Geological and Logging Data of the NIED Boreholes, Japan,－Active fault, Seismogenic zone, Hingeline－

(1)

Technical Note of the National Research Institute

for Earth Science and Disaster Prevention

No.310

March 2008

防災科学技術研究所研究資料

第310号

Geological and Logging Data of the NIED Boreholes, Japan

－

Active Fault, Seismogenic Zone, Hingeline

－

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

－

National Research Institute for Earth Science and Disaster Prevention, Japan 独立行政法人

防災科学技術研究所

National Research Institute for Earth Science and Disaster Prevention

Tennodai 3-1, Tsukuba, Ibaraki, 305-0006 Japan

防災科学技術研究所研究資

料

第

三

一

〇

号

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

防災科学技術研究

所

(2)

－ 1 －

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 2,000m

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

(3)

－ 2 －－2－ 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 550m 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

500m. 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 25cm (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

(4)

－ 3 －

Geological and Logging Data of the NIED Boreholes, Japan －_{T. MATSUDA et al.}

－3－ 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/cm3₎ 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 (gammaray, 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, ) 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 °C

(5)

－ 4 －－4－ 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.

(6)

－ 5 －

－5－

Table 1 Location data of the boreholes (International Terrestrial Reference Frame) .

Fig. 1 Locations of the drilling sites in central Japan.

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

(7)

－ 6 －

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.

Fig. 2 Atera fault system and the locations of drilling sites (from Strip Map of the Atera Fault

System, Geological Survey, Japan, 1993).

g g g g g g ( AG IW AR A . ISH IU ED A 9UGAM_INE -IY_ACHI F'ERO +O WA CHI F !TER A 5M AGO TO GE F 4SUKECHI +AWAUE Mt. Ontake Mt. Ena Nakatsugawa City Ena City Nagano Pref. Gifu Pref. 5ENO &UKUOKA (ATAJIRI (AGIWARA ²g ²g ²g ²g ²g ²g

Site name _(mV)SP _(ohm-m)SN _(ohm-m)LN _(ohm-m)Micro1 _(ohm-m)Micro2 _(ohm-m)MG _(km/sec)Vp _(km/sec)Vs _(g/cmDensity3₎ Porosity_(%) GammaRay_(API) Caliper-X_(mm) Caliper-Y_(mm) Temperature_(㷄) _(%)K _(ppm)U _(ppm)Th

Ashio 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Tsukechi 䃢䃢 Kawaue 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Fukuoka 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Hatajiri 䃢䃢䃢䃢䃢䃢䃢 Ueno 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Hagiwara 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Gofukuji 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Midori (vertical) 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Midori (inclined) 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Hirabayashi 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Iwaya 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Kabutoyama 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢 Shingu 䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢䃢－6－

Table 2 List of the geophysical logging items in the boreholes.

Fig. 2 Atera fault system and the locations of drilling sites (from Strip Map of the Atera Fault

(8)

－ 7 －

－7－

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.

(9)

－ 8 －

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. 10 Location of the Gofukuji borehole plotted on a 1:25,000 topographic map of Yamabe 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. 8 Location of the Ueno borehole plotted on a 1:25,000 topographic map of Tsukechi published by the Geographical Survey Institute of Japan.

(10)

－ 9 －

－9－

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. 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. 14 Location of the Kabutoyama borehole plotted on a 1:25,000 topographic map of Takarazuka 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.

(11)

－ 10 －

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.

(12)

－ 11 －

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 2,000m 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

(13)

Fig. 16 Geologic column and geophysical logging charts of the Ashio borehole. 1m:2900m ₀ ₄₀₀ ₁ ₁₀₀₀₀ LN, ohm-m 1 10000 1 10000 Micro2, ohm-m 1 10000 1 3 0 60 0 1000 -400 400 Caliper-Y, mm 400 -400 0 100 K (%) 0 5 U (ppm) 0 20 Th (ppm) 0 30 1 7 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 520.0 540.0 560.0 580.0 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 1000.0 1020.0 1040.0 1060 0

GRD

(14)

－ 13 －

Fig. 16 Geologic column and geophysical logging charts of the Ashio borehole (continued). 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

(15)

13－

Fig. 17 Geologic column and geophysical logs for the Tsukechi borehole.

1m:2900m ₀ ₁₀₀₀ ₀ ₁₀₀ 0.0 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

RHY

(16)

－ 15 －－_14－

Fig. 18 Geologic column and geophysical logs for the Kawaue borehole

Depth 1m:2900m SP, mV 0 400 SN, ohm-m 1 10000 LN, ohm-m 1 10000 Micro1, ohm-m 1 10000 Micro2, ohm-m 1 10000 Density, g/cm3 1 3 Vp, km/sec 1 7 Vs, km/sec 1 7 Porosity, % 0 60 GammaRay, API 0 1000 Caliper-X, mm -400 400 Caliper-Y, mm 400 -400 Temperature, C 0 100 Lithology 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 520.0 540.0 560.0 580.0 600.0 620.0 640.0

ADM

AND

RHY

(17)

15－

Fig. 19 Geologic column and geophysical logs for the Fukuoka borehole.

1m:2900m ₀ ₄₀₀ ₁ ₁₀₀₀₀ LN, ohm-m 1 10000 1 7 1 3 0 60 0 1000 -400 400 Caliper-Y, mm 400 -400 0 100 0.0 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

ADM

(18)

－ 17 －－_16－

Fig. 20 Geologic column and geophysical logs for the Hatajiri borehole.

