坦桑尼亚滨海盆地陆坡峡谷沉积特征及其控制因素*

东非陆缘深水盆地具有巨大油气资源潜力,但对陆坡峡谷沉积特征研究较少,制约有利储集层预测。本研究利用三维地震资料,对东非坦桑尼亚滨海盆地陆坡峡谷开展精细研究。结果表明:(1)研究区陆坡发育多条大型海底峡谷;上陆坡处,坡度较陡,峡谷内以侵蚀作用为主,沉积物主要局限在褶皱推覆带的翼部;褶皱推覆带之外的下陆坡区,坡度变缓,峡谷末端发育席状砂质沉积及砂泥混杂的碎屑流沉积,同时在峡谷北侧发育向北延伸的泥质漂积体;在陆坡边缘,发育海底滑塌,形成块体搬运沉积。(2)峡谷沉积受陆源物质供给、褶皱推覆带、北大西洋底流以及陆坡边界断层等因素控制。受东非裂谷海域分支活动影响,研究区陆架窄、陆坡陡,陆源物质可迅速通过陆架,进入陆坡峡谷:与河流相连的峡谷,物源充足、规模较大,有沉积物发育而没有与河流直接相连的峡谷物源有限、规模较小,峡谷内无明显沉积;褶皱推覆带通过改变海底地形来控制峡谷内沉积分布,褶皱翼部发育沉积,核部则以侵蚀为主;褶皱推覆带外,北大西洋底流与峡谷末端重力流发生交互作用,细粒物质被搬运至峡谷北岸形成漂积体;陆坡边缘断层活跃,峡谷被断层切割,形成断崖,并引发海底滑塌,陆坡处不发育水道及朵体沉积,陆源物质通过峡谷被搬运至更深的深海盆地内。     

Distribution of contourite drifts on convergent margins: Examples from the Hikurangi subduction margin of New Zealand

Contourite drift systems form a significant component of the marine clastic sedimentary record. Although contourites form in all tectonic settings, few studies have described their development along convergent margins; such characterization is needed to underpin oceanographic and palaeoenvironmental studies in active settings. This study is the first to document contourite drift development along the Hikurangi subduction margin of New Zealand. Integration of bathymetric, seismic and well data enables five classes of drift to be recognized around the subduction wedge, occurring in three principal associations: (i) an upper slope drift association of giant elongate mounded (ca 150 km long, 50 km wide and up to 1100 m thick) and plastered drifts (ca 300 km long, 8 km wide and <600 m thick), which occurs upon and inboard of a major intrabasinal thrust‐cored high, whose long axis parallels the coast; shallow bottom currents disperse sub‐parallel to this axis; (ii) a spatiotemporally discontinuous association of confined and mounded hybrid drifts (ca 500 m long, <2 km wide and up to 500 m thick) that occurs along the mid‐to‐outer slope domain of the wedge, recording the interaction of along‐slope and downslope currents within trench‐slope basins; and (iii) a trench fill assemblage that implies the passage of abyssal bottom currents across a 40 km reach of the trench‐axial Hikurangi Channel‐levée, with associated modification of the channel form and of overbank sediment waves. The fundamental presence of contourites along this margin appears to depend on the orientation and strength of oceanographic bottom currents. However, drift type and evolution vary depending on the slope gradient and the presence of irregular seafloor topography created by tectonic structures. The documented drifts are generally smaller, less continuous, and develop more intermittently than similar styles of drifts documented on passive margins; this mode of occurrence may be characteristic of contourite development on convergent margins.     

High‐ to ultrahigh‐temperature metamorphism in the lower crust: An example resulting from Hikurangi Plateau collision and slab rollback in New Zealand

