Earth & Environmental Sciences
platinum group element
100%
siderophile element
88%
Cretaceous-Paleogene boundary
78%
impact structure
48%
chronology
38%
astronomy
37%
solar system
33%
fossil record
31%
Archean
29%
iridium
28%
eukaryote
25%
geology
24%
Cretaceous
23%
crater
20%
ejecta
18%
Eocene
18%
impactite
18%
rock
17%
river
15%
endosymbiont
15%
transition
13%
common ancestry
13%
cell
13%
critical analysis
12%
mitochondrion
12%
impactor
11%
isotopic ratio
11%
melt
11%
comet
11%
asteroid
11%
genomics
10%
terrestrial ecosystem
10%
fill
9%
crystal
9%
ocean
9%
extinction
8%
uplift
8%
plate tectonics
8%
fossil
7%
continental crust
7%
history
7%
accretion
7%
organism
7%
animal
7%
magnetic field
6%
bacterium
6%
zircon
6%
continent
6%
geochemistry
6%
phlogopite
6%
greenstone belt
6%
vaporization
6%
methodology
6%
bioturbation
6%
magma
6%
carbon
5%
background level
5%
reworking
5%
Earth science
5%
chondrite
5%
meteorite
5%
sedimentation rate
5%
energy
5%
trace metal
5%
diagenesis
5%
sediment
5%
Physics & Astronomy
Cretaceous-Tertiary boundary
65%
spherules
52%
fossils
42%
chronology
38%
eukaryotes
33%
spinel
30%
platinum
30%
planets
29%
vapors
23%
geology
23%
oceans
22%
chemistry
22%
bombardment
19%
interrogation
18%
plates (tectonics)
18%
prokaryotes
17%
geochemistry
17%
biology
16%
astronomy
16%
continents
16%
solar system
16%
jacks
16%
general overviews
15%
magma
15%
ecosystems
14%
Earth surface
13%
mitochondria
13%
rivers
13%
crusts
13%
histories
12%
organisms
11%
cells
11%
bacteria
11%
animals
10%
extinction
8%
signatures
8%
Republic of South Africa
8%
crystals
7%
atmospheres
7%
feldspars
7%
carbon
7%
ejecta
6%
water
6%
liquids
5%
magnetic fields
5%