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Show ft OILFIELD EtOLOEJfSTIIDlEO Government Reports Upon Structure of Upton-Thornton Upton-Thornton District. Sixteen Producing Wells Yield Crude of Excellent Quality. WASIIINTITO.V, I). C, Cmt. 1. Thn Upton-Thornton oil diMtrict lips on tin; western west-ern flak of tho i:l:u-k illllrt, In ru-it'-m Wyoming, in W.-yiun nn'l Crook roun-tii;H. roun-tii;H. TI10 oil field itHt:If i.s in sn-tiori 4, lownnWlp -is north, r;uiyo 0i wn.-it, ami Ktictlon ;;;!, township 49 north, rantf'i GO wont, about threo nilli;H northwest of the town of Thornton, on tlio Chi';i.o, Ihir-Ington Ihir-Ington Si Quiru-y railroad. It in about twenty mlh-H southeast of the .Moorcroft oil field, ninety miles not L'n. n .st of the 1 Salt Creek oil field, and about eighty t irillen duo north of the Jnuu Crctik oil field. An area of about nixty square miles, whl-h includes the territory where the producing weila havo been drilled and 1 the ndjaeent country, h;is recently been exatnined by K. T. 1 lancmrk of the United states KuoloKlcal survey, department depart-ment of the interior, who lias submitted a report on it for publieation. The report re-port is accompanied by a map showing the boundaries of the feeologto lormations, with contours showing the K'eoloKie structure, struc-ture, and cross pactions showing the relations re-lations of the different formations to ono another and to sea level. High Grade Oil Yielded. Thore wero slxtenn produnhitf wells In the flokl whrai thu oxiiininullon was raaflii, mid thlrtten of thu.su ImlonB to the Suuthwfiat (Ml rnmpiuiy, whl'-ti enn-tiol.s enn-tiol.s a largo part fit tho liclil. Tlio nil oonins from a Hlnglo steeply dliipiiiK wind, which 1h reached at UepUi.s raimliiK from 448 to 843 feet. Tho yield per well la ' low, averaKlriK hetween fivo and ten bnr-I bnr-I rels 11 day. Tho oil la of excellent finality final-ity and has a Rpoclfio gravity ranKintr from o.gso to 0.826 at 15 deques eenti-Biado. eenti-Biado. It Is taken by a small refinery EolonKlny to the Southwest till company, which supplies local trado with gasoline, and other products. Tlio oil field Is not an anticlinal fold, hut appears to bo on a struciur.il terrace, ter-race, where ' the rocks dip much less steeply than they do in the surrounding urea. An outcrop of tho steeply dipping oil-bearing sand is only half a mile from ! tho nearest well and a mile and a half I from tho most remote, a fact that not only permits a close suulv of the character of the sand, but that helps to show tho fallacy ot tlio contention of some geolo-Bists geolo-Bists that whereven an oil-bearing sand I Is exposed so much of its oil will escape ; as to preclude accumulation In commer-: commer-: olal quantities near by. Tho extent to which the oil escapes, or its escape at nil, probably depends on a change in tho dip of the bed in which it is contained or on variations in the texture tex-ture of tho rock that forms that bed, as well as on tho level of tho ground water ; and other conditions, all of which are subject to considerable variation. New Sources May Be Found. Within tho Upton-Thornton district, hut outside tho proved field, there are two domellko anticlines which appear structurally suited to bring about accumulations accumu-lations of oil. Ono of these anticlines, oalled the Thornton dome, is in sections 1 7, 8. 17, 18 and 20, township 4S north, range 65 west; tho other, called the Upton Up-ton dome, is in sections 31 and 35, township town-ship 48 north, range Ho west, and 2 and 3. township 47 north, range 66 west. Tho oil-bearing sand of the producing wells in section 4, township 43 north, range 66 I west, and also tho sand in the lower part of the Graneros formation, which is com-! com-! monly oil bearing in this region, havo j been eroded from the higher parts of the ! Thornton dome, but they may yield oil I in walls drilled far down tho flank of the dome. However, it is possible that the deeper Mlnnelusa sand of the carboniferous age, which Is reported to contain oil In the Old Woman anticline, seventy-five miles to tho south, may he present in this region, re-gion, and wells should be drilled deep enough to test it before the dome is condemned con-demned as barren of oil. This dome has been drilled at two points, and tho appearance ap-pearance of the sludgo piles at the abandoned aban-doned wells indicates that the drill entered en-tered tho TTlasslo red beds. ; The Upton dome is probably a less promising source of oil and gas. than the Thornton dome, for it is much less pronounced, pro-nounced, having a closure of but fifty feet, against a closure of 500 feet on the Thornton dome, in tho Upton dome the sandstone in the lower part of the Graneros Gra-neros formation lies beneath about 150 reet of Mowry shalo, but it is thin and is not covered with a cap rock sufficiently Impervious to hold the oil. |