Earth science: In the beginning. . .

  title={Earth science: In the beginning. . .},
  author={Alexander N. Halliday},
Grains of the mineral zircon have survived from way back in Earth's history. Analysis of these grains provides information on the state of our planet as long as 4.4 billion years ago. 
The Geological Context for the Origin of Life and the Mineral Signatures of Fossil Life
Life arose in a very different environment compared to that of the modern Earth. Unfortunately we have very little direct evidence of the conditions of the young Earth because of plate-tectonic
The oldest rocks on Earth: time constraints and geological controversies
Abstract Ages in the range 3.6–4.0 Ga (billion years) have been reported for the oldest, continental, granitoid orthogeneisses, whose magmatic precursors were probably formed by partial melting or
Processes on the Young Earth and the Habitats of Early Life
Conditions at the surface of the young (Hadean and early Archean) Earth were suitable for the emergence and evolution of life. After an initial hot period, surface temperatures in the late Hadean may
The evolution of the atmosphere in the Archaean and early Proterozoic
Key steps in atmospheric evolution occurred in the Archaean. The Hadean atmosphere was created by the inorganic processes of volatile accretion from space and degassing from the interior, and then
Darwin’s warm little pond revisited: from molecules to the origin of life
In this review, this review has concentrated on experimental and theoretical research published over the last two decades, which has added a wealth of new details and helped to close gaps in previous understanding of this multifaceted field.
Does the rapid appearance of life on Earth suggest that life is common in the universe?
It is found that on terrestrial planets, older than approximately 1 Gyr, the probability of biogenesis is > 13% at the 95% confidence level, which quantifies an important term in the Drake Equation but does not necessarily mean that life is common in the Universe.
Cosmic Thermobiology: Thermal Constraints on the Origin and Evolution of Life in the Universe
We review the thermal history of the Universe. We obtain a new estimate for the thermal history of the Earth over the past four billion years using a biological thermometer based on (1) a rough


Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4 Gyr ago
The discovery of a detrital zircon with an age as old as 4,404 ± 8 Myr is reported, about 130 million years older than any previously identified on Earth and represents the earliest evidence for continental crust and oceans on the Earth.
Oxygen-isotope evidence from ancient zircons for liquid water at the Earth's surface 4,300 Myr ago
In situ U–Pb and oxygen isotope results for detrital zircons found within 3-Gyr-old quartzitic rocks in the Murchison District of Western Australia are consistent with the presence of a hydrosphere interacting with the crust by 4,300 Myr ago and are postulated to form from magmas containing a significant component of re-worked continental crust.
Nature of the Earth's earliest crust from hafnium isotopes in single detrital zircons
Continental crust forms from, and thus chemically depletes, the Earth's mantle. Evidence that the Earth's mantle was already chemically depleted by melting before the formation of today's oldest
Xenon from the chondritic meteorite Richardton was found to be heavily enriched in Xe/sup 129/. This isotope almost centainly was formed from the decay of I/sup 129/, extinct at present as a natural
Metal‐silicate fractionation in the growing Earth: Energy source for the terrestrial magma ocean
Based on the homogeneous accretion model of planets, thermal evolution of the growing earth has been studied. After the surface of the growing earth starts melting owing to the blanketing effect of
Ion microprobe identification of 4,100–4,200 Myr-old terrestrial zircons
We report here the existence of detrital zircons from Western Australia which are far older than any known terrestrial rocks. They are from quartzites at Mt Narryer (Fig. 1), a locality which has
Jack Hills, evidence of more very old detrital zircons in Western Australia
The age of the Earth's oldest crustal minerals sets a time-limit on the earliest preservation of buoyant solid crust. The oldest mineral ages reported so far are ∼4,180 Myr for detrital zircons from