Depth-Dependent Transformation of Kaolinite to Dickite In Sandstones of the Norwegian Continental Shelf

AbstractReplacement of kaolinite by dickite has been observed to occur with increasing depth of burial in sandstones from three different basins on the Norwegian continental shelf. In the Garn Formation (Middle Jurassic) of Haltenbanken, samples from 1.4-2-7 km below the sea floor (110°C) contain kaolinite, whereas deeper than 3.2 km (130°C) mainly dickite is present. In the Statfjord Formation (Late Triassic-Early Jurassic) from Gullfaks and Gullfaks Sør Fields, transformation of kaolinite to dickite occurs at ~3.1 km below the sea floor (120°C) From the Stø and Nordmela Formations (Lower to Middle Jurassic) to the Troms Area, kaolin polytypes have been identified in only two shallow and two deep samples, but the results are consistent with the transformation depth determined in two other areas studied. These occurrences are significant because they allow the temperature of the kaolinite/dickite transformation to be established with greater confidence than had been possible previously. Also the observation of this transformation in all three areas so far examined indicates that it may be a general and predictable feature of kaolinbearing sandstones worldwide and therefore a potentially reliable paleogeothermometer. In most cases, the kaolinite occurs as relatively large vermicular crystals, whereas dickite forms more euhedral, blockier crystals. This morphological difference, together with the nature of the structural difference in octahedral occupancy between the kaolinite and dickite, suggests that the transformation occurs by dissolution and reprecipitation, rather then in the solid state.

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Provenance of Jurassic sedimentary rocks of south-central Quesnellia, British Columbia: implications for paleogeography

Canadian Journal of Earth Sciences ◽

10.1139/e03-073 ◽

2004 ◽

Vol 41 (1) ◽

pp. 103-125 ◽

Cited By ~ 12

Author(s):

Nathan T Petersen ◽

Paul L Smith ◽

James K Mortensen ◽

Robert A Creaser ◽

Howard W Tipper

Keyword(s):

Detrital Zircon ◽

Middle Jurassic ◽

Sedimentary Rocks ◽

Source Area ◽

Lower Jurassic ◽

Early Jurassic ◽

Late Triassic ◽

Nd Isotopes ◽

South Central ◽

History Of

Jurassic sedimentary rocks of southern to central Quesnellia record the history of the Quesnellian magmatic arc and reflect increasing continental influence throughout the Jurassic history of the terrane. Standard petrographic point counts, geochemistry, SmNd isotopes and detrital zircon geochronology, were employed to study provenance of rocks obtained from three areas of the terrane. Lower Jurassic sedimentary rocks, classified by inferred proximity to their source areas as proximal or proximal basin are derived from an arc source area. Sandstones of this age are immature. The rocks are geochemically and isotopically primitive. Detrital zircon populations, based on a limited number of analyses, have homogeneous Late Triassic or Early Jurassic ages, reflecting local derivation from Quesnellian arc sources. Middle Jurassic proximal and proximal basin sedimentary rocks show a trend toward more evolved mature sediments and evolved geochemical characteristics. The sandstones show a change to more mature grain components when compared with Lower Jurassic sedimentary rocks. There is a decrease in εNdT values of the sedimentary rocks and Proterozoic detrital zircon grains are present. This change is probably due to a combination of two factors: (1) pre-Middle Jurassic erosion of the Late Triassic Early Jurassic arc of Quesnellia, making it a less dominant source, and (2) the increase in importance of the eastern parts of Quesnellia and the pericratonic terranes, such as Kootenay Terrane, both with characteristically more evolved isotopic values. Basin shale environments throughout the Jurassic show continental influence that is reflected in the evolved geochemistry and SmNd isotopes of the sedimentary rocks. The data suggest southern Quesnellia received material from the North American continent throughout the Jurassic but that this continental influence was diluted by proximal arc sources in the rocks of proximal derivation. The presence of continent-derived material in the distal sedimentary rocks of this study suggests that southern Quesnellia is comparable to known pericratonic terranes.

