砂岩为主。对蓝田支家沟红河组（时代为46~33 Ma）2910个样品的磁化率测试表明,红河组沉积物磁化率值在0~20×10^-8 m³/kg之间,整体偏低,频率磁化率值也相对较低（0~11%）,与中国西北部新生代红层磁化率总体较低相似。高分辨率磁化率测试证实了红河组堆积时期干湿变化的多旋回和阶段性,受到太阳辐射变化影响,并受到下垫面的反馈驱动。红河组泥岩和粉砂岩的磁化率值偏高,而砂岩的磁化率值较低,载磁矿物以赤铁矿为主。盆地周围岩体弱磁性物质的快速输入,降低了红河组粗颗粒沉积物的磁化率值。在中、晚始新世的轨道-构造时间尺度,红河组沉积序列粒度变化受到湖面波动控制。湖面上升时湖滨地区沉积物颗粒偏细,磁化率值高;反之,磁化率值低。因此,磁化率高低变化指示了湖面高低波动,进而指示了气候的干湿变化。分析还表明,中、晚始新世渭河盆地湖面多旋回变化和阶段性变干,与全球温度变化和降温过程可良好对比,指示全球温度降低可能抑制水汽循环,进而驱动始新世东亚内陆干旱的发展。

     

现代渭河西安段沉积体沉积相与岩相特征

以渭河西安段草滩沉积体为例, 通过剖面和探槽的详细研究, 结合野外密集采样及样品的分析结果, 对现代渭河草滩沉积体的粒度特征、沉积相、岩相、地层层序及沉积模式进行了综合研究。结果表明, 现代渭河草滩河流沉积体主要由砂质、泥质和少量砾质沉积物组成, 是一个由三期沉积旋回组成的曲流河沉积体。在现代渭河草滩沉积体内部, 共识别出6种岩相, 即平行层理含细砾粗砂岩相、槽状交错层理中细砂岩相、平行层理中细砂岩相、块状层理含砾中砂岩相、交错层理含砾中砂岩和块状层理泥岩相;3种沉积微相, 即河床滞留沉积、边滩和泛滥平原, 这些沉积微相构成了草滩沉积体内部垂向上三套不同的沉积层序:下部为含砾粗砂和中砂组成的河床亚相层序, 砂质沉积厚度较大;中部为一个完整的曲流河沉积层序, 由滞留沉积、边滩和泛滥平原沉积构成;上部则主要为边滩和泛滥平原沉积层序。粒度分析结果表明河床滞留沉积物中的砂体粒径多分布在0.2~1.2 mm, 边滩沉积物中砂体粒径多分布在0.1~1.0 mm, 两者均是良好的砂矿体, 是建筑用砂的良好来源。     

渭河盆地新生代孢粉组合与植被演化特征

在新生代全球变冷的背景下,亚洲环境变化的主要特征之一是季风气候的形成和演化。渭河盆地具有连续的新生代沉积序列,为研究新生代植被演化历史,探究季风的阶段性变化特征提供了良好材料。文章通过分析和综合集成渭河盆地新生代的孢粉记录,初步重建了新生代以来的古植被和古气候变化序列。始新世植被以含热带亚热带乔木成分的落叶阔叶林为主,气候暖湿;渐新世植被类型为含常绿树种的落叶阔叶林,气候相对暖热湿润;早中新世植被以落叶阔叶树为主,气候温暖湿润,晚中新世植被以森林草原为主,气温和降水比早中新世略有降低;上新世植被为落叶阔叶林和针叶林交替出现,后期变为森林草原,气候向干凉方向发展;第四纪以来,植被向森林草原—稀疏的森林草原—草原发展,气候变化趋于凉干。新生代以来降水阶段性减少,与全球变冷趋势基本一致,可能揭示了全球变冷对构造时间尺度亚洲季风降水和植被演替的影响。

     