Lower crustal xenoliths erupted from an intraplate diatreme reveal that a portion of the New Zealand Gondwana margin experienced high‐temperature (HT) to ultrahigh‐temperature (UHT) granulite facies metamorphism just after flat slab subduction ceased at c. 110–105 Ma. P–T calculations for garnet–orthopyroxene‐bearing felsic granulite xenoliths indicate equilibration at ~815 to 910°C and 0.7 to 0.8 GPa, with garnet‐bearing mafic granulite xenoliths yielding at least 900°C. Supporting evidence for the attainment of HT and UHT conditions in felsic granulite comes from re‐integration of exsolution in feldspar (~900–950°C at 0.8 GPa), Ti‐in‐zircon thermometry on Y‐depleted overgrowths on detrital zircon grains (932°C ± 24°C at aTiO₂ = 0.8 ± 0.2), and correlation of observed assemblages and mineral compositions with thermodynamic modelling results (≥850°C at 0.7 to 0.8 GPa). The thin zircon overgrowths, which were mainly targeted by drilling through the cores of grains, yield a U–Pb pooled age of 91.7 ± 2.0 Ma. The cause of Late Cretaceous HT‐UHT metamorphism on the Zealandia Gondwana margin is attributed to collision and partial subduction of the buoyant oceanic Hikurangi Plateau in the Early Cretaceous. The halt of subduction caused the fore‐running shallowly dipping slab to rollback towards the trench position and permitted the upper mantle to rapidly increase the geothermal gradient through the base of the extending (former) accretionary prism. This sequence of events provides a mechanism for achieving regional HT–UHT conditions in the lower crust with little or no sign of this event at the surface.     

Sedimentary architecture beneath lakes subjected to storms: Control by turbidity current bypass and turbidite armouring,interpreted from ground‐penetrating radar images

Turbidites within Holocene lacustrine sediment cores occur worldwide and are valued deposits that record a history of earthquakes or storms. Without sedimentary architecture, however, interpretation of the cause, provenance and behaviour of their parent turbidity currents are speculative. Here, these interpretations are made from two‐dimensional ground‐penetrating radar images of ‘shore to shore’ architecture beneath three, previously cored lakes within the low seismicity New England (USA ) region. Shallow depths, low water and sediment conductivities, and signal sensitivity to density contrasts uniquely provided up to 30 m of sediment signal penetration. Core comparisons and signal analysis reveal that most horizons represent multidecimetre‐thick clusters of Holocene turbidites, which are denser than their organic‐rich silt matrix. Some horizons also represent erosional unconformities and sediment bypass interfaces. The key, common, architectural consequences of turbidity current activity include limited foreset progradation, conformably pinched or unconformable layers of organic‐rich sediment onlapped against slopes beneath 5 to 6 m of water, and mounded stratified sediments beneath rises. These features indicate that turbidity currents repeatedly bypassed the same slope without deposition and regardless of dip, and then simultaneously armoured and bypassed inter‐turbidite sediment along rises and basins to provide basinward, generally age‐conformable accumulation. The mounding precludes significant basinward focusing. Variable horizon amplitude suggests metre‐scale changes in armouring density. Unconformities localized near breaks in dip beneath slopes suggest erosive hydraulic jumps. One lake shows evidence of historically maintained channels associated with specific deltas. Shelf strata indicating inland current generation, similar key architecture in other, uncored lakes, countable, lake‐wide horizons, and absent slumps, slides and faults are consistent with storm‐driven turbidity currents, and with previous, core‐based conclusions that severe, Holocene storms were episodic throughout this region. The results generalize marine bypass and armouring to lacustrine settings, and so probably occur worldwide in lakes subject only to storms, including lakes where ground‐penetrating radar may locate core sites.     

A depositional model for deep‐lacustrine,partially confined,turbidite fans: Early Cretaceous,North Falkland Basin

This paper presents a model of facies distribution within a set of early Cretaceous, deep‐lacustrine, partially confined turbidite fans (Sea Lion Fan, Sea Lion North Fan and Otter Fan) in the North Falkland Basin, South Atlantic. As a whole, ancient deep‐lacustrine turbidite systems are under‐represented in the literature when compared with those documented in marine basins. Lacustrine turbidite systems can form extensive, good quality hydrocarbon reservoirs, making the understanding of such systems crucial to exploration within lacustrine basins. An integrated analysis of seismic cross‐sections, seismic amplitude extraction maps and 455 m of core has enabled the identification of a series of turbidite fans. The deposits of these fans have been separated into lobe axis, lobe fringe and lobe distal fringe settings. Seismic architectures, observed in the seismic amplitude extraction maps, are interpreted to represent geologically associated heterogeneities, including: feeder systems, terminal mouth lobes, flow deflection, sinuous lobe axis deposits, flow constriction and stranded lobe fringe areas. When found in combination, these architectures suggest ‘partial confinement’ of a system, something that appears to be a key feature in the lacustrine turbidite setting of the North Falkland Basin. Partial confinement of a system occurs when depositionally generated topography controls the flow‐pathway and deposition of subsequent turbidite fan deposits. The term ‘partial confinement’ provides an expression for categorising a system whose depositional boundaries are unconfined by the margins of the basin, yet exhibit evidence of internal confinement, primarily controlled by depositional topography. Understanding the controls that dictate partial confinement; and the resultant distribution of sand‐prone facies within deep‐lacustrine turbidite fans, is important, particularly considering their recent rise as hydrocarbon reservoirs in rift and failed‐rift settings.     

