OREGOM GEOLOGY published by the Oregon Department of Geology and Mineral Industries VOLUME 45, NUMBER 5 MAY 1983 OREGOM GEOLOGY OIL AND GAS NEWS (ISSN 0164-3304) Clatsop County VOLUME 45, NUMBER 5 MAY 1983 Drilling permits continue to be applied for in Clatsop County. Published monthly by the State of Oregon Department of Geology Diamond Shamrock has filed for a location in sec. 11, T. 6 N., R. 6 and Mineral Industries (Volumes 1 through 40 were entitled The Ore W. (see table below). The well, Clatsop County 33-11, has a Bin). proposed total depth of6,000 ft and will probably be the next well to be drilled by the operator in the state. The tract on which this well is to be drilled was offered by Clatsop County at a sealed bid auction Governing Board on February 9, 1983. The parcel had originally been nominated for C. Stanley Rasmussen ...................... Baker leasing by Diamond Shamrock and went for a bonus bid of $338 per Allen P. Stinchfield .................... North Bend acre. Donald A. Haagensen .................... Portland State Geologist. Donald A. Hull Gas prices at Mist Gas Field The U.S. Natural Gas Policy Act (NGPA) became effective Deputy State Geologist ................ John D. Beaulieu December 1, 1978. The Federal Energy Regulatory Commission (FERC), which implements the NGPA, determined several catego­ Publications Manager/Editor ............. Beverly F. Vogt ries of gas wells. These categories are used to establish gas prices. FERC is required to compute and publish maximum lawful prices Associate Editor ................. Klaus K.E. Neuendorf each month. The monthly equivalent of the annual inflation adjust­ ment allows the price to be increased each month. The prices are in Main Office: 1005 State Office Building, Portland 97201, phone (503) 229-5580. dollars per million British thermal units ($/MMBTU) and are published in the Federal Register. Baker Field Office: 2033 First Street, Baker 97814, phone (503) After passage of the act, each state formulated a determination 523-3133. process for natural gas well categories. In Oregon, the Oregon Howard C. Brooks, Resident Geologist Department of Geology and Mineral Industries is the jurisdictional agency which processes applications for Determination of Max­ Grants Pass Field Office: 312 S.E. "H" Street, Grants Pass 97526, imum Lawful Price under the Natural Gas Policy Act. phone (503) 476-2496. Mist Gas Field gas is priced under NGPA Section 102, New Len Ramp, Resident Geologist Natural Gas, Category B. Following are prices for Mist gas at Mined Land Reclamation Program: 1129 S.E. Santiam Road, Albany various selected times: December 1979, $2.336/MMBTU; De­ 97321, phone (503)967-2039. cember 1980, $2. 640/MMBTU; December 1981, $2.9711 Paul F. Lawson, Supervisor MMBTU; December 1982, $3.274/MMBTU; and April 1983, $3.367/MMBTU. Subscription rates: I year, $6.00; 3 years, $15.00. Single issues, $.75 at counter, $1.00 mailed. Oregon Gas Production 1979-1982 Available back issues of The Ore Bin: $.50 at counter, $1.00 mailed. The Mist Gas Field first went on production in December 1979, after completion of four wells and construction of a pipeline. Address subscription orders, renewals, and changes of address to The heating value of the gas measures from 890 to 960 Btu per cubic Oregon Geology, 1005 State Office Building, Portland, OR 97201. foot, depending on the individual pool and well. Send news, notices, meeting announcements, articles for publica­ The following table gives cumulative production figures for tion, and editorial correspondence to the editor, Portland office. The the field at the end of each year of production: Department encourages author-initiated peer review for technical articles prior to submission. Any review should be noted in the Cumulative production at acknowledgments. Year year's end (Mct) 1979 15,160 Permission is granted to reprint information contained herein. 1980 4,947,190 Credit given to the Oregon Department of Geology and Mineral 1981 9,867,623 Industries for compiling this information will be appreciated. 1982 13,266,806 Second class postage paid at Portland, Oregon. Recent permits Postmaster: Send address changes to Oregon Geology, 1005 State Office Building, Portland, OR 97201. Permit Operator, well, Status, proposed no. API number Location total depth (ft) 233 Diamond Shamrock SE',4 sec. II Application Clatsop County 33-11 T.6N.,R.6W. 007-00014 Clatsop County 234 Reichhold Energy SE',4 sec. 21 Application COVER PHOTO Werner 34-21 T. 5S., R. 2W. South Sister, one of the Three Sisters in Oregon's central 047-00014 Marion County D Cascade Range. Volcanoes such as this suggest the possibility of geothermal potential at depth, and the focus of geothermal explora­ tion has shifted from eastern Oregon to this part of the state. See article beginning on p. 56 for summary of 1982 geothermal activity CONTENTS in Oregon. Photo courtesy Oregon State Highway Commission. Results of geothermal resource assessment of Ashland area 51 GRC calls for papers for October meeting in Portland . .. 