Preliminary chart showing distribution of rock types, lithologic groups, and depositional environments for some Tertiary, Upper and Lower Cretaceous, and Upper and Middle Jurassic rocks in the subsurface between Altamont oil field and San Arroyo gas field, north-central to southeastern Uinta Basin, Utah

Abstract The Mauddud Formation is Iraq’s most significant and widely distributed Lower Cretaceous formation. This Formation has been investigated at a well-23 and a well-6 within Ratawi oil field southern Iraq. In this work, 75 thin sections were produced and examined. The Mauddud Formation was deposited in a variety of environments within the carbonate platform. According to microfacies analysis studying of the Mauddud Formation contains of twelve microfacies, this microfacies Mudstone to wackestone microfacies, bioclastic mudstone to wackestone microfacies, Miliolids wackestone microfacies,Orbitolina wackestone microfacies, Bioclastic wackestone microfacies, Orbitolina packstone microfacies, Peloidal packstone microfacies, Bioclastic packstone microfacies, Peloidal to Bioclastic packstone microfacies, Bioclastic grainstone microfacies, Peloidal grainstone microfacies, Rudstone microfacies. Deep sea, Shallow open marine, Restricted, Rudist Biostrome, Mid – Ramp, and Shoals are the six depositional environments in the Mauddud Formation based on these microfacies.

EXAMPLES OF ICHNOFOSSIL ASSEMBLAGES IN THE LOWER CRETACEOUS WABISKAW MEMBER AND THE CLEARWATER FORMATION OF THE MARTEN HILLS GAS FIELD, NORTH-CENTRAL ALBERTA, CANADA

Applications of Ichnology to Petroleum Exploration ◽

10.2110/cor.92.01.0383 ◽

1992 ◽

pp. 383-399 ◽

Cited By ~ 3

Author(s):

T. L. Bradley ◽

S. G. Pemberton

Keyword(s):

Lower Cretaceous ◽

Gas Field ◽

North Central ◽

Clearwater Formation

J. A. Jeletzky 1980. Lower Cretaceous and Jurassic rocks of McDougall Pass area and some adjacent areas of north-central Richardson Mountains, northern Yukon Territory and northwestern district of Mackenzie, N.W.T. (NTS-116P/9 and 116P/10): a reappraisal. Geol. Surv. Can. Paper 78–22. vi + 35 pp., 9 figs (1 in pocket), 3 plates. Ottawa. Price $5.00 (Canada); $6.00 (other countries). ISBN 0 660 10280 3.

Geological Magazine ◽

10.1017/s0016756800028818 ◽

1980 ◽

Vol 117 (5) ◽

pp. 510-510

Author(s):

C. A. G. P.

Keyword(s):

Lower Cretaceous ◽

Yukon Territory ◽

North Central ◽

Jurassic Rocks ◽

Richardson Mountains

OFFSHORE GIPPSLAND BASIN FIELDS

The APPEA Journal ◽

10.1071/aj70015 ◽

1971 ◽

Vol 11 (1) ◽

pp. 85 ◽

Cited By ~ 1

Author(s):

B. R. Griffith ◽

E. A. Hodgson

Keyword(s):

Lower Cretaceous ◽

Oil And Gas ◽

Oil Field ◽

Gas Field ◽

Field Development ◽

Oil And Gas Field ◽

Cumulative Production ◽

Gippsland Basin ◽

Offshore Field ◽

Unconformity Surface

The offshore Gippsland Basin, underlies the continental shelf and slope between eastern Victoria and Tasmania.The basin is filled with up to 25,000' of sediment, varying in age from Lower Cretaceous to Recent. The Lower Cretaceous section is represented by at least 10,000' of nonmarine greywackes of the Strzelecki Group. The overlying sediments of Upper Cretaceous to Eocene age comprise the interbedded sandstones, siltstones, shales and coals of the Latrobe Group, with a cumulative thickness of about 15,000'. Offshore, the Latrobe Group is overlain unconformably by up to 1500' of calcareous mudstones of the Lakes Entrance Formation and up to 5000' of Gippsland Limestone carbonates. Pliocene to Recent carbonates, reaching a maximum thickness of about 1000', complete the sedimentary section of the basin.Australia's first commercial offshore field, the Barracouta oil and gas field, was discovered in the Gippsland Basin in February 1965. Further exploratory drilling over the following two and a half years led to the discovery of the Marlin gas field and the Kingfish and Halibut oil fields.The principal hydrocarbon accumulations are reservoired by sediments of the Latrobe Group within closed structural highs on the Latrobe unconformity surface. Seal is provided by the mudstones and marls of the Lakes Entrance Formation and Gippsland Limestone.A field development programme was initiated immediately after Barracouta had been confirmed as a commercial gas reservoir. By the end of 1967, the Barracouta 'A' platform had been erected. Construction and positioning of the Marlin, Halibut and the two Kingfish platforms followed.To date development drilling has been completed on the Barracouta and Halibut fields, while development of the Marlin field has been temporarily suspended following completion of four wells. Development of the Kingfish oil field which commenced in March 1970, is still in a relatively early stage.The Barracouta field has been producing gas and oil since March and October, 1969 respectively. The Marlin gas field was put on stream in November, 1969 and the Halibut oil field in March 1970. As yet no wells drilled in the Kingfish oil field have been completed for production.The four fields provide a major source of hydrocarbons for the Australian market. By the end of September, 1970 cumulative production of sales quality gas from the Barracouta and Marlin fields was almost 23 BCF. Cumulative production of stabilised oil from Barracouta was 2 million barrels and over 26 million barrels from Halibut.

