ISSN 0917-057X March 2008 310 Technical Note of the National Research Institute for Earth Science and Disaster Prevention No.310 防 災 科 学 技 術 研 究 所 による 中 部 日 本 における 孔 井 検 層 データ - 活 断 層, 震 源 域,ヒンジライン - Geological and Logging Data of the NIED Boreholes, Japan - Active Fault, Seismogenic Zone, Hingeline - National Research Institute for Earth Science and Disaster Prevention, Japan
Report of the National Research Institute for Earth Science and Disaster Prevention, No. 310 ; March, 2008 Geological and Logging Data of the NIED Boreholes, Japan -Active Fault, Seismogenic Zone, Hingeline- Tatsuo MATSUDA *, Kentaro OMURA *, and Ryuji IKEDA ** * Earthquake Reseach Departmant, National Research Institute for Earth Science and Disaster Prevention, Japan ** Faculty of Science, Hokkaido University Abstract The National Research Institute for Earth Science and Disaster Prevention (NIED) has drilled fourteen boreholes in Central Japan, twelve of which (excluding the boreholes at Ashio and Shingu) were drilled as part of the Active Fault Zone Drilling Project. Ashio borehole was drilled to examine the stress state, pore water pressure, and heat flow within a seismogenic region, while Shingu borehole was drilled to monitor temporal changes in in situ stress and strain and to reveal their accumulation processes in relation to a great inter-plate earthquake. In this note, we present geologic columns and geophysical logging data for the boreholes, including spontaneous potential, resistivity, sonic velocity, bulk density, neutron porosity, total gamma ray, spectro-gamma ray, caliper, and temperature. The geophysical data and columns are presented at a scale of 1/2900. We hope that the data included in this note will contribute to the analysis of the crustal structure of these regions. Key words : Active fault drilling, Geologic column, Geophysical logging, Central Japan 1. Introduction In situ downhole measurements and coring within and around active fault zones are required to gain a better understanding of the structure and material properties of fault rocks and the physical state of active faults and intra-plate crust. In particular, the relationship between stress concentration and the strength heterogeneity of an earthquake fault zone is important in investigating earthquake generation mechanisms. To understand seismogenesis, it is necessary to compare active faults at different stages of the seismic cycle and under different geophysical and geological conditions; however, there exists little information on the deep structure and continuity of the fault zones associated with active faults. To better understand the structure and environmental conditions of fault zones, NIED carried out the Active Fault Zone Drilling Project in Central Japan (Ikeda et al., 1998). As part of this project, boreholes were drilled through the fault fracture zones of the Nojima fault, which appeared on the surface during the 1995 Great Kobe earthquake (M=7.2), and the Neodani fault, which formed during the 1981 Nobi earthquake (M=8.0), the greatest inland earthquake to have occurred in Japan. A similar investigation focused on the Atera fault, involving surface geophysical surveys and in situ stress measurements within six boreholes drilled around the fault. In this case, resistivity and gravity data obtained from surface geophysical surveys were compared with physical properties determined by borehole logging and measurements of core samples. These results were also compared with in situ stress data derived from hydraulic fracturing within the boreholes (Ikeda, 2001). In the Ashio area, shallow seismic activity is most active in the Kanto region. We drilled a borehole to 2,000 m depth to access the hypocentral region of these * Tennodai 3-1, Tsukuba, Ibaraki, 305-0006, Japan ** Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan - 1 -