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Mesozoic Intracontinental Orogeny in the Tectonic History of the Kolyvan’– Tomsk Folded Zone (Southern Siberia): a Synthesis of Geological Data and results of Apatite Fission Track Analysis

Russian Geology and Geophysics ◽

10.2113/rgg20204172 ◽

2021 ◽

Vol 62 (9) ◽

pp. 1006-1020

Author(s):

F.I. Zhimulev ◽

E.V. Vetrov ◽

I.S. Novikov ◽

G. Van Ranst ◽

S. Nachtergaele ◽

...

Keyword(s):

Early Cretaceous ◽

Middle Jurassic ◽

Late Jurassic ◽

Fission Track ◽

Early Jurassic ◽

Late Triassic ◽

Apatite Fission Track ◽

History Of ◽

Paleozoic Rocks ◽

Orogenic Events

Abstract —The Kolyvan’–Tomsk folded zone (KTFZ) is a late Permian collisional orogen in the northwestern section of the Central Asian Orogenic Belt. The Mesozoic history of the KTFZ area includes Late Triassic–Early Jurassic and Late Jurassic–Early Cretaceous orogenic events. The earlier event produced narrow deep half-ramp basins filled with Early–Middle Jurassic molasse south of the KTFZ, and the later activity rejuvenated the Tomsk thrust fault, whereby the KTFZ Paleozoic rocks were thrust over the Early–Middle Jurassic basin sediments. The Mesozoic orogenic events induced erosion and the ensuing exposure of granitoids (Barlak complex) that were emplaced in a within-plate context after the Permian collisional orogeny. Both events were most likely associated with ocean closure, i.e., the Paleothetys Ocean in the Late Triassic–Early Jurassic and the Mongol–Okhotsk Ocean in the Late Jurassic–Early Cretaceous. The apatite fission track (AFT) ages of granitoids from the Ob’ complex in the KTFZ range between ~120 and 100 Ma (the Aptian and the Albian). The rocks with Early Cretaceous AFT ages were exhumed as a result of denudation and peneplanation of the Early Cretaceous orogeny, which produced a vast Late Cretaceous–Paleogene planation surface. The tectonic pattern of the two orogenic events, although being different in details, generally inherited the late Paleozoic primary collisional structure of the Kolyvan’–Tomsk zone.

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TRIASSIC-JURASSIC DEPOSITIONAL HISTORY OF THE DAMPIER AND BEAGLE SUB-BASINS, NORTHWEST SHELF OF AUSTRALIA

The APPEA Journal ◽

10.1071/aj79003 ◽

1980 ◽

Vol 20 (1) ◽

pp. 25

Author(s):

A. Crostella ◽

T. Barter

Keyword(s):

Middle Jurassic ◽

Early Jurassic ◽

Late Triassic ◽

Depositional History ◽

Reservoir Rocks ◽

Potential Source ◽

Regional Tectonic ◽

History Of ◽

Extensional Faulting ◽

Coastal Sedimentation

Very large gas accumulations were discovered in the Dampier Sub-basin on the Northwest Shelf of Australia during the early 1970's. The majority of the reservoirs are fluvial and marginal marine sandstones within a thick intra-cratonic clastic sequence of Early Triassic to Middle Jurassic age. Parts of this succession have been penetrated by more than 60 wells within the Dampier Sub-basin and the adjacent Beagle and Barrow Sub-basins.Broad regional palaeoenvironmental episodes have been established using oriented core supplemented by seismic, palaeontologic and wireline log data. The earliest episode was an Early to Middle Triassic transgressive-regressive cycle which led to marine and marginal marine deposition, followed during the Middle to Late Triassic by dominantly fluvial deposition. A transgression began in the early Rhaetian, characterised by deltaic, estuarine, lagoonal and coastal sedimentation which gave way to fully marine conditions during the Early Jurassic (Hettangian); this was followed by a regressive cycle.A regional tectonic episode followed which resulted in development of troughs, and brought about associated extensional faulting. Marine conditions which typified the Early Jurassic (Sinemurian) persisted until the beginning of the Middle Jurassic (Bajocian) in the Dampier Sub-basin, but passed rapidly to a fluvio-deltaic cycle in the Beagle Sub-basin. Regressive conditions extended gradually westward until sedimentation was interrupted by the onset of major continental break-up toward the end of the Middle Jurassic.The deposition of an alternating sequence of thick shale and sand during mainly restricted marine and continental conditions has provided the area with potential source and reservoir rocks.