晚始新世-早渐新世渭河盆地古气候变化的碳酸盐记录

晚始新世-早渐新世转变期（约34 Ma,EOT）温度降低是新生代显著气候事件之一,对亚洲环境演变有深刻影响。本研究基于渭河盆地厚度为413.95 m的支家沟剖面34.89~31.51 Ma时段的河湖相沉积,获得高分辨率总碳酸盐、方解石含量变化序列,结合薄片及扫描电镜分析,尝试建立晚始新世-早渐新世渭河盆地气候和环境演变时间序列,探讨EOT期间渭河盆地古气候对全球温度变化的响应。镜下岩石薄片鉴定显示,沉积物粒度变化与岩相变化对应较为一致。34.89~33.89 Ma,高含量的总碳酸盐、方解石指示气候较为温暖干旱,沉积序列指示从滨湖相向湖泊三角洲相过渡;33.89~33.09 Ma期间,低含量的总碳酸盐、方解石指示气候偏凉且相对湿润,沉积环境为湖泊三角洲向滨浅湖过渡,水位逐渐上升;33.09~31.51 Ma,总碳酸盐、方解石含量变化与地层岩性变化有较好的一致性,此时沉积相为滨湖相,湖泊水位可能高于34.89~33.89 Ma,但低于33.89~33.09 Ma。结合全球温度变化序列,本研究认为渭河盆地始新世晚期-渐新世早期湿度变化可能受全球温度驱动的蒸发量控制,但明确的驱动机制有待进一步研究。

     

Quaternary alluvial fans in the Gobi of southern Mongolia: evidence for neotectonics and climate change

Alluvial fans in southern Monglia occur along a group of narrow discontinuous mountain ranges which formed as transpressional uplifts along a series of strike-slip faults. They provide information on the nature of neotectonic activity in the eastern Gobi Altai range and on palaeoclimate change. Alluvial fan formation was dominated by various geomorphological processes largely controlled by climatic changes related to an increase in aridity throughout late Quaternary times. Their sedimentology shows that initially they experienced humid conditions, when the sedimentary environments were dominated by perennial streams, followed by a period of increasing aridity, during which coarse fanglomerates were deposited in alluvial fans by ephemerial streams and active-layer structures were produced by permafrost within the alluvial fan sediments. With climatic amelioration during early Holocene times, the permafrost degraded and fan incision and entrenchment dominated. Sedimentation was then confined to the upper reaches of the fans, adjacent to steep mountain slopes, and within the entrenched channels. The alluvial fans have been neotectonically deformed, faulted and their surface warped by small thrust faults that propagate from the mountain fronts into their forelands. Localised uplift rates are in the order of 0.1 to 1 m Ka⁻¹. © 1997 John Wiley & Sons, Ltd.     

Late Quaternary Activity of the Huashan Piedmont Fault and Associated Hazards in the Southeastern Weihe Graben, Central China

The Weihe Graben is not only an important Cenozoic fault basin in China but also a significant active seismic zone. The Huashan piedmont fault is an important active fault on the southeast side of the Weihe Graben and has been highly active since the Cenozoic. The well–known Great Huaxian County Earthquake of 1556 occurred on the Huashan piedmont fault. This earthquake, which claimed the lives of approximately 830000 people, is one of the few large earthquakes known to have occurred on a high–angle normal fault. The Huashan piedmont fault is a typical active normal fault that can be used to study tectonic activity and the associated hazards. In this study, the types and characteristics of late Quaternary deformation along this fault are discussed from geological investigations, historical research and comprehensive analysis. On the basis of its characteristics and activity, the fault can be divided into three sections, namely eastern, central and western. The eastern and western sections display normal slip. Intense deformation has occurred along the two sections during the Quaternary; however, no deformation has occurred during the Holocene. The central section has experienced significant high–angle normal fault activity during the Quaternary, including the Holocene. Holocene alluvial fans and loess cut by the fault have been identified at the mouths of many stream valleys of the Huashan Mountains along the central section of the Huashan piedmont fault zone. Of the three sections of the Huashan piedmont fault, the central section is the most active and was very active during the late Quaternary. The rate of normal dip–slip was 1.67–2.71±0.11 mm/a in the Holocene and 0.61±0.15 mm/a during the Mid–Late Pleistocene. As is typical of normal faults, the late Quaternary activity of the Huashan piedmont fault has produced a set of disasters, which include frequent earthquakes, collapses, landslides, mudslides and ground fissures. Ground fissures mainly occur on the hanging–wall of the Huashan piedmont fault, with landslides, collapses and mudslides occurring on the footwall.     

