Relative and absolute ages in the histories of Earth and the Moon: The Geologic Time Scale

Building on earlier telescopic observations, our knowledge about the Moon was transformed by the wealth of information provided by Apollo and other space missions. These demonstrated the value of the Moon for understanding the fundamental processes that drive planetary formation and evolution. The Moon was understood as an inert body with its geology mainly restricted to impact and volcanism with associated tectonics, and a relative simple composition. Unlike Earth, an absence of plate tectonics has preserved a well-defined accretion and geological evolution record. However recent missions to the Moon show that this traditional view of the lunar surface is certainly an over simplification. These volatiles are likely to be formed as a result of hydration processes operating at the lunar surface including the production of H2O and OH by solar wind protons interacting with oxygen-rich rock surfaces produced during micrometeorite impact on lunar soil particles. Moreover, on the basis of Lunar Prospector gamma-ray data, the lunar crust and underlying mantle has been found to be divided into distinct terranes that possess unique geochemical, geophysical, and geological characteristics. The concentration of heat producing elements on the nearside hemisphere of the Moon in the Procellarum KREEP Terrane has apparently led to the nearside being more volcanically active than the farside.

Lunar Rocks

It was seen as a waste of money by some , but almost 40 years since the launch of Apollo 17, we are still seeing significant returns on the investment. Among the most significant of those returns is the valuable information the lunar landings provided about our moon and, in turn, the planet we call home. Have you seen my rock collection? Prior to the Apollo missions, knowledge about the moon was limited to remote sensing , modelling and speculation. It was unclear what the moon was composed of, whether it was young or old, whether it harboured life, and whether it contained water.

For anyone looking to purchase authentic moon rocks, an authentic soil sample could be yours for a price ranging anywhere from $, to $1 million. Overall, the sample has 70 elements dating to be over billion years old. To some, this price may very well seem reasonable, though.

Mosaic of Curiosity rover Mastcam images of layered rocks in Gale Crater, including the mudstone that Farley and colleagues studied. Click for more information and higher-resolution versions. In a recent Science publication Kenneth Farley California Institute of Technology and colleagues lay out the framework for their ground-breaking work.

In March , Curiosity drilled a number of holes into mudstone at Gale Crater see image on the right collecting the powder to perform geochemical analyses, including determining the ages of the rocks. Farley and coauthors used the potassium-argon dating technique, which uses measurements of the amount of argon gas trapped inside the rock. Basically, rocks contain radioactive potassium that, over time, decays into stable argon.

This decay occurs at a known rate allowing the scientists to calculate the age of a rock sample once the amount of argon inside is known. The amazing part of age dating using the instruments on the Curiosity rover is that it has never been done anywhere but on Earth due to the sophisticated equipment required to measure the amount of argon in a rock sample.

So, prior to the mission’s launch on November 26, NASA put out a call for new and exciting experiments that could be run simultaneously with Curiosity’s prearranged experiments. Farley and his team answered that call by proposing the rover carry equipment similar to what we use to date rocks in Earth-bound laboratories. The team measured the potassium concentration in the rock powder using the APXS, and then Curiosity’s on-board equipment took the rock powder, heated it to temperatures high enough for the argon to escape and then let the mass spectrometer on the SAM instrument do the heavy lifting.

The team found that the mudstone has a Noachian to early-Hesperian age, 4. This result was not completely unexpected.

How Do Scientists Determine the Age of Dinosaur Bones?

Radiometric Dating Does Work! Radiometric dating of rocks and minerals using naturally occurring, long-lived radioactive isotopes is troublesome for young-earth creationists because the techniques have provided overwhelming evidence of the antiquity of the earth and life. Some so-called creation scientists have attempted to show that radiometric dating does not work on theoretical grounds for example, Arndts and Overn ; Gill but such attempts invariably have fatal flaws see Dalrymple ; York and Dalrymple

We have rocks from the Moon (brought back), meteorites, and rocks that we know came from Mars. We can then use radioactive age dating in order to date the ages of the surfaces (when the rocks first formed, i.e. when the lava cooled and crystallized).

As water expands it puts great pressure on the walls of anything containing it, including any rocks which happen to be surrounding it. When water falls into the cracks of rocks and freezes, the force of the pressure exerted on the rock surrounding it is enough to wedge the walls of the crack farther apart, thus expanding and deepening the crack. Ice wedging is what causes pot holes in city streets. Water freezes in the cracks under the pavement. As it expands it forces the pavement up, and when the water thaws the pavement falls back down and creates a pot hole.

Plant and Animal Action Some plants like mosses and lichens are capable of growing without soil on bare rock. When they do this their roots penetrate pores and crevices and cause rocks to split apart as the roots force their way down through the rocks. Animals can indirectly cause mechanical weathering by digging holes in the soil that allows water to reach down to the bedrock and cause weathering there. Just like mechanical weathering, chemical weathering can occur via several different methods: Some minerals such as feldspar, amphibole, and augite, react with water to form clay.

