0 200

Km

-10

-5

0

km

km

-10 -5 0 5 10

1-10

-5

0

-10 -5 0 5 10

km

2-10

-5

0

-10 -5 0 5 10km

3

a) Map of 1997 Colfiorito sequence, b) set of three vertical cross sections. The red stars are the hypocenter of mainshocks a) Map of 1997 Colfiorito sequence, b) set of three vertical cross sections. The red stars are the hypocenter of mainshocks

(M> 4.5) and yellow ones are the hypocenter of mainshocks (4.0 <M< 4.5), (from Chiaraluce et al., 2005).(M> 4.5) and yellow ones are the hypocenter of mainshocks (4.0 <M< 4.5), (from Chiaraluce et al., 2005).

1

2

30

Km

1

COLLECROCE

BASIN

ANNIFO

BASIN

COLFIORITO

SWAMP

COLFIORITO

BASIN

S.MARTINO

BASIN

CESI

BASIN

RICCIANO

BASIN

ARVELLO

BASIN

VERCHIANO

BASIN

Mt. Faeto

Mt.Burano

Mt.Pennino

Mt. Le Scalette

Mt.Prefoglio

Mt. Cavallo

Mt.Tolagna

3

8

213

4

7 6

5

N

Mw=5.2 11:08

97/10/12

Mw=5.7 00:33

97/09/26

Mw=4.3 12:00

97/10/16

Mw=5.2 08:55

97/10/03

Mw=5.4 23:24

97/10/06

Mw=5.6 15:23

97/10/14

Mw=6.0 09:40

97/09/26

3

44

5

7

6

2

1

8Mw=4.5 22:07

97/09/03

a )

b)

LEGEND

strike-slip faults

thrust faults

normal faults

mainshocks (M>4.5)

mainshocks (4.0<M<4.5)

aftershocks

Seismogenic box of

Colfiorito earthquake

traces of

cross-sectionCOLFIORITO

AREA

http://www.icdp-online.org

x

(modified from Barchi, 2002)

SD-PG2 boreholes (projected)

Perugia Mts. Tiber Valley

Tiber Valley

Subasio Mt.

Le Scalette Mt.FaultColfiorito Inner Ridge

Thrust

Western Umbria Thrust

GubbioFault

NE

E

Km

Km

SW

W

Km

Km

ATF Section

ATF

ATF Colfiorito Section

0

1

2

3

4

5

6

7

8

9

10

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

10

0

1

2

3

4

5

6

7

8

9

5 Km

xPliocene-Quaternary deposits

LEGEND

Thrust Fault Strike-slip Fault

Normal Fault

Upper Cretaceous-Paleogene carbonates of the Umbria-Marche pelagic sequence

Lower Jurassic-Lower Creataceous carbonates of the Umbria-Marche pelagic sequence

Triassic Anhydrites and Dolomites

Miocene urbidites Phyllitic BasamentAlto Tiberina Fault (ATF)

Geological-structural map (A) and cross sections (B).

B

S ibillini

Mts.

Thru

st

Norcia

(modified from Barchi et al., 2001)

0 20 40 60Km

Spoleto

43.0˚

44.0˚

Pisa

Larderello

Siena

Apuane Alps

Firenze

Ancona

Gubbio

Città di Castello

Gualdo Tadino

Trasimeno Lake

Bolsena Lake

Rimini

Tiber Valley

Chiana Valley

Arezzo

M. Amiata

PerugiaAssisi

Colfiorito

Arno Valley

Adriatic Sea

ATF

SD

MC

PG2

Pliocene-

LEGEND

Lower Jurassic-Paleogene

Neogene

Ligurides and

Oligo-Miocene

Tuscan metamorphic

Messinian-lower

Triassic-Paleogene

Miocene turbidites

Oligo-Miocene Epiligurian deposits

turbidites of the Tuscan nappe

Tuscan nappe

units

Pliocene turbidites

carbonates of the Umbria-Marchepelagic sequence

Quaternary deposits

volcanic rocks

Rome

Bologna

Thrust Fault

Normal Fault

Alto Tiberina Fault (ATF)

Well

N12.0˚ 13.0˚11.0˚10.0˚A

Martani M

ts.

