Continental Drift and Its Historical Development

Eighty question-and-answer flashcards cover the origins, evidence, criticisms, evolution, and modern relevance of Alfred Wegener’s continental drift theory, its predecessors, and its integration into the plate-tectonics framework.

Who formally proposed continental drift in 1912?

Alfred Wegener

What was the single supercontinent hypothesized by Wegener to exist about 200 million years ago?

Pangaea

Which modern continents fit together like a jigsaw puzzle, supporting Wegener’s idea?

South America and Africa

What ancient reptile fossil was found on both South American and African coasts, supporting continental drift?

Mesosaurus

What land reptile fossils were discovered in Antarctica, India, and Africa, indicating past continental connection?

Lystrosaurus

Which extinct seed-fern fossils appeared in Gondwana continents, strengthening Wegener’s hypothesis?

Glossopteris

What specific geological evidence involves similar rock layers of the same age found on now-separated continents?

Matching rock formations

Which North American mountain range aligns in age and structure with mountains in eastern Greenland and western Africa?

The Appalachian Mountains

Which present-day icy continent has coal deposits, implying it once lay in a warmer, equatorial zone?

Antarctica

What type of climatic evidence, such as ancient glacial striations in present-day tropical areas, supports continental drift?

Paleoclimatic indicators

What major scientific theory of the 1960s provided the mechanism validating Wegener’s continental drift?

Plate tectonics

According to plate tectonics, what are the rigid outer sections of Earth that move over the asthenosphere?

Lithospheric plates

What process at mid-ocean ridges creates new oceanic crust, driving plate movement?

Seafloor spreading

What two internal Earth processes are chiefly responsible for moving tectonic plates?

Mantle convection and slab pull

What cause did Roberto Mantovani’s 1889–1909 expansion hypothesis attribute to continental separation?

Thermal expansion driven by volcanic activity

What is the approximate upper limit of Earth’s radius increase detected by modern geodetic measurements?

Approximately 0.21 mm per year

Toward what geographic feature did Frank B. Taylor’s 1908 "continental creep" theory suggest continents moved?

The Equator

What celestial body did Taylor believe caused continental movement during the Cretaceous?

The Moon’s gravitational pull

What was the main reason for early 20th-century scientists' skepticism of continental mobility theories?

They lacked a credible mechanism to move continents across a rigid crust

What was the dominant geological model of the time opposing ideas of mobile continents?

The contraction (shrinking Earth) model

What was Wegener’s estimate of the North America–Europe separation rate?

Over 250 cm/year

According to modern GPS, what are the average actual drift rates between plates?

A few centimeters per year (about 2–5 cm)

What type of evidence from Wegener was nicknamed the “continental jigsaw puzzle”?

The fit of continental coastlines

What was the seminal 1915 book where Wegener compiled his evidence for continental drift?

"The Origin of Continents and Oceans"

What term describes fossil, rock, and climatic clues found on widely separated landmasses?

Interdisciplinary evidence

What geological feature concentrates most earthquakes and volcanoes, as explained by plate tectonics?

Plate boundaries

What type of convergent boundary forms mountains like the Himalayas?

Continental-continental collision boundary

What undersea topographic feature marks sites of seafloor spreading?

Mid-ocean ridges

Deep-sea trenches are most commonly associated with what type of plate interaction?

Subduction zones

How does continental drift help biologists understand species distribution?

By reconstructing past land connections for migration routes

Which South American coast holds 2 billion-year-old rocks matching those in western Africa?

The Brazilian coast

What fossil evidence indicates Gondwana continents shared similar flora 250 million years ago?

Glossopteris fossils

What modern discipline uses continental drift principles to locate fossil fuels like oil and coal?

Economic geology / resource exploration

What was the reason for the initial rejection of Wegener’s hypothesis despite strong evidence?

He lacked a convincing mechanism for continental movement

What 20th-century technological advance allowed precise measurement of plate motion, corroborating continental drift?

Global Positioning System (GPS)

What is a practical application of plate-tectonic knowledge in public safety?

Earthquake and volcanic hazard assessment

Who is the Italian scientist cited on Chemeurope.com discussing Mantovani’s theory?

Chemeurope does not specify a scientist; it is a reference site describing Mantovani

What is the typical precision range of modern geodetic instruments when measuring Earth’s size?

0.17 mm/yr to 0.21 mm/yr

Which foundation’s online textbook discusses the similarities between the Appalachian and Greenland mountains?