Report of the National Research Institute for Earth Science and Disaster Prevention, No. 310 ; March, 2008 earthquakes, and measured the stress state, pore water pressure, and heat flow in the borehole. Our analysis revealed several important characteristics of the stress state within a hypocentral region: very high levels of differential stress occur around the hypocentral region, but these levels show a sharp decline around fracture zones (Tsukahara et al., 1996). Measurements of crustal stress and strain in deep boreholes are essential when studying subduction-related earthquakes. Especially in the case of earthquakes within the Nankai Trough, it is expected that crustal movements would be detectable even on land, because the focal region associated with subduction of the Philippine Sea plate is located close to land. These basic data, of crustal stress and the physical properties of rocks, were acquired by drilling to a depth of 550 m at Shingu City, Wakayama prefecture, on the Kii Peninsula. In situ experiments were conducted within the borehole, including measurements of crustal stress using the hydraulic fracturing method. We also used an intelligent strain meter to measure in situ stress, via the over-coring method, at depths greater than 500 m. The final goal of this study was to monitor temporal changes in in situ stress and strain, and to reveal their accumulation processes in relation to a great inter-plate earthquake (Ikeda et al., 2001). 2. Locations of the NIED boreholes Fig. 1 shows locations of drilling sites in Central Japan. Table1 shows the latitude, longitude (International Terrestrial Reference Frame), and elevation of each borehole, while Fig. 2 shows the Atera fault system and locations of drilling sites in the Atera area. Fig. 3 15 show the location of each borehole plotted on a 1:25,000 topographic map published by the Geographical Survey Institute of Japan. 3. Geophysical logging items and method 3. 1 List of the geophysical logging items Table 2 lists the geophysical logging items measured in the boreholes. 3. 2 Methods employed in measuring the geophysical logging items (SPWLA, 1984; Chapellier, 1992; Hearst, 2000) 3.2.1 Spontaneous potential log: SP (spontaneous potential, mv) An SP log measures the difference in electrical potential between an electrode moving along the borehole and a reference electrode fixed at the surface. SP arises mainly from electrochemical effects when fluids of contrasting salinities are encountered, such as drilling mud and water within the rock around the borehole through which the log is passing. An SP log is useful in examining the distribution of porous and permeable/impermeable zones in the drilled rock. 3.2.2 Electrical log: SN (short normal, ohm-m); LN (long normal, ohm-m); Micro1 (micro log 1 inch, ohm-m); Micro2 (micro log 2 inch, ohm-m); MG (medium guard, ohm-m) An electrical log measures the resistivity of the rocks around the borehole. Various types of tools can be used, each with different configurations of electrodes. For a normal log, a current electrode and potential electrode are configured on the tool. Potential difference is measured between the potential electrode and a reference electrode at the surface while a constant current passes between the current electrode and the surface electrode. Because the electrodes on the surface are situated in an infinite space, the measured potential difference depends on the characteristics of the rock around the current and potential electrodes on the tool. The distances between the two electrodes are 25 cm (short normal) or 100 cm (long normal). For a micro log, the resistivity is measured by a simple array of three button electrodes at 1-inch spacings on a pad pressed against the borehole wall. The current electrode occupies the lowermost position. The potential