55 Geothermal exploration in Oregon. 1982 ................. 56 50 Fireballs sighted in Oregon. .. 58 Results of a geothermal resource assessment of the Ashland, Oregon, area, Jackson County by Gerald L. Black, Oregon Department of Geology and Mineral Industries, and Monty Elliott, lad D'Allura, and Bill Purdom, Southern Oregon State College, Ashland, Oregon 122"4!::' 42'15' Ir, -1-9---=--=-----O--~,-"--- ,-..:-?r-----,----,'Tr."-T7-=--~,._,_,__,____,__-.,____-_._--_,__,__A~",.,,,I EXPLANATION Landsl ide deposits J-;--- I Basic intrusive rocks 1 ?,ifF Payne Cl iffs fonnation uncoRfonni ty Ashland Greenhouses drill hole ) 1 ~ Hornbrook Fonnation DOGAI.fI drill hole nonconfomit.v I. Butler Ford QIJ Mount Ashland Pluton 2. Darex 3. Just i ce Center ~ Applegate Group 4. sasc Gym GEOLOGIC SYMBOLS 5. Rodeo_ Groundsv , lUurr'lI!l Complex intrusive contact -- Contact --l- Fault, dashed where approximate ball on downthrown side ...J!" Strike and dip of bedding Base map by U. S. Geological Survey ___~L-~~-L~~~~~~~~~~_~~_~~~ ___~ Figure J. Geologic map of the Ashland, Oregon, area. INTRODUCTION GEOLOGY As part of its low-temperature geothermal resource assess­ The city of Ashland lies on the boundary between the ment program, the Oregon Department of Geology and Min­ Klamath Mountains and Western Cascades physiographic eral Industries (DOGAMI) drilled five temperature-gradient provinces. The geology in the immediate vicinity of the city holes in the Ashland, Oregon, area during June of 1982. A was mapped in 1981 by three of the authors (Elliott, D'Allura, sixth hole was drilled in the Cascade Mountains east of Ash­ and Purdom) specifically for the low-temperature geothermal land during the same period. This last hole was drilled as part resource assessment project. Figure 1 is taken from their map. of a continuing evaluation of the geothermal potential of the Quartz diorites of the Late Jurassic Mount Ashland Cascade Range in Oregon: It was sited to aid in defining the Pluton dominate the terrain west of the city. The rocks of the position and/ or existence of a transition from lower ( - 40 milli­ pluton were encountered in two of the five temperature­ watts per square meter [mWm-2]) to higher (>100 mWm-2) gradient holes drilled for the project (Darex at 93 m [305 ft] heat flow which has been identified in the northern and central and SOSC Gym at 120 m [392 ft]; see Figure 2). In addition, a Cascade Range in Oregon. well drilled at the Ashland Greenhouses (Figure 1) encountered Ashland, a city of 14,975 inhabitants, is located in south­ the contact between the pluton and the overlying Hornbrook western Oregon in Jackson County (Figure 1). There are four Formation at a depth of 299 m (982 ft). warm springs located in or near the city (Figure 1). Jackson Cropping out northwest of the city are rocks of the Late Hot Springs, the warmest of the four, is located northwest of Triassic Applegate Group. These rocks were contact metamor­ the city limits (Figure 1). A temperature of 35° C has been phosed during the emplacement of the Mount Ashland reported for Jackson Hot Springs (Berry and others, 1980), Pluton. The Butler Ford hole encountered Applegate Group but DOGAMI personnel have measured temperatures as high rocks at 352 m (115 ft) (Figure 2). The contact between the as 43.5° C in the warmest of the approximately ten orifices metamorphic rocks and the pluton is a zone of mixed rocks, which occur in the hot springs area. The three other springs lie where stringers of quartz diorite complexly intrude the Apple­ on a north-northwest-trending line within the city limits gate Group. Jackson Hot Springs is located near the contact (Figure 1). They include Helman Hot Springs (31.5° C), White between the Applegate Group, the Mount Ashland Pluton, Sulphur Spring (28.5° C), and the Southern Pacific Spring. A and the Hornbrook Formation. resort located at Jackson Hot Springs represents the only com­ Greenish to gray sandstones and mudstones of the Late mercial use of geothermal fluids in Ashland. Cretaceous Hornbrook Formation nonconformably overlie OREGON GEOLOGY, VOL. 45, NO.5, MAY 1983 51 the Mount Ashland Pluton and the associated metamorphic The heat-flow data for the six holes drilled as part of the rocks of the Applegate Group. The Hornbrook Formation, Ashland low-temperature assessment project are summarized which represents a marine onlap sequence, dips rather in Table I. Also included in Table 1 are heat-flow data for a uniformly northeastward at about 25 ° (Figure I). The four 344-m (I,13Q-ft) well drilled at the Ashland Greenhouses warm springs occurring in the Ashland area are located al the (39S/ 1E-4BBD) during 1981 and 1982.