South Pass Research Articles

Geology of South Pass Block 27 Field, Offshore, Plaquemines Parish, Louisiana

The South Pass Block 27 field, located in the coastal waters of Louisiana, is associated with an intermediate-depth salt dome. Only the north flank of this salt-dome structure has been explored and developed, but proved reserves already exceed 200 million barrels of oil and 220 billion cubic feet of gas. The field ranks high among the giant oil fields of Louisiana in terms of ultimate oil recovery. The unexplored areas show excellent productive promise and the South Pass Block 27 field may eventually yield the largest field reserve yet found in the offshore waters of the Gulf of Mexico. All production is from sands of Plio-Miocene age between the depths of 6,000 and 10,400 feet. One hundred fifty-three producing wells have been completed and cumulative production from these wells was 12,251,700 barrels of oil and condensate and 10,016,341 MCF of gas through September, 1959. Active development of the field is still in progress. Contemporaneous faults traversing the structure have a marked effect on structural configuration. These faults are classified as contemporaneous because movement along the fault plane appears to have been contemporaneous with deposition over a part of the fault history. This type of faulting, commonly encountered in the Gulf Coast, is characterized by a greater thickness of sediments in the downthrown block than in the upthrown block and by an increase in throw of the fault with increasing depth. The major part of proved oil reserves is entrapped in the western part of the north flank on the upthrown side of a large contemporaneous fault which strikes essentially north-south. Maps contoured on top of the D4 sand, the N4 sand, and salt are included to illustrate the structural aspects of the field. These maps are supplemented by structural cross sections and schematic diagrams. In addition structure maps on four typical producing beds are presented to delineate the more important producing areas of the field.

Developments in Louisiana Gulf Coast in 1960

The Louisiana Gulf Coast, as treated in this analysis, consists of the 38 southern parishes and the 16 adjacent continental shelf areas offshore. Production is obtained from sediments ranging in age from Cretaceous to Pleistocene. The 2,251 development and exploratory wells drilled in 1960 are favorably comparable in number and in results with those of 1959. Of the 769 exploratory wells, 44.4% were successful. The Southeast District continued to be the most important in both development and exploratory drilling. The Offshore District had a 69.4% increase in exploratory drilling. Of the 50 new-field discoveries (42 onshore, 8 offshore) the most important are: South Chauvin field, Terrebonne Parish; Pierre Pass field, Assumption Parish; and Eugene Island Block 100 field. The most important of the 292 new pools and extensions include Buck Point field, Vermilion Parish, and South Pass Block 27 field. Leasing continued to be very active with large blocks of acreage being assembled and traded. Subsurface geology increased in importance as more well control became available. Seismic exploration continued to be extensive. In 1960, the high level of activities recorded in 1957 and 1959 was maintained.

Developments in Louisiana Gulf Coast in 1954

The level of operations in the Louisiana Gulf Coast in 1954 was higher than in the last five years. In all, 1,703 tests were drilled, 552 of which were exploratory tests and 1,151 field wells. Thirty-six per cent of the exploratory tests and 82 per cent of the development wells were successfully completed. Production of oil was less in 1954 than in 1953 but gas production increased over the preceding year. Thirty-four new fields were found as the result of drilling 201 new-field wildcats, or a successful rate of 17 per cent. The most important new fields are considered to be Bayou Sorrel, Crab Lake, Dixon Bay, East Lake Palourde, Eugene Island Block 18, South Pass Block 27, West Cameron Block 110, and West Cameron Block 192. In addition, 351 other exploratory tests located on proved structures were also drilled, 166 of which were completed as producing wells. The reflection seismograph continues to be the most important exploratory tool used in the Louisiana Gulf Coast, and the level of seismic activity increased in 1954. The level of gravity activity showed a slight decrease in 1954 from the 1953 level. The major concentration of exploratory effort is still expended in the belt of Miocene objectives, with the Oligocene belt second. Activity in the offshore areas more than doubled compared with 1953 as a result of the Tidelands decision. No significant changes in the over-all levels of exploration are expected on land for 1955, but the level in the offshore areas is expected to increase.