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Stratigraphic architecture of the northern Oman continental margin - Mesozoic Hamrat Duru Group, Hawasina complex, Oman

GeoArabia ◽

10.2113/geoarabia090281 ◽

2004 ◽

Vol 9 (2) ◽

pp. 81-132 ◽

Cited By ~ 8

Author(s):

Ingo Blechschmidt ◽

Paulian Dumitrica ◽

Albert Mater ◽

Leopold Krystyn ◽

Tjerk Peters

Keyword(s):

Late Cretaceous ◽

Middle Jurassic ◽

Early Jurassic ◽

Late Triassic ◽

Time Interval ◽

Oman Mountains ◽

Stratigraphic Architecture ◽

Lithostratigraphic Units ◽

Nappe Complex ◽

Arabian Platform

ABSTRACT The Triassic to Late Cretaceous deep-marine sediments of the Hamrat Duru Group, Oman Mountains, represent a subunit of the Hawasina nappe-complex which was deposited in a deep marine basin. During the Late Cretaceous SSW-directed obduction of the Semail Ophiolite, the Hawasina complex was emplaced onto the autochthonous cover of the Arabian basement, while the original configuration of the basin was destroyed. New lithostratigraphic results and high-resolution radiolarian and conodont biostratigraphy lead to a revised stratigraphic scheme of the Hamrat Duru Group which conforms with the standard stratigraphical nomenclature. The Hamrat Duru Group is divided into six formations: (1) The Early Triassic (Olenekian) to Late Triassic (Upper Norian) Zulla Formation (Limestone and Shale Member, Sandstone and Shale Member, Radiolarian Chert Member and Halobia Limestone Member); (2) The Late Triassic (late Norian to Rhaetian) Al Ayn Formation; (3) The Early Jurassic (late Pliensbachian) to Middle Jurassic (early Callovian) Guwayza Formation (Tawi Sadh Member and Oolitic Limestone Member); (4) Middle Jurassic (Callovian) to Late Cretaceous (Cenomanian?) Sid’r Formation (Lower Member, Upper Member); (5) Late Cretaceous (Cenomanian? to Santonian?) Nayid Formation; and (6) Late Jurassic (early Callovian) to Early (Late?) Cretaceous Wahrah Formation. Most of the lithostratigraphic units (formations and members) show isochronous boundaries between the different outcrop areas. The stratigraphic architecture of the Hamrat Duru Group megasequence is controlled by alternating siliciclastic and carbonate sedimentation possibly related to the second-order sea-level variations. The sediments accumulated on the continental rise of the Arabian margin mostly by submarine sediment-gravity flows and hemipelagic to pelagic rainout. A close relationship of the evolution of the Arabian Platform and the adjoining slope and basinal environments is evident. Changes in carbonate supply, oceanographic circulation and/or variations in silica productivity resulted in two distinct phases of radiolarian sedimentation. The first phase corresponds to the Triassic late Anisian-early Norian time interval; the second started in the Early Jurassic late Pliensbachian and lasted, with some interruptions, up to the Late Cretaceous Coniacian. The litho- and biostratigraphic similarities between the Mesozoic Hamrat Duru Basin of the northern/central Oman Mountains and the Mesozoic Batain Basin of northeastern Oman are seen as related to Neo-Tethys-wide palaeoceanographic changes and suggest a strong interdependence of the two basins with the evolution of the Arabian Platform.

