Showing 113–125 of 125 results

Gas bubble visualization. Slide contains petroleum, sulfides, gold, graphite, iron and other minerals.

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Petrology (from the Greek πέτρος, pétros, “rock” and λόγος, lógos, “subject matter”, see -logy) is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions, igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because they both contain heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is, on the other hand, commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock.[1]

Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks while petrography is the speciality that deals with microscopic details.

In the petroleum industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through, and drawn on a log called a mud log. As the cuttings are circulated out of the borehole they are sampled, examined (typically under a 10× microscope) and tested chemically when needed.

Gold and Silver in Thin Section

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Petrology (from the Greek πέτρος, pétros, “rock” and λόγος, lógos, “subject matter”, see -logy) is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions, igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because they both contain heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is, on the other hand, commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock.[1]

Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks while petrography is the speciality that deals with microscopic details.

In the petroleum industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through, and drawn on a log called a mud log. As the cuttings are circulated out of the borehole they are sampled, examined (typically under a 10× microscope) and tested chemically when needed.

Tephra

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Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Tephra

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Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Tephra and Sulfur

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Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Solidified Sulfur flow with Tephra

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Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Popcorn Tephra

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Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Black Scoria from Rangitoto, New Zealand

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Rangitoto Island is a volcanic island in the Hauraki Gulf near Auckland, New Zealand. The 5.5 km wide island is an iconic and widely visible landmark of Auckland with its distinctive symmetrical shield volcano cone rising 260 metres (850 ft) high over the Hauraki Gulf.[1][2] Rangitoto is the most recent and the largest (2311 hectares)[3] of the approximately 50 volcanoes of the Auckland volcanic field.[2] It is separated from the mainland of Auckland’s North Shore by the Rangitoto Channel. Since World War II it has been linked by a causeway to the much older, non-volcanic Motutapu Island.[4]

 

Red Scoria from Rangitoto, New Zealand

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Rangitoto Island is a volcanic island in the Hauraki Gulf near Auckland, New Zealand. The 5.5 km wide island is an iconic and widely visible landmark of Auckland with its distinctive symmetrical shield volcano cone rising 260 metres (850 ft) high over the Hauraki Gulf.[1][2] Rangitoto is the most recent and the largest (2311 hectares)[3] of the approximately 50 volcanoes of the Auckland volcanic field.[2] It is separated from the mainland of Auckland’s North Shore by the Rangitoto Channel. Since World War II it has been linked by a causeway to the much older, non-volcanic Motutapu Island.[4]

 

Internal Mold of a Turretellid Gastropod: Fossil

$59.00

The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylumMollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to large. There are many thousands of species of sea snails and sea slugs, as well as freshwater snails, freshwater limpetsland snails and land slugs.

The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. There are 611 families of gastropods known, of which 202 are extinct and appear only in the fossil record.