Modeling of thermal and burial histories for selected deep formations in the Middle-Jurassic to Lower Cretaceous in Siba Gas field, Southern Iraq

Modeling Earth Systems and Environment ◽

10.1007/s40808-020-00717-w ◽

2020 ◽

Vol 6 (2) ◽

pp. 627-643 ◽

Cited By ~ 1

Author(s):

Mohammed Q. Aljazaeri ◽

Amna M. Handhal

Keyword(s):

Lower Cretaceous ◽

Middle Jurassic ◽

Gas Field ◽

Southern Iraq

Palaeoenvironments of northwestern Bulgaria and northeastern Serbia during the Jurassic

Geologica Balcanica ◽

10.52321/geolbalc.49.1.67 ◽

2020 ◽

Vol 49 (1) ◽

pp. 67-72

Author(s):

Platon Tchoumatchenco

Keyword(s):

Middle Jurassic ◽

Sedimentary Facies ◽

Depositional Environments ◽

Moesian Platform ◽

Sketch Maps ◽

Danube Region ◽

Jurassic Rocks ◽

The Subject ◽

Depositional Setting ◽

Middle Callovian

Jurassic rocks in the Danube Region of northwestern Bulgaria and northeastern Serbia have been the subject of numerous earlier studies that have shown notable similarities between their sedimentary facies and depositional environments. In terms of regional palaeotectonic zonation, this area represents the westernmost parts of the Vidin Early–Middle Jurassic Complex Horst and the Mihaylovgrad Early–Middle Jurassic Graben in NW Bulgaria, as well as the easternmost part of the Lower Danubicum in NE Serbia, which collectively take part of the Jurassic Moesian Platform. For compiling an overall conception of the palaeoenvironments that existed during the Jurassic, nine palaeoenvironmental sketch maps, from the Aalenian to the late Tithonian, have been composed in this study, based on reinterpretation of the data borrowed from previous literature. It became evident that the Middle Jurassic sedimentary successions of the Danube Region record an evolution from an initially isolated lacustrine-palustrine depositional setting (Aalenian) to rapidly expanding shallow to moderately deeper-marine sandy-calcareous setting (late Bajocian–early Callovian). From the middle Callovian and onwards, during the Late Jurassic, the region became an area of laterally extensive pelagic and platform carbonate deposition. This interpretation is consistent with the available earlier data, but it links the facies and their respective settings from NW Bulgaria to NE Serbia, which has not been made to date and will be of benefit for future regional correlations.

Lower Cretaceous and Jurassic rocks of McDougall Pass area and some adjacent areas of north-central Richardson Mountains, northern Yukon Territory and northwestern District of Mackenzie, N.W.T. (NTS-116P/09 and 116P/10): a reappraisal

10.4095/106235 ◽

1980 ◽

Cited By ~ 1

Author(s):

J A Jeletzky

Keyword(s):

Lower Cretaceous ◽

Yukon Territory ◽

North Central ◽

Jurassic Rocks ◽

Richardson Mountains

Jura-Cretaceous (Oxfordian to Cenomanian) stratigraphy of the north-central Bowser Basin, northern British Columbia

Canadian Journal of Earth Sciences ◽

10.1139/e89-081 ◽

1989 ◽

Vol 26 (5) ◽

pp. 1001-1012 ◽

Cited By ~ 8

Author(s):

H. O. Cookenboo ◽

R. M. Bustin

Keyword(s):

British Columbia ◽

Lower Cretaceous ◽

Middle Jurassic ◽

Late Jurassic ◽

Upper Jurassic ◽

Thick Section ◽

North Central ◽

The North

Three new formations of Late Jurassic and Early to mid-Cretaceous age are defined for a 2000 m thick section of Jura-Cretaceous rocks exposed in the north-central Bowser Basin. The Currier Formation (Oxfordian to Kimmeridgian or Tithonian) consists of 350–600 m of interbedded shales, siltstones, sandstones, coals, and carbonates. The McEvoy Formation (Barremian to as young as Albian) consists of 400–800 m of siltstones and shales with minor sandstones, thin coals, limestones, and conglomerates. The Devils Claw Formation (in part mid-Albian to Cenomanian) consists of 300–600 m of strata characterized by thick pebble and cobble conglomerates, with associated coarse sandstones and minor siltstones and shales.Two successive coarsening-upward sequences are identified in the study area. The first begins with Middle Jurassic marine shales of the Jackson unit grading upwards to coarser Upper Jurassic facies of the Currier Formation. The Currier Formation is conformably or unconformably overlain by siltstones and shales of the Lower Cretaceous McEvoy Formation, which forms the base of a second coarsening-upward sequence. Conglomerates appear with increasing frequency in the upper McEvoy and are the dominant lithology of the overlying Devils Claw Formation. The contact between the McEvoy and Devils Claw formations is gradational. The Devils Claw Formation forms the top of the second coarsening-upward sequence.The Currier Formation (Late Jurassic) is equivalent to the upper units of the Bowser Lake Group. The McEvoy and the Devils Claw formations (Barremian to Cenomanian) are coeval with the Skeena Group (Hauterivian? to Cenomanian). A probable unconformity separating the Upper Jurassic Currier Formation from the Lower Cretaceous McEvoy Formation correlates with a hiatus in the southern Bowser Basin and probably represents a regional unconformity.