渭河盆地末次冰盛期以来沉积环境变化研究

研究过去气候快速变化能为当前极端气候分析和未来环境预测提供自然背景理解。亚洲季风在北半球乃至全球的第四纪气候变化中扮演着重要角色,其演化是全球气候变化背景下的典型区域响应。然而,不同地质载体及不同指标所记录的亚洲冬、夏季风变化存在着较大差异,产生差异的原因及受到的动力机制是值得深入研究的科学问题。渭河盆地位于黄土高原和古三门湖沉积交叠的区域,是研究第四纪亚洲季风演化的理想场所。在盆地西南部西安市户县和长安县获取了两个黄土沉积钻孔,户县ZZC孔长4 m,长安县XFC孔长3 m,两孔的年代均超过25 ka。通过两钻孔的粒度和元素地球化学等代用指标研究,对比分析不同指标对气候变化的敏感度差异,反演了末次冰盛期（LGM）以来的区域沉积环境变化,并尝试探讨该时期发生的气候突变事件及反映的季风强度变化。结果表明,两钻孔的平均粒径从LGM到中全新世逐渐变细,中全新世之后少许变粗,空间上表现出一致性,总体反映了末次冰盛期以来的冬季风强度演化;Ca/Ti反映了与季风降水相关的淋溶强度,从LGM到全新世暖期夏季风逐渐减弱,并记录了若干次气候快速变化。粒度和元素比值变化表明,渭河盆地沉积良好地记录了末次冰盛期至全新世的大幅冷干-暖湿波动及若干次持续时间较短的快速水文变化事件,主要是受到太阳辐射和冰量等因素调控的影响。由于渭河盆地有上千米的新生代沉积,未来开展高分辨率研究有望揭示不同时间尺度季风变化特征及其与区域和全球变化的联系。

     

Facies and provenance analysis of Paleogene‐age alluvial conglomerates from the northern part of the Mesta Basin,SW Bulgaria

The Mesta Basin in southwest Bulgaria is a graben that contains a Paleogene‐age siliciclastic and volcaniclastic succession deposited in alluvial and fluvial settings. A sedimentological analysis has shed light on conglomerate provenance, and the links between deposition and tectonic setting. Petrographical and chemical analysis of conglomerate clasts and matrix from the Dobrinishka, Gradinishka, Osikovo (or Osenovo) and Zlataritsa formations reveal both local, and more distal source provenance ages. The basal conglomerates are subdivided into three types, a lower and upper polymictic and a middle granitic conglomerate type. Petrographical and chemical analysis reveals granite, gneiss and amphibolite clasts that were sourced from the Sidironero–Mesta Unit of the Middle Allochthon of the Rhodope Metamorphic Complex, and the Rila–Rhodope Batholith to the east of the basin. Cathodoluminescence analysis of quartz sand grains reveals an increased input of red‐ and violet‐luminescent volcanic grains. Volcanic quartz in the oldest conglomerates indicates a hitherto unknown early (pre‐Oligocene) phase of volcanic activity in the vicinity of the Mesta Basin. The conglomerates were deposited in association with movement on the Ribnovo low‐angle normal fault during the Late Eocene, creating subsidence and the development of considerable accommodation space. The establishment of a fluvial environment followed subsequent Oligocene‐age volcanic activity. Copyright © 2012 John Wiley & Sons, Ltd.     

