黑龙江东部中-新生代盆地演化

黑龙江省东部中-新生代盆地基底由佳木斯地块和完达山地体复合而成.佳木斯地块以加里东期变质岩及花岗岩为主,东缘发育晚古生代和早中生代大陆边缘沉积.完达山地体在中-晚侏罗世就位在佳木斯地块东缘,并在早白垩世早期逆冲到佳木斯地块之上,形成具有前陆盆地性质的大三江盆地.大三江盆地在早白垩世晚期遭受逆冲、走滑构造改造.敦密断裂以北的诸多盆地均属大三江盆地改造后的残余盆地.这些残余盆地和完达山地体之下可能存在隐伏的晚古生代和早中生代大陆边缘沉积.三江盆地东部是古近纪断陷的主要发育区,可能存在一与佳依地堑平行的深断陷.隐伏的大陆边缘沉积和断陷是值得重视的油气勘探领域.     

The Middle Jurassic radiolarites and pelagic limestones of the Nieves unit (Rondaide Complex, Betic Cordillera): basin starvation in a rifted marginal slope of the western Tethys

Middle Jurassic radiolarites and associated pelagic limestones occur in the Rondaide Nieves unit of the Betic Cordillera, southern Spain. The Rondaide Mesozoic includes: (a) a thick succession of Triassic platform carbonates, comparable to the Alpine Hauptdolomit and Kössen facies; (b) Lower Jurassic pelagic limestones comparable to the Alpine Hierlatz and Adnet facies; (c) the Middle Jurassic Parauta Radiolarite Formation, described herein; and (d) a thin Upper Jurassic-Cretaceous condensed limestone succession. The Parauta Radiolarite Formation and associated limestones were studied with respect to stratigraphy, petrography, micropalaeontology (radiolarians, calcareous nanno- and microfossils) and facies. Radiolarite sedimentation occurred in the Middle Bathonian in a restricted and dysoxic deep Nieves basin, perched in the distal zone of a continental margin fringing the Tethyan ocean. This margin was adjacent to a young narrow oceanic basin between the South-Iberian margin and a continental block called Mesomediterranean Terrane. The Nieves basin was part of a marine corridor between the Proto-Atlantic and Piedmont-Ligurian basins of the Alpine Tethys. The regional tectonic position, the stratigraphical evolution since the Triassic, the age and the nature of the Mesozoic facies and the palaeogeographic relations to adjacent domains show striking analogies between the Betic Rondaide margin and coeval units of the Alps.     

Geochemical Constraints of the Ediacaran Volcano-Sedimentary Succession of the Sa’al Metamorphic Complex at Wadi Zaghra, South Sinai, Egypt

The volcano-sedimentary succession around Wadi Zaghra in Sinai, at the northernmost segment of the Arabian Nubian Shield, comprises volcanic rocks interbedded with rather immature sediments. The succession is dominated by intermediate to silicic volcanics of medium-to high-K calc-alkaline affinity. It is divided into two units, the lower unit includes intermediate rocks and dacites interbedded with graywackes, semi-pelites and pelites and topped by polymict conglomerates. This unit is subjected to folding and regional metamorphism(up to garnet zone) and is intruded by quartz diorite-granodiorite inducing, locally, low-pressure contact thermal metamorphism. The unmetamorphosed upper unit encompasses acid volcanics intercalated with litharenite, sublitharenite and minor arenite. The rhyolites of this unit pertain to the highly fractionated granites and are characterized by an agpaitic index(NK/A) ranging from 0.87 to 0.96. They may reflect either extensive interaction of subduction-related magmas with the continental crust or a change in the tectonic regime. The present lithological and geochemical characteristics of the studied sediments together with available zircon ages indicate rather distal provenance of their detritus. This detritus comprises fluvial-alluvial sediments accumulated in the intermontane basins, which are half-grabens or tilted fault blocks. The tectonic setting of the depositional basins is active continental margin and continental island arcs. Geochemical patterns of the Zaghra volcano-sedimentary succession indicate their correlation with the Dokhan Volcanics-Hammamat Clastics sequence of the Eastern Desert of Egypt. Also, the Zaghra volcanics display geochemical similarities with those exposed in Sinai, at the Rutig, Ferani and Iqna Shar'a areas. The Zaghra succession is dated as Ediacaran but is not related either to the ensimatic island arc assemblage or to the rift-related assemblage formed during the early stages of the break-up of Rodinia as previously thought.     