A LT O T I B E R I N A F A U LT A R E AA LT O T I B E R I N A F A U LT A R E A

0.0

1.0

2.0

(sec

)

1:50.000

tLev1

tLev2tLev2

tLev3

AtF

SsF

Seismic commercial profile (ENI) crossing the Tiber Basin north of Città di Castello (courtesy by M.G. Ciaccio in GNDT, Final Report 07/2006 - coordinated by Massimo Cocco).

Map view distribution of the 621 earthquakes (black open circles) located within 500 m of the ATF detachment surface represented by the isobaths (solid black lines). The red circles represent the multiplets. Minor grey squares labeled 1, 2, and 3 show the locations of the repeaters (from Chiaraluce et al., 2007).

Stratigraphy and borehole breakouts in two wells of the ATF area.

Fault

Discontinuity

Verrucano Fm. (Carnico)

Burano evaporite Fm.

(Norian-Rhaetian)

Turbiditic Fm.

(Aquitanian-Langhian)

Analysed interval

Breakout interval

Umbro-marchean carbonatic

Fm. (Sinemurian-Hettangian)

Umbro-marchean pelagic Fm.

(Sinemurian-Eocene)

0 m

326

3030

4763 m

4485

SD well

Shmin

= N40E ± 20

SHmax

= N50W ± 20

29 number of breakouts

429 m of breakout

Quality C

0 m

1400

1139

580

980

2255

2841

4763

4485

5600 m

MC well

Shmin

= N13E ± 29

SHmax

= N77W ± 29

48 number of breakouts

1190 m of breakout

ATF

Multidisciplinary Observatory and Laboratory of ExperimentsThe MOLEMOLE Drilling Project: Laboratory at Depth on an Active Fault in Central Italy

Massimo Cocco1, Paola Montone 1, Massimiliano R. Barchi 2 , Georg Dresen 3, Mark D. Zoback 4 , M.Teresa Mariucci 1, Simona Pierdominici 1

1 Istituto Nazionale di Geofisica e Vulcanologia, sezione di Sismologia e Tettonofisica, Rome, Italy2 Dipartimento di Scienze della Terra, Università di Perugia, Perugia, Italy

3 GFZ Potsdam, Germany 4 Stanford University, CA, US

paola.montone@ingv.it

http://mole.icdp-online.orghttp://www.ingv.it/servizi-e-risorse/archivio-congressi/convegni-2007/MOLE

mole.workshop@ingv.it

AGU, Fall Meeting. San Francisco, 10-14 Dec. 2007AGU, Fall Meeting. San Francisco, 10-14 Dec. 2007

T31C-0582T31C-0582

A LT O T I B E R I N A F A U LT A R E AA LT O T I B E R I N A F A U LT A R E A

A

B

C

1

23

45

6

Gualdo Tadino

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

Gubbi o

Gubbi o

1

2

3

4

5

6

F2

F1

F1

0 5 10

km

0

8

16

-12 0 12

0

8

16

-12 0 12

0

8

16

-12 0 12

0

8

16

-12 0 12

0

8

16

-12 0 12

0

8

16

-12 0 12

0

8

16

-12 0 12

0

8

16

-12 0 12

0

8

16

-12 0 12

B15°

43.5

13.0

A

Colfiorito

AssisiPerugia

Perugia Mts.

Tiber basin

Tiber basin

Città di Castello

-24 -20 -16 -12 -8 -4 0 4 8 12 16 20 24-24 -20 -16 -12 -8 -4 0 4 8 12 16 20 24-24 -20 -16 -12 -8 -4 0 4 8 12 16 20 24-24 -20 -16 -12 -8 -4 0 4 8 12 16 20 24 -24 -20 -16 -12 -8 -4 0 4 8 12 16 20 24-24 -20 -16 -12 -8 -4 0 4 8 12 16 20 24-24 -20 -16 -12 -8 -4 0 4 8 12 16 20 24-24 -20 -16 -12 -8 -4 0 4 8 12 16 20 24

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

0

4

8

12

16

20

(A) Map of the area and seismic sections location. (B) Vertical cross section perpendicular to the Apenninic chain showing

both the relocated composite seismicity and the 1984 Gubbio sequence. (C) Six vertical cross sections showing the

seismicity distribution and the available fault plane solutions computed for the 2000–2001 data. Their positions are

shown in (A) together with the width used to plot hypocenters. The heavy grey lines plotted in each cross section

represent the trace of the ATF fault as imaged on the depth-converted seismic reflection profiles (modified from

Chiaraluce et al., 2007).

