Cretaceous / Paleogene Extinction

Question 1

What occurred in the aftermath of K/Pg?

Answer 1

Evolution of life

Question 2

What were some victims of the K/Pg mass extinction?

Answer 2

Belemnites- bivalves
Ammonites
Dinosaurs pterosaurs and marine dinosaurs

Question 3

What was used by the Alvarez’s to hint at the driver of the K/Pg?

Answer 3

Iridium found in cosmic dust flux within a clay layer in Italy caused by rapid sediment change usually thought to be unconformity but high level of cosmic dust in layer meant there was change to constant flux

Question 4

What profound organism change was seen by both Smit and Alvarez around the K/Pg

Answer 4

Change in small marine organisms
End cretaceous diverse micro fossils (multi chambered)
Bottom Cenezoic little diversity

Question 5

What are microtektites?

Answer 5

Tiny glass spherules found in land environments

Question 6

What are microtektites associated with?

Answer 6

Molten rock being flung into atmosphere and cooling as it falls to surface

Question 7

What is the problem with Spherules from around the K/Pg boundary being found?

Answer 7

These areas are not located near volcanoes

Question 8

Where can examples of Microtektite locations associated with the K/Pg?

Answer 8

Raton, Colorado
Caravaca, Spain

Question 9

Why is shocked quartz an example of a high impact event having occurred at the K/Pg?

Answer 9

Quartz is very string and resistant it would need strong and instantaneous pressure to be altered

Question 10

What is the change form quartz to shocked quartz?

Answer 10

Quartz - undulating extinction, no good cleavages conchoidal fractures with no internal layers
Shocked quartz - distinct planar features, coloured birefringence

Question 11

What within the clay layer of the K/Pg shows there was massive global wildfires?

Answer 11

High levels of soot

Question 12

What idea tried to rebuke the impact theory?

Answer 12

Uniformitarianism (present key to past) as impact theory shows something outside of system can have a fast and dramatic impact

Question 13

Where was the K/Pg impact crater located?

Answer 13

In the Yucatan

Question 14

What evidence was there for massive tsunamis from the K/Pg impact?

Answer 14

metre thick sand deposits from a relatively small time period

Question 15

What environmental evidence is there for the impact direction of K/Pg being NW?

Answer 15

Fern spike” in North America due to lack of competition and Higher flora extinctions in North America

Question 16

What gravitational and seismic evidence is there for the K/Pg impact direction being NE?

Answer 16

Elongate central structure
Widening of the 180 km ring
“Twin peaks” alignment
Asymmetry in inner ring and peak ring
Thrusting downrange
Downrange depression
NE compressional shearing

Question 17

What was the size of the impactor for K/Pg?

Answer 17

~12km Bolide (what remains when enters atmosphere)

Question 18

What is the size of the K/Pg crater?

Answer 18

35km deep and 100km wide

Question 19

What was the timeframe to produce the K/Pg crater?

Answer 19

300 to 600 seconds

Question 20

Why was a double peak created in the k/Pg event crater?

Answer 20

the crater went so deep it reached rock undergoing flow which rebounded

Question 21

How many atomic bombs was K/Pg equivalent to?

Answer 21

100 million

Question 22

What was the energy distribution of the K/Pg impact?

Answer 22

1% of energy turned into (200 m) tsunamis and hurricane force winds
99% of energy caused melting, vaporization, ejecta & magnitude 13 earthquakes

Question 23

What was the problem caused by ejecta from K/Pg?

Answer 23

Hot molten material in the atmosphere essentially cooked life from above

Question 24

What was the selectivity/ bias from the K/Pg event?

Answer 24

Larger animals which couldn’t hide and have high metabolic requirements less favoured to survive

Question 25

What was the climate impact of K/Pg?

Answer 25

Sulphur rich rocks burnt releasing sulphur dioxide into the atmosphere causing a nuclear winter

Question 26

What was the effect on ozone after K/Pg?

Answer 26

Increased sulphate created hole in ozone increasing UV reaching surface

Question 27

What occurred at the same time as K/Pg some some try to argue was a potential driver of extinction like PTME?

Answer 27

Deccan traps (Large igneous province)

Question 28

Why did avian dinosaurs survive the K/Pg?

Answer 28

evolution of small body size (~1kg) over at least 60 million years
prior to K/Pg

Question 29

What is the Lilliput event and why is it common among mass extinctions?

Answer 29

Effect that smaller organisms most commonly survive mass extinctions - widespread dwarfing can change efficiency of energy use within and among taxa

Question 30

What was the major earth system perturbation of K/Pg?

Answer 30

~93% species extinction in the calcifying marine algae (coccolithophores) which affected bio pump and food chain