2.3.2. FIELD AND LABORATORY ACTIVITIES FOR NEW GEOLOGICAL AND

GEOPHYSICAL DATA AQUISITION IN ORDER TO SOLVE THE RELATIONSHIP

BETWEEN TECTONIC AND VOLCANIC STRUCTURAL FEATURES. ROCK

SAMPLING FOR SPECIFIC GEOCHEMICAL AND PETROPHYSICAL ANALYSES

(I).

(2) 3.2.1. GEOLOGICAL INVESTIGATIONS

The results geological observations obtained during the field campaign have allowed the

construction two detailed maps for the southern part of the INSTEC perimeter.

It is about the new geological map of Ciomadul volcano and Persani Mts. alkali basaltic

volcanism. The Persani Mts new volcanologic map is shown along the geophysical

interpretations in Fig. 19.

We show below a new simplified 3D map of Ciomadul volcano (fig. 24), showing also the

published and unpublished K/Ar data that will be published soon in an international journal

along with volcanological interpretations:

Fig. 26.

(2) 3.2.2. GEOPHYSICAL INVESTIGATIONS

During the second stage, geophysical research have been conducted into two main directions:

- field observations

- lab determinations and data processing

FIELD GEOPHYSICAL ACTIVITIES

New data acquisition have been performed in order to complement the current information and to

advance the state-of-the-art knowledge in the investigated area.

As long as the National Agency for Mineral Resources denies the access to the previously

obtained information, the role of data acquisition in the project has been considerably increased.

Many areas previously covered by geophysical observations had to be re-surveyed, increasing

resources spent for field activities in the detriment of data processing and interpretation.

The much more extended surface to be covered by field activities has determined a thorough

planning of the areas to be surveyed each year of the project. The specific scheduling is

presented in the next figure.

Fig. 27 - SCHEDULING FIELD SURVEYS WITHIN THE INSTEC PROJECT

1, INSTEC overall perimeter; 2, area covered during 2014 field campaign; 3, planned works during 2015 field

campaign; 4, area to be covered during 2016

I, INSTEC-SUD perimeter; I.1, Perşani sub-perimeter; I.2. Ciomadu sub-perimeter

L35-014 L35-015 L35-016 L35-017

L35-026 L35-027 L35-028 L35-029

L35-038 L35-039 L35-040 L35-041

L35-050 L35-051 L35-052 L35-053

L35-062 L35-063 L35-064 L35-065

L35-074 L35-075 L35-076 L35-077

0km 10km 20km 30km

24 30' 25 00' 26 30' 27 00' 27 30'

46 00'

46 20'

46 40'

47 00'

47 20'

47 40'

45 40'

II.1

I.2

1 2 3 4

From the methodological point of view, research performed can be grouped into:

- gravity survey

- ground magnetics

GRAVITY SURVEYS

Gravity observations has been performed by employing a Canadian gravity meter Scintrex CG-5

AUTOGRAV (1 microgal accuracy).

a) preparative activities: consisted of checking-out operations for gravity scale and drift factor

Fig. 28 - CG-5 AUTOGRAV METER OPERATED IN THE SEDD GRAVITY LAB FOR DRIFT FACTOR

DETERMINATION

b) observations on the gravity reference network for transferring absolute gravity values

Fig. 29 - CG-5 AUTOGRAV METER OPERATED ON THE P116-SANZIENI (TG. SECUIESC) PILLAR

OF THE GRAVITY REFERENCE NETWORK

c) current survey in the study area

Fig. 30 - CG-5 AUTOGRAV METER OPERATED IN THE CENTRAL BASE-STATION OF THE 2014 SURVEY: LEPSA FROM

THE 2nd ORDER GRAVITY NETWORK OF ROMANIA

Fig. 31 - CG-5 AUTOGRAV METER OPERATED IN A CURRENT STATION IN THE FIELD

GROUND MAGNETICS

Geomagnetic field observations have been performed by using two types of instruments own by

the Solid Earth Dynamics Department (SEDD):

a) proton magnetometer Geometrics G856 AX (10-9

T accuracy) - usually employed in current

field survey

Fig. 32 - MAGNETICS TEAM OPERATING THE G856 AX IN THE DOPCA BASE-STATION

B) optical-pump magnetometer Scintrex SM-5 NAVMAG (10-12

T accuracy) mainly

employed for the determination of the effect of the external sources of the geomagnetic field.

