| Word | Definition & Example |
|---|---|
| tectonic adj. |
Relating to the structure and large-scale movement of Earth's crust. "The Himalayas continue to rise as a result of ongoing tectonic activity along the Indian-Eurasian boundary." Collocations: tectonic plate, tectonic activity |
| sediment n. |
Solid material that settles to the bottom of a liquid, especially particles deposited by water or wind. "Annual layers of lake sediment can record local climate conditions for thousands of years." Collocations: layer of sediment, fine sediment |
| erosion n. |
The gradual wearing away of rock or soil by natural forces. "Wind erosion has shaped the dramatic rock formations seen in much of the American Southwest." Collocations: soil erosion, coastal erosion |
| weathering n. |
The breakdown of rocks at the Earth's surface through physical or chemical processes. "Chemical weathering converts feldspar minerals into clay over geological timescales." Collocations: chemical weathering, mechanical weathering |
| stratum n. (pl. strata) |
A horizontal layer of rock or sediment with consistent characteristics. "Each stratum exposed in the canyon wall represents a distinct period of deposition." Collocations: rock strata, distinct stratum |
| mineral n. |
A naturally occurring inorganic solid with a specific chemical composition. "Quartz is the most abundant mineral in the Earth's continental crust." Collocations: mineral deposit, abundant mineral |
| outcrop n. |
A section of bedrock that is visible above the surface. "Field geologists rely on outcrops to study rock formations directly without the need for drilling." Collocations: rocky outcrop, exposed outcrop |
| fault n. |
A fracture in the Earth's crust along which blocks of rock have moved. "The San Andreas Fault marks the boundary between the Pacific and North American plates." Collocations: fault line, active fault |
| crust n. |
The outermost solid layer of the Earth. "Oceanic crust is denser and thinner than continental crust, which explains why it tends to subduct beneath it." Collocations: continental crust, oceanic crust |
| magma n. |
Molten rock beneath the Earth's surface. "Magma chambers beneath active volcanoes can hold enormous volumes of partially molten rock." Collocations: magma chamber, rising magma |
| igneous adj. |
Describing rock formed from cooled and solidified magma or lava. "Granite is a coarse-grained igneous rock that cools slowly underground." Collocations: igneous rock, igneous origin |
| sedimentary adj. |
Describing rock formed from compressed layers of sediment. "Most fossils are found in sedimentary rock because the rapid burial protects organic remains from decay." Collocations: sedimentary rock, sedimentary basin |
| metamorphic adj. |
Describing rock altered by heat, pressure, or chemical processes. "Marble is a metamorphic rock formed from limestone subjected to high temperatures and pressures." Collocations: metamorphic rock, metamorphic process |
| fossil n. |
The preserved remains or trace of a once-living organism. "Trace fossils such as footprints can reveal behaviour that body fossils cannot." Collocations: fossil record, trace fossil |
| geomorphology n. |
The study of the physical features of the Earth's surface and how they form. "Glacial geomorphology helps researchers reconstruct ice-sheet behaviour during the last ice age." Collocations: glacial geomorphology, fluvial geomorphology |
| groundwater n. |
Water held underground in soil or in rock pores and fractures. "Excessive groundwater extraction has caused measurable subsidence in parts of California's Central Valley." Collocations: groundwater table, groundwater extraction |
| aquifer n. |
An underground layer of rock or sediment that holds and transmits groundwater. "The Ogallala aquifer supplies water to a vast region of the central United States." Collocations: confined aquifer, recharge an aquifer |
| subduction n. |
The process by which one tectonic plate slides beneath another. "Subduction zones are responsible for some of the most powerful earthquakes ever recorded." Collocations: subduction zone, oceanic subduction |
| isotope n. |
A variant of a chemical element with a different number of neutrons, often used in dating rocks. "Geologists use the ratio of uranium to lead isotopes to date some of the oldest rocks on Earth." Collocations: radioactive isotope, isotope ratio |
| deposit n. / v. |
A layer of material that has accumulated in one place over time; to lay something down. "Glaciers deposit unsorted debris known as till as they retreat." Collocations: ore deposit, deposit sediment |
| abundance n. |
The amount of something present in a particular environment. "The relative abundance of certain elements in meteorites helps researchers infer conditions in the early solar system." Collocations: relative abundance, in abundance |
| uplift n. |
The geological raising of a region above its previous level. "Continued uplift of the Tibetan Plateau is thought to influence the Asian monsoon." Collocations: tectonic uplift, regional uplift |
| drainage n. |
The natural flow of water across a landscape into rivers, lakes, or oceans. "A drainage basin is the area of land where all the water flows into a single river system." Collocations: drainage basin, drainage pattern |
| porous adj. |
Having small spaces that allow liquid or gas to pass through. "Sandstone is porous enough to act as a reservoir for oil, gas, or groundwater." Collocations: porous rock, highly porous |
| exposure n. |
The condition of being uncovered, especially of rock surfaces revealed by erosion. "Surface exposure dating measures how long a rock has been exposed to cosmic rays." Collocations: surface exposure, prolonged exposure |
How this vocabulary appears on the TOEFL
Geology terms appear in Reading passages on rock cycles, plate tectonics, glaciation, and dating methods, and in Listening lectures from earth-science courses. The questions that target this vocabulary most often are paraphrase identification (the test rewords a sentence using a synonym from this list), inference questions (you need the term's meaning to follow the cause-and-effect chain), and reference questions (a pronoun later in the passage refers back to one of these nouns). Knowing the term plus one or two natural collocations is what lets you decode passages quickly without re-reading.
How to study this list effectively
Don't try to memorise the whole list in one sitting. Effective vocabulary study works in three passes: (1) recognise — read each entry once until the word feels familiar; (2) retrieve — cover the definitions and try to recall each one from the word alone; (3) produce — write a sentence of your own that uses the word in a TOEFL context, ideally one that links it to another word on the list (e.g. weathering produces sediment that is later deposited as sedimentary strata). The chained sentence forces you to encode the relationships between the terms, not just their isolated meanings.
Practise this vocabulary on real TOEFL tests
- Reading practice tests — passages on academic topics including geology and earth sciences
- Listening practice tests — academic talks on earth-science topics
- Full-length practice tests — vocabulary in context across all four sections
- More TOEFL vocabulary by topic