2000–2001 relocated seismicity aftershocks of the 1984 Gubbio (Mw 5.1) earthquake [Collettini et al., 2003].

REFERENCESAbers, G.A., 1991, Possible seismogenic shallow-dipping normal faults in the Woodlark-D'Entrecasteaux extensional province, Papua New Guinea: Geology, v. 19, 1205-1208.Abbott R.E. et al., 2001, Geophysical confirmation of low-angle normal slip on the historically active Dixie Valley fault, Nevada. J. Geophys. Res., 106, 4169-4181.Amato A. et al., 1998, The 1997 Umbria-Marche, Italy, earthquake sequence: a first look at the main shocks and aftershocks. Geophys. Res. Let., 25, 15, 2861-2864.Ambrosetti P. et al., 1987, Il Pliocene ed il Pleistocene inferiore del bacino del Fiume Tevere nell'Umbria meridionale. Geog. F. Din. Quat., 10, 10-33.Anderson H.J., Jackson J.A., 1987, Active tectonics of the Adriatic region. Geophys. J. Astr. Soc., 91, 937-983.Antonioli A. et al., 2005, Fluid flow and seismicity pattern: Evidence from the 1997 Umbria-Marche (central Italy) seismic sequence. Geophys. Res. Let., 32, L10311, doi:10.1029/2004GL022256. Axen G.J, 1992, Pore pressure, stress increase, and fault weakening in low-angle normal faulting. J. Geophys. Res., B, Solid Earth and Planets, 97, 6, 8979-8991.Barchi et al., 2001, Outer Northern Apennines. In Vai and Martini (eds) Anatomy of an Orogen:the Apennines and Adjacent Mediterranean Basin, pp. 215-254, Kluwer Academic Publishers.Barchi M.R., 2002, Lithological and structural controls on the seismogenesis of the Umbria region: Observations from seismic reflection profiles. Bull. Soc. Geol. It., 1, 855-864.Boncio P. et al., 2000, Architecture and seismotectonics of a regional low-angle normal fault zone in central Italy. Tectonics 19, 1038-1055.Boschi E. et al., 1995, Catalogo dei forti terremoti in Italia dal 461 a.C. al 1980. Pubblicazione dell'Istituto Nazionale di Geofisica, 973 pp.Brozzetti F., Lavecchia, G., 1994, Seismicity and related extensional stress field: the case of the Norcia seismic zone. Annales Tectonicae 8, 38-57.Byerlee, J. D. Friction, overpressure and fault normal compression. Geophys. Res. Lett. 17, 2109±2112 (1990).Caskey, S. J., S. G. Wesnousky, P. Zhang, and D. B. Slemmons, 1996, Surface faulting of the 1954 Fairview Peak (Ms=7.2) and Dixie Valley (Ms=6.9) earthquakes, central Nevada.Bull. Seism. Soc. Am., v. 86, p. 761-787.