of the uppermost electrode with respect to a remote reference electrode yields 2-inch normal resistivity. At the same time, the potential difference between the upper two electrodes gives 1-inch lateral resistivity. The micro log consists of two resistivity curves that are expected to coincide with each other in the absence of mud cake on the borehole wall. A guard log is a type of focused log. A central current electrode is placed between upper and lower supplementary guard electrodes. A controlled current is transmitted from the guard electrodes to maintain them at the same potential such that the current from the central electrode flows in a thin horizontal layer at an angle of 90 degrees to the tool. Apparent resistivity is obtained by measuring the potential of the central electrode. The employed focusing technique means that the guard log is advantageous in obtaining the fine structure of thin beds in the rock around the borehole. 3.2.3 Sonic log: Vp (P wave velocity, km/sec); Vs (S wave velocity, km/sec) A sonic log is an acoustic log that measures the interval transit time of compressive and shear waves in the rock around the borehole. There are one transmitter and two receivers on the tool. The tool measures directly the travel time from transmitter to receiver, comprising the travel time through mud located between the transmitter and the -2- - 2 -
Geological and Logging Data of the NIED Boreholes, Japan - T. MATSUDA et al. borehole wall, between the borehole wall and the receiver, and through the wall rock along the same distance as that between the transmitter and receiver. The difference between the two travel times represents the travel time through the wall rock along the fixed distance between the two receivers, generally a distance of 1 foot. The difference in travel time represents the interval transit time, which is converted to the acoustic velocity of the rock around the borehole. 3.2.4 Formation density log (sometimes called a gamma-gamma log): Density (density, g/cm 3 ) A formation density log measures the intensity of backscattered gamma rays from the rock around the borehole using a detector mounted in the tool and shielded from a gamma ray source (e.g., 137 Cs). The intensity of backscattered gamma rays depends on the electron density, which is closely related to the bulk density of the rock around the borehole. The intensity of the backscattered gamma rays is converted to rock density using a calibration curve. 3.2.5 Neutron (Porosity) log : Porosity ( porosity, %) A neutron log counts the neutrons emitted from a neutron source installed within the tool and scattered by the rock around the borehole. Fast neutrons continuously emitted from the source (a radioisotope of Am Be) are slowed by collisions with atomic nuclei within the rock around the borehole, thereby becoming low-energy thermal neutrons that are captured by the neutron detector. Because collisions with hydrogen atoms which have similar masses to the neutrons are by far the most effective in terms of slowing the neutrons, the number of neutrons recorded by the detector is inversely proportional to the concentration of hydrogen in the rock around the borehole. In water-saturated rock, the hydrogen content is equivalent to the pore water content, i.e., porosity. The porosity is derived from the number of detected neutrons via an empirically determined relationship. 3.2.6 Gamma-ray log : GammaRay (gamma- ray, API) A gamma-ray log counts all of the gamma rays, without energy discrimination, radiated from natural radioactive isotopes in the rock around the borehole, being mainly uranium ( 238 U), thorium ( 232 Th), and potassium ( 40 K). The API (American Petroleum Institute) unit for radioactivity is employed, based on an artificial radioactive concrete block housed in the API calibration facility at the University of Houston, Texas, USA. 3.2.7 Spectral gamma-ray log. K (potassium, %) ; U (uranium, ppm) ; Th (thorium, ppm) A spectral gamma-ray log counts gamma rays at specific energy levels radiated from radioactive isotopes in the rock around the borehole. The isotope species and element concentrations can be determined once the specific energy levels and amounts of gamma rays at the specific energy levels (API unit) are known. 