Oxidation reactions are the reason that many things rust over time.

Changing Views of the History of the Earth

The interior of the moon is cooler than the interior of the Earth. Since the moon is so small and so its surface area to volume ratio is large compared to that of the Earth , it loses its heat quickly into space. Since the Earth and the moon formed, the moon has cooled down much more than the Earth.

A new laser mass spectrometer designed as a space prototype has been used to date an earthbound rock which is regarded as an analogue of basalts on the Moon, setting the stage for dating of approximately 32% of the nearside of the lunar surface in situ.

Lunar breccias, formed largely by the immense basin-forming impacts, are dominantly composed of highland lithologies because most mare basalts post-date basin formation and largely fill these impact basins. The ferroan anorthosite suite is the most common group in the highlands, and is inferred to represent plagioclase flotation cumulates of the lunar magma ocean, with interstitial mafic phases formed from trapped interstitial melt or rafted upwards with the more abundant plagioclase framework.

This reflects the extreme depletion of the bulk moon in alkalis Na, K as well as water and other volatile elements. Ferroan anorthosites have been dated using the internal isochron method at “circa” 4. These rocks represent later intrusions into the highlands crust ferroan anorthosite at round 4. An interesting aspect of this suite is that analysis of the trace element content of plagioclase and pyroxene require equilibrium with a KREEP -rich magma, despite the refractory major element contents.

The alkali suite is so-called because of its high alkali content—for moon rocks. The alkali suite consists of alkali anorthosites with relatively sodic plagioclase An , norites plagioclase-orthopyroxene , and gabbronorites plagioclase-clinopyroxene-orthopyroxene with similar plagioclase compositions and mafic minerals more iron-rich than the magnesian suite. The alkali suite spans an age range similar to the magnesian suite.

Lunar granites are relatively rare rocks that include diorites , monzodiorites, and granophyres. They consist of quartz, plagioclase, orthoclase or alkali feldspar, rare mafics pyroxene , and rare zircon. The alkali feldspar may have unusual compositions unlike any terrestrial feldspar, and they are often Ba-rich. These rocks apparently form by the extreme fractional crystallization of magnesian suite or alkali suite magmas, although liquid immiscibility may also play a role.

U-Pb date of zircons from these rocks and from lunar soils have ages of 4.

Talk:Moon rock

Reconstruction Intrusive igneous rocks Erosion of volcanoes will immediately expose shallow intrusive bodies such as volcanic necks and diatremes see Figure 6. Many craterlike depressions may be filled with angular fragments of country rock breccia and juvenile pyroclastic debris. When eroded, such a depression exposes a vertical funnel-shaped pipe that resembles a volcanic neck with the exception of the brecciated filling.

sizes are found on the Moon, and it is easy to see why a wide range of breccia types is also present. Lunar monomict breccias are cataclastic rocks formed by in-situ brecciation of a single lithology (monolithologic). Polymict (or polylithologic) breccias consist, of two main the sawn surface of lunar breccia illustrating clasts.

This is what archaeologists use to determine the age of human-made artifacts. But carbon dating won’t work on dinosaur bones. The half-life of carbon is only 5, years, so carbon dating is only effective on samples that are less than 50, years old. Dinosaur bones, on the other hand, are millions of years old — some fossils are billions of years old. To determine the ages of these specimens, scientists need an isotope with a very long half-life. Some of the isotopes used for this purpose are uranium , uranium and potassium , each of which has a half-life of more than a million years.

Unfortunately, these elements don’t exist in dinosaur fossils themselves. Each of them typically exists in igneous rock, or rock made from cooled magma. Fossils, however, form in sedimentary rock — sediment quickly covers a dinosaur’s body, and the sediment and the bones gradually turn into rock. But this sediment doesn’t typically include the necessary isotopes in measurable amounts.

Radiometric Dating and the Geological Time Scale

Although they also posed new questions, the thousands of satellite photographs brought back from the Moon have permitted us to map its surface with greater accuracy than Earth could be mapped a few decades ago. We now have over kg of rocks from nine places on the Moon, rocks that have been analyzed by hundreds of scientists from many different countries.

Data from a variety of experiments have revealed much about the Moon’s deep interior. As it turns out, the Moon is truly a whole new world, with rocks and surface features that provide a record of events that occurred during the first billion years of the solar system. This record is not preserved on Earth because all rocks formed during the first million years of Earth’s history were recycled back into the interior. The importance of the Moon in studying the principles of geology is that it provides an insight into the basic mechanics of planetary evolution and events that occurred early in the solar system.

Moon Rocks are rocks that are on the moon they are made from much of the things earth is made of but it has no nutriance from the animals plants and humans who died As well as using carbon to carbon decay, geologists also measure the decay of potassium to argon in dating rocks. The decay of rubidium to strontium is used to.