Some Wyoming Speech Patterns

HANS KURATH'S Word Geography of the Eastern United States2 presents in i graphic form a model for speech analysis. Speech patterns are neatly bounded, and heavy black lines mark with confidence the New England, the Pennsylvania, and the Southern speech areas, or indicate more local pockets of idiom. It is unlikely that such clearly marked isoglosses would appear as often on dialect maps of the Western states. Population is mobile and more recent, and often of mixed origin. Hence, conclusions must be more tentative than in the older parts of our country. Since no study has yet been made of Wyoming, I venture here a few preliminary observations based largely on population statistics and on questionnaires answered by some two hundred Wyoming-born students at the State University. The questionnaire, based on a form used at the University of Michigan and the University of Colorado, deals only with word distributions, not with pronunciations. Furthermore, it appears now that this questionnaire needs revision for the Western states, since it makes no provision for, say, the Spanish infiltrations into New Mexico and Texas, or regional cowboy terms in Wyoming and Montana. My paper has thus only a preliminary or introductory value. Wyoming until I890o presented the smallest population figures of any territory or state in the Union, and even now, though sixth in area among the states exceeds only Nevada in population. In 1870, Wyoming territory had five counties, running in parallel lines from south to north, from Colorado to Montana. The total population was but 9,118 persons, of whom, except for the few at Fort Laramie and South Pass, none was north of the recently completed Union Pacific railroad line. Located chiefly at Cheyenne and Laramie, this population was fully one-third foreign born, as compared with a national average of slightly over 13 percent, and more than one half was of foreign parentage.3 Twenty-one percent of the total population was from the British

MUDLUMPS AT THE MOUTHS OF THE MISSISSIPPI RIVER

Mudlump is a popular name for the upswellings of clay which commonly form islands near the mouths of the Mississippi River passes. These features usually are associated with the bars at the river mouths. The bars are localized sedimentary deposits formed where the river waters enter the relatively still Gulf of Mexico. At present the mudlumps are found within a few thousand feet of the mouth of North Pass, Pass A Loutre, Northeast Pass, Southeast Pass, old Balize Bayou, South Pass and Southwest Pass. Mudlumps appear to be a phenomenon unique to the Mississippi River Delta for they are unreported from any other locality.

Notes on General Ashley, the Overland Trail, and South Pass. By Donald McKay Frost. Reprinted from the Proceedings of the American Antiquarian Society for October, 1944. (Worcester, Mass.: American Antiquarian Society, 1945. 154 pp. Index. $2.00 from the Society.)

Notes on General Ashley, the Overland Trail, and South Pass. By Donald McKay Frost. Reprinted from the Proceedings of the American Antiquarian Society for October, 1944. (Worcester, Mass.: American Antiquarian Society, 1945. 154 pp. Index. $2.00 from the Society.)

Notes on General Ashley, the Overland Trail, and South Pass Donald McKay Frost

Notes on General Ashley, the Overland Trail, and South Pass Donald McKay Frost

Southwest from Salt Lake in 1849

Most summary accounts of the gold rush give the impression that the forty-niners moved en masse over a well defined trail to California. For the majority of the overland travelers such was the case. Bancroft's estimate is that five-eighths of the land travelers came by the Platte-South Pass-Humboldt itinerary, which was the first recommendation of the guidebooks, and that another fifth used the Santa F&-Gila-Yuma route.' With the major overland trails worked out before 1849 by Santa Fe traders and Oregon missionaries, by the fur trappers and the pioneer settlers, the men of the gold rush had little real need for anything but trail following. But one cannot read far in the journals of this great trek without finding numerous instances of departure from the beaten path, of search for short-cuts, of experimentation with new routes. Some of these experiments had comic results, as when Lewis Manly and his companions essayed to reach California by floating down the Green River. Others, for example Delano's venture on Lassen's Cut-off, are recorded with a sheepish recognition of the wisdom of experience. Still others, notably those connected with Death Valley, had tragic outcomes. No catalog of these optimistic ventures has been attempted. Nor could such a catalog pretend to completeness, because of the obviously fragmentary nature of our records. It appears, however, that for an adequate representation of the overland routes in '49 we need a network of lines across the western map, lines which should converge at Fort Laramie, South Pass, and Soda Springs or Salt Lake City, and for the southern route at Santa