Sedimentology of a Devonian fault-bounded braidplain and lacustrine fill in the lower part of the Skrinkle Sandstones, Dyfed, Wales

The Upper Devonian to Lower Carboniferous Skrinkle Sandstones of the Pembroke Peninsula are predominantly continental deposits from the post-Caledonian synrift succession at the southern margin of the Upper Palaeozoic Welsh Landmass. The lower part of the Sandstones record deposition in the 30 × 10 km Tenby–Angle fault block, from which a 6- to 68-m-thick interval is described and interpreted as a lacustrine deposit succeeded by a high-energy sandy braidplain succession. The lacustrine deposit is dominated by red mudstones and ripple cross-laminated sandstones. Interbedded quartzose sandstones form a coarsening-upward sequence from the red mudstones in the basin centre, suggesting a deltaic origin, and a smooth-fronted braidplain delta model is proposed. The sequence introduces the braidplain succession, composed of groups of horizontal/low-angle laminated and trough cross-bedded sandstones. These are compared with recent ephemeral stream and sheetflood sediments and their characteristics used to depict a system of mutually erosive sheetflood and channel bodies, the latter produced during the rising and falling stages of flood events, which alternate to produce a thick multistorey sandstone. Palaeocurrent data indicate an axial drainage system from the north-west, running parallel to the main faults of the area. This is supported by the maturity and sandy nature of the sediments. Basin closure towards the south and the postulated Bristol Channel Landmass is inferred.     

Syn- and post-sedimentary controls on clay mineral assemblages in a tectonically active basin,Andean Argentinean foreland

In the northern part of the Calchaquí Valley (NW Argentina), Palaeogene Andean foreland sediments are represented by a 1400-metre-thick continental succession (QLC: Quebrada de Los Colorados Formation) consisting of claystones, siltstones, sandstones, and conglomerates representing sedimentation in fluvial-alluvial plains and alluvial fan settings. To understand the main syn- and postsedimentary variables controlling the clay mineral assemblages of this succession, we have studied the fine-grained clastic sediments by X-ray diffraction and electron microscopy, along with a detailed sedimentary facies analysis, for two representative sections. In the northern section, the whole succession was sampled and analysed by XRD, whereas in the second section, a control point 15 km to the south, only the basal levels were analysed. The XRD study revealed a strong contrast in clay mineral assemblages between these two sections as well as with sections in the central Calchaquí Valley studied previously. In the northernmost part of the study area, a complete evolution from smectite at the top to R3 illite/smectite mixed-layers plus authigenic kaolinite at the bottom, through R1-type mixed-layers in between, has been recognized, indicating the attainment of late diagenesis. In contrast, the clay mineral assemblages of equivalent foreland sediments cropping out only 15 km to the south contain abundant smectite and micas, subordinate kaolinite and chlorite, and no I/S mixed-layers to the bottom of the sequence. Early diagenetic conditions were also inferred in a previous study for equivalent sediments of the QLC Formation cropping out to the south, in the central Calchaquí Valley, as smectite occurs in basal strata. Burial depths of approximately 3000 m were estimated for the QLC Formation in the central and northern Calchaquí Valley; in addition, an intermediate to slightly low geothermal gradient can be considered likely for both areas as foreland basins are regarded as hypothermal basins. Consequently, the attainment of late diagenesis in the northernmost study area cannot be explained by significant differences in burial depth nor in geothermal gradient in relation to the section 15 km to the south nor with the central Calchaquí Valley. The formation of R3 mixed-layer I/S and authigenic kaolinite in the northern study area was most likely controlled by the circulation of hot, deep fluids along the reverse faults that bounded the Calchaquí valley. These faults were active during the Cenozoic, as evidenced by the syndepositional deformation features preserved in the studied sediments. Stress could also have been a driving force in burial diagenesis at the R3 mixed-layer I/S stage in these young continental sediments.     

Tectonics and petroleum potential of the East Arctic province

Tectonics and petroleum potential of the underexplored East Arctic area have been investigated as part of an IPY (International Polar Year) project. The present-day scenery of the area began forming with opening of the Amerasia Ocean (Canada and Podvodnikov—Makarov Basins) in the Late Jurassic—Early Cretaceous and with Cretaceous—Cenozoic rifting related to spreading in the Eurasia Basin. The opening of oceans produced pull-apart and rift basins along continental slopes and shelves of the present-day Arctic fringing seas, which lie on a basement consisting of fragments of the Hyperborean craton and Early Paleozoic to Middle Cretaceous orogens. By analogy with basins of the Arctic and Atlantic passive margins, the Cretaceous—Cenozoic shelf and continental slope basins may be expected to have high petroleum potential, with oil and gas accumulations in their sediments and basement.     

