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 lightweight metal detector Rover UC allows treasure hunting in rough terrain, since only a smartphone is required for the first evaluation of the measured data. Without much preparation, the metal detector is immediately ready-to-use and does not only detect metals, but also distinguish between ferromagnetic and non-ferromagnetic metals.
In this case, the Rover UC detected a cavity while treasure hunting in the Middle East: A hidden burial chamber at 2 m depth was found in an ancient temple ruin. The treasure hunter was astonished as his discovery revealed valuable objects that are not made of gold. With the 3D ground scan function, his Rover UC tracked down the underground vault and led the treasure hunter to a successful discovery. The smartphone with the Rover UC App finally became a light source to illuminate the treasure find.
The discovered glass mosaic bowl with a diameter of 14.5 cm and a height of 4.5 cm weighs about 145 g, according to the treasure hunter. At first sight, the bowl appears to be very detailed, but rather inconspicuous in color. On closer inspection, the artfully arranged glass stones stand out, revealing their full splendor only above a light source: A beautiful, green shining mosaic showing fish around a spiral-shaped center. The discoverer of this treasure find describes the art object as a Phoenician glass mosaic bowl.
The glass production was originally brought to Egypt by craftsmen from Mesopotamia. Syria and Mesopotamia became important centers of glass production in the Mediterranean region in the 9th century BC. In the Hellenistic period, i.e. in the reign of Alexander the Great, Egyptian glass works in Alexandria again acquired a leading role. From there the technique of glass processing finally reached Rome.
Early on it was possible to make open vessels such as jugs and bowls from colored, translucent glass stones. Together with the mosaic technique, complex patterns were created, as the presented treasure trove shows. By fusing glass threads together, further forms and stripes could be created.
In fact, the Phoenicians were not only sovereign in the production of beautiful glass mosaic bowls, but also in the trade with the extraordinary objects. The entire Mediterranean area was supplied from the glass manufactories in the coastal towns in today’s Syria. The utility glass from Sidon and the glass artworks from Alexandria were exported in large quantities to Rome.
In its peak between 1200 and 900 BC, Phoenicia dominated the entire Mediterranean region as far as the Atlantic and was thus the greatest trading and naval power of antiquity. Phoenicia was famous in the ancient world mainly for its textiles and dyes (purple), objects made of precious metals, ivory carvings and glassware and had a significant influence on Greek art. Impressed by the production of glass, art spread throughout the Roman Empire and brought glass objects via the Silk Road to China.
A client of OKM detectors sent us 3D images and photos of his grave chamber find in Tunisia. The discoverer did not comment on found artifacts and burial valuables such as weapons and jewelry. Without any further information on the burial site, it is uncertain for whom it was built and which epoch of Tunisia’s lively history the discovery belongs to – starting with the Phoenicians, influenced by the trading power of Carthage and the competition with the Roman Empire, through numerous battles for supremacy and religion to the French colonial domination.
Discovery of burial chamber with Rover C II
Numerous data were collected during the measurement with the Rover C II as well as during the immediate inspection of the site. The measurement data were evaluated with the OKM software Visualizer 3D and clearly show a long cavity. According to the client’s specifications, the burial chamber is located at a depth of about 9,8 to 13,2 ft (3 to 4 m). Pictures testify to the underground find and illustrate the nature of the walls of the site.
The metal detector Rover C II is not an ordinary metal detector with sound output, but a grave and cavity detector which can create excellent three-dimensional graphics of the scanned underground. The combination of geoelectrical measurement and metal detection makes this treasure hunter particularly interesting for archaeologists and cavity seekers looking for treasures, burial caves and buried artifacts.
The Rover C II has meanwhile been replaced by the advanced OKM treasure and cavity detector Rover C4. The current model Rover C4 offers:
multilingual user interface
LED illumination for night measurements
wireless data transfer
4 memory locations for measurement data
Standard probe and Super Sensor with innovative LED orbit
different modes of operation that make the Rover C4 a versatile treasure detector.
