Geology of the Gladys McCall Geopressured-Geothermal Prospect, Cameron Parish, Louisiana

1988 ◽  
Vol 110 (4) ◽  
pp. 255-261
Author(s):  
Chacko J. John

The Gladys McCall prospect lies at the western edge of the Rockefeller Wildlife Refuge about 88 km (55 mi) southeast of Lake Charles in Cameron Parish, Louisiana. The test well is 4825 m (15,831 ft) deep and was drilled in 1981 under the U. S. Department of Energy geopressured-geothermal research program. The well was shut in at the end of October 1987 after it had produced over 27 million barrels of brine and 676 MMscf gas, without any significant pressure decline. The stratigraphic section seen in this test well consists of alternating sandstones and shales with about 350 m (1150 ft) of net sand between 4393 m (14,412 ft) and 4974 m (16,320 ft). The producing reservoir is bounded on the north and south by faults. The east-west dimension is poorly defined due to lack of deep well control. Eleven prospective production zones have been identified. The pressure maintenance and the continuous high brine yield from the reservoir may be due to laterally overlapping and connected sandstones, communication between overlying and/or underlying reservoirs, growth faults acting as passageways for brine, shale dewatering, or possible communication of zones behind the casing.

1957 ◽  
Vol S6-VII (4-5) ◽  
pp. 571-583 ◽  
Author(s):  
Paul Celet

Abstract The stratigraphic sequence of the Parnassus massif in Greece begins with coral-bearing upper Triassic dolomites and limestones, which are overlain by a thick series of Mesozoic limestones capped by red shaly marls and sandy Flysch formations. The structure was influenced by the rigidity of the limestone cover, which is faulted and overthrust in slices toward the east-northeast. The massif as a whole is cut by deep east-west-trending faults, along which the large grabens bounding the massif on the north and south were downdropped.


2005 ◽  
Vol 51 (174) ◽  
pp. 469-482 ◽  
Author(s):  
Ian S. Evans ◽  
Nicholas J. Cox

AbstractNorth–south and east–west differences in firn-line altitude, equilibrium-line altitude or middle altitudes of glaciers can be separated by regression on the cosine and sine of glacier aspect (accumulation area azimuth). Allowing for regional trends in altitude, the north–south differences expected from radiation and shade effects can be reliably quantified from World Glacier Inventory (WGI) data. The north–south differences are greater in sunnier climates, mid-latitudes and steeper relief. Local altitude differences between north- and south-facing glaciers are commonly 70–320 m. Such asymmetry is near-universal, although weak in the Arctic and tropics. East–west contrasts are less, and found mainly in the tropics and areas most exposed to strong winds. Altitude, latitude, glacier gradient and height range, calculable from most of the WGI data, are potential controls on the degree of north–south contrast, as well as surrogates for climatic controls (temperature, precipitation, radiation and cloudiness). An asymmetric sine–cosine power model is developed to describe the variation of north–south contrast with latitude. Multiple regression over 51 regions shows altitude and latitude to be the strongest controls of this contrast. Aspect–altitude analysis for former glaciers provides new evidence of cloudiness.


2020 ◽  
Vol 500 (1) ◽  
pp. 311-322 ◽  
Author(s):  
Carlos A. Vargas ◽  
Gustavo A. Gutiérrez ◽  
Gustavo A. Sarmiento

AbstractOn the eastern margin of the Panama Basin, the Nazca oceanic plate converges towards the continental plate of South America at approximately 53 mm a−1. Subduction processes are accompanied by the presence of anomalous bathymetric elements including the Sandra Ridge. This east–west-orientated ridge is catalogued as an aborted rift derived from a magmatic spreading axis that was active between 12 and 9 Ma. Seismic activity within this structure is considered evidence of fault reactivation and tectonism. Once the structure reached the subduction trench several submarine landslides were triggered. Run-out lengths of these submarine landslides are perpendicular to the convergence of the structure with some units spreading and forming a wide fan that reaches tens of kilometres to the north and south of the trench. The area affected by the three main landslides varies between 130 and 300 km2 approximately, with relatively superficial earthquakes (<33 km) and with magnitudes that reach up to Mw 7.2. The morphology of the landslides suggests a retrogressive nature with younger events proximal to shore. This paper presents estimates of the age of these landslides and discusses sources of uncertainty regarding these times of occurrence.