3.2.8 Caliper log: Caliper-X (caliper x-axis, mm); Caliper-Y(caliper y-axis, mm) A caliper log measures the borehole diameter. The tool has one or more arms that are extended mechanically and placed in contact with the borehole wall. The degree of extension of the arm(s) is converted to the length from the center of the tool to the borehole wall. 3.2.9 Temperature log: Temperature (temperature, C) A temperature log measures temperature within the borehole using a thermistor sensor installed within the tool such that fluid passes over the sensor as the tool travels down the borehole. 4. Legend of the geologic columns Abbreviations in the geologic columns are as follows. ADM : adamellite AND : andesite BRE : breccia BST : basalt CHT : chert CMS : conglomerate and mudstone CSS : conglomerate and sandstone FRZ : fracture zone GCG : granitic conglomerate GRD : granodiorite PHT : porphyrite RHY : rhyolite SCG : sandy conglomerate SLT : slate SMA : sandstone and mudstone alternation SMS : sandy mudstone TNT : tonalite 5. Geologic column and geophysical logs of the NIED boreholes Geophysical logs for the NIED boreholes are shown in Figs. 16 29 alongside geological columns. Logs were compiled for various rock types. Broadly speaking, we found correlations among electrical, sonic, density, and neutron logs, while gamma-ray logs discriminate different rock types. Some of the log items show drastic changes within fracture zones relative to values in adjacent host rocks, irrespective of rock type. These findings suggest that the logging data presented in this note will contribute to studies of crustal structure and petrophysics. Acknowledgements We would like to thank the staff of Geophysical -3- - 3 -
Report of the National Research Institute for Earth Science and Disaster Prevention, No. 310 ; March, 2008 Surveying Co., Ltd. and Sumiko Consultants Co., Ltd. involved in the measurements. References 1) Chapellier, D. (1992): Well logging in hydrogeology, 175 pp., A.A. Balkema Pub., Brookfield. 2) Hearst, J. R., Nelson, P. H., and Paillett, F. L. (2000): Well logging for physical properties, second ed., 483 pp, John Wiley & Sons Ltd., West Sussex. 3) Ikeda, R., Omura, K., and Iio, Y. (1998): Stress measurements around active fault. Earth Monthly, 21, 91-96. (in Japanese) 4) Ikeda, R., (2001): Outline of the fault zone drilling project by NIED in the vicinity of the 1995 Hyogo-ken Nanbu earthquake, Japan. The Island Arc, 10-3/4, 199-205. 5) Ikeda, R., Omura, K., Iio, Y., Ishii, H., Kobayashi, Y., Nishigami, K., and Yamauchi, T. (2001): Crustal stress and strain measurements on land for studying the Nankai trough earthquake. Journal of geography, 110, 544-556. 6) SPWLA (1984): Glossary of terms & expressions used in well logging, second ed., 116 pp., Society of Professional Well Log Analysts, Houston. 7) Tsukahara, H., Ikeda, R., and Omura, K. (1996): In-situ stress measurements in an earthquake focal area, Tectonophysics, 262, 281-290. (Accepted : February 5, 2008) -4- - 4 -
