Articles tagged with Stratigraphy
Researchers refine classic stratigraphic model of the Grand Canyon's Tonto Group, shedding light on sea-level rise, catastrophic storms and rapid trilobite diversification during the Cambrian period. The study offers a deeper understanding of global changes in climate and tectonics.
A team of sedimentologists and stratigraphers found that gap regularity, not incompleteness, determines evolutionary history reconstruction. Incompleteness can be overcome with geological knowledge, enabling accurate reconstruction of evolution hundreds of millions of years ago.
Research in the Alaskan-Aleutian subduction zone found evidence of splay fault uplift generating additional tsunami activity in half of last eight earthquakes. Splay faults can create local tsunamis reaching shores in under 30 minutes, exacerbating coastal destruction.
A new study published in PLOS ONE provides detailed insights into the timing of events in ancient Gezer, a city known from Egyptian, Assyrian, and Biblical texts. The radiocarbon dates suggest that some proposed correlations between the archaeological record and ancient texts are plausible.
Researchers have discovered a series of bird footprints from the Early Cretaceous period in Victoria, Australia, indicating that diverse birds lived in southern polar environments during this time. The discovery provides new insights into the distribution and dispersal of early birds across landmasses.
Researchers have identified finger-marks on a cave wall in France as the oldest known Neanderthal engravings, dating back to around 75,000 years ago. The marks were made using a plotting analysis and photogrammetry to create 3D models, confirming that they are deliberate, organized shapes created by human hands.
A new analysis by Devin McPhillips reveals that the recurrence interval for earthquakes along some California faults may be 16% longer than previously estimated. This is due to the incorporation of event likelihood, a variable quantifying how likely it is that a past earthquake is real and unique.
Researchers investigated habitat conditions at Blick Mead site, finding partially open woodland conditions that would have supported large grazing herbivores. The study suggests hunter-gatherers used this space for 4,000 years before early farmers and monument-builders arrived in the region.
The Bushveld Complex functioned as a gigantic magma body, with a column of melt likely several km thick, contradicting the prevailing theory of non-existent large, long-lived and largely molten magma chambers. This discovery was made possible by 3D high-resolution X-ray computed tomography studies of chromitite.
Researchers found physical differences in femur, dental structures across specimens suggesting re-categorization into three groups or species. Two new species, T. imperator and T. regina, are proposed based on analysis of 37 Tyrannosaurus specimens.
The world's largest ammonite species, Parapuzosia seppenradensis, reached diameters of 1.5-1.8 meters around 80 million years ago. This evolution likely helped the species evade predation and survive in its environment.
The new radiometric dating of the Tianqiaoling Formation provided an age of 212.8±2.5 Ma, indicating the peak development of the Tianqiaoling flora. This finding contributes to a better understanding of Late Triassic phytogeography in East Asia.
Researchers analyzed detrital-zircon data from sandstones in the Ouachita orogen, revealing a mix of sediment dispersal pathways from multiple provenances. In Scotland, the Moine thrust zone hosted highly alkaline syenite intrusions with high-temperature contact metamorphic aureoles.
Researchers have revised the record of glacial and warm intervals in southern Finland, pushing back the timeline by 200,000 years. This discovery provides new insights into the paleogeography, vegetation, and climate of Fennoscandia during different interglacials.
The study investigates carbonate deposition with different depositional environments, using a three-dimensional basin-fill model and sensitivities analysis. It demonstrates that stratal completeness is controlled by sea level changes, depositional environments, carbonate growth rates, and tectonic subsidence patterns.
Research reveals that ordinary river deposits dominate the stratigraphic record due to hierarchical organization in river dynamics. This understanding solves a long-standing enigma in geology and has implications for modern river systems affected by climate change and sea level rise.
Researchers have found a new type of projectile point technology in North America, dating back at least 16,000 years. This discovery suggests that humans occupied the Americas prior to the Clovis culture, which is currently considered one of the oldest Paleo-Indian cultures.
An international team has found the world's most pristine record of tsunamis in a sea cave in Indonesia, spanning 5,000 years and revealing highly erratic tsunami recurrence. The discovery provides new insights into seismic activity along the Sunda Megathrust.
Scientists say human activity has left a pervasive signature on Earth that warrants recognition as a new geological time unit. This 'Anthropocene' epoch will be marked by uniquely human products and global markers such as carbon particulates, nitrogen, phosphorus, and nuclear fallout.
Researchers have found that sea levels in the Chesapeake Bay region deviate from global trends due to glacio-isostatic adjustment, with implications for future subsidence and sea-level rise. The study suggests that the region will continue to experience subsidence for millennia, exacerbating coastal erosion and resource loss.
