Events of the KT Boundary: Part 2

in #geology2 years ago

Events of the KT Boundary lists several major events at the K/T Boundary for consideration. Here is a continuation of the list.

Additional geological events dated to ~66Ma:

MORE impacts:

After

  1. Chicxulub Crater,

  2. Nadir Crater,

  3. Boltysh Crater, and

  4. Shiva Crater, all discussed previously,

  5. Tefe River Structure in Brazil dates to KT boundary: Geophysical Evidence Of A Possible Impact Structure At The K-T Boundary Of The Solimões Basin, Brazil
    The Cretaceous-Tertiary boundary in the context of impact geology and sedimentary record-an analytical review of 10 years of researches in Brazil

  6. The Silverpit Crater is controversially ~65-60Ma, and debated on whether it is an impact structure or a pull-apart basin: A 20-km-diameter multi-ringed impact structure in the North Sea

  7. Dumas Magnetic Anomaly in Canada, believed to be from a meteorite impact, formed late cretaceous, 70+/- 5Ma: Magnetic Fields Associated with a Probable Late Cretaceous Astrobleme at Dumas, Saskatchewan

  8. The Jebel Hadid structure in Libya was formed after early Cretaceous and prior to late Miocene rivers and is compared to the Tin Bider impact crater in Algeria: The Jebel Hadid structure (Al Kufrah Basin, SE Libya)—A possible impact structure and potential hydrocarbon trap?

  9. The Tin Bider Impact is poorly constrained to <66Ma by stratigraphy, the youngest geological unit affected by the event being ~66Ma limestones: Shock-metamorphic microstructures in quartz grains from Albian sandstones from the Tin Bider impact structure, Algeria

10, 11. Kara/Ust-Kara twin impact structure dates variously to 60Ma-70Ma and has been considered as a possible K/T Boundary event: The Kara/Ust-Kara twin impact structure; A Large-scale impact event in the Late Cretaceous

The Kara and Ust-Kara impact structures (USSR) and their relevance to the K/T boundary event

12. In D.R. Congo the age of the Omeonga structure can be constrained to the Late Cretaceous-Cenozoic, according to the youngest units in which the ring structure was formed: Omeonga––A possible large impact structure on the Eastern Kasai Province(D.R. Congo)

That's right; there are at least 11 additional K/T boundary suspects or confirmed "impact craters." Coupled with what else was occurring on Earth, this strongly suggests the craters are the result of the Earth's own processes.

Additional Events at the K/T Boundary:

A major step in Himalayas mountain formation process occurred; Trans-Tethyan subduction zone between India and Eurasia active 66-62Ma: Paleocene latitude of the Kohistan–Ladakh arc indicates multistage India–Eurasia collision

Tibet's Dianzhong Formation 66-63Ma: Origin of the volcanic rocks in Dianzhong Formation, central Lhasa Terrane, Tibet: implication for the genesis of syn-collisional magmatism and Neo-Tethyan slab roll-back

Mingshui Formation also dates ~66Ma: Mesozoic–Cenozoic tectonic evolution and dynamics of the Songliao Basin, NE Asia: Implications for the closure of the Paleo-Asian Ocean and Mongol-Okhotsk Ocean and subduction of the Paleo-Pacific Ocean

The Alps have several locations with apparent ages ~66Ma: Preservation of sub-microscopic structural relicts in micas from the Gran Paradiso Massif (Western Alps): Implications for 40Ar–39Ar geochronology

Time constraints on the metamorphic and structural evolution of the southern Sesia-Lanzo Zone, Western Italian Alps

Metamorphic evolution of the Sesia-Lanzo Zone, Western Alps: time constraints from multi-system geochronology

Late Cretaceous mixed sediments along the Argentine Margin indicate a change from gravity dominated deposition style along the margin to bottom current dominated 66Ma marking the cessation of mixed system due to bottom current intensification and transition to a pure contourite system: A Late Cretaceous mixed (turbidite-contourite) system along the Argentine Margin: Paleoceanographic and conceptual implications

Moeraki Boulders, Koutu, and other large round boulders of New Zealand date to 66Ma: Treasured Spheres Protecting New Zealand's Heritage of Spherical Concretions

What is believed to be A Mega-Tsunami Deposit at the KT Boundary on Tora Coast of New Zealand

Central and western Solomon Islands are composed of exceptionally thick succession of Lower Cretaceous to Holocene rocks: GEOLOGY OF THE CENTRAL AND WESTERN SOLOMON ISLANDS

Formation of the East Sikhote-Alin area of far east Russia included eruptions from 66Ma to 46Ma: Late Cretaceous palaeomagnetic results from Sikhote Alin, far eastern Russia: tectonic implications for the eastern margin of the Mongolia Block

The Louisville Seamount Chain in the Pacific Ocean contains the Osbourn Seamount at the westernmost end of the chain which has rocks dated to ~66Ma: Seamounts, Islands, and Atolls, Volume 43 Petrologic Evolution of the Louisville Seamount Chain

Isotopic Evidence for a Hotspot Origin of the Louisville Seamount Chain

Cerro Quema and other Gold-Copper deposits throughout the world, especially around the Pacific Rim, were formed ~66Ma: Cerro Quema (Azuero Peninsula, Panama): Geology, Alteration, Mineralization, and Geochronology of a Volcanic Dome-Hosted High Sulfidation Au-Cu Deposit

Ore Deposits in Butte, Montana date to the 67-65Ma, and similar ages: Two-event lode-ore deposition at Butte, USA: 40Ar/39Ar and U-Pb documentation of Ag-Au-polymetallic lodes overprinted by younger stockwork Cu-Mo ores and penecontemporaneous Cu lodes