粤北丹霞盆地晚白垩世丹霞组锦石岩段砂岩沉积特征及成因

丹霞山是“中国丹霞”世界自然遗产的典型代表,目前对其成景地层（上白垩统丹霞组）沉积环境的研究程度不高,尤其对丹霞组锦石岩段沉积环境还存在争议。锦石岩段以厚层—巨厚层状中-细砂岩为主,发育大型交错层理,夹薄层—极薄层状泥岩、粉砂质泥岩以及钙质层。本文通过对丹霞盆地丹霞组锦石岩段砂岩进行扫描电镜、粒度分析以及岩石地球化学等方面的研究,探讨该套砂岩的沉积特征及成因。研究表明：该套砂岩以长石石英砂岩为主,显微镜下石英颗粒常见港湾状撞击凹坑,颗粒边缘发育铁、锰及泥质边框,胶结物主要为蒙脱石和方解石。扫描电镜下石英颗粒表面可见碟形撞击坑,具有风成沉积特征。该段砂岩粒度范围窄,分选性好,其稀土总量ΣREE = 40.2×10-6～215.0×10-6,LREE/HREE = 5.54～12.46,轻稀土相对富集,重稀土相对亏损。δEu负异常明显,Ce无异常,具有与中国大陆上地壳相似的高场强元素（Pb、Zr、Hf）和大离子亲石元素（Rb、Ba）组成,化学蚀变指数（CIA）值介于56.99～75.87之间,反映了较低的古风化程度,指示了干旱、炎热的的古气候条件。La/Yb-ΣREE图解和F1-F2判别函数图解研究表明,丹霞组锦石岩段砂岩的母岩物质成分以古老上地壳的长英质为主,具有被动大陆边缘属性的陆内裂谷特征。丹霞盆地晚白垩世锦石岩段沉积时期,具有干燥的地表沉积环境,可能与晚白垩世中期Campanian期东亚中纬度地区的干旱古气候条件相关。     

渭河盆地始新世-渐新世沉积物源变化的钻探样品Sr和Nd同位素证据

始新世暖期和始新世-渐新世降温阶段（EOT）在地球气候系统演化中具有代表性,对认识现代全球变暖过程和机制有参考价值。渭河盆地堆积了始新世以来连续的河湖相沉积序列,对其进行沉积物源示踪研究有助于重建渭河流域地貌演化、沉积过程和气候环境变化。本研究对渭河盆地新生代沉积中心固市凹陷荔参1井（钻探井深6535 m）下部的始新世红河组（6527~5529 m）和渐新世白鹿塬组（5315~4759 m）样品进行了Sr和Nd同位素分析,探索古近纪渭河盆地的物源变化过程。结果显示,红河组样品Sr和Nd同位素平均值分别是⁸⁷Sr/⁸⁶Sr=0.716127和ε_Nd=-13.5,白鹿塬组Sr和Nd同位素平均值分别是⁸⁷Sr/⁸⁶Sr=0.720461和ε_Nd=-12.4。分粒级（< 2 μm,2~64 μm和>64 μm）Sr和Nd同位素测试结果表明,粒度效应对渭河盆地始新世-渐新世沉积物硅酸盐矿物的Sr同位素值影响较大,而对Nd同位素影响较小,表明硅酸盐矿物Nd同位素值可作为渭河盆地沉积物物源的指示。结合潜在源区Sr和Nd同位素分布特征,发现渭河盆地始新世和渐新世沉积物主要来自于秦岭造山带和鄂尔多斯地块的贡献,其物源变化与构造抬升和气候演变密切相关。渭河盆地始新世和渐新世沉积物传输和堆积过程与晚新生代相似,具有相对稳定的两端元物源,为利用红河组和白鹿塬组沉积序列重建古气候古环境奠定了良好的基础。

     

鄂尔多斯盆地东缘大宁—吉县地区山西组页岩岩相与沉积相特征

以鄂尔多斯盆地东缘大宁—吉县地区二叠系山西组为研究对象,综合应用岩心、薄片及测井资料,开展山32亚段岩相类型、岩相组合和沉积相研究,研究结果表明:山32亚段包括粉砂质泥岩/页岩相、纹层状层理含粉砂泥岩/页岩相、透镜状层理粉砂质泥岩/页岩相、钙质页岩相、煤层、碳质页岩相、黑色页岩相、波状层理泥质粉砂岩相、交错层理中—细砂...     

陕西渭河盆地氦气资源赋存状态及其意义

氦气资源是一种稀有紧缺性战略资源。渭河盆地具有良好的氦气资源显示,前人认为区内氦气及伴生气资源为水溶气。通过已有石油井、地热井录井、样品测试、动态监测等资料分析,认为渭河盆地不仅存在水溶气资源,也存在游离态氦及伴生气资源,即具有富氦天然气层(藏),这一认识对进一步的氦气资源评价与开发利用具有重要意义。     

Late Quaternary landscape development along the Rancho Marino coastal range front (south‐central Pacific Coast Ranges,California, USA)