FIG. 33 - SCINTREX SM-5 NAVMAG OPERATED FOR DIURNAL ACTIVITY SERVICE

MAIN RESULTS

The results obtained during the field campaign have allowed the construction of several models

of the gravity/geomagnetic field in the study area such as:

- regional-scale geomagnetic images for INSTEC-SUD area

- semi-detailed images were obtained for the CIOMADU and PERSANI sub-perimeters

REGIONAL-SCALE IMAGES

LOCAL-SCALE IMAGES

520000 525000 530000 535000 540000 545000 550000 555000 560000 565000 570000 57500048

50

00

49

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00

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00

00

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51

00

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50

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00

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52

50

00

MerestiMartinis

Ulies

Ocland

Cata

Rupea Homorod

Racos

Varghis Bradut

Talisoara

Filia

Racosu de Sus

CapeniAugustin

Lazaresti

Cozmeni

Malnas

Micfalau

Bixad

Tusnad

Cetatuia

MiclosoaraOrmenis

Aita Seaca

Bodoc

Biborteni Batani

Herculian

UngraHoghiz

Comana

Aita Mare

Apata

Belin

Maierus

Bodoc

Ghidfalau

Valea Crisului

SF GHEORGHE Moacsa

Albis

Cernatu de Jos

Cernatu de Sus

Dl DaltaDl Portii

Dl Mare

Merca

Vf Ocland

SAnpaul

Drauseni SE

Dealul Nisipos

Izvorul cu TrestiiBeiu est

Dl Paznicului

Dl Strajii

Dl Chingii

Dl Capului

Fata JimboruluiDl Teisului

Rupea NE

Rupea

Gorganu

Dealul Lung La Movile

Varful Negru

Capul Mare

Dl CornuluiDl Crungilor

Chicioara

Dl. Meresti

Varful Ascuns

Vf. Tiva

Vf. Izvorului

Compesti

Dl. Fierarului

Dealul Rotund

Varghis

Dl. Plesuv

Dl. PusniculuiDl. Izvoarelor

Dealul Lung

Vf. Dealului

Muntele Mare

Dl. Cozmeni

Dl. Bordas

Vf. Lazaresti

Dl. Bailor

Varful Mare

Vf. Carpinis

Vf. Ursilor

Vf. Poienii

Vf. Padurii

Dl. Buturugi

Dl. Merilor

Vf. Poplis

Ciomatul Mare

Haramul Mare

Lazaresti

Dl. Tusnadul Nou

Dealul Pietrod

Pilisca Mare

Vf. Murgu

Obcina Izvoarelor

Muntele Cucului

Aita Seaca

Dl. CruciiDeasupra Dealului

Vf. Porcului

Vf. Caprei

Covasul Frumos

Vf Strajii

Cuciulata nord

Maguricea Mare

Muntele Negru

Vf Piatra Mare

Vf Dalma

Piscul Inalt

Dl Trestia

Vf Pietrisu

Pleasa

Comana de Jos sud

La Maguri

Calabaciu

Apata NV

Aita Mare NE

Dealul Lung

Apata SV

Fata cu MaraciniDl din Tabla

Vadul Rosu

Dl Bodos

poiana MarePietroasa

Vf Parcul micDl inflorit

vf Taieturii

Sugag

Culmea Ascutita

Dl Curat

P-na Maroc

Vf Caprei

Valea Crisului N

Valea Crisului SE

Dl Paius

Pivnitele Mari

Pd Frumoasa

Semeria

Olteni

Zoltan

Dalnic NV

Vf. Mesteacanului

P-na Fierbinte

Dealul Frumos

400 m450 m500 m550 m600 m650 m700 m750 m800 m850 m900 m950 m1000 m1050 m1100 m1150 m1200 m1250 m1300 m1350 m1400 m1450 m1500 m1550 m1600 m1650 m1700 m