Geological and Logging Data of the NIED Boreholes, Japan - T. MATSUDA et al. Fig. 1 Locations of the drilling sites in central Japan. Table 1 Location data of the boreholes (International Terrestrial Reference Frame). Site name Latitude, Longitude Elevation, m Address Ashio 36 37 5.9 139 23 59.4 642 3658, 3596, Ashio, Nikko, Tochigi pref. 36.61831 139.39983 Tsukechi 35 38 15.3 137 27 22 495 Nakano, Tsukechi, Nakatsugawa, Gifu pref. 35.63758 137.45611 Kawaue 35 36 32.5 137 29 49.9 460 Kawaue, Nakatsugawa, Gifu pref. 35.60903 137.49719 Fukuoka 35 34 35.5 137 27 57.2 383 Fukuoka, Nakatsugawa, Gifu pref. 35.57653 137.46589 Hatajiri 35 33 35.7 137 26 47 305 1605-1-2, Fukuoka, Nakatsugawa, Gifu pref. 35.55992 137.44639 Ueno 35 35 47.8 137 29 1.4 526 245-2, 3, Ueno, Nakatsugawa, Gifu pref. 35.59661 137.48372 Hagiwara 35 56 14.2 137 11 32.5 509 1943-3, Ozaki, Hagiwara, Gifu pref. 35.93728 137.19236 Gofukuji 36 10 9.1 138 0 9 783 Gofukuji, Uchida, Matsumoto, Nagano pref. 36.16919 138.00250 Midori 35 36 51.7 136 37 13.9 160 Neomidori, Motosu, Gifu pref. 35.61436 136.62053 Hirabayashi 34 34 54.6 134 58 13.7 65 Nojimahirabayashi, Awaji, Hyogo pref. 34.58183 134.97047 Iwaya 34 35 26.9 135 0 3.3 120 Iwaya, Awaji, Hyogo pref. 34.59081 135.00092 Kabutoyama 34 46 27.7 135 19 32.7 222 Kabutoyama, Nishinomiya, Hyogo pref. 34.77436 135.32575 Shingu 33 41 19.4 135 58 6.8 24 1510, Sano, Shingu, Wakayama pref. 33.68872 135.96856-5 - -5-
Report of the National Research Institute for Earth Science and Disaster Prevention, No. 310 ; March, 2008 Report of the National Research Institute for Earth Science and Disaster Prevention, No. 310 ; March, 2008 Table 2 List of the geophysical logging items in the boreholes. Table 2 List of the geophysical logging items in the boreholes. Site name SP (mv) SN (ohm-m) LN (ohm-m) Micro1 (ohm-m) Micro2 (ohm-m) MG (ohm-m) Vp (km/sec) Vs (km/sec) Density (g/cm 3 ) Porosity (%) GammaRay Caliper-X (API) (mm) Caliper-Y Temperature (mm) ( ) K (%) U (ppm) Th (ppm) Ashio Tsukechi Kawaue Fukuoka Hatajiri Ueno Hagiwara Gofukuji Midori (vertical) Midori (inclined) Hirabayashi Iwaya Kabutoyama Shingu Mt. Ontake Nagano Pref. Gifu Pref. Nakatsugawa City Ena City Mt. Ena Fig. 2 Atera fault system and the locations of drilling sites (from Strip Map of the Atera Fault Fig. 2 System, Atera fault Geological system and Survey, the Japan, locations 1993). of drilling sites (from Strip Map of the Atera Fault System, Geological Survey, Japan, 1993). -6- - 6 - -6-
Geological and Logging Data of the NIED Boreholes, Japan - T. MATSUDA et al. Fig. 3 Location of the Ashio borehole plotted on a 1:25,000 topographic map of Ashio published by the Geographical Survey Institute of Japan. Fig. 4 Location of the Tsukechi borehole plotted on a 1:25,000 topographic map of Tsukechi published by the Geographical Survey Institute of Japan. Fig. 5 Location of the Kawaue borehole plotted on a 1:25,000 topographic map of Tsukechi published by the Geographical Survey Institute of Japan. Fig. 6 Location of the Fukuoka borehole plotted on a 1:25,000 topographic map of Minofukuoka published by the Geographical Survey Institute of Japan. - 7 - -7-
Report of the National Research Institute for Earth Science and Disaster Prevention, No. 310 ; March, 2008 Fig. 7 Location of the Hatajiri borehole plotted on a 1:25,000 topographic map of Minofukuoka published by the Geographical Survey Institute of Fig. 8 Location of the Ueno borehole plotted on a 1:25,000 topographic map of Tsukechi published by the Geographical Survey Institute of Japan. Fig. 9 Location of the Hagiwara borehole plotted on a 1:25,000 topographic map of Yamanokuchi published by the Geographical Survey Institute of Japan. Fig. 10 Location of the Gofukuji borehole plotted on a 1:25,000 topographic map of Yamabe published by the Geographical Survey Institute of Japan. - 8 - -8-
Geological and Logging Data of the NIED Boreholes, Japan - T. MATSUDA et al. Fig. 11 Location of the Midori borehole plotted on a 1:25,000 topographic map of Tarumi published by the Geographical Survey Institute of Japan. Fig. 12 Location of the Hirabayashi borehole plotted on a 1:25,000 topographic map of Kariya published by the Geographical Survey Institute of Japan. Fig. 13 Location of the Iwaya borehole plotted on a 1:25,000 topographic map of Suma published by the Geographical Survey Institute of Japan. Fig. 14 Location of the Kabutoyama borehole plotted on a 1:25,000 topographic map of Takarazuka published by the Geographical Survey Institute of Japan. - 9 - -9-