The middle pleistocene deposits of Waverley Wood Pit,Warwickshire, England

A complex of channels underlying the Baginton-Lillington Gravel (Baginton Formation) at Waverley Wood Quarry, Warwickshire is described. Fossil pollen and plant macrofossils, Coleoptera, Ostracoda, Mollusca and Mammalia are described from the channel-fill deposits. Consideration of all the evidence allows the identification of four separate stages of channel fill which largely occurred under a cool temperate climate. At the top of Channel 2 evidence for a cold, continental climatic episode can be recognised, suggesting that the whole complex was deposited under a fluctuating climate at the end of a temperate stage. At two levels in the channels human artefacts were recovered confirming the presence of Palaeolithic people in Warwickshire during the deposition of the sediments. Amino-acid geochronology suggests an age within the ‘Cromerian Complex’ Stage for the channels. The small vertebrate and molluscan faunas indicate that the deposits are no older than the latter part of the ‘Cromerian Complex’ Stage of East Anglia. The regional stratigraphic significance of the Waverley Wood succession is outlined.     

Petrology and geochemistry of greywackes of the ~1.6 Ga Middle Aravalli Supergroup,northwest India: evidence for active margin processes

Geochemical and petrological studies of the well-preserved greywacke horizon of the ‘Middle Aravalli Group’ were carried out to constrain the early evolution of the Aravalli basin. Petrological and geochemical attributes of Middle Aravalli greywackes (MAGs) such as very poor sorting, high angularity of framework grains, presence of fresh plagioclase and K-feldspars, variable Chemical Index of Alteration (CIA) index (46.7–74.5, avg. 61), and high Index of Compositional Variability (ICV) value (~1.05) suggest rapid physical erosion accompanying an active tectonic regime. The sediments record post-depositional K-metasomatism and extraneous addition of 0–25% (avg. ~10%) K is indicated. Assuming close system behaviour of immobile elements during sedimentation, various diagnostic element ratios such as Th/Sc, La/Sc, Zr/Sc, and Co/Th, Eu anomaly and rare earth element patterns of MAG suggest that the Archaean Banded Gneissic Complex (BGC) basement was not the major source of sediments. In conjunction with the dominant 1.8–1.6 Ga detrital zircon age peaks of Middle Aravalli clastic rocks, these data rather indicate that the sediments were derived from a young differentiated continental margin-type arc of andesite–dacite–rhyodacite composition. A highly fractionated mid-oceanic-ridge-basalt-normalized trace element pattern of MAGs, with characteristic enrichment of large-ion lithophile elements (LILEs), depletion of heavy rare earth elements, negative Nb-Ta, Ti and P anomalies, positive Pb anomaly, and distinctive Nb/Ta, Zr/Sm, Th/Yb, and Ta/Yb, Ce/Pb ratios envelop the composition of modern continental arc magmas (andesite–dacite) of the Andes, suggesting a subduction zone tectonic setting for precursor magma. High magnitude of LILE enrichment and high Th/Yb ratios in these sediments indicate that thick continental crust (~70 km) underlay the ‘Middle Aravalli’ continental arc, similar to the Central Volcanic Zone of the modern Andes. We propose that eastward subduction of Delwara oceanic crust beneath the BGC continent led to the formation of a continental volcanic arc, which supplied detritus to the forearc basin situated to the west. This model also explains the opening of linear ensialic basins in the Bhilwara terrain, such as in Rajpura–Dariba and Rampura–Agucha in a classical back-arc extension regime, similar to the Andean continental margin of the Mesozoic. On the basis of the recent ²⁰⁷Pb/²⁰⁶Pb detrital zircon age of Middle Aravalli sediment, a time frame between 1772 and 1586 Ma can be assigned for Middle Aravalli continental arc magmatism.     