0 km 2.5 km 5 km 7.5 km

I.2

I.1

520000 m 525000 m 530000 m 535000 m 540000 m 545000 m 550000 m 555000 m 560000 m 565000 m 570000 m 575000 m

48

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m4

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0 m

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m5

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0 m

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m5

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m5

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50

00

m

MerestiMartinis

Ulies

Ocland

Cata

Rupea Homorod

Racos

Varghis Bradut

Talisoara

Filia

Racosu de Sus

CapeniAugustin

Lazaresti

Cozmeni

Malnas

Micfalau

Bixad

Tusnad

Cetatuia

MiclosoaraOrmenis

Aita Seaca

Bodoc

BiborteniBatani

Herculian

UngraHoghiz

Comana

Aita Mare

Apata

Belin

Maierus

Bodoc

Ghidfalau

Valea Crisului

SF GHEORGHE Moacsa

Albis

Cernatu de Jos

Cernatu de Sus

Dl DaltaDl Portii

Dl Mare

Merca

Vf Ocland

SAnpaul

Drauseni SE

Dealul Nisipos

Izvorul cu TrestiiBeiu est

Dl Paznicului

Dl Strajii

Dl Chingii

Dl Capului

Fata JimboruluiDl Teisului

Rupea NE

Rupea

Gorganu

Dealul Lung La Movile

Varful Negru

Capul Mare

Dl CornuluiDl Crungilor

Chicioara

Dl. Meresti

Varful Ascuns

Vf. Tiva

Vf. Izvorului

Compesti

Dl. Fierarului

Dealul Rotund

Varghis

Dl. Plesuv

Dl. PusniculuiDl. Izvoarelor

Dealul Lung

Vf. Dealului

Muntele Mare

Dl. Cozmeni

Dl. Bordas

Vf. Lazaresti

Dl. Bailor

Varful Mare

Vf. Carpinis

Vf. Ursilor

Vf. Poienii

Vf. Padurii

Dl. Buturugi

Dl. Merilor

Vf. Poplis

Ciomatul Mare

Haramul Mare

Lazaresti

Dl. Tusnadul Nou

Dealul Pietrod

Pilisca Mare

Vf. Murgu

Obcina Izvoarelor

Muntele Cucului

Aita Seaca

Dl. CruciiDeasupra Dealului

Vf. Porcului

Vf. Caprei

Covasul Frumos

Vf Strajii

Cuciulata nord

Maguricea Mare

Muntele Negru

Vf Piatra Mare

Vf Dalma

Piscul Inalt

Dl Trestia

Vf Pietrisu

Pleasa

Comana de Jos sud

La Maguri

Calabaciu

Apata NV

Aita Mare NE

Dealul Lung

Apata SV

Fata cu MaraciniDl din Tabla

Vadul Rosu

Dl Bodos

poiana MarePietroasa

Vf Parcul micDl inflorit

vf Taieturii

Sugag

Culmea Ascutita

Dl Curat

P-na Maroc

Vf Caprei

Valea Crisului N

Valea Crisului SE

Dl Paius

Pivnitele Mari

Pd Frumoasa

Semeria

Olteni

Zoltan

Dalnic NV

Vf. Mesteacanului

P-na Fierbinte

Dealul Frumos

0 km 3 km 6 km 9 km

200 nT

240 nT

280 nT

320 nT

360 nT

400 nT

440 nT

480 nT

520 nT

560 nT

600 nT

640 nT

680 nT

720 nT

760 nT

800 nT

840 nT

880 nT

930 nT

970 nT

I.2

I.1

Proiectie stereografica STEREO 1970Elipsoid KrasovskiSistem de cote: Marea Neagra 1975