Cello G. et al., 2000, Geological constraints for earthquake faulting studies in the Colfiorito area (central Italy). J. Seism. 4, 357-364.Chiarabba, C., Amato, A., 2003, Vp and Vp/Vs images in the Mw 6.0 Colfiorito fault region (central Italy): A contribution to understand seismotectonic and seismogenic processes. J. Geophys. Res., 108, doi: 10.1029/2001JB001665.Chiaraluce et al., 2005, Connecting seismically active normal faults with Quaternary geological structures in a complex extensional environment: The Colfiorito 1997 case history (northern Apennines, Italy). Tectonics, 24, TC1002, doi:10.1029/2004TC001627, 2005Chiaraluce et al., 2007, Architecture and mechanics of an active low angle normal fault: the Alto Tiberina fault (northern Apennines, Italy) case study. JGR,VOL. 112, B10310, doi:10.1029/2007JB005015, 2007Chiodini G. et al., 2004, Carbon dioxide Earth degassing and seismogenesis in central and southern Italy. Geophys. Res. Let., 31, 7, L07615, doi:10.1029/2004GL019480.Ciaccio M.G. et al., 2005, Seismological, geological and geophysical constraints for the Gualdo Tadino fault, Umbria-Marche Apennines (central Italy). Tectonophysics, 406, 233-247.Cinti F.R. et al., 1999, The 1997 Umbria-Marche (Italy) earthquake sequence: relationship between ground deformation and seismogenic structure. Geophys. Res. Let., 26, 7, 895-898.Collettini, C., M. R. Barchi, L. Chiaraluce, F. Mirabella, and S. Pucci, 2003, The Gubbio fault: Can different methods give pictures of the same object, J. Geodyn., 36, 51–66.Cox M. 1999, Static corrections for seismic reflection surveys. Soc. Explor. Geophys., 531.Deschamps A. et al., 2000, Spatio-temporal distribution of seismic activity during the Umbria-Marche crisis, 1997. J. Seismol., Special Issue, 4, 377-386.Doser, D., 1986, Earthquake processes in the Rainbow Mountain-Fairview Peak-Dixie Valley, Nevada region 1954-1959: J. Geophys. Res., v. 91, p. 12572-12586. Ekstrom G. et al., 1998, Moment tensor analysis of the central Italy earthquake sequence of September-October 997. Geophys. Res. Lett., 25, 1971-1974.Frepoli, A., Amato, A., 1997, Contemporaneous extension and compression in the Northern Apennines from earthquake fault-plane solutions. Geophys. J. Int., 129, 2, 368-388.Galli P., Galadini F., 1999, Seismotectonic framework of the 1997-1998 Umbria-Marche (central Italy) earthquakes. Seism. Res. Lett. 70, 4, 417-427.

Haessler H. et al., 1988, The Perugia (Italy) earthquake of 29, April 1984: a microearthquake M. Survey. Bull. Seismol. Soc. Am., 78, 1948-1964.Hatzfeld, D., V. Karakostas, M. Ziazia, I. Kassaras, E. Papadimitriou, K. Makropoulos, N. Voulgaris, and C. Papaioannou, Microseismicity and faulting geometry in the Gulf of Corinth (Greece). Geophys. J. Int., 141, 438-456, 2000.Jackson J.A., 1987, Active normal faulting and extension. In Continental Extensional Tectonics, 28, edited by M.P. Coward, J.F. Dewey.Johnson, R. A., and K. L. Loy, Seismic reflection evidence for seismogenic low-angle faulting in southeastern Arizona. Geology, 20, 597-600, 1992.Kennedy B.M. et al.,1997, Mantle fluids in the San Andreas fault system, California. Science, 278,1278-1281.Lavecchia G. et al., 1994, Seismotectonic zoning in East-Central Italy deduced from the analysis of the Neogene to present deformations and related stress fields. Bull.Geol. Soc. Am., 106, 1107-1120.Mariucci M. T., 1999, Recent tectonic evolution and present stress in the northern Apennines. Tectonics, 18, 108-118.Miller S.A. et al., 2004, Aftershocks driven by a highpressure CO2 source at depth. Nature, 427, 724-727.Montone P. et al., 2004, An improved stress map for Italy and surrounding regions (central Mediterranean). J. Geophysical Research, 109, B10410, doi:10.1029/2003JB002703.Pialli G. et al., 1998, Results of the CROP03 deep seismic reflection profile. Mem. Soc. Geol. It., 52, 654 pp.Piccinini D. et al., 2003, A microseismicity study in a low seismicity area of Italy: the Città di Castello 2000-2001 experiment. Annals of Geophysics, 46, 6, 1315-1324.Sibson R.H., 2000, Fluid involvement in normal faulting. In The Resolution of Geological Analysis and Models for Earthquake Faulting Studies, edited by G. Cello and E. Tondi. J. Geodyn., 29, 469-499.Wernicke B.P., 1995, Low-angle normal faults and seismicity: A review. J. Geophys. Res., 100, 20159-20174. Zollo A. et al., 1999, The Umbria-Marche 1997 (central Italy) earthquake sequence: Insight on the mainshock rupture from near source strong motion records. Geophys. Res. Lett., 26, 3165-3169.