南秦岭古生代热水沉积盆地与热水沉积成矿

扬子地块北部被动边缘的南秦岭古生代沉积盆地中,发育一套自早古生代—中生代以来的碳酸盐岩夹细碎屑岩沉积建造,形成规模巨大独具特色的以铅锌金为主的多金属成矿带。伸展构造体制下形成的裂陷或断陷型盆地中,正常水成沉积与热水沉积同盆共存。正常水成沉积中叠加的热水沉积是一个"突发事件或灾变事件",具有特殊的物质组成和产态。通过对区内沉积成矿盆地的识别、分级,二级沉积盆地中边缘部位常发育多个三级构造热水沉积成矿盆地,它受控于沉积盆地中的同生断裂,具有沉积岩相、热水沉积岩组合、显著成矿作用及物化探异常广布的特点。三级构造热水沉积成矿盆地是矿床定位的构造空间,四级热水沉积洼地为矿体(矿层)的容纳空间。区内热水沉积岩主要为重晶石(毒重石)岩、硅质岩、钠长石岩和铁碳酸盐岩类,铅锌重晶石等矿产多产于热水沉积岩中或上盘。热水沉积形成一般由早期的热水喷发交代→主期热水喷流→晚期热水喷气演变。早期的热水喷发交代往往沿矿液喷发通道,形成网脉状、角砾状矿化;主期热水喷流主要形成多金属及热水喷流相,形成块状、条带状、层纹状矿石或热水沉积岩;晚期热水喷气主要形成浸染状矿石和热水喷气岩石。     

中国滇西-泰国地区侏罗纪——第四纪盆地发育及其对比研究

 侏罗纪时东南亚大陆上形成两个大盆地,西为海相盆地,东为陆相红盆。白垩纪时大盆地闭合或解体。第三纪出现裂谷盆地,其发育受燕山期构造格局控制;拉张应力自南向北变弱,裂谷发育自南向北变晚。第四纪为上叠盆地阶段。滇西与泰国各时期盆地的对比研究有助于更好地认识其演化特征,恢复东南亚大陆侏罗纪以来不断碎裂、局部解体的历史。     

中国滇西-泰国地区侏罗纪——第四纪盆地发育及其对比研究

侏罗纪时东南亚大陆上形成两个大盆地,西为海相盆地,东为陆相红盆。白垩纪时大盆地闭合或解体。第三纪出现裂谷盆地,其发育受燕山期构造格局控制;拉张应力自南向北变弱,裂谷发育自南向北变晚。第四纪为上叠盆地阶段。滇西与泰国各时期盆地的对比研究有助于更好地认识其演化特征,恢复东南亚大陆侏罗纪以来不断碎裂、局部解体的历史。     

Interbasin correlation of the Devonian and Lower Carboniferous Angarida continental deposits

Devonian and Lower Carboniferous continental deposits in the south of the Siberian Platform formed in eight sedimentary basins localized within stable ancient land Angarida (Angaraland). Interbasin correlation of the stratigraphic units of these deposits was based mainly on analysis of paleontological data and marker horizons. It has been established that: (1) the Early and Middle Devonian flora of Angarida grew locally and only in its western part (Minusa and Rybinsk paleobasins); (2) in the Late Devonian, vegetation was dispersed over a vast area, as evidenced from the findings of its imprints in all existed sedimentary basins of continental lithogenesis; and (3) the Early Carboniferous in Angarida was the time of the flourishing of higher plants, which were abundant but poor in species. Lithologic benchmarks at different age levels of paleobasin sediments have been recognized. The most important marker horizons are composed of porcelain-like silicified tuffs, limestones with inclusions of brown chalcedony, calcilutites, salt rock, wax-like bentonitic mudstones, flint clays, tripolis, etc.     

Ammonite biostratigraphy of the Albian in the Kirchrode II borehole, Hannover, Germany

The ammonite biostratigraphy of the 279.35 m of sediments of mid-Late Albian–Early Albian age traversed by the Kirchrode II (1/94) boring is described. The borehole was drilled in the Hermann-Löns Park, Kirchrode (Hannover), northwest Germany, in the central region of the Lower Saxony sedimentary basin. The core commenced within the Kirchrode Mergel Member of the Gault Formation in sediments of Callihoplites auritus Subzone age and showed a Late Albian ammonite zonal succession similar to that previously described by Wiedmann and Owen from the lower part of the nearby Kirchrode I (1/91) core, with which it is correlated. The thick underlying clay sediments of the Minimus Ton Member (Middle Albian–late Early Albian) provided a relatively sparse ammonite fauna. In the Middle Albian part of the sediment succession, several hiatuses are present and only sediments of the lower Euhoplites loricatus Zone (Anahoplites intermedius Subzone) and the Hoplites dentatus Zone (Hoplites spathi Subzone) have been identified. This is followed downward by a thick sedimentary succession through the upper part of the Early Albian Douvilleiceras mammillatum Superzone (Otohoplites auritiformis Zone). Earlier mammillatum and perhaps latest Leymeriella tardefurcata Zone portions of the core straddling the Minimus Ton/Schwicheldt Ton boundary, did not yield ammonites. The underlying sediments at the top of the Schwicheldt Ton Member, consist of dark clays and mudstones with a good representation of the Leymeriella (Neoleymeriella) regularis Subzone and the uppermost part of the Leymeriella acuticostata Subzone (Leymeriella tardefurcata Zone). Of particular importance is the succession through the sediments of the L. (N.) regularis Subzone, hitherto poorly known in north Germany. A brief comparison and correlation is made with other surface and borehole sections in northern Germany and elsewhere. The Boreal and more cosmopolitan Tethyan elements of the fauna are indicated and discussed. An appendix of ammonites obtained from the Mittellandkanal section at Misburg of latest Albian, Arraphoceras (Praeschloenbachia) briacensis Subzone age, completes the study.     