Model camp de referinta: IGRF 11Altitudine de referinta: 2000 m

Metoda interpolare: kriggingDimensiuni grid: 2 km x 2 kmEchidistanta izodiname: 10 nT

Perimetrul INSTEC-SUD: anomalia scalarului intensitatii totale a campului geomagnetic la altitudinea de 2000 m

Fig. 34 - INSTEC-SUD: Bouguer anomaly for a reference density of 2.67 g/ccm

Fig. 35 - INSTEC-SUD: Total intensity scalar geomagnetic anomaly on a plan located at 2000 m altitude

564000 565000 566000 567000 568000 569000 570000 571000 572000 573000 574000 575000

510000

511000

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517000

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519000

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521000

522000

Ciomatul Mare

Dl. Bailor

Dl. Tusnadul Nou

Haramul Mare

Lazaresti

Varful Mare

Vf. Poplis

0 km 1 km 2 km 3 km

100 nT

150 nT

200 nT

250 nT

300 nT

350 nT

400 nT

450 nT

500 nT

550 nT

600 nT

650 nT

700 nT

750 nT

800 nT

850 nT

900 nT

950 nT

1000 nT

1050 nT

1100 nT

1150 nT

Fa

564000 565000 566000 567000 568000 569000 570000 571000 572000 573000 574000 575000

510000

511000

512000

513000

514000

515000

516000

517000

518000

519000

520000

521000

522000

0 km 1 km 2 km 3 km

600 m

650 m

700 m

750 m

800 m

850 m

900 m

950 m

1000 m

1050 m

1100 m

1150 m

1200 m

1250 m

Fig. 36 - CIOMADUL AREA: Total intensity scalar geomagnetic anomaly on a plan located at 1000 m altitude

Fig. 37 - CIOMADUL AREA: Bouguer anomaly for a reference density of 2.67 g/ccm

ROCK PHYSICS DETERMINATIONS

522000 523000 524000 525000 526000 527000 528000 529000 530000

491000

492000

493000

494000

495000

496000

497000

498000

499000

500000

Pleasa

Dl Trestia

Vf Dalma

Maguricea Mare

Hoghiz

Lupsa

Dopca

Bogata

Fantana

Fa

-1600 nT

-1400 nT

-1200 nT

-1000 nT

-800 nT

-600 nT

-400 nT

-200 nT

0 nT

200 nT

400 nT

600 nT

800 nT

1000 nT

1200 nT

1400 nT

1600 nT

0 km 0.75 km 1.5 km 2.25 km

522000 523000 524000 525000 526000 527000 528000 529000 530000 531000491000

492000

493000

494000

495000

496000

497000

498000

499000

500000

501000

Pleasa

Dl Trestia

Vf Dalma

Maguricea Mare

Hoghiz

Lupsa

Dopca

Bogata

Fantana

E

F

C

D

A

B

440 m460 m480 m500 m520 m540 m560 m580 m600 m620 m640 m660 m680 m700 m720 m740 m760 m780 m800 m820 m840 m860 m880 m

0 km 1 km 2 km 3 km

Fig. 38 - PERSANI AREA: Ground total intensity scalar geomagnetic anomaly

Fig. 39 - PERSANI AREA: Bouguer anomaly for 2.67 g/ccm reference density versus topography

ROCK SAMPLING AND PRESERVING

During the geophysical surveys within the Persani area, additional activities for sampling

outcrops were conducted.

In the next figure, blue stars mark location of the sampled outcrops.

Fig. 40 - PERSANI AREA: Location of the sampled outcrops for rock-physics determination

Samples collected by the geophysical team are stored in the especially designed DDGT

warehouse, and prepared for specific weight and magnetic susceptibility determinations.

