Geoscience Australia Buys 10 New Phoenix UMT Systems

I S S U E 6 2 SEPTEMBER 2017 © PHOENIX GEOPHYSICS Published by Phoenix Geophysics Limited

C O N T E N T S

2 Geoscience Australia Data

3 Phoenix Around the World President’s Message

4 On the Road Transmitter Improvements Coming Up

The new Phoenix UMT (ultra-wideband

MT) system was developed in part to

meet Geoscience Australia’s (GA’s) instru-

mentation needs. Geoscience Australia took

delivery of two prototype systems in 2015 and

an additional ten systems in June 2017.

The new UMT system uses a single wide-

band magnetic induction sensor model MTC-

150 (see Phoenix News #61), and 8-channel,

low-power recording unit (MTU-8A) to cap-

ture simultaneously the entire AMT/MT spec-

trum from 10 kHz to approx. 50,000 seconds

in one recording. Various industry-standard

fluxgate magnetometers may also be used at

the same time as the induction sensors, at the

user’s option. (See plot, page 2)

The MTC-150 is a breakthrough in UMT

magnetic sensor design, permitting acquisition

of UMT data without any interruption in time

series recording, providing faster acquisition

of long period data. Sensor types (or sensor

modes) no longer need to be switched from

AMT to MT to LMT (LongPeriod MT).

GA strives to acquire “dual-use” data of

interest to both the research community and

the natural resource exploration sector, to

motivate more, and more effective, explora-

tion investment in Australia.

GA programs include AusLAMP

(Australian Lithospheric Architecture

Magnetotelluric Project) which deploys long-

period MT systems Australia-wide on a grid

approx. ½ degree x ½ degree, to understand

the deeper crustal architecture.

Another GA project is called “UNCOVER”.

One goal of UNCOVER is to map the thick-

ness of the sedimentary basins, as well as the

conductive tropical weathered layer (up to

200m thick) which overlies much of Australia.

These conductive surface rocks impede the

use of traditional EM exploration for metal

deposits. n

See more about AusLAMP and UNCOVER

on the Phoenix Geophysics LinkedIn page.

Damien Fox, project manager for UMT receiver develop-ment and Steve Wilton, receiver designer

2 The Phoenix k Issue 62 SEPTEMBER 2017

Geoscience Australia (continued)GA’s LP-MT data showed evidence of broad

low-resistivity zones in the crust, which can

be interpreted as “mantle plumes” or prob-

able relict pathways of ascending fluids.

These “mantle plumes” are seen only at

macroscopic scale. When BMT data is added

to the LP-MT data, the resulting higher

resolution inversions coincide spatially with

known orebodies such as the well-known

Olympic Dam deposit.

This has energized a new way of thinking

about “mineral systems”, and highlights MT

as a key geophysical technique not just in

localized exploration, but also for tracing the

conductive relict fluid pathways in the crust.

GA’s diverse range of objectives and

depths (from surface to 100 km+) means

that the widest possible bandwidth MT

instrumentation is the most useful to GA.

In the past, it was difficult and/or costly

to acquire UMT data because two or even

three separate systems had to be deployed

sequentially.

The new UMT system captures all the re-

quired bandwidth in a single pass. UMT sys-

tem advantages include: basic interoperability

with older equipment; larger memory; lower

power; simplified, faster operations, process-

ing and calibrations; mitigation of MT static

shift by use of high frequency (~10 kHz) data;

avoidance of mismatch due to different cali-

brations and use of different sensors; optimal

capture of AMT deadband data at local mid-

night; uninterrupted time series without need

to switch magnetic sensors (or sensor modes)

from AMT to MT to LP-MT; improved inver-

sions and last, but not least, significant capital

cost and operating cost savings.

A powerful and flexible new software

package called EMPower – coded, main-

tained and under continuous development

by a team of professional software engineers

– is also provided. n

Durability An MTU-5C receiver emerges from a cold test at -25˚C.

Geophysicist Wenping Jiang of Geoscience Australia working with the new UMT system.

MTC-150 vs. Fluxgate The plot above shows resistivity and phase spectra from 10 kHz to 50,000 sec, from a 560-h (23 day) recording in Nevada, USA. The bright symbols show data from the new wideband MTC-150 induction sensor; the faint symbols show data from a fluxgate sensor LEMI-039, recorded simul-taneously with the 8-channel MTU-8A receiver. The MTC-150 results are the same as the fluxgate results at periods >100 seconds to ~25,000 sec. Both sensors provide noisy data at periods >25,000 sec due to tidal/diurnal effects. The fluxgate data diverges from MTC-150 data between 100 sec and 10 sec because the MT signal in this range during the recording was often below the fluxgate noise floor. MT signal strength cannot be predicted; therefore induction sensor data (with lower noise than the fluxgate) is more reliable in this range.

SEPTEMBER 2017 The Phoenix k Issue 62 3

PHOENIX AROUND THE WORLD

Canada 150: It is timely and suitable that Exploration’17 coincides

with Canada’s 150th anniversary. The first decennial conference,

Exploration ‘67, took place as a “Canada 100th birthday project in

1967. In the same positive spirit of innovation that characterized

the original Exploration’67 (and the Expo’67 World Fair in Mon-

tréal), Phoenix continues to introduce a wave of new technology as

the Phoenix innovation machine accelerates.