Flow dynamics at the origin of thin clayey sand lacustrine turbidites: Examples from Lake Hazar,Turkey

Turbidity currents and their deposits can be investigated using several methods, i.e. direct monitoring, physical and numerical modelling, sediment cores and outcrops. The present study focused on thin clayey sand turbidites found in Lake Hazar (Turkey) occurring in eleven clusters of closely spaced thin beds. Depositional processes and sources for three of those eleven clusters are studied at three coring sites. Bathymetrical data and seismic reflection profiles are used to understand the specific geomorphology of each site. X‐ray, thin sections and CT scan imagery combined with grain‐size, geochemical and mineralogical measurements on the cores allow characterization of the turbidites. Turbidites included in each cluster were produced by remobilization of surficial slope sediment, a process identified in very few studies worldwide. Three types of turbidites are distinguished and compared with deposits obtained in flume studies published in the literature. Type 1 is made of an ungraded clayey silt layer issued from a cohesive flow. Type 2 is composed of a partially graded clayey sand layer overlain by a mud cap, attributed to a transitional flow. Type 3 corresponds to a graded clayey sand layer overlain by a mud cap issued from a turbulence‐dominated flow. While the published experimental studies show that turbulence is damped by cohesion for low clay content, type 3 deposits of this study show evidence for a turbulence‐dominated mechanism despite their high clay content. This divergence may in part relate to input variables, such as water chemistry and clay mineralogy, that are not routinely considered in experimental studies. Furthermore, the large sedimentological variety observed in the turbidites from one coring site to another is related to the evolution of a sediment flow within a field‐scale basin made of a complex physiography that cannot be tackled by flume experiments.     

鄂尔多斯盆地西南缘上奥陶统平凉组岩石特征及沉积环境

为研究鄂尔多斯盆地西南缘上奥陶统平凉组岩石特征及沉积环境,基于沉积学相关理论和方法,根据野外露头、古生物及粒度分析等资料,对研究区岩石特征、沉积相及主控因素开展了研究。结果表明：①研究区平凉组可划分3种岩相和2种岩相组合。②通过综合研究岩性、古生物、沉积构造及粒度参数等资料,确定平凉组沉积环境为深水斜坡。③沉积相为海底扇,在此基础上可划分为中扇和下扇2个亚相,近端朵叶和远端朵叶2个微相。④海底扇的主控因素为相对海平面升降、构造运动和物源供给。     

The stratigraphic record and processes of turbidity current transformation across deep‐marine lobes

Sedimentary facies in the distal parts of deep‐marine lobes can diverge significantly from those predicted by classical turbidite models, and sedimentological processes in these environments are poorly understood. This gap may be bridged using outcrop studies and theoretical models. In the Skoorsteenberg Formation (South Africa), a downstream transition from thickly bedded turbidite sandstones to argillaceous, internally layered hybrid beds, is observed. The hybrid beds have a characteristic stratigraphic and spatial distribution, being associated with bed successions which generally coarsen and thicken‐upward reflecting deposition on the fringes of lobes in a dominantly progradational system. Using a detailed characterization of bed types, including grain size, grain‐fabric and mineralogical analyses, a process‐model for flow evolution is developed. This is explored using a numerical suspension capacity model for radially spreading and decelerating turbidity currents. The new model shows how decelerating sediment suspensions can reach a critical suspension capacity threshold beyond which grains are not supported by fluid turbulence. Sand and silt particles, settling together with flocculated clay, may form low yield strength cohesive flows; development of these higher concentration lower boundary layer flows inhibits transfer of turbulent kinetic energy into the upper parts of the flow ultimately resulting in catastrophic loss of turbulence and collapse of the upper part of the flow. Advection distances of the now transitional to laminar flow are relatively long (several kilometres) suggesting relatively slow dewatering (several hours) of the low yield strength flows. The catastrophic loss of turbulence accounts for the presence of such beds in other fine‐grained systems without invoking external controls or large‐scale flow partitioning and also explains the abrupt pinch‐out of all divisions of these sandstones. Estimation of the point of flow transformation is a useful tool in the prediction of heterogeneity distribution in subsurface systems.     