Report of the National Research Institute for Earth Science and Disaster Prevention, No. 310 ; March, 2008 Fig. 15 Location of the Shingu borehole plotted on a 1:25,000 topographic map of Shingu published by the Geographical Survey Institute of Japan. - 10 - -10-
Print Sample of Japanese Manuscripts for Transactions of NIED T. MATSUDA et al. 防 災 科 学 技 術 研 究 所 による 中 部 日 本 における 孔 井 検 層 データ - 活 断 層, 震 源 域,ヒンジライン- * * ** 松 田 達 生 小 村 健 太 朗 池 田 隆 司 * ** 独 立 行 政 法 人 防 災 科 学 技 術 研 究 所 地 震 研 究 部 北 海 道 大 学 大 学 院 理 学 研 究 院 要 旨 独 立 行 政 法 人 防 災 科 学 技 術 研 究 所 は 日 本 中 部 において 14 井 の 掘 削 を 行 った.そのうち, 足 尾 及 び 新 宮 を 除 く 12 井 は, 同 研 究 所 による 活 断 層 掘 削 プロジェクト によるものである. 足 尾 は, 同 地 域 周 辺 が 関 東 地 方 でも 浅 い 地 震 活 動 が 最 も 活 発 なことから,その 震 源 域 まで 到 達 する 深 さ 2,000 m の 掘 削 井 において 応 力 状 態, 間 隙 水 圧, 熱 流 量 などを 主 に 測 定 した. 新 宮 は, 南 海 地 震 のような 海 溝 型 巨 大 地 震 における 応 力 等 の 蓄 積 の 仕 方 を 調 べるために, 孔 井 内 の 原 位 置 測 定 によるモニタリングを 目 的 としたものである. 本 研 究 資 料 では,これ らの 研 究 を 行 う 上 での 基 礎 データとなる 各 孔 井 の 地 質 柱 状 図 及 び 各 種 物 理 検 層 データをまとめた. キーワード: 活 断 層 ドリリング, 地 質 柱 状 図, 物 理 検 層, 中 部 日 本 - 11 -
Depth Lithology SP, mv SN, ohm-m Micro1, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m Micro2, ohm-m 1 3 U (ppm) 0 60 Th (ppm) 0 1000 K (%) -400 400 Caliper-Y, mm 0 100 0.0 0 20 0 30 0 5 400-400 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 GRD 520.0 540.0 560.0 580.0 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 1000.0 1020.0 1040.0 1060 0 Fig. 16 Geologic column and geophysical logging charts of the Ashio borehole. - 12 -
1060.0 1080.0 1100.0 1120.0 1140.0 1160.0 1180.0 1200.0 1220.0 1240.0 1260.0 1280.0 1300.0 1320.0 1340.0 1360.0 1380.0 1400.0 1420.0 1440.0 1460.0 1480.0 1500.0 1520.0 1540.0 1560.0 1580.0 1600.0 1620.0 1640.0 1660.0 1680.0 1700.0 1720.0 1740.0 1760.0 1780.0 1800.0 1820.0 1840.0 1860.0 1880.0 1900.0 1920.0 1940.0 1960.0 1980.0 2000.0 GRD Fig. 16 Geologic column and geophysical logging charts of the Ashio borehole (continued). - 13 -
Depth Lithology GammaRay, API Temperature, C 1m:2900m 0.0 0 1000 0 100 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 RHY 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 Fig. 17 Geologic column and geophysical logs for the Tsukechi borehole. --13-14 -
Depth Lithology SP, mv SN, ohm-m Micro1, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m Micro2, ohm-m Vs, km/sec 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 ADM 60.0 80.0 AND 100.0 120.0 140.0 160.0 180.0 200.0 ADM 220.0 240.0 260.0 280.0 300.0 320.0 RHY 340.0 360.0 380.0 400.0 ADM 420.0 440.0 460.0 480.0 ADM 500.0 520.0 540.0 ADM 560.0 580.0 ADM 600.0 620.0 640.0 ADM Fig. 18 Geologic column and geophysical logs for the Kawaue borehole --14-15 -
Depth Lithology SP, mv SN, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 ADM 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 Fig. 19 Geologic column and geophysical logs for the Fukuoka borehole. --15-16 -
Depth Lithology SP, mv SN, ohm-m Vp, km/sec Density, g/cm3 Temperature, C 1m:2900m 0 400 LN, ohm-m Vs, km/sec 1 3 0 100 0.0 20.0 40.0 60.0 80.0 100.0 RHY 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 GRD 320.0 340.0 360.0 380.0 400.0 Fig. 20 Geologic column and geophysical logs for the Hatajiri borehole. --16-17 -
Depth Lithology SP, mv SN, ohm-m Micro1, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m Micro2, ohm-m 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 BST 60.0 80.0 100.0 BST CSS 120.0 140.0 CSS 160.0 180.0 200.0 RHY 220.0 240.0 260.0 280.0 300.0 GRD 320.0 340.0 360.0 380.0 400.0 Fig. 21 Geologic column and geophysical logs for the Ueno borehole. --17-18 -