SCIENTIFIC OBJECTIVES

1) to collect extremely important information concerning composition, structure, mechanical and physical properties of the shallow crust in the region;2) to sample the fault core in order to investigate the mineral composition, the mechanical and rheological properties of the fault zone materials;3) to determine the active stress field around and within the fault zone;4) to measure the poro-elastic properties and to better understand fluid circulation at seismogenic depth;5) to install borehole instruments in order to create a permanent geophysical and geochemical deep observatory;6) to promote the deployment of permanent geophysical and geochemical networks at the Earth surface in the area;7) to collect data and observations for better understanding and forecast the occurrence of repeated main shocks sequences.

INTRODUCTION INTRODUCTION Following an ambitious idea to drill a very deep borehole in Central Italy we submitted a preliminary proposal in January 2006 to the ICDP. A fter a positive answer we proposed to organize a workhop to promote the creation of an international multidisciplinary team of scientists for a drilling project in Central Italy: the MOLE drilling Project . The Workshop Proposal (submitted in January 2007) has been positively reviewed by the Science Advisory Group of the ICDP. Successively, the ICDP Executive Committee agreed to provide a financial support for the Workshop organization.

The Workshop will be held in Spoleto (Perugia, Umbria) next spring 5-8 May 2008 (see EOS call).

The drilling project is aimed to investigate the shallow crust and the inner structure of normal faults in Northern Apennines.

The Umbria-Marche sector of Northern Apennines offers a unique opportunity to reach a complexsystem of normal faults among which we selected two possible targets: 1) The active Colfiorito fault dipping about 45˚ toward SW, which ruptured during the 1997 M=6 earthquake sequence (Colfiorito fault)(Colfiorito fault) or 2) the Alto Tiberina low angle normal fault dipping 15˚-25˚ towards ENE, which moves through a combination of aseismic creep and repeating microearthquakes, (Alto Tiberina Fault, ATF)(Alto Tiberina Fault, ATF).

The project is motivated by the need to answer to fundamental issues concerning: 1) the geophysical and geochemical processes controlling normal faulting during moderate-to-large seismic events (3-4 km borehole) or 2) the low angle normal fault mechanical paradox (5-6 km borehole).

LOW ANGLE NORMAL FAULTS IN THE WORLD

1) Dixie Valley - Nevada Ms= 6.82) Eastern Papua New Guinea (Solomon Sea ocean basin), M=6.23) Basin and Range Province (Utah, Idaho)4) Basin and Range Province Death Valley

ICDP Workshop Announcement

MOLE Drilling Project (Multidisciplinary Observatory and Laboratory of Experiments along a Drilling

in Central Italy)Perugia (Italy), May 5-8, 2008

The MOLE drilling proposal strives to investigate the inner structure of normal faults and the shallow crust in the Northern Apennines. The project is motivated by the need to answer fundamental issues on geophysical and geochemical processes controlling normal faulting during moderate to large seismic events and on the low angle normal fault mechanical paradox. Drilling the Umbria-Marche sector of the Northern Apennines offers the unique opportunity to reach a seismogenic fault: either the 45˚-dipping Colfiorito Fault which ruptured in a M6 earthquake in 1997, or the 20˚ dipping normal Alto Tiberina Fault, which moves through creep and microearthquakes. The project aims to collect novel data while drilling and to monitor an active fault zone through a multidisciplinary observatory at depth.

During the upcoming workshop, to be held in Perugia, Italy, May 5-8, 2008, including a half-day field trip to potential drilling sites, the science rationale behind the project will be reviewed by invited speakers. Scientific targets and technical challenges will be discussed to plan the drilling project and develop a draft full proposal. Interested parties are welcome to submit an application to the Scientific Organizing Committee (mole.workshop@ingv.it) no later than January 15, 2008, including name, affiliation, brief summary of research interests, relevant expertise and intended contribution. Selected participants will be invited on the basis of their research interests related to the project goals and will be notified in February 2008. Limited travel and participation funding is available for up to 40 scientists; preference will be given to those from ICDP member countries.

In addition to ICDP, the workshop is sponsored by the Istituto Nazionale di Geofisica e Vulcanologia, Roma. More information is available at: http://mole.icdp-online.org/ and http://www.ingv.it/servizi-e-risorse/archivio-congressi/convegni-2007/MOLE.

EOS CALLEOS CALL