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Reappraisal of the Mesozoic tectonic transition from the Paleo-Tethyan to Paleo-Pacific domains in South China

Geological Society of America Bulletin ◽

10.1130/b35755.1 ◽

2021 ◽

Author(s):

Chengshi Gan ◽

Yuzhi Zhang ◽

Yuejun Wang ◽

Xin Qian ◽

Yang Wang

Keyword(s):

South China ◽

Middle Jurassic ◽

Late Jurassic ◽

Sedimentary Rocks ◽

Early Jurassic ◽

Igneous Rocks ◽

Late Triassic ◽

Geochemical Data ◽

South China Block ◽

Tectonic Transition

The southeastern (SE) South China Block was mainly influenced by the Paleo-Tethyan and Paleo-Pacific dynamic domains during the Mesozoic. The initial timing of the tectonic transition between these two domains in the SE South China Block still remains debated. The transition would affect the nature of the lithosphere and material provenance of sediments, and, therefore, igneous and sedimentary rocks in the area could record such dynamic processes. In this study, published geochronological and geochemical data of the Triassic and Jurassic igneous rocks and detrital zircon data of contemporaneous sedimentary rocks in the SE South China Block were compiled, aiming to provide constraints on the tectonic transition via tracing the spatial-temporal variations in the nature of the lithosphere and sedimentary provenance signals. The compiled results suggest that the magmatic intensity and volume decreased significantly from the Late Triassic to Early−Middle Jurassic, with an obvious magmatic quiescence between them, and increased from the Early−Middle Jurassic to Late Jurassic. The εNd(t) and zircon εHf(t) values of mafic rocks, granitoids, and shoshonitic rocks remarkably increased from the Late Triassic to Early−Middle Jurassic, indicative of variations in the lithospheric mantle and continental crust. Such variations suggest that the initial tectonic transition occurred at the earliest Early Jurassic. Based on the southward paleocurrents from Early Jurassic sandstone, E-W−trending extension of Early−Middle Jurassic mafic and shoshonitic rocks, and similar sedimentary provenances of Late Triassic and Early−Middle Jurassic sedimentary rocks, these features imply that the SE South China Block was not immediately influenced by the Paleo-Pacific domain during the Early−Middle Jurassic. However, from the Early−Middle Jurassic to Late Jurassic and Early Cretaceous, the spatial distribution, geochemical signatures, magmatic intensity, and magmatic volume of igneous rocks and provenance of sedimentary rocks exhibit obvious variations, and the regional fold hinge direction changed from E-W−trending to NE-trending, suggesting significant effects from Paleo-Pacific subduction on the SE South China Block. Thus, the Mesozoic tectonic transition from the Paleo-Tethyan to the Paleo-Pacific dynamic domain in the SE South China Block likely occurred during the Early−Middle Jurassic.

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Geochemical discriminators and the palaeotectonic environment of the North Mountain basalts, Nova Scotia

Canadian Journal of Earth Sciences ◽

10.1139/e80-181 ◽

1980 ◽

Vol 17 (12) ◽

pp. 1740-1745 ◽

Cited By ~ 10

Author(s):

J. M. Wark ◽

D. B. Clarke

Keyword(s):

Nova Scotia ◽

Continental Crust ◽

Early Jurassic ◽

Late Triassic ◽

Chemical Characteristics ◽

Sea Floor ◽

The North ◽

Sea Floor Spreading

The late Triassic – early Jurassic North Mountain basalts of Nova Scotia have been analyzed for various elements believed to be useful in determining the palaeotectonic environment of eruption. The discriminant diagrams show these basalts to have within-plate affinities, with a possible indication of oceanic chemical characteristics. An oceanic environment, however, is at variance with the field relations, which show the within-plate environment to be continental; thus the oceanic chemical characteristics may suggest eruption through a continental crust that was thinning prior to the onset of active sea-floor spreading later in the Jurassic.