Evolution,architecture and hierarchy of distributary deep‐water deposits: a high‐resolution outcrop investigation from the Permian Karoo Basin,South Africa

Sea floor and shallow seismic data sets of terminal submarine fan lobes can provide excellent planform timeslices of distributive deep‐water systems but commonly only limited information on cross‐sectional architecture. Extensive outcrops in the Tanqua depocentre, south‐west Karoo Basin, provide these three‐dimensional constraints on lithofacies distributions, stacking patterns, depositional geometries and the stratigraphic evolution of submarine lobe deposits at a scale comparable with modern lobe systems. Detailed study (bed‐scale) of a single‐lobe complex (Fan 3) over a 15 km by 8 km area has helped to define a four‐fold hierarchy of depositional elements from bed through to lobe element, lobe and lobe complex. The Fan 3 lobe complex comprises six distinct fine‐grained sandstone packages, interpreted as lobes, which display compensational stacking patterns on a 5 km scale. Between successive lobes are thin‐bedded, very fine‐grained sandstones and siltstones that do not change lithofacies over several kilometres and therefore are identified as a different architectural element. Each lobe is built by many lobe elements, which also display compensational stacking patterns over a kilometre scale. Thickness variations of lobe elements can be extremely abrupt without erosion, particularly in distal areas where isopach maps reveal a finger‐like distal fringe to lobes. Lobe deposits, therefore, are not simple radial sheet‐dominated systems as commonly envisaged.     

Architecture and depositional development of the Eocene deep‐marine Morillo and Coscojuela Formations,Aínsa Basin,Spain

The Aínsa Basin of northern Spain contains a deep‐marine succession comprising up to 24 sandstone bodies separated by thick marl‐rich units. A detailed analysis of nine outcrops (>900 m of sediment profiles) from the Morillo Formation of the San Vicente Group, from the upper part of the basin succession, has enabled a reappraisal of the unit. Within the Morillo Formation, sediment transport was to the NW, and a range of environments are recognized including channels, lobes and pelagic deposits. The overlying Coscojuela Formation, which partly cuts into the Morillo Formation, shows W‐directed palaeocurrents in its proximal reaches, with flows being deflected to the N along an adjacent slope. Destabilization of the adjacent carbonate platform resulted in a significant input of carbonate material into the flow. The final phases of sedimentation within the Aínsa Basin were more complex than previously suspected, probably as a result of a combination of factors, including tectonic activity, resulting in basin narrowing due to anticlinal growth, as well as encroachment and/or destabilization of the adjacent regional carbonate platforms. Copyright © 2013 John Wiley & Sons, Ltd.     

柴达木盆地东北缘中新统遗迹化石组合及其沉积环境

研究遗迹化石对于恢复古生物活动方式、习性和古环境具有重要意义。在柴达木盆地东北缘双湖地区中新统发现了遗迹化石。经鉴定,研究区的遗迹化石主要包括2大类4属4种:居住迹Palaeopycus heberti（赫伯特古藻迹）,Skolithos verticalis（垂直石针迹）;进食迹Scoyenia gracilis（纤细斯柯茵迹）和Taenidium satanassi（箱形条带迹）。根据研究区的遗迹化石分布及沉积环境分析,该地可划分出一个遗迹组合:Scoyenia-Taenidium-Skolithos遗迹组合, 代表了潮湿气候条件下的浅湖环境。当前化石的发现填补了柴达木盆地东北缘双湖地区中新世遗迹化石研究的空白。     

蒙古国东部塔木察格盆地南部白垩系地层结构及沉积充填特征

盆地的古地形及构造坡折带的形态和类型决定其沉积充填的特征和储集层砂体的分布。根据对蒙 古国东部塔木察格盆地南部地区南贝尔凹陷和塔南凹陷的盆地边缘的古地貌结构特征分析,将南贝尔凹陷和塔 南凹陷白垩纪发育的古构造坡折带划分为4种类型,分别控制着4种类型沉积相的形成和分布。断崖型坡折带 控制近岸水下扇相及前方的远岸湖底扇相的形成和分布;断阶型坡折带控制扇三角洲相和近岸水下扇相的形成 和分布;缓坡型坡折带控制扇三角洲相的形成和分布。在基准面下降阶段,盆内坡折带控制着远岸湖底扇的形 成和分布。     