Depth Lithology SP, mv SN, ohm-m MG, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 GRD 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 Fig. 22 Geologic column and geophysical logs for the Hagiwara borehole. --18-19 -
Depth Lithology SP, mv SN, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 60.0 80.0 100.0 120.0 140.0 BRE 160.0 180.0 200.0 GCG 220.0 240.0 260.0 280.0 SCG 300.0 320.0 340.0 BRE 360.0 380.0 SMA 400.0 Fig. 23 Geologic column and geophysical logs for the Gofukuji borehole. --19-20 -
Depth Lithology SP, mv SN, ohm-m Micro1, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m Micro2, ohm-m 1 3 U (ppm) 0 60 Th (ppm) 0 1000 K (%) -400 400 Caliper-Y, mm 0 100 0.0 0 20 0 30 0 5 400-400 20.0 40.0 CHT 60.0 80.0 100.0 120.0 140.0 SLT 160.0 180.0 200.0 220.0 240.0 260.0 CHT 280.0 300.0 SLT 320.0 340.0 FRZ 360.0 FRZ 380.0 400.0 420.0 440.0 460.0 480.0 500.0 520.0 540.0 560.0 580.0 SLT 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 CHT 940.0 960.0 980.0 1000.0 1020.0 FRZ 1040.0 1060 0 Fig. 24 Geologic column and geophysical logs for the Midori (vertical) borehole. --20-21 -
1060.0 1080.0 1100.0 1120.0 1140.0 1160.0 1180.0 1200.0 1220.0 1240.0 1260.0 1280.0 1300.0 FRZ CHT Fig. 24 Geologic column and geophysical logs for the Midori (vertical) borehole (continued). --21-22 -
Depth Lithology SP, mv SN, ohm-m Micro1, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m Micro2, ohm-m 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 60.0 80.0 100.0 CMS 120.0 140.0 160.0 180.0 200.0 220.0 BST 240.0 260.0 280.0 300.0 SMS 320.0 340.0 360 0 Fig. 25 Geologic column and geophysical logs for the Midori (inclined) borehole. --22-23 -
Depth Lithology SP, mv SN, ohm-m Micro1, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m Micro2, ohm-m 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 60.0 80.0 GRD 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 TNT 520.0 540.0 560.0 580.0 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 1000.0 1020.0 1040.0 1060 0 Fig. 26 Geologic column and geophysical logs for the Hirabayashi borehole. --23-24 -
1060.0 1080.0 1100.0 1120.0 1140.0 1160.0 1180.0 1200.0 1220.0 1240.0 1260.0 1280.0 1300.0 1320.0 1340.0 1360.0 1380.0 1400.0 1420.0 1440.0 1460.0 1480.0 1500.0 1520.0 1540.0 1560.0 1580.0 1600.0 1620.0 1640.0 1660.0 1680.0 1700.0 1720.0 1740.0 1760.0 1780.0 1800.0 1820.0 1840.0 1860 0 FRZ GRD TNT GRD GRD TNT PHT TNT FRZ FRZ TNT Fig. 26 Geologic column and geophysical logs for the Hirabayashi borehole (continued). --24-25 -
Depth Lithology SP, mv SN, ohm-m Micro1, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m Micro2, ohm-m 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 GRD 520.0 540.0 560.0 580.0 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 1000.0 Fig. 27 Geologic column and geophysical logs for the Iwaya borehole. --25-26 -
Depth Lithology SP, mv SN, ohm-m Micro1, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m Micro2, ohm-m 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 GNT 520.0 540.0 560.0 580.0 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 1000.0 1020.0 1040.0 1060 0 Fig. 28 Geologic column and geophysical logs for the Kabutoyama borehole. --26-27 -
1060.0 1080.0 1100.0 1120.0 1140.0 1160.0 1180.0 1200.0 1220.0 1240.0 1260.0 1280.0 1300.0 1320 0 GNT FRZ Fig. 28 Geologic column and geophysical logs for the Kabutoyama borehole (continued). --27-28 -
Depth Lithology SP, mv SN, ohm-m Micro1, ohm-m Vp, km/sec Density, g/cm3 Porosity, % GammaRay, API Caliper-X, mm Temperature, C 1m:2900m 0 400 LN, ohm-m Micro2, ohm-m Vs, km/sec 1 3 0 60 0 1000-400 400 Caliper-Y, mm 0 100 0.0 400-400 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 SMA 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 Fig. 29 Geologic column and geophysical logs for the Shingu borehole. --28-29 -