What are the elements or rock found on the moon? From Apollo, we know that the moon has large supplies of silicon, iron, aluminum, calcium, magnesium, titanium and oxygen BUT the Moon lacks light elements volatiles , such as carbon and nitrogen, although there is some evidence of hydrogen near the north and south poles. Magnesium and iron rich zones found in the lunar highlands are usually associated with large impact basins, not highland terrain.

Traditionally, lunar basalts have been classified according to their titanium content, with classes being named high-Ti, low-Ti, and very-low-Ti. Overall, there is much less of the element titanium in the Apollo 12 samples than in the Apollo 11 samples, which explains the more reddish color of this region. Basalts are dark-colored rocks solidified from molten lava.

Radiometric Dating Does Work!

Before use, they would need to be pre-treated to smooth them out, then sieved to obtain the right grain size. This would ensure the fluidized bed reactor can operate safely. According to Denk, the machine can process a 25kg particle load in under an hour. In just one hour, it can make kg of water — and, in four hours, it could produce 2. The machine has now completed a six-month test run, and according to the creator, it can make enough oxygen and water to supply up to eight astronauts Most of the electricity would be dedicated to the process of splitting the oxygen from the hydrogen in the water molecules.

When astronauts first flew to the Moon, one of their most important tasks was to bring back lunar rocks for radioactive age-dating. Until then, astronomers and geologists had no reliable way to measure the age of the lunar surface.

While there are numerous natural processes that can serve as clocks, there are also many natural processes that can reset or scramble these time-dependent processes and introduce uncertainties. To try to set a reasonable bound on the age, we could presume that the Earth formed at the same time as the rest of the solar system. If the small masses that become meteorites are part of that system, then a measurement of the solidification time of those meteorites gives an estimate of the age of the Earth.

The following illustration points to a scenario for developing such an age estimate. Some of the progress in finding very old samples of rock on the Earth are summarized in the following comments. It is a compound of zirconium, silicon and oxygen which in its colorless form is used to make brilliant gems. Samples more than 3. Older ages in the neighborhood of 4.

How Old is Earth?

This book could very well be the most mind-boggling experience of your life. When I first stumbled across the shocking Soviet theory revealing the true nature of the Moon, I was staggered. At first I found it unbelievable and naturally rejected it. Then, as scientific information from our Apollo expeditions brought back more and more facts that backed the Soviet theory, I found myself forced to accept it. All my life I have been fascinated by the sky and the stars.

The bright, fire-laden Moon was no exception.

Isotopic dating of Moon rocks yields dates of up to Ga, and dates on meteorites have yielded ages as old as Ga. Geologists consider Ga meteorites to be fragments of planetesimals like those from which the Earth first formed.

The mind grows giddy gazing so far back into the abyss of time. We have seen that isotopic dating can be used to date the time when igneous rocks formed and when metamorphic rocks metamorphosed, but not when sedimentary rocks were deposited. So how do we determine the numerical age of a sedimentary rock? We must answer this question if we want to add numerical ages to the geologic column. Geologists obtain dates for sedimentary rocks by studying cross-cutting relationships between sedimentary rocks and datable igneous or metamorphic rocks.

If a datable basalt dike cuts the strata, the strata must be older than the dike. And if a datable volcanic ash buried the strata, then the strata must be older than the ash. The Geologic Time Scale Geologists have searched the world for localities where they can recognize cross-cutting relations between datable igneous rocks and sedimentary rocks or for layers of datable volcanic rocks inter-bedded with sedimentary rocks.

By isotopically dating the igneous rocks, they have been able to provide numerical ages for the boundaries between all geologic periods. For example, work from around the world shows that the Cretaceous Period began about million years ago and ended 65 million years ago. So the Cretaceous sandstone bed in first figure was deposited during the middle part of the Cretaceous, not at the beginning or end. Figure above shows the currently favoured numerical ages of periods and eras in the geologic column as of

Clocks in the Rocks

We received this letter from a visitor to our web site. Hello, I believe a scientist whose name is Mitsunobu Tatsumoto ascertained that the earth is 4. This was probably early ‘s. It is my understanding that younger scientists now believe the earth is closer to 4. I believe you missed a link.

The ages of Earth and Moon rocks and of meteorites are measured by the decay of long-lived radioactive isotopes of elements that occur naturally in rocks and minerals and that decay with half lives of million to more than billion years to stable isotopes of other elements.

Which age is correct? Sample was dated by five different sources with nineteen different results. Here is how one of those sources tried to spin the results. The 40K Ar ages are for No. Comparison of mineral and rock data demonstrates gas loss. The plagioclase for No. The concordance of He and Ar ages must be fortuitous. The maximum age is equal to the Rb-Sr age, and the general pattern is compatible with the Sr results.

Seven crystalline rock samples returned by Apollo 11 have been analyzed in detail by means of the 40Ar Ar dating technique.

Enrico Sangiuliano – Moon Rocks [Drumcode]