ABSTRACT: Organic-rich, Oil-prone Triassic-Lower Jurassic Source Rocks and a New Exploration Play Type in Southern Colville Basin and East-central Brooks Range Foothills, Northern Alaska

AAPG Bulletin ◽  
2001 ◽  
Vol 85 ◽  
Author(s):  
C.G. Mull1, Ellen E. Harris1, M.T.
Keyword(s):  
Lower Jurassic ◽  
Source Rocks ◽  
Brooks Range ◽  
East Central ◽  
Northern Alaska

Timing of fluorite mineralization and exhumation events in the east Central Alborz Mountains, northern Iran: constraints from fluorite (U–Th)/He thermochronometry

2021 ◽  
pp. 1-17
Author(s):  
Behnam Shafiei Bafti ◽  
István Dunkl ◽  
Saeed Madanipour
Keyword(s):  
Thermal Relaxation ◽  
Geothermal Gradient ◽  
Source Rocks ◽  
Lower Amount ◽  
Mining District ◽  
Northern Iran ◽  
East Central ◽  
Central Alborz ◽  
Ore Mineralization ◽  
History Of

Abstract The recently developed fluorite (U–Th)/He thermochronology (FHe) technique was applied to date fluorite mineralization and elucidate the exhumation history of the Mazandaran Fluorspar Mining District (MFMD) located in the east Central Alborz Mountains, Iran. A total of 32 fluorite single-crystal samples from four Middle Triassic carbonate-hosted fluorite deposits were dated. The presented FHe ages range between c. 85 Ma (age of fluorite mineralization) and c. 20 Ma (erosional cooling during the exhumation of the Alborz Mountains). The Late Cretaceous FHe ages (i.e. 84.5 ± 3.6, 78.8 ± 4.4 and 72.3 ± 3.5 Ma) are interpreted as the age of mineralization and confirm an epigenetic origin for ore mineralization in the MFMD, likely a result of prolonged hydrothermal circulation of basinal brines through potential source rocks. Most FHe ages scatter around the Eocene Epoch (55.4 ± 3.9 to 33.1 ± 1.7 Ma), recording an important cooling event after heating by regional magmatism in an extensional tectonic regime. Cooling of the heated fluorites, as a result of thermal relaxation in response to geothermal gradient re-equilibration after the end of magmatism, or exhumation cooling during extensional tectonics characterized by lower amount of erosion are most probably the causes of the recorded Eocene FHe cooling ages. Oligocene–Miocene FHe ages (i.e. 27.6 ± 1.4 to 19.5 ± 1.1 Ma) are related to the accelerated uplift of the whole Alborz Mountains, possibly as a result of the initial collision between the Afro-Arabian and Eurasian plates further to the south.

Regionally metamorphosed, calc-silicate-hosted deposits of the Brooks Range, northern Alaska

1986 ◽  
Vol 81 (7) ◽  
pp. 1728-1752 ◽  
Author(s):  
R. J. Newberry ◽  
J. T. Dillon ◽  
D. D. Adams
Keyword(s):  
Brooks Range ◽  
Northern Alaska

scholarly journals Three source rocks discovered in the Mid-Lower Jurassic, Dunhuang Basin in China

China Geology ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 162-163
Author(s):  
Cai-qin Bi ◽  
◽  
Zhong-kai Lin ◽  
Ya Tian ◽  
Zhi-li Du ◽  
...  
Keyword(s):  
Lower Jurassic ◽  
Source Rocks

HYDROCARBON HABITAT OF THE SURAT/BOWEN BASIN

1982 ◽  
Vol 22 (1) ◽  
pp. 213 ◽  
Author(s):  
B. M. Thomas ◽  
D. G. Osborne ◽  
A. J. Wright
Keyword(s):  
Oil And Gas ◽  
Lower Jurassic ◽  
Source Rocks ◽  
Lateral Migration ◽  
Early Maturity ◽  
Oil And Gas Fields ◽  
Basement Rocks ◽  
Origin Of Oil ◽  
Gas Fields ◽  
Geochemical Studies

Ever since the early discoveries at Cabawin (1960) and Moonie (1961), the origin of oil and gas in the Surat/Bowen Basin has been a subject of speculation. Hydrocarbons have been found in reservoirs ranging in age from Permian to Early Jurassic; even fractured pre-Permian 'basement' rocks have occasionally recorded shows.Recent geochemical studies have identified rich source rocks within the Jurassic, Triassic and Permian sequences. The Middle Jurassic Walloon Coal Measures are thermally immature throughout the Surat Basin and are unlikely to have generated significant amounts of hydrocarbons. Lower Jurassic Evergreen Formation source rocks have reached 'nominal early maturity' (VR = 0.6) in parts of the basin. The Middle Triassic Moolayember Formation lies within the oil generation zone in the northern Taroom Trough. However, no oil has yet been confidently correlated with either a Jurassic or a Triassic source. On geochemical and geological grounds it is likely that most, if not all, of the hydrocarbons discovered to date were generated from Permian source rocks.The probability of finding gas as well as oil in Permian, Triassic or Jurassic reservoirs increases from south to north, in accord with organic maturity trends in the Permian of the Taroom Trough. On the narrow thrust-bounded eastern flank, vertical migration has occurred, resulting in oilfields at Moonie and Bennett. In contrast, extensive lateral migration of hydrocarbons across the gentle western flank of the basin is indicated by numerous small oil and gas fields on the Roma Shelf and Wunger Ridge.