522

00

0523000

524

00

0525000

526

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0527000

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501

000

Ho

gh

iz

Lu

ps

a

Do

pca

Bo

ga

ta

Fan

tan

a

Ple

as

a

Dl

Tre

sti

a

Vf

Dalm

a

Ma

gu

rice

a M

are

OC

P1

OC

P2

OC

P3

OC

P4 O

CP

5O

CP

6

OC

P7

OC

P8

OC

P9

OC

P1

0

OC

P1

1

OC

P1

2

OC

P1

3

OC

P1

4

OC

P1

7O

CP

18

OC

P1

9

OC

P2

0 OC

P2

1 OC

P2

2O

CP

23 O

CP

24 O

CP

25

OC

P2

6

OC

P2

7

1 T

rias

sic

bas

alt

2 (T

rias

ic, ca

lcar

e)

3 Ju

rass

ic l

imes

tone

4 C

reta

ceous

lim

esto

nes

and f

lysh

5 M

ioce

ne

sand

stones

, co

nglo

mer

ates

, m

arls

6 M

ioce

ne

tuf

7 P

leis

toce

ne

(san

ds,

gra

vel

s)

Lava flows

Piroclastite

1142 +

11

1060 +

10

799 +

21

68

4 +

21

N/A

8 c

rate

rial

zone

9 s

cori

a

10 t

uf

12 P

leis

toce

ne

(lac

ust

rine

sedim

ents

)

13 H

olo

cen

L E

G E

N D

A

Ag

e

0 k

m1 k

m2 k

m3 k

m

_ _ _

_11 P

leis

toce

ne,

posi

ble

fre

ato-m

agm

atic

dep

osi

ts

14

sam

ple

d o

utc

rop

15 r

ive

rs

16 s

ettle

me

nts

17 p

icks

Fig. 41 - DDGT ESPECIALLY DESIGNED DEPOSIT FOR PRESERVING ROCK SAMPLES AIMED AT

ROCK PHYSICS DETERMINATIONS

SPECIFIC WEIGHT DETERMINATIONS

Specific weight determinations were conducted in the DDGT rock-physics lab by the double-

weighting (air/water) methodology using a high accuracy analytical ballance.

Fig. 42 - ANALYTICAL BALLANCE FOR SPECIFIC WIGHT DETERMINATIONS

DETERMINATION OF ROCK MAGNETIC PROPERTIES

Rock sampling for paleomagnetic observations

About 50 special rock samples from Neogene volcanic rocks were employed for paleomagnetic

determinations.

The study area corresponds to Persani Mts. (Racos quarry, Racos – Heghes, Comana, Valea

Stanciului, Valea Saratii, Maguricea, Hoghiz, Valea Barc, Valea Bogata, Gruiu - Valea Stanii,

Valea Pietrele).

Rock samples core of 2.5 cm diameter have been extracted by the help of a portable drilling

device. The orientation of the core samples has been determined by employing a Brunton

compass and a solar compass (see the next figure) where possible.

Fig. 43 - ROCK-SAMPLING FOR PALEOMAGNETIC DETERMINATIONS

Localisation of outcrops – Latitude (o), longitude (

o) and altitude (m). Location of the

sampled outcrops has been determined with a portable GPS Magellan Explorist 600.

Fig. 44 - GPS -Magellan Explorist 600

Paleomagnetic determinations were conducted in the Paleomagnetism Laboratory of the

Bucharest University by the courtesy of Professor Cristian Panaiotu.

The lab has state-of-the-art facilities for the determinations of rock magnetic properties.

Determination of the magnetic susceptibility (K)

The observations on the magnetic susceptibility of the rock samples were performed by

employing the MFK1A (AGICO) device (see the next figure)

Fig 45 - MFK1A (AGICO)

Determination of the natural remnant magnetisation (NRM)

NRM determinations have been conducted by the help of the spin magnetometer JR-6A

(AGICO) credited with an accuracy of 2x10-6

A/m

Fig. 46 - SPIN MAGNETOMETER JR-6A