Silurian to mid-Devonian basin development of the Melbourne Zone, Lachlan Fold Belt, southeastern Australia

The Melbourne Zone comprises Early Ordovician to Early Devonian marine turbidites, which pass conformably upward into a mid-Devonian fluviatile succession. There are four pulses of Silurian to mid-Devonian deep-marine sandstone-dominated sedimentation: Early Silurian (late Llandovery), Late Silurian (Ludlow), earliest Devonian (Lochkovian) and late Early Devonian (Emsian). Two dispersal patterns have been defined using more than 1100 palaeocurrent measurements, mainly from sole marks and cross-laminations in graded beds, together with sandstone compositions. The older pattern, of Silurian to earliest Devonian age, contains the lowest three sandstone pulses. Palaeocurrents and provenance define a wedge of southwesterly derived sediment, of largely cratonic provenance, thinning eastward. This older dispersal pattern is part of an Early Ordovician to earliest Devonian east-facing passive continental margin succession. Palaeocurrents and provenance in the Emsian sandstone pulse comprise three patterns: (1) west- to southwesterly directed palaeocurrents associated with fine- to coarse-grained, locally conglomeratic, lithic sandstones containing a high proportion of volcanic detritus; (2) east- to northeasterly directed palaeocurrents associated with fine- to medium-grained quartz-lithic sandstones; (3) north- to northwesterly and south- to southeasterly directed palaeocurrents associated with fine- to medium-grained sandstones of variable lithic composition. The palaeocurrent and provenance pattern defines a NNW-elongate basin with a tectonically active eastern margin, and is similar to the coeval Mathinna basin of northeastern Tasmania. Both basins are part of the same system of wrench basins, which developed along the western side of the Wagga–Omeo Metamorphic Belt during the earliest Devonian to Middle Devonian. The change in tectonic setting in the earliest Devonian appears to have occurred during an interval of significant dextral translation of the eastern Lachlan Fold Belt towards the SSE along the Governor and associated fault zones.     

The caradoc rocks around llyn cowlyd,North Wales

A thick succession of Middle Caradoc sediments (Glanrafon Beds) with occasional volcanic horizons is described. Faunas found within the succession prove a Soudleyan to Lower Longvillian age for these sediments. Detailed mapping has shown the presence of an unconformity between the Glanrafon Beds and the overlying Lower Rhyolite Tuff of the Snowdon Volcanic Series. A new fauna from the sediments within the Capel Curig Volcanic Series proves a Soudleyan (?Lower) age for this period of vulcanicity.     

Cenozoic graben facies in the Middle Amur sedimentary basin as inferred from seismic and electrical exploration

Most of the grabens of the Middle Amur sedimentary basin (MASB) are usually characterized by similar structures typical of continental rifts. Based on models elaborated for the sedimentary infill in well-studied rift basins, seismic facies developed in grabens of the MASB are first analyzed. The analysis revealed seismic facies characteristic of different parts of asymmetrical basins: facies of fans developed on steep slopes and facies of coastal shoals, alluvial plains, and deltas occurring on gentle slopes. Seismic facies peculiar of deep lacustrine settings that are considered promising with respect to oil-and gas-bearing source rocks is recognized. Correlation of seismic and drilling data confirms the correctness of the interpretations and shows that boreholes penetrated a thin sequence of deep-water lacustrine sediments. Using the vertical electrical sounding method, a low-resistivity sequence that is most promising for discovery of lacustrine sediments is defined in the southwestern and eastern parts of the MASB. The lowest values of the specific resistivity in this sequence (7–8 Ohm · m) are recorded in its southeastern part, where a borehole partly recovered a relatively thick silty-clayey sequence.     