The Capitanian extinction, dated to 262 million years ago, is now recognized as a major extinction event globally, with severe losses in brachiopods at high latitudes and widespread loss of carbonates across the Boreal Realm. This new evidence supports its status as a true mass extinction, updating the 'Big 5' list to the 'Big 6'.
Scientists at UCL conclude humans became a geological power with global environmental changes starting around 1610. A golden spike marker, the 'Orbis Spike', was found in Antarctic ice-core records, indicating an irreversible exchange of species between the Old and New Worlds.
A new study by Andrew J. Retzler and colleagues presents a revised map characterizing the size and shape of the Alamo crater. The researchers estimate the crater's diameter to be between 111 and 150 km, more than double previous estimates. This places the Alamo crater as one of the largest marine impacts in the last 550 million years.
Researchers have discovered detrital pyrite and uraninite grains in sedimentary rocks, which constrain the rise of oxygen to younger than 2.415 billion years ago. A new model also reveals an ancient atmosphere with less than ~10^-5 atm of O2 at 2.4 billion years ago.
Researchers study beach nourishment decisions and find that decentralized management can lead to resource inefficiencies. The stratigraphic record is controlled by physical processes such as sediment deposition rates and river channel migration, with gaps often left due to pauses in deposition or heightened erosion.
Researchers study Carboniferous collision in central Asia, crystal xenoliths in Bolivia, and the Tsakhir Event in southern Mongolia. The GSA Bulletin also examines iron oxide deposits in Brazil, paleotopography of Norway, and the Cheyenne belt suture zone.
Researchers used numerical dating to test the sequence stratigraphy model, validating its predictions and improving understanding of long-term climate changes and extinction events. The findings also provide insights into human-induced changes in ecosystems that predate the Anthropocene Epoch.
Recent GSA Bulletin articles discuss tectonics, mineral formation, the Moho, age dating using zircon crystals, atmospheric CO2, and early animal evolution. Slow faults in Spain produce large earthquakes with thousand-year recurrence periods.
A team of international researchers discovered evidence of pre-13,000-year-old non-Clovis cultures in North America, contradicting the long-held 'Clovis First' theory. The findings include Western Stemmed projectile points and DNA-profiling of human coprolites from the Paisley Caves.
Scientists study silicic calderas and crustal structure in the Iberian Peninsula, finding links to tectonic controls. Researchers also analyze eolian dynamics and sediment mixing in the Gran Desierto dune field using thermal infrared spectroscopy and remote-sensing data.
This article highlights new findings on late Cenozoic deformation in the Greater Caucasus Mountains, an important structure in the Arabia-Eurasia collision zone. The study also reports on a crucial upper age bound for the disappearance of the North Tian Shan Ocean and collision between the Yili and Junggar blocks in western China.
A new sediment curve derived from Paleozoic Era sediments provides a predictive model for tracking sediment migration. The tool covers the entire Paleozoic Era, spanning 542 to 251 million years ago, and can help the oil industry with discoveries in previously unexplored areas.
A geologist at the University of Leicester has proposed an enormous exhibition to showcase the Earth's 64-million-year history, highlighting the brevity of human civilization. The massive core would measure 1.5km long, with key events marked along its length, including the evolution of humans and past climactic upheavals.
Researchers identify significant human effects on the environment, including altered sediment patterns, carbon cycle disruptions, and ocean acidification. The International Commission on Stratigraphy is considering formal adoption of the Anthropocene as a new geological epoch.
The Vilama Caldera's 8.4 million-year-old mega eruption is considered one of the world's largest known eruptions, emitting approximately 2000 cubic kilometers of pyroclastic material. The size and volume of the associated caldera put it among the world's largest known eruptions, differing from Yellowstone's three cataclysmic events.
The Mars Express and NASA's Mars Reconnaissance Orbiter missions are providing valuable insights into Mars' upper interior. The combination of radars on the two missions will directly map the structure of the upper portions of the interior, revealing information about water, ice caps, and crust deformation.
A team of archaeologists has confirmed the historicity of King Solomon's reign, citing evidence from excavations at Tel Rehov in Israel. The findings, published in Science magazine, provide a strong anchor for dating other sites with similar material culture to the time of the United Monarchy.
Lawrence H. Tanner found evidence of a Manicouagan impact causing an earthquake in the Fundy Rift Basin, a sedimentary basin 700 km away from the impact site. The association between the impact and paleoseismicity was made using shocked quartz grains, providing a stratigraphic context for the event.