Explore the vast range of titles available.

Earths surface isn't just dirt and rock. It features majestic mountains and verdant valleys, rolling rivers and violent volcanoes. Readers are whisked away on a tour of the planet and it's many fascinating landforms. They will see many of Earth's most interesting natural locations and learn how they were formed.

Planetary Crusts explains how and why solid planets and satellites develop crusts. Extensively referenced and annotated, it presents a geochemical and geological survey of the crusts of the Moon, Mercury, Venus, Earth and Mars, the asteroid Vesta, and several satellites like Io, Europa, Ganymede, Titan and Callisto. After describing the nature and formation of solar system bodies, the book presents a comparative investigation of different planetary crusts and discusses many crustal controversies. The authors propose the theory of stochastic processes dominating crustal development, and debate the possibility of Earth-like planets existing elsewhere in the cosmos. Written by two leading authorities on the subject, this book presents an extensive survey of the scientific problems of crustal development, and is a key reference for researchers and students in geology, geochemistry, planetary science, astrobiology and astronomy.

Most efforts to characterize the size and composition of the mantle that complements the continental crust have assumed that the mid‐ocean ridge basalt (MORB) source is the incompatible‐element depleted residue of continental crust extraction. The use of Nd isotopes to model this process led to the conclusion that the “depleted MORB reservoir” is confined to the upper ∼30% of the mantle, leaving the lower mantle in a more “primitive” state. Here, we use Nb/U and Ta/U to evaluate mass and composition of the mantle reservoir residual to continent extraction and find that it exceeds 60% of the total mantle. Thus, the (Nb, Ta)/U‐based mass balance conflicts with the ε(Nd)‐based mass balance, and this invalidates the classical 3‐reservoir silicate Earth model (continental crust, depleted mantle, and primitive mantle). Including the combined MORB + ocean island basalt (OIB) sources in the ε(Nd)‐based mass balance does not reconcile the conflict as it would require their average ε(Nd) to be ≤3.0, much lower than observed MORB + OIB ε(Nd) averages. We resolve this conflict by invoking an additional, “early enriched reservoir” (EER), formed prior to extraction of significant continental crust, but now hidden or lost. This EER differs from EERs previously invoked by having no Nb‐Ta anomaly. We suggest that it originated as an early mafic crust, which had unfractionated (Nb, Ta)/U but fractionated Sm/Nd ratios. The corresponding “early depleted” reservoir generated the present‐day continental crust and the “residual mantle” MORB‐OIB reservoir, which occupies at least 63% of the present‐day mantle and is only moderately depleted in incompatible trace elements. Plain Language Summary The Earth's continental crust makes up only about half a percent of Earth's mass, but it contains a large portion of its total budget of uranium and thorium, which produce much of Earth's interior heat. In making the crust, these elements have been extracted via melts and volcanism from Earth's mantle. But what portion of the mantle was involved in making the continents? Previously, geochemists concluded that only its uppermost 30% was involved, leaving the lower two‐thirds of the mantle essentially untouched. The measure used for this estimate has been the difference in the isotope ratios of neodymium, 143Nd/144Nd, between crust and mantle. However, when we use an alternative measure for the same calculation, namely the ratio of niobium to uranium, Nb/U, we find the depleted mantle fraction to be greater than 60%. We therefore need an Earth model that involves an additional “reservoir” with crust‐like Nd isotopes but mantle‐like Nb/U. We model this as an early Earth basaltic crust, which may have been lost to space, or may now be hidden at the base of the mantle. A buried ancient crust might well explain the large density/temperature anomalies recently discovered at the base of the mantle by seismologists. Key Points A new assessment of the depleted mantle (DM) mass (>63%) based on (Nb, Ta)/U conflicts with conventional estimates using Nd isotopes (<50%) This invalidates the classic 3‐reservoir silicate Earth (continental crust, DM, and primitive mantle) The observable, present‐day mantle was permanently depleted by segregation or loss of an early enriched reservoir

The history of the growth of continental crust is uncertain, and several different models that involve a gradual, decelerating, or stepwise process have been proposed 1 – 4 . Even more uncertain is the timing and the secular trend of the emergence of most landmasses above the sea (subaerial landmasses), with estimates ranging from about one billion to three billion years ago 5 – 7 . The area of emerged crust influences global climate feedbacks and the supply of nutrients to the oceans 8 , and therefore connects Earth’s crustal evolution to surface environmental conditions 9 – 11 . Here we use the triple-oxygen-isotope composition of shales from all continents, spanning 3.7 billion years, to provide constraints on the emergence of continents over time. Our measurements show a stepwise total decrease of 0.08 per mille in the average triple-oxygen-isotope value of shales across the Archaean–Proterozoic boundary. We suggest that our data are best explained by a shift in the nature of water–rock interactions, from near-coastal in the Archaean era to predominantly continental in the Proterozoic, accompanied by a decrease in average surface temperatures. We propose that this shift may have coincided with the onset of a modern hydrological cycle owing to the rapid emergence of continental crust with near-modern average elevation and aerial extent roughly 2.5 billion years ago. The use of triple-oxygen-isotope data from continental shales spanning the past 3.7 billion years suggests that continental crust with near-modern average elevation and extent emerged about 2.5 billion years ago.

Carbon and other volatiles are transported from Earth’s surface into the mantle at subduction margins. The efficiency of this transfer has profound implications for the nature and scale of geochemical heterogeneities in Earth’s deep (mantle) and shallow (crustal) reservoirs, as well as Earth’s oxidation state. However, the proportion of volatiles released in the forearc and backarc are not well constrained compared to fluxes from the volcanic front. Here, we use helium and carbon isotope data from deeply sourced springs along two cross-arc transects to show that ~91% of carbon released from the slab/mantle beneath the Costa Rica forearc is sequestered within the crust by calcite deposition, and an additional ~3% is incorporated into biomass through microbial chemolithoautotrophy. We estimate that ~1.2 × 10(exp 8) to 1.3 × 10(exp 10) mol CO2/yr are released from the slab beneath the forearc, resulting in up to ~19% less carbon being transferred to Earth’s deep mantle than previously estimated.

Constructed on one continuous folded page, this book explores the layers of the Earth from human-made structures like sewers, subways, and archeological finds, down through various formations of rock, to the Earth's core and back up again.

Earth as an Evolving Planetary System is based on Kent Condie's classic text, Plate Tectonics and Crustal Evolution, which has been revamped and renamed in order to reflect a new emphasis on the evolving interactions of the Earth's systems.