水下喷发火山碎屑岩储层特征及主控因素:以新西兰Taranaki盆地中新世Kora火山为例

新西兰Taranaki盆地中新世Kora火山是海底喷发形成的碎屑岩型火山,可代表浅埋藏火山岩的储层特征.本文根据5口钻井的孔隙度、渗透率、孔隙孔径和铸体薄片开展Kora火山的储层特征、储集空间组成、缝宽以及原生和次生孔隙之间关系的分析.研究结果如下:(1)储集空间主要为次生孔隙,然后是裂缝和原生孔隙;Kora火山具有高...     

海底水道体系沉积构型样式及控制因素:以尼日尔三角洲盆地陆坡区为例*

作为当今油气勘探开发的重要目标,海底水道的沉积构型样式复杂多变,其控制因素目前尚无定论,这大大增加了相关油气藏的钻探风险和开发难度。以尼日尔三角洲盆地陆坡区为例,以近海底高频地震信息为原型,揭示了海底水道体系的外部形态样式和内部结构样式,探究了水道体系与复合水道形态特征参数间的相互关系,分析了海底水道体系沉积构型控制因素。研究认为: (1)水道体系可分为限制性、半限制性和非限制性3个大类,限制性水道体系的边界为一明显的大型下切谷界面(或峡谷),半限制性水道体系的边界也发育明显的大型下切谷,但其界面两侧发育大型天然堤沉积,非限制性水道体系则不发育大型下切谷,其中每个大类又可依据其内部复合水道的类型,细分为2个小类(下切式和包络式)。(2)水道体系内部复合水道间存在垂向和侧向2种类型的叠置,前者可细分为孤立式、叠加式和切叠式3类,后者则包括叠合式和分离式2类。(3)地形坡度与水道体系类型和规模具有一定的耦合与关联,在类似油藏规模的局部沉积体内部,陡坡段(坡度大于1°)主要发育限制性水道体系,缓坡段(坡度0.5°~1°)主要发育半限制性水道体系,平坦段(坡度小于0.5°)主要发育非限制性水道体系;随着地形坡度的增大,水道体系的宽度减小、深度增加、宽深比减小,即向“窄深型”形态发展。该项研究不仅对深水沉积学的发展具有较大的理论意义,而且对高效开发海底水道油气藏具有重要的实际意义。     

Sedimentary characteristics of large‐scale lacustrine beach‐bars and their formation in the Eocene Boxing Sag of Bohai Bay Basin,East China

The beach‐bar reservoir play has become an important exploration target within the Bohai Bay Basin, especially in the Boxing Sag within the Dongying Depression, where a large‐scale lacustrine beach‐bar oil pool has been discovered recently. The sedimentary characteristics, distribution patterns and formation mechanisms of beach‐bar sand bodies in the upper fourth member of the Eocene Shahejie Formation (Es4s) in the Boxing Sag were studied in detail based on seismic, well log data and core data. The Es4s in the Boxing Sag is composed of a third‐order sequence consisting of three systems tracts, i.e. a lowstand systems tract, a transgressive systems tract and a highstand systems tract. Beach‐bar sand bodies were deposited widely in the basin during the lowstand systems tract period. The sandy beach‐bars are characterized by siltstones, fine‐grained silty sandstones interbedded with thin mudstone units. The presence of well‐developed sedimentary structures, such as swash bedding, parting lineation, parallel bedding, ellipsoidal mud clasts, ripples, terrestrial plant debris and vertical burrows, suggests that beach‐bars were deposited in a relatively shallow water environment under the influence of strong hydrodynamics. Laterally, the sandy beach facies occurred as a more continuous sheet‐like body around the sandy bar in most parts of the sag. Stratigraphically, beach‐bars were distributed mainly in the lowstand systems tract and they were less well‐developed in the transgressive systems tract and highstand systems tract. Several factors were probably responsible for the occurrence of the large‐scale beach‐bars during the lowstand systems tract period, including: (i) a gentle palaeoslope and relatively weak structural activities; (ii) a shallow‐water condition with a strong hydrodynamic environment; (iii) high‐frequency oscillations of the lake level; and (iv) an abundant terrigenous clastic feeding system with multiple‐point and linear sediment sources.     