STRATIGRAPHIC CONCEPTS AND PETROLEUM POTENTIAL OF THE DENISON TROUGH, QUEENSLAND

1979 ◽  
Vol 19 (1) ◽  
pp. 43
Author(s):  
R. J. Paten ◽  
L. N. Brown ◽  
R. D. Groves
Keyword(s):  
Structural Control ◽  
High Potential ◽  
Source Rocks ◽  
East Central ◽  
Petroleum Potential ◽  
Area Source ◽  
Depositional Processes ◽  
Diagenetic Processes ◽  
Gas Fields ◽  
Active Exploration

The Denison Trough in east central Queensland contains up to 4600m of both marine and non-marine, Permian and Triassic rocks. The sequence comprises thick mature source rocks interlayered and interfingering with thick sandstone intervals. Good to excellent sandstone reservoirs occur, though their distribution and development is sporadic and controlled by both despositional and diagenetic processes. This is the main limitation to the potential of the area. Source rocks appear to be gas or gas/condensate prone, although liquids generation cannot be discounted.Exploration to date, comprising extensive seismic and the drilling of 39 exploration and 29 assessment wells, has led to the discovery of four small gas fields with combined reserves of approximately 850-1140m3 x 106. These reserves are insufficient to justify exploitation at this time. Apart from the fields, numerous gas shows and minor oil shows have been recorded throughout the Permian sequence, establishing beyond doubt that the trough is a hydrocarbon province.The trough is assessed as having a high potential for the discovery of additional gas reserves, with a possible 15-55m3 x 109 being present both in deep structural plays and in shallower, essentially stratigraphic, plays. Further successful exploration will require both good quality structural control, particularly at depth and a sound understanding of the depositional processes controlling the development of reservoir sands. Since active exploration effectively ceased in the area in 1970, a great deal of stratigraphic information has become available. This has led to a better understanding of the stratigraphy than was previously possible. In addition, advances in seismic technology over the last decade have made available much more reliable exploration tools, with respect to achieving good quality, deep structural control and to stratigraphic interpretation and reservoir trend prediction.The Denison Trough is considered to be one of the most prospective of Australia's onshore basins. It remains to be seen; however, if the application of present stratigraphic/depositional knowledge and new seismic technology will result in its potential being realised.

SIMPSON DESERT SUB-BASIN—A PROMISING PERMIAN TARGET

1973 ◽  
Vol 13 (1) ◽  
pp. 33
Author(s):  
George E. Williams
Keyword(s):  
Lower Jurassic ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Seismic Exploration ◽  
Upper Permian ◽  
Lower Permian ◽  
Geophysical Surveys ◽  
Carbonaceous Shales ◽  
Cap Rock ◽  
Simpson Desert

Sediments of three major basins occur in the Simpson Desert region of central Australia:Cambro -Ordovician dolomites and sandstones, and Siluro- Devonian conglomerates, sandstones and shales, related to the Amadeus Basin:Permian conglomerates, sandstones, shales and coals of the Simpson Desert Sub-basin, the extensive eastern lobe of the Pedirka Basin:Mesozoic sandstones and shales of the Eromanga Basin.Principal petroleum exploration interest is presently directed toward the Permian sediments, which have many features in common with the petroleum producing Permian section of the neighbouring Cooper Basin.Lower Permian sediments known from drilling in the Simpson Desert Sub-basin comprise glaciofluvial conglomerates and sandstones overlain by fluvial and lacustrine sandstones, silt-stones, shales and coals. The maximum thickness encountered in wells is 1,479 ft (448 m) in Mokari 1.Recent seismic exploration 50 to 100 mi (80-160 km) west of Poeppel Corner in the deeper part of the Simpson Desert Sub-basin indicates that an additional sediment package up to 1,500 ft (350 m) thick occurs at depths of 6,500 to 7,500 ft (2,000-2,300 m) between Lower Permian and Lower Jurassic sections. This sediment package, nowhere penetrated by drilling, may be Middle to Upper Permian and/or Triassic in age. It is of great significance to petroleum exploration in the sub-basin and substantially upgrades the hydrocarbon prospects of the region.Permian sediments in the Simpson Desert Sub-basin thin by onlap, wedge out and stripping over the crests of anticlinal growth structures. Crestal sediments probably comprise mainly porous sandstones, grading off-structure into thicker sequences containing carbonaceous shales and coals. Such carbonaceous potential source rocks are probably best developed in the deepest part of the sub-basin, where Triassic cap rock may also be present. Two particularly promising drilling targets—the Colson Anticline and the East Colson Anticline—have been revealed by recent geophysical surveys in this portion of the sub-basin. Wells drilled on these structures may intersect Permo-Triassic sediments up to 2,200 + ft (670 in) thick which are comparable in age and type with producing sections in the Cooper Basin.

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