Building of Mississippi Delta

The delta of Mississippi River seems not to extend much, if any, above Baton Rouge and not to be as old as the Pliocene Citronelle formation. Its coarsest sediments are fine sands with very fine sand, coarse and fine silt, and clay admixtures. Its finest sediments are clays or ultra-clays. With the exception of Old River, through which Mississippi River waters commonly discharge into Atchafalaya River, all the natural distributaries are closed artificially by levees down as far as the Forts. Below the lower ends of the maintained levees there are three distributaries: Batiste Colet's Bayou, the Jump, and Cubit's Gap. At Head of Passes the river breaks up finally to form Pass a Loutre, South Pass, and Southwest Pass. An explanation of the method and rate of delta building s attempted.

South pass: A study in the historical geography of the United States

South pass: A study in the historical geography of the United States

Overland Journey to California By Platte River Route and South Pass in 1850

Overland Journey to California By Platte River Route and South Pass in 1850

The South Pass Jetties.–Ten Years Practical Teachings in River and Harbor Hydraulics

The South Pass Jetties.–Ten Years Practical Teachings in River and Harbor Hydraulics

The South Pass Jetties—Ten Years' Practical Teachings in River and Harbor Hydraulics

The South Pass Jetties—Ten Years' Practical Teachings in River and Harbor Hydraulics

Notes on the South Pass Jetties

At the request of Mr. E. L. Corthell, Resident Engineer, and as an addendum to the paper of the writer of last year, the following brief notes are submitted relating to the maintenance of the channel at the South Pass Jetties, and the general condition of the works. At the head of the passes the 30-feet channel is now 450 feet wide, with a least depth of 30.1 feet. The improvement during the last year has been constant and more marked than at any period heretofore.

Discussion on “Notes on the South Pass Jetties”

Discussion on “Notes on the South Pass Jetties”

The South Pass Jetties. Notes on the Consolidation and Durability of the Works, with a Description of the Concrete Block and Other Constructions of the Last Year

The South Pass Jetties. Notes on the Consolidation and Durability of the Works, with a Description of the Concrete Block and Other Constructions of the Last Year

The South Pass Jetties: Descriptive and Incidental Notes and Memoranda

The South Pass Jetties: Descriptive and Incidental Notes and Memoranda

Improvement of the south pass of the Mississippi

Improvement of the south pass of the Mississippi

Discussion on “The South Pass Jetties”

Discussion on “The South Pass Jetties”

American Notes *

THE official report of the geological explorations prosecuted during the past summer by Prof. F. V. Hayden, under the authority of the Department of the Interior, has just been published by the Government in a well-printed volume of over five hundred pages, containing a full account of the geology and natural history of the region traversed. It embraces an article by Prof. Hayden upon the physical character and local geology of the different sections of his route, which extended from Cheyenne, by way of Fort Fetterman, South Pass, Fort Bridger, the Uinta Mountains, to Green River, and back again, viâ Bridger's Pass, to Cheyenne. This is followed by an account of the Geology of the Missouri Valley from Omaha to Salt Lake Valley, with observations on the mines, ores, coals, and salts. An appendix contains an article by Prof. Cyrus Thomas upon the agricultural possibilities of the country, with a list of the orthopterous insects, including a number of new species, followed by a number of special reports—as one by Prof. Meek, on the invertebrate fossils; on the Tertiary coals of the West, by Prof. Hodge; on the ancient lakes of Western America, by Prof. Newberry; on the vertebrate fossils of the Tertiary formation, by Prof. Leidy; on the fossil plants of the Cretaceous and Tertiary formations of Kansas and Nebraska, by Mr. Lesquereux; on the fossil reptiles and fishes of the Cretaceous rocks of Kansas, the fossil fishes of the Green River group, and the recent reptiles and fishes, by Prof. Cope; and on the industrial resources of Western Kansas and Eastern Colorado, by Mr. Elliott. Lists of the mammals, molluscs, and birds, of the coleoptera, hemiptera, and plants, are also included, together with an account of the general meteorology of the expedition. A large number of new species of different kinds are described, and the whole work forms a very important addition to our information relative to the geology, geography, and natural history of the West.