We have Rover C4 on sale and you can buy it here
It is not uncommon for concrete contractors to request the location of rebar, conduits, post-tension cables, electrical, or plumbing in order to aid in remediation risks. Additionally, savvy contractors have been using GPR technology to determine concrete slab thickness. This provides the concrete contractor with several benefits including: the proper assignment of concrete cutting and coring tools, and the ability to better quote the work required. Trained and certified GPR operators understand the benefits and limitations of the technology and how to determine the best course of action in challenging survey conditions. Yet, even the most knowledgeable operators will wonder if there’s a tip or trick that they can deploy in the field to collect better data. Here we explore the difference between suspended slab and slab-on-grade surveys, and infield processing techniques which operators can use to get the best out of their slab-on-grade data.
The detectability of the slab bottom depends on the underlying material and amount of steel within the slab. It is easier to see when a contrasting material such as water, air or metal is under the slab because they will have a stronger dielectric contrast. In Figure 1, the data is representative of an elevated concrete slab. Note the several hyperbolic reflections on the screen, this is indicative of a double rebar mat. Towards the bottom of the data image, there is a strong dielectric contrast at the concrete-to-air boundary and therefore products a clear indicator of the bottom of the slab.
In slab-on-grade situations, the bottom may be very weak or invisible if the slab rests on sand or another concrete structure (supporting beam, for instance) with similar dielectric properties. This can be challenging due to the low dielectric contrast for the concrete-to-sand boundary and intersecting hyperbolic tails from objects embedded in the slab. The former results in weak or non-existent reflections and the latter tends to mask the reflection from the bottom of the concrete interface. Figure 2 illustrates a reinforced concrete roadway with a strong reflective boundary towards the center of the roadway. This is an example of a void. The concrete-to-grade boundary is less reflective as the air-filled void.
2-D versus 3-D Data Collection: In most cases, GPR manufacturers recommend using 2D scanning for real-time locating and simple imaging services, and to use 3D data collection for complex survey sites. However, slab-on-grade surveys are an exception to this rule. It is recommended to conduct 2D scanning in these situations because the layer interface is a planer target which is more easily viewed from the side.
Depth Setting: Conducting a preliminary scan of the area will help the operator determine the appropriate GPR system settings. A common mishap is that the system is set to a depth that is less than the overall concrete depth. This inherently causes data loss at the deeper levels. Remember to always set the depth range 2-3 inches deeper than the expected slab thickness to ensure that the full slab thickness is captured.
Gain: Display Gain and System Gain can be used to brighten a weak back reflection. However, these settings should be used with caution. Display Gain and System Gain settings often influence the rest of the data. Some systems apply a correction factor to gain based on assumed material dielectric.
Migration: Migration eliminates hyperbolas by collapsing them into dots representing the actual targets. This can be helpful to make target identification more intuitive and makes the data easier to interpret. This is especially true for slab-on-grade because the tails of hyperbolic targets can sometimes intersect and hide the concrete-to-sand boundary reflection. By collapsing the hyperbolas into dots, the bottom of the slab can become more recognizable.
Cross Polarization: When detecting linear metal targets (pipes, rebar, etc.), antenna orientation relative to the target becomes important. Antenna dipoles (transmitter and receiver) are most sensitive to the metal targets that are parallel to them. In other words, if an operator is scanning across the slab with the GPR system in its normal orientation, it is sensitive to targets that are running perpendicular to the direction the operator is moving (parallel to the antenna dipoles).
Some systems can be modified to turn the antenna 90 degrees. This method is known as “cross-polarizing”. If the operator scans over a metal target that is again perpendicular to their direction of travel, the GPR system is not as sensitive to it. This “weakens” the amplitude of the metallic objects and may result in a stronger concrete bottom reflection.
In summary, GPR interpretation and survey efficiency is a skill that requires training, field experience, time, and practice. These tips are intended to help operators troubleshoot a very specific type of survey scenario. An operator may employ all of them, some of them, or only one of them in an attempt to conduct a successful survey. In some extreme cases none of the solutions may work, and only a trained operator will know what tools to use and when.