CK-12 Foundation

What key phrase is attributed to Wegener’s idea by the U.S. PBS network?

Continents once formed a single landmass that broke apart and drifted

Which organization’s 2019 article details Wegener’s interdisciplinary data compilation?

American Physical Society

How does plate tectonics explain the distribution of coal beds in now-cold regions?

Continents moved from tropical latitudes to polar positions after coal formed

What is the term for ancient climate evidence preserved in rocks and fossils?

Paleoclimatic indicators

What did early contraction theorists believe caused Earth’s mountains?

Cooling and shrinking of a once-molten Earth

What is the definition of the term "Gondwana"?

The southern supercontinent comprising Africa, South America, Antarctica, India, and Australia

Who are the 2023 authors cited for summarizing Wegener’s contribution?

Baxter & Jaeger

What 2024 study source discusses Mesosaurus and Lystrosaurus fossil findings?

Johnson et al., 2024

Which learning resource highlights the fossilized Glossopteris leaves?

study.com

What online illustration famously realigns South America and Africa to show their fit?

The PopSciColl.org diagram

What is the meaning or context of "NEXT IAS" as used in the lecture notes?

An educational institute/source summarizing Continental Drift relevance

What geological discovery technique reveals identical rock layers across oceans?

Stratigraphic correlation

What shallow oceanic process replaces old crust with new, enabling plate motion?

Seafloor spreading

What physical science field did Wegener originally train in, influencing his data approach?

Meteorology

According to Wegener, why can Mesosaurus fossils not be explained by land bridges alone?

There is no evidence of land bridges spanning the South Atlantic in the Permian

How did Wegener’s interdisciplinary approach differ from earlier single-discipline theories?

He synthesized data from geology, paleontology, climatology, and geography

What rock types are specifically mentioned as matching along the Brazilian and African coasts?

Metamorphic and igneous rocks

Which academic institution’s resource notes that Taylor’s ideas were ahead of their time?

University of Oregon

What was the accepted state of Earth’s crust according to most geologists in Wegener’s time?

Solid and immovable

What is the general age of the Appalachian and corresponding Greenland mountain formations?

Hundreds of millions of years (Paleozoic era)

What term describes the slow, vertical changes that rebound continents after glaciation, unrelated to continental drift?

Isostatic adjustment

What physical features along plate boundaries explain the "Ring of Fire" around the Pacific?

Subduction zones and transform faults

How does continental drift assist climatologists studying past global temperatures?

By locating continents’ former latitudes, revealing ancient climate zones

What two processes drive mantle convection currents beneath plates?

Heat from radioactive decay and residual heat from Earth’s formation

Why did Mantovani’s expansion model fail despite explaining fossil distribution?

It required an unobserved significant increase in Earth’s mass and radius

What plate-tectonic features form when an oceanic plate dives beneath a continental plate?

A volcanic arc and deep ocean trench

What is an example of a fossil-plant indicator besides Glossopteris that supports continental drift?

Coal swamp plant fossils in Antarctica

According to current geology, what is the approximate age marking the initial breakup of Pangaea?

About 200 million years ago (Late Triassic to Early Jurassic)

How do matching glacial deposits on separated continents serve as evidence for continental drift?

They show glaciers once spread across connected landmasses now far apart

What encyclopedia is cited discussing modern plate tectonics?

Encyclopaedia Britannica

What oceanic feature records symmetrical magnetic stripes, confirming seafloor spreading?

Oceanic crust’s magnetic anomaly patterns

What is the definition of "plate tectonics"?

The scientific theory that Earth’s lithosphere is divided into moving plates driven by mantle processes

Was there an ancient southern supercontinent preceding Gondwana?

No; Gondwana was itself part of Pangaea in this context.

How does continental drift theory aid in earthquake preparedness?

By identifying active plate boundaries where earthquakes are most likely

What is the significance of matching Paleozoic rock belts across oceans?

They indicate continents were once joined during Paleozoic mountain-building events

What "Science for the Public" site summarizes Taylor’s "bow-shaped mountain belts" idea?

Science for the Public

What instrument network globally measures plate motions today?

GPS (Global Positioning System) stations

What is a modern analogue of continental rifting observable on Earth today?

The East African Rift

What modern branch of geophysics studies current plate motions to millimeter precision?

Space geodesy

Graduate-level open textbook (libre site) cited for "geosciences" explanations

Geosciences LibreTexts