浅成侵入岩储层分布模式——以新西兰Lyttelton火山中新世浅成岩脉为例

侵入岩油气藏广泛分布于世界各盆地中,具有良好的油气勘探潜力。但对原生孔隙发育的岩脉储层模式的研究尚未引起足够的关注。本文以新西兰基督城Lyttelton火山西北部的中新世浅成岩脉为研究对象,根据野外露头调查、孔渗测试、图像分析和经验公式的渗透率计算,对其孔隙构成、储层分布模式和储层控制因素进行分析。结果表明:该区浅成侵入岩为孔隙-裂缝型储层,储集空间以气孔为主,冷凝收缩缝次之;气孔可见定向拉长的大直径椭圆形和离散的小直径圆形两类,对孔隙度的贡献以前者为主;柱状节理可见规则和不规则两类,后者的裂缝面密度较高;具有中孔-中渗的特征,局部高孔-高渗;柱体横截面形态和规则性是影响地层渗透性的关键因素。整体上,浅成岩脉从下到上孔隙度由小变大,柱状节理由规则变为不规则;气孔可由柱状节理沟通,其连通性受柱状节理缝间距、缝宽,以及定向拉长气孔与柱状节理之间的夹角控制;Lyttelton火山的浅成岩脉显示,冷凝固结阶段气孔的初始连通率可高达35%。综上,浅成岩脉可具有良好的储集性能,气孔初始连通性较高,可作为有利的勘探目标。     

Multi‐scale classification of fluvial architecture: An example from the Palaeocene–Eocene Bighorn Basin,Wyoming

Fluvial channel geometry classification schemes are commonly restricted in relation to the scale at which the study took place, often due to outcrop limitations or the need to conduct small‐scale detailed studies. A number of classification schemes are present in the literature; however, there is often limited consistency between them, making application difficult. The aim of this study is to address this key problem by describing channel body geometries across a depositional basin to ensure that a wide range of architectures are documented. This was achieved by studying 28 locations over 4000 m of vertical succession in Palaeocene‐aged and Early Eocene‐aged deposits within the Bighorn Basin, Wyoming, USA. Five different channel body geometries have been defined based on the external geometric form, and internal arrangement and nature of storey contacts. These include the massive channel body geometry, semi‐amalgamated channel body geometry, internally amalgamated channel body geometry and offset stacked channel body geometry, which are considered to be subdivisions of the sheet geometry of many other classifications. An isolated channel body geometry has also been recognized alongside splay channel and sheet sandstone geometries in the floodplain facies associations. Field evidence, including the stacking style of storey surfaces, suggests that the different geometries form a continuum. The nature and degree of amalgamation at the storey scale are important in producing the different geometries and are related to the degree of channel migration. It is speculated that this is the result of differences in sediment supply and available accommodation. In contrast to previous schemes, the classification scheme presented here recognizes the importance of transitional geometries. This geometrical range has been recognized because of the basin‐scale nature of the study.     

Sedimentary architecture and growth pattern of turbidite systems in distal part of a median fan; example of the Upper Miocene sedimentary sequence of the Lower Congo basin

The understanding of deep-water turbidite systems implies a preliminary detailed analysis of the architectural elements which compose them. Using 3D seismic data, three architectural elements are recognized including a new one: the “meandering erosional nested channels”. The spatial organisation and the relative stratigraphic position of these “elementary bricks” allow to define four stages which form the sedimentary history of the distal part of a upper Miocene turbidite system of the Lower Congo basin: 1, depositional stage with frontal splay development; 2, erosional channel and prograding system; 3, depositional stage with vertical aggradation of the channel and 4, abandonment phase with channel avulsion.     

A New Fossil Termite(Isoptera,Stolotermitidae,Stolotermes)from the Early Miocene of Otago,New Zealand

<正>The forewing of a termite from Early Miocene lake sediments in Otago,southern New Zealand is figured and described.It exhibits the generic characters of the damp-wood termite Stolotermes Hagen,but differs from forewings of the known species in size and venation pattern and is described as Stolotermes kupe sp.nov.S.kupe represents the first confident record of fossil Stolotermitidae and extends the fossil record of the family back to the Early Miocene.It also is the first direct evidence of fossil Isoptera from New Zealand,though silicified termite faecal pellets,referable to Kalotermes brauni,have been previously described.S.kupe indicates that Stolotermitidae has been present in the Australasian region since at least the Early Miocene.