In a previous issue (Phoenix 61), we focused on the new wideband

magnetic sensor MTC-150. In this issue, we focus on the new

receiver technology – the MTU-8A and MTU-5C family – both of

which are interoperable with the current MTU-5A system via the

new software package EMPower, which we will describe in the

next issue. ~ Leo Fox

France As part of the Critex project (www.critex.fr/), a team from Pierre and

Marie Curie University (led by Dr. Christian Camerlynk) and a second

team from École et Observatoire des Sciences de la Terre (led by Dr. Pascal

Sailhac), worked together to purchase a complete 12-channel V8 system

with T-3 transmitter.

The scientists are using natural source and controlled source measure-

ments to study the “critical zone” – the thin surface layer of the Earth

where life evolved and resides – and where water, gases, and rocks all

interact. Critex aims to develop a holistic, cross-disciplinary understand-

ing of the critical zone.

Phoenix geophysicist Yann Avram traveled to Strasbourg, France in July

for training on, and acceptance of, the Phoenix system (right). According

to Dr. Sailhac, the ability of the system to display nine processed channels,

in real time, in the field, for CSAMT SIP, TDIP, and TDEM is cutting-edge,

and will improve the efficiency of their field operations.

Bolivia Long-time Phoenix client Nordwest of Moscow, Russia, won two

large-scale MT surveys in Bolivia for client YPFB-Andinas. These

surveys required wideband MT data using a single magnetic sen-

sor; Nordwest opted for the new MTC-150.

YPFB (the state-owned Bolivian oil company) operates sev-

eral divisions, including YPFB-Andinas. Andinas explores for oil

and gas in the eastern foothills of the Andes; the mountains and

foothills were created by compressional forces from the subduct-

ing Pacific Plate. In the foothills, sections of the “layer-cake” of

rocks have been forced on top of one another, with dense base-

ment rocks now atop less-dense hydrocarbon-bearing sedimen-

tary rocks. This geological structure (sometimes with very steep

bedding) is challenging for seismic exploration, hence the need

for MT.

The MT surveys operate in parallel with seismic surveys, us-

ing the same field camp to reduce cost. MT and seismic data are

interpreted together.

PRES IDENT ’ S MESSAGE

Djibouti Phoenix geophysicists have carried out three geothermal MT

surveys in Djibouti; shown during the the most recent survey are

Murat Urakov (right) installing an MT site on the typical steep and

rocky terrane and Caroline Finateu (below) checking equipment.

4 The Phoenix k Issue 62 SEPTEMBER 2017

Phoenix GeophysicsPhoenix Geophysics3781 Victoria Park Avenue, Unit 3Toronto, Ontario, Canada M1W 3K5

Tel +1 416 491-7340 Fax +1 416 491-7378mail@phoenix-geophysics.com www.phoenix-geophysics.com

n Oct 2-4: Geothermal Resources Council confer-

ence, Salt Lake City

n Oct 22-25: Exploration ’17 Decennial

Conference, Toronto

n Oct 22-27: UGM Union Geofisica de Mexico,

Puerto Vallarta

n Nov 5-9: Balkan Geophysical Congress,

Ankara, Turkey

n Nov 8-10: SEGJ Fall meeting, Yokohama

n Nov 10-12: China EM, Wuhan

n Looking forward to 2018: Phoenix will be at

the Australian SEG, February 18-21 in Sydney,

and the PDAC in Toronto, March 4-7.

COMING UP

ON THE ROADP

rinted in Canada

South America: Latin America sales manager Carlos

Guerrero represented Phoenix at Exponor Chile 2017 in Antofagasta,

Chile in May; in June he attended the Argentina Shale Gas and Oil

Summit in Buenos Aires; and in August he was at the 15th Interna-

tional Congress of SBGF and EXPOGEF in Rio, Brazil.

Japan: In June,

geophysicists Caroline

Finateu and Mitsuru

Yamashita attended the

SEGJ in Tokyo. Mits

presented “Updated

Magnetotelluric System:

real-time control,

operation, monitoring and

data filing using multiple

remote sites”; Caro gave “A new generation induction sensor for

broadband magnetotelluric measurements”.

South Africa: Tes Haile attended the South African Geo-

physicists Association 2017 Conference & Exhibition in Cape Town

in September. Shown below, left to right: Dr. Ame Thato Selepeng,

Botswana International University of Science & Technology (BIUST).

BIUST purchased one MT system in June 2017; David Ngobeni,

Geophysicist, Council for Geoscience (CfG), South Africa (CfG pur-

chased 2 Phoenix MT systems in July 2017); Tes of Phoenix; and Dr.

Andriamiranto Raveloson, University of Witwatersrand, South Africa

TXU-30 Transmitter ImprovementsThe TXU-30 has been an industry standard since its introduction

in late 2006. One of the main innovations of the TXU-30 was to

permit the use of standard third-party 208-volt 3-phase motor

generators to provide clients with cost savings, greater reliability

and greater flexibility.

Two improvements to the TXU-30 were recently released:

model TXU-30A and TXU-30B (see below). Any standard motor

generator with power min. 45 kW and suitable output voltage

can be used with the TXU-30A or TXU-30B.

The TXU-30A provides a 50% increase in output current, to

60 amperes. Several contractors in Canada and Australia have

purchased the new TXU-30A high-power transmitter for deep

TDEM work. Higher current permits deeper TDEM exploration

(as deep as 1000 m) with negligible increase in cost. Existing

TXU-30 units can be upgraded to the “A” configuration; in fu-

ture, the “A” model will replace the older TXU-30.

The TXU-30B (also with 60 amperes output) permits use of

380 Volt ±10% 3-phase MGs which, in many countries, are much

easier to obtain than 208 volt units. This simplifies the procure-

ment of MGs. n

Phoenix engineer Harry Song testing the 380 V input at the Phoenix test site.