Late Quaternary landscape development along the Rancho Marino coastal range front in the central‐southern Pacific Coast Ranges of California has been documented using field mapping, surveying, sedimentary facies analysis and a luminescence age determination. Late Quaternary sediments along the base of the range front form a single composite marine terrace buried by alluvial fans. Marine terrace sediments overlie two palaeoshore platforms at 5 m and 0 m altitude. Correlation with the nearby Cayucos and San Simeon sites links platform and marine terrace development to the 125 ka and 105 ka sea‐level highstands. Uplift rate estimates based on the 125 ka shoreline angle are 0.01–0.09 m ka^?1 (mean 0.04 m ka^?1), and suggest an increase in regional uplift along the coast towards the NW where the San Simeon fault zone intersects the coastline. Furthermore, such low rates suggest that pre‐125 ka uplift was responsible for most of the relief generation at Rancho Marino. The coastal range front landscape development is, thus, primarily controlled by post 125 ka climatic and sea‐level changes. Post 125 ka sea‐level lowering expanded the range front piedmont area to a width of 7.5 km by the 18 ka Last Glacial Maximum lowstand. This sea‐level lowering created space for alluvial fan building along the range front. A 45 ± 3 ka optically stimulated luminescence (OSL) age provides a basal age for alluvial fan building or marks the time by which distal alluvial fan sedimentation has reached 300 m from the range front slope. Fan sedimentation is related to climatic change, with increased sediment supply to the range front occurring during (1) glacial period cold stage maxima and/or (2) the Late Pleistocene–Holocene transition, when respective increases in precipitation and/or storminess resulted in hillslope erosion. Sea‐level rise after the 18 ka lowstand resulted in range front erosion, with elevated localised erosion linked to the higher relief and steeper slopes in the SE. This study demonstrates that late Quaternary coastal range front landscape development is driven by interplay of tectonics, climatic and sea‐level change. In areas of low tectonic activity, climatic and sea‐level changes dominate coastal landscape development. When the sea‐level controlled shoreline is in close proximity to the coastal range front, localised patterns of sedimentation and erosion are passively influenced by the pre‐125 ka topography. Copyright © 2008 John Wiley & Sons, Ltd.     

陕西渭河盆地氦气资源赋存状态及其意义

氦气资源是一种稀有紧缺性战略资源。渭河盆地具有良好的氦气资源显示,前人认为区内氦气及伴生气资源为水溶气。通过已有石油井、地热井录井、样品测试、动态监测等资料分析,认为渭河盆地不仅存在水溶气资源,也存在游离态氦及伴生气资源,即具有富氦天然气层（藏）,这一认识对进一步的氦气资源评价与开发利用具有重要意义。     

Late Quaternary climate change record from two long sediment cores from Guaymas Basin,Gulf of California

Modern Guaymas Basin (Gulf of California, Mexico) is a region of high diatom productivity where exceptional preservation factors maintain biannually alternating sediment deposition as annual varves. New sediment cores from Guaymas Basin (MD02‐2512 and MD02‐2515) present the opportunity to construct climate records from below the last glacial period. A low‐resolution age model has been constructed from oxygen isotope analysis, correlation with other dated short piston cores from Guaymas Basin and an estimate of sedimentation rate. MD02‐2512 from eastern Guaymas Basin has an age range from the Holocene to late marine isotope stage 6 (MIS 6); MD02‐2515 from western Guaymas Basin has an age range from ～8000 to 40 000 yr. Shipboard analyses of colour reflectance, magnetic susceptibility and sediment density are combined with continuous X‐ray fluorescence scans to reconstruct a picture of glacial climate in the Gulf of California. Eastern Guaymas Basin is affected by glacial sea level fall, which results in a drastic change in productivity rates and sediment type. The laminated record of MIS 5 allows comparison with the Holocene, showing a similarity of sedimentation patterns during deglaciation and a series of very rapid variations just prior to the last glaciation. In western Guaymas Basin there are a series of Younger Dryas‐like events during the glacial, typified by low productivity and high terrigenous input. Long‐term climate and productivity changes appear to be caused by the southward displacement of the Subtropical High pressure zone. Copyright © 2005 John Wiley & Sons, Ltd.     