Gondwana biostratigraphy of the Purnea Basin (eastern Bihar,India), and its correlation with Rajmahal and Bengal Gondwana basins

Integrated biostratigraphic studies are undertaken on the newly discovered Gondwana successions of Purnea Basin which have been recognized in the subsurface below the Neogene Siwalik sediments. The four exploratory wells, so far drilled in Purnea Basin, indicated the presence of thick Gondwana sussession (± 2450m) with varied lithological features. However, precise age of different Gondwanic lithounits of this basin and their correlation with standard Gondwana lithounits is poorly understood due to inadequate biostratigraphic data.Present biostratigraphic studies on the Gondwana successions in the exploratory wells of PRN-A, RSG-A, LHL-A and KRD-A enable recognition of fifteen Gondwanic palynological zones ranging in age from Early Permian (Asselian-Sakmarian) to Late Triassic (Carnian-Norian). Precise age for the Gondwanic palynological zones, recognized in the Purnea Basin and already established in other Indian Gondwana basins, are provided in the milieu of additional palynological data obtained from the Gondwana successions of this basin.The Lower Gondwana (Permian) palynofloras of Purnea Basin recorded from the Karandighi, Salmari, Katihar and Dinajpur formations resemble the palynological assemblages earlier recorded from the Talchir, Karharbari, Barakar and Raniganj formations respectively, and suggests the full development of lower Gondwana succession in this basin. The Upper Gondwana (Triassic) succession of this basin is marked by the Early and Middle to Late Triassic palynofloras that resemble Panchet and Supra-Panchet (Dubrajpur/Maleri Formation) palynological assemblages, and indicates the occurrence of complete Upper Gondwana succession also in the Purnea Basin.The lithological and biostratigraphic attributes of Gondwana sediments from Purnea, Rajmahal and western parts of Bengal Basin (Galsi Basin) are almost similar and provides strong evidences about the existence of a distinct N-S trending Gondwana Graben, referred as the Purnea-Rajmahal-Galsi Gondwana Graben. Newly acquired biostratigraphic data from the Gondwana sediments of CHK-A, MNG-A and PLS-A wells from central part of Bengal Basin and Bouguer anomaly data suggest that these wells fall in a separate NE-SW trending graben of “Chandkuri-Palasi-Bogra Gondwana Graben”. Although, the post-Gondwana latest Jurassic-Early Cretaceous Rajmahal Traps and and intertrappean beds succeed the Upper Gondwana successions in Rajmahal, Galsi and Chandkuri-Palasi Gondwana basins, but not recorded in the drilled wells of Purnea Basin, instead succeeded by the Neogene Siwalik sediments.     

Evidence for Jurassic subduction from the Northern Calcareous Alps (Berchtesgaden; Austroalpine,Germany)

The closure of the western part of the Neotethys Ocean started in late Early Jurassic. The Middle to early Late Jurassic contraction is documented in the Berchtesgaden Alps by the migration of trench-like basins formed in front of a propagating thrust belt. Due to ophiolite obduction these basins propagated from the outer shelf area (=Hallstatt realm) to the interior continent (=Hauptdolomit/Dachstein platform realm). The basins were separated by nappe fronts forming structural highs. This scenario mirrors syn-orogenic erosion and deposition in an evolving thrust belt. Active basin formation and nappe thrusting ended around the Oxfordian/Kimmeridgian boundary, followed by the onset of carbonate platforms on structural highs. Starved basins remained between the platforms. Rapid deepening around the Early/Late Tithonian boundary was induced by extension due to mountain uplift and resulted in the reconfiguration of the platforms and basins. Erosion of the uplifted nappe stack including obducted ophiolites resulted in increased sediment supply into the basins and final drowning and demise of the platforms in the Berriasian. The remaining Early Cretaceous foreland basins were filled up by sediments including siliciclastics. The described Jurassic to Early Cretaceous history of the Northern Calcareous Alps accords with the history of the Western Carpathians, the Dinarides, and the Albanides, where (1) age dating of the metamorphic soles prove late Early to Middle Jurassic inneroceanic thrusting followed by late Middle to early Late Jurassic ophiolite obduction, (2) Kimmeridgian to Tithonian shallow-water platforms formed on top of the obducted ophiolites, and (3) latest Jurassic to Early Cretaceous sediments show postorogenic character.