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LA-ICP-MS U–Pb ages of detrital zircons from Middle Jurassic sedimentary rocks in southwestern Fujian: Sedimentary provenance and its geological significance

Open Geosciences ◽

10.1515/geo-2020-0185 ◽

2020 ◽

Vol 12 (1) ◽

pp. 958-976

Author(s):

Xu Zhongjie ◽

Kong Jintao ◽

Cheng Rihui ◽

Lan Yizhi ◽

Wang Liaoliang

Keyword(s):

Modal Analysis ◽

Middle Jurassic ◽

Sedimentary Rocks ◽

Early Jurassic ◽

Detrital Zircons ◽

Late Triassic ◽

Geochemical Analysis ◽

Magmatic Rocks ◽

Early Mesozoic ◽

Southwestern Fujian

AbstractIn order to determine the tectonic regime change of the early Mesozoic in the South China Block, this study analyzed sedimentary rocks in the Middle Jurassic of southwestern Fujian by modal analysis of sandstones, elemental geochemical analysis of mudstones, and detrital zircons U–Pb dating. The results show that the detrital zircons in Southwestern Fujian mainly consist of Paleoproterozoic to early Mesozoic zircons in the Middle Jurassic. Within the Dongkeng profile of the Zhangping Formation, DK5 sample (lower part) showed a major age peak at ca. 1,848 Ma and two secondary age peaks at ca. 235 and 180 Ma, while DK15 sample (middle part) showed a major age peak at ca. 1,876 Ma and two secondary age peaks at ca. 233 and 190 Ma; the age compositions of these two samples’ were similar. Modal analysis of sandstones indicated that sediments of Zhangping Formation might source from arc orogen and recycled orogen, and element geochemical analysis showed that source rocks of Zhangping Formation might be sedimentary rocks and granites. The Indosinian zircons were mainly derived from the Wuyi region, and the Yanshanian zircons were mainly derived from the Nanling region. The major age group changes from ca. 230 to 220 Ma of the Late Triassic – Early Jurassic to ca. 190 to 180 Ma of the Middle Jurassic in Southwestern Fujian, and main sources changed from Indosinian magmatic rocks in the Late Triassic – Early Jurassic to early Yanshanian magmatic rocks in the Middle Jurassic.

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The Canadian Cordillera, the Hellenides, and the Sea-Floor Spreading Theory

Canadian Journal of Earth Sciences ◽

10.1139/e72-060 ◽

1972 ◽

Vol 9 (6) ◽

pp. 709-743 ◽

Cited By ~ 32

Author(s):

Jean Dercourt

Keyword(s):

Pacific Ocean ◽

Oceanic Crust ◽

Continental Margin ◽

Middle Jurassic ◽

Late Jurassic ◽

Late Triassic ◽

Canadian Cordillera ◽

Transform Faults ◽

Sea Floor ◽

Sea Floor Spreading

The theory of plate tectonics is applied to the tectonic evolution of the Hellenides and the Canadian Cordillera. In the Hellenides a Tethyan zone of sea-floor spreading developed within the continental crust during Triassic time and functioned until the end of the Middle Jurassic. It led to the formation of two plates, each with continental and oceanic segments, that were separated in some places by accreting plate margins and in others by transform faults. In Late Jurassic time the mid-Tethyan ridge became inactive as new ridges developed in the Atlantic Ocean. From Late Jurassic to Recent time, Tethyan oceanic crust largely disappeared under one of the cratons. The chronology of tectonic events in the Hellenides corresponds well with that of sea-floor spreading in the Atlantic.Four periods of sea-floor spreading were involved in the formation of the Canadian Cordillera: (1) a Silurian? to Early Devonian period when an Archeo-Pacific Ocean separated the Canadian craton with a stable sedimentary margin from a volcanic archipelago; (2) a Middle Devonian to Permian period when the extinct volcanic archipelago was bounded to the west by a spreading Paleo-Pacific Ocean, and to the east by a tectonic contact which was consuming Archeo-Pacific oceanic crust; part of this crust was obducted over the continental margin; (3) a Late Triassic to Middle Jurassic period when a second volcanic archipelago separated a spreading Neo-Pacific Ocean from the continental margin; and (4) a Late Jurassic to Recent period where spreading occurred in both the Atlantic and Pacific Oceans, subjecting the second volcanic archipelago and the continental margin to major tectonism; since the Paleocene, the Cordillera has slid towards the NNW along transform faults.

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