Depth 1m:2900m SP, mV 0 400 SN, ohm-m 1 10000 LN, ohm-m 1 10000 Vp, km/sec 1 7 Vs, km/sec 1 7 Density, g/cm3 1 3 Temperature, C 0 100 Lithology 0.0 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

RHY

GRD

(19)

17－

Fig. 21 Geologic column and geophysical logs for the Ueno borehole.

1m:2900m ₀ ₄₀₀ ₁ ₁₀₀₀₀ LN, ohm-m 1 10000 1 10000 Micro2, ohm-m 1 10000 1 7 1 3 0 60 0 1000 -400 400 Caliper-Y, mm 400 -400 0 100 0.0 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

BST

CSS

RHY

GRD

BST CSS

(20)

－ 19 －－_18－

Fig. 22 Geologic column and geophysical logs for the Hagiwara borehole.

Depth 1m:2900m SP, mV 0 400 SN, ohm-m 1 10000 LN, ohm-m 1 10000 Vp, km/sec 1 7 Density, g/cm3 1 3 Porosity, % 0 60 GammaRay, API 0 1000 Caliper-X, mm -400 400 Caliper-Y, mm 400 -400 Temperature, C 0 100 Lithology MG, ohm-m 1 10000 0.0 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

GRD

(21)

19－

Fig. 23 Geologic column and geophysical logs for the Gofukuji borehole.

1m:2900m ₀ ₄₀₀ ₁ ₁₀₀₀₀ LN, ohm-m 1 10000 1 7 1 3 0 60 0 1000 -400 400 Caliper-Y, mm 400 -400 0 100 0.0 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

BRE

SMA

GCG

SCG

(22)

－ 21 －－_20－

Fig. 24 Geologic column and geophysical logs for the Midori (vertical) borehole.

Depth 1m:2900m SP, mV 0 400 SN, ohm-m 1 10000 LN, ohm-m 1 10000 Micro1, ohm-m 1 10000 Micro2, ohm-m 1 10000 Vp, km/sec 1 7 Density, g/cm3 1 3 Porosity, % 0 60 GammaRay, API 0 1000 K (%) 0 5 Th (ppm) 0 30 U (ppm) 0 20 Caliper-X, mm -400 400 Caliper-Y, mm 400 -400 Temperature, C 0 100 Lithology 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 520.0 540.0 560.0 580.0 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 1000.0 1020.0 1040.0 1060 0

SLT

CHT

FRZ

CHT

(23)

21－

Fig. 24 Geologic column and geophysical logs for the Midori (vertical) borehole (continued). 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

CHT

FRZ

(24)

－ 23 －－_22－

Fig. 25 Geologic column and geophysical logs for the Midori (inclined) borehole.

Depth 1m:2900m Density, g/cm3 1 3 GammaRay, API 0 1000 Micro1, ohm-m 1 10000 Micro2, ohm-m 1 10000 Porosity, % 0 60 SP, mV 0 400 Temperature, C 0 100 Vp, km/sec 1 7 Caliper-X, mm -400 400 Caliper-Y, mm 400 -400 Lithology SN, ohm-m 1 10000 LN, ohm-m 1 10000 0.0 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

SMS

CMS

BST

(25)

23－

Fig. 26 Geologic column and geophysical logs for the Hirabayashi borehole.

1m:2900m ₀ ₄₀₀ ₁ ₁₀₀₀₀ LN, ohm-m 1 10000 1 10000 Micro2, ohm-m 1 10000 1 7 1 3 0 60 0 1000 -400 400 Caliper-Y, mm 400 -400 0 100 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 520.0 540.0 560.0 580.0 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 1000.0 1020.0 1040.0 1060 0

GRD

TNT

(26)

－ 25 －－_24－

Fig. 26 Geologic column and geophysical logs for the Hirabayashi borehole (continued). 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

PHT

FRZ

GRD

FRZ

GRD

TNT

FRZ

TNT

(27)

25－

Fig. 27 Geologic column and geophysical logs for the Iwaya borehole.

1m:2900m ₀ ₄₀₀ ₁ ₁₀₀₀₀ LN, ohm-m 1 10000 1 10000 Micro2, ohm-m 1 10000 1 3 1 7 0 60 0 1000 -400 400 Caliper-Y, mm 400 -400 0 100 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 520.0 540.0 560.0 580.0 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 1000.0

GRD

(28)

－ 27 －－_26－

Fig. 28 Geologic column and geophysical logs for the Kabutoyama borehole.

Depth 1m:2900m Density, g/cm3 1 3 GammaRay, API 0 1000 Micro1, ohm-m 1 10000 Micro2, ohm-m 1 10000 Porosity, % 0 60 SN, ohm-m 1 10000 SP, mV 0 400 Temperature, C 0 100 Vp, km/sec 1 7 Caliper-X, mm -400 400 Caliper-Y, mm 400 -400 Lithology LN, ohm-m 1 10000 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 220.0 240.0 260.0 280.0 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 500.0 520.0 540.0 560.0 580.0 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 1000.0 1020.0 1040.0 1060 0

GNT

(29)

27－

Fig. 28 Geologic column and geophysical logs for the Kabutoyama borehole (continued). 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

FRZ

GNT

(30)

－ 29 －－_28－

Fig. 29 Geologic column and geophysical logs for the Shingu borehole.

Depth 1m:2900m SP, mV 0 400 SN, ohm-m 1 10000 LN, ohm-m 1 10000 Micro1, ohm-m 1 10000 Vp, km/sec 1 7 Vs, km/sec 1 7 Density, g/cm3 1 3 Porosity, % 0 60 GammaRay, API 0 1000 Caliper-X, mm -400 400 Caliper-Y, mm 400 -400 Temperature, C 0 100 Lithology Micro2, ohm-m 1 10000 0.0 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