渭河盆地东南缘主要断裂晚更新世以来的活动性及灾害效应

渭河盆地是中国中部地区一个重要的新生代断陷盆地, 也是一条重要的地震活动带, 属于汾渭地震带的一部分。中国西部政治、经济、文化中心西安就位于其上。渭河盆地东南缘活动断裂非常发育、地震活动频繁, 而且有1556年华县8级特大地震发生的背景。华县大地震是发生在高角度正断层上为数不多的强震之一, 并且其发震构造目前还存在争议。华山山前断裂为正断型活动断裂, 是研究正断型活动断裂与其灾害效应的典型实例。本论文通过对正断型断层活动与大地震及其灾害关系的研究, 为评价西安等重要城市群的稳定性提供科学依据。     

粤北丹霞盆地晚白垩世丹霞组沉积相及古气候意义

粤北丹霞山作为世界自然遗产"中国丹霞"的典型代表,在地貌方面已经积累了丰富的研究成果,但是对丹霞地貌成景地层(晚白垩世红层)的沉积环境和古气候的研究较少。通过对巴寨剖面丹霞组的野外观测、砾石统计、室内砂岩样品薄片鉴定及粒度分析,进行详细的沉积相研究。巴寨剖面丹霞组出露巴寨段和锦石岩段,前者以砾岩为主,发育粒序层理及平行层理、底侵蚀面、叠瓦状构造等,而后者以发育大型交错层理的风成砂岩夹古土壤为特征。在盆地其他位置,可见丹霞组白寨顶段砾岩地层。研究结果表明,在巴寨剖面的晚白垩世丹霞组红层中,可以识别出正粒序层理砾岩、逆粒序层理砾岩、平行层理砾岩、无沉积构造砾岩、大型交错层理风成砂岩、中—薄层砂岩、古土壤7种岩相。巴寨段砾石大小主要为0.5～9.5 cm,成分以脉石英、石英砂岩及砖红色砂岩为主。锦石岩段砂岩粒径为0.03～0.5 mm,分选性好,以跳跃组分为主,指示风成环境。丹霞组从巴寨段到锦石岩段沉积物粒度变细、沉积速率由快变慢,指示了由河流主导的冲积扇沉积体系向沙漠沉积体系的转变,反映了古气候向干热变化,锦石岩段的风成砂岩可能与东亚中纬度地区晚白垩世Campanian期古气候广泛的干旱化有关。丹霞组沉积末期(白寨顶段),古气候条件再次变湿,降水增加,河流将粗粒碎屑物再次搬运到盆地发生沉积,新的冲积扇叠覆在锦石岩段风成砂岩—古土壤序列之上。     

济源盆地中侏罗统马凹组砂岩粒度特征分析

济源盆地中侏罗统马凹组下段发育厚约80m的中细粒砂岩,前人在许多文献中称其为长石石英砂岩.通过对所取砂岩样品薄片镜下观察,将其命名为岩屑石英砂岩.该段砂岩自下而上粒度具有以下特征:平均粒径(Mz)总体由大变小,标准偏差(σ)反映砂岩分选由中等逐渐变好,标准偏差(σ)和偏度(SK1)都具有典型河流沉积物特征.频率曲线表现为不对称三峰或双峰,概率累积曲线由“低斜四段”式渐变为“高斜跳悬两段”式.该套砂岩沉积时期水流不稳,有多期洪流出现,表现为平均粒径和标准偏差的局部来回振荡.其C-M图显示主要发育牵引流PQ、QR、RS段,符合经典曲流河沉积模式.     

陕西渭河盆地富氦天然气异常的影响因素

通过对渭河盆地22口钻井中富氦天然气的同位素分析,认为盆地中氦气以壳源氦为主,局部伴有少量幔源氦。针对盆地中氦气异常的现象,结合对盆地特性的分析,认为渭河盆地氦气异常的影响因素包括:1盆地地壳较薄,莫霍界面呈明显的隆起,热流体活动发育,有利于氦气运移;2花岗岩体和通过水系统运移到沉积地层中的放射性元素衰变,为氦气成藏提供了有力的气源保障;3盆地内十分发育的断裂体系,不仅为氦气运移提供了连通通道,还在活动过程中释放氦气,为氦气局部聚集提供了有利空间。