A precious coin treasure was recently recovered: The shiny, well-preserved silver coins rested at a depth of 2.5 m (8.2 ft). We congratulate the treasure hunter on locating the hoard and are pleased to be allowed to present this discovery with our professional metal detector eXp 6000.
Ancient silver coins found: The obverse shows the head of a man looking to the right - probably Kings Antiochos and/or Seleukos. Successful treasure hunt thanks to professional metal detector. The powerful treasure detector and ground scanner eXp 6000 locates treasures and cavities to a depth of 25 m (82 ft). Thanks to various probes, the eXp 6000 can be used for different treasure hunting tasks:
The story behind the silver coins:
The idea of coins is about 2500 years old. The currency was invented almost simultaneously in China and the Middle East. The distribution of coins from Asia Minor to Persia, Greece, the Roman Empire and into the world was driven by the flourishing long-distance trade of that time.
Historical value of the silver coins: The splendor of these ancient coins, which probably originate from the Seleucid Empire, not only impresses the discoverer of the coin treasure. On the one hand, it is an impressive discovery of a largely unknown treasure of this size. On the other hand, it is also fascinating to touch silver coins which were once taken as travel duties or from royal estates or were in circulation in exchange for goods and services within and outside the oriental empire – a piece of living history. The historical value of these 2000 year old coins now exceeds the original value as a means of payment.
Historical and geographical classification of silver coins: With his victory over the Persians, Alexander the Great extended his territory and reign to India. After his death, the Alexander Empire disintegrated into numerous empires – such as the Seleucid Kingdom, which was located in the area of the extinct ancient Persian Empire (Achaemenid Empire) in the Near East.
Map of the Macedonian Empire (334 - 323 B.C.): The Macedonian Empire was an ancient kingdom in the northern-most part of ancient Greece, bordering the kingdom of Epirus on the west and the region of Thrace to the east. For a short period of time it became the most powerful state in the ancient Near East.(Public Domain/Wikimedia Commons)The favorable location on the Silk Road favored trade within and outside the Seleukid Empire. Transport routes and ports were expanded, goods such as ceramics and metal jewelry made of silver, gold and bronze were exported to Iran and Greece, and craftsmen such as mosaic layers were hired in neighboring empires. Glass foundry and shipbuilding were also up-and-coming crafts that emerged in Syria and Phoenicia, while in Mesopotamia and Babylonia textile textile manufacturing became the focus.
Shiny, well preserved coin find: The ancient Greek coins are a fascinating piece of history.
Ancient treasure trove of coins: The silver coins seem to originate from the Seleucid kingdom around 270 to 220 BC.Is the coin treasure maybe the hidden savings of a merchant? Perhaps a trader was surprised by a storm on his journey and had an accident. Was the collection of silver coins stolen and hidden by a thief? The details remain uncertain, but it is clear: The flourishing trade inside and outside the Hellenistic empires such as the Alexander Empire and the Seleucid Empire brought numerous coins on the market and holds further treasures such as jewelry, ceramics and mosaics awaiting their discovery.
The extraction of underground oil or gas usually also generates large amounts of water, called 'produced water'. If not properly managed, it can cause local soil and water pollution.
In this case study, a GEM-2 handheld conductivity meter was used to quickly identify problem areas. In this case, the conductivity variations were large enough that the operator could explore the areas of greatest interest (as constrained by the local terrain) rather than following a fixed grid. This type of opportunistic approach can be very efficient. The whole survey area covered several square miles, but the immediately mapped area shown here required less than 2 man-days to survey.
This case study confirms that maps of apparent electrical conductivity (EC) are very useful in locating potential soil contamination. In the case of brine contamination, the EC values correlate well with laboratory analyses of both soil conductivity and concentration of chlorides. More generally, any type of contaminant whose EC contrasts with the environment can be delineated.
e GEM-2 'ski' is a hand-held, digital, multi-frequency broadband electromagnetic sensor. It operates in a frequency range of 30 Hz to 93 kHz, and can transmit an arbitrary waveform containing multiple frequencies. The unit is capable of transmitting and receiving any digitally-synthesized waveform by means of the pulse-width modulation technique.
A frequently-asked question is the "Depth of Investigation." This is a very complex question because the answer depends on many factors, particularly on ground conductivity and ambient electromagnetic noise. Based on many analyses and field data, we estimate the GEM-2 should be able to see about 20-30m in resistive areas (>1000ohm-m) and about 10-20m in conductive areas (<100ohm-m). This figure assumes an ambient noise level of 5ppm.
The noise level is generally high in urban areas and low in rural areas. For typical applications, we do not recommend the GEM-2 for depths deeper than 30m.
The GEM-2 ski contains three coils: transmitter, bucking, and receiver coils. For frequency-domain operation, the GEM-2 prompts for a set of desired transmitter frequencies. Built-in software converts this into a digital "bit-stream," which is used to construct the desired transmitter waveform (Figs 1 and 2). This bit-stream represents the instruction on how to generate a complex waveform that contains all frequencies specified by the operator.
Figure 1. A three-frequency transmitter waveform.
Figure 2. First 33 points of Figure 1.
Figure 3. The base period of the bit-stream for the GEM-2 is set to 1/30th of a second for areas having a 60-Hz power. The TX switches at 192 kHz and, therefore, the bit-stream contains 6,400 steps within the period. Through a Fourier transform of the transmitter current waveform above, we obtain a power spectrum of the primary field, which shows each transmitted frequency.
Figure 4. With multiple frequencies, one can determine layered conductivity structure of the earth, conceptually shown below. This is called "frequency sounding" method.
What is EM Locator Technology?
Electromagnetic (EM) Locator technology relies upon the detection of an alternating magnetic field. This magnetic field is created by the flow of current through a conductor, whether a wire, cable, pipe, or other conductive material. Often, additional ‘tracer wires’ are run in parallel to non-conductive pipes such as gas lines expressively for the purpose of facilitation such detection. AC power utilities, as long as current is flowing in the form of power usage, usually radiate a very detectable magnetic field as a side-effect of normal operation. It is also possible to intentionally induce a ‘tracer’ current (by inductive clamp or direct attachment) onto otherwise passive conductors in order to create a detectable field that can be followed.
LineTrac technology is a multi-sensor fashion technology that combines the power and advantage of GPR with the specific target-identifying capabilities of EM location. Linetrac operates in both “Power” (50 or 60 HZ Utility Power) and in arbitrary “Frequency Mode” up to 50KHz, using a customer-supplied transmitter.
We provide two models of EM locator technology. The LineTrac system for our UtilityScan series and the LineTrac XT for our StructureScan Mini XT system.