1971 ◽  
Vol 8 (4) ◽  
pp. 423-434 ◽  
Author(s):  
P. R. Hooper ◽  
R. W. Ojakangas

The structure of the Precambrian rocks of the Vermilion district is critically examined. It is demonstrated that two significant deformations (F1 and F2) have affected the area in addition to a later set of faults, joints, and kink-bands (F3). The F1 folds are tight to isoclinal with gently plunging axes and vertical axial planes trending west–northwest and containing iron formation and greenstones in anticlinal cores. The second deformation forms a series of open to close asymmetric folds (F2) with steep axes and vertical axial planes trending east–west. Of these, F1 has the more significant effect on the pattern of rock outcrop and it is suggested that it is directly related to the diapiric rise of the batholiths lying immediately to the north and south. The F2 folds may be accounted for by further compression between the two granite bodies.


1996 ◽  
Vol 36 (1) ◽  
pp. 142 ◽  
Author(s):  
D. M. Brooks ◽  
A. K. Goody ◽  
J. B. O'Reilly ◽  
K. L. McCarty

The Bayu/Undan Gas-Condensate Field straddles the boundary between the ZOCA 91-12 and ZOCA 91-13 PSC areas, within the Timor Gap Zone of Cooperation Area A (ZOCA). The field is located approximately 450 km north­west of Darwin, NT, and 350 km east-southeast of Kupang, Timor. The closure is the culmination of the Flamingo High, a major structural element within the northern Bonaparte Basin. This structure has been viewed as having significant hydrocarbon potential since Flamingo-1 recovered gas from Berriasian sandstones in 1971.The discovery well, Bayu-1, was drilled by the ZOCA 91-13 contract operator, Phillips Petroleum Company ZOC, in early 1995. Bayu-1 intersected a gross 155m gas-condensate column within Middle Jurassic sandstones at a depth of 2,954.5 mSS. The ZOCA 91-12 joint venture then drilled Undan-1,10 km northwest of Bayu-1, on a separate culmination within the closure defined by the Bayu-1 gas-water contact. Undan-1 and subsequent wells have confirmed the existence of one large gas-conden­sate field, with a most likely areal extent of over 160 km2.The sandstone reservoir consists of late Oxfordian to Callovian shallow marine, deltaic to shoreface, coarsen­ing upward parasequences, overlying Callovian to Bajocian marginal marine to coastal plain sediments. The trap is an east-west oriented horst block bounded by en-echelon normal faults to the north and south, with dip closure to the east and west. Seal is provided by Tithonian to Barremian marine claystones. A likely hydrocarbon source is contained within the Barremian to Callovian interval, some of which are mature for condensate and wet gas expulsion in the southern Sahul Syncline and Malita Graben.


1976 ◽  
Vol 66 (4) ◽  
pp. 1085-1099
Author(s):  
K. M. Lahr ◽  
J. C. Lahr ◽  
A.G. Lindh ◽  
C. G. Bufe ◽  
F. W. Lester

abstract On August 1, 1975, a magnitude 5.9 (mb) earthquake occurred approximately 8 km SSE of the town of Oroville, California. This earthquake and its associated foreshock-aftershock sequence are of particular interest because of their possible relation to the impounding of the 4.3 billion m3 Lake Oroville. Hypocenter locations for 336 aftershocks that occurred during August define a fault plane striking N3°E and dipping 60° to the west to a depth of 10 km. Dimensions of the epicentral area are approximately 7 km in an east-west direction by 15 km in a north-south direction. The fault plane passes beneath Oroville Dam at 5-km depth, and if projected up dip, would crop out beneath the reservoir to the east. The distribution in space and time of foreshocks and aftershocks suggests that rupture began at depth and progressed up dip and to the north and south.


2021 ◽  
Vol 9 (01) ◽  
pp. 289-326
Author(s):  
Berna Hepbilgin ◽  

Ida Mountain presents a peculiar geographical structure in terms of the distribution of tree stands, like all the geographical differences on the north and south slopes with its location in the north of Edremit bay and with lying east-west direction roughly.Covering the area of ​​1823 km2 with its immediate surroundings, Ida Mountains natural forest section forms approximately 60% of the area. In the natural forest area of ​​Ida Mountain, Pinus brutia, Pinus nigra, Quercus, Abies, Fagus and Castanea are found as pure tree communities, and related varieties formed by the combination of these species in different bulk densities. In the eco-geographic study of forest areas, the two most basic bioclimatic factors are: knowing the temperature and precipitation preferences of tree species and stands. In this study, monthly, seasonal and annual temperature and precipitation preferences of tree stands in Ida Mountain were obtained by modeling the temperature and precipitation data obtained from meteorological stations around Mt. Ida. This case study aims to contribute to the future eco-geographical evaluations on the tree stands of Ida Mountain.


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