ASBOG Paleontology and Geochronology 3

Question 1

The Permian-Triassic boundary (~252 Ma) marks the transition between which two geologic eras?

Accepted Answer

Paleozoic Era to Mesozoic Era

Answer

Proterozoic Eon to Paleozoic Era

Answer

Cenozoic Era to Mesozoic Era

Answer

Mesozoic Era to Cenozoic Era

Question 2

Trilobites are most characteristic of which geologic era and are used to zone strata within it?

Accepted Answer

Paleozoic Era

Answer

Mesozoic Era

Answer

Cenozoic Era

Answer

Proterozoic Eon

Question 3

The study of fossil pollen grains and spores to interpret past vegetation and climate is called:

Accepted Answer

Palynology

Answer

Ichnology

Answer

Taphonomy

Answer

Biochronology

Question 4

Chemostratigraphy correlates rock units using changes in:

Accepted Answer

Isotopic and elemental geochemical signals (e.g., δ¹³C, δ¹⁸O)

Answer

Fossil assemblages and biozone boundaries

Answer

Remnant magnetic polarity directions in rocks

Answer

Seismic reflection profiles across sedimentary basins

Question 5

The Holocene Epoch, the current epoch of geologic time, began approximately:

Accepted Answer

11,700 years ago at the end of the last glacial maximum

Answer

2.6 million years ago at the onset of Pleistocene glaciation

Answer

66 million years ago following the K-Pg extinction

Answer

252 million years ago following the Permian-Triassic extinction

Question 6

Steno's Law of Original Horizontality states that:

Accepted Answer

Sedimentary layers are deposited in essentially horizontal or near-horizontal sheets

Answer

Younger strata are deposited above older strata in an undisturbed sequence

Answer

Any feature that cuts across a rock unit is younger than that unit

Answer

Fossil assemblages succeed one another vertically in a predictable order

Question 7

The Cretaceous-Paleogene (K-Pg) boundary at ~66 Ma is globally identified in the rock record by an anomalously high concentration of:

Accepted Answer

Iridium (Ir)

Answer

Gold (Au)

Answer

Platinum (Pt)

Answer

Osmium (Os)