Cenozoic: Global Events 65.5 Ma- Present
Major Tectonic Events The Rise of the Himalayas and Closure of the Tethyan Ocean Caused Climate Change Equatorial Ocean Closed Rifting in Western North America (Rio Grande Rift and Basin and Range) Opening of the Drake Passage (South America/Antarctica and Global Climate Change Rise of the Alps (Europe) Closure of the Panamanian Isthmus Rifting in East Africa: (Gave birth to humankind?)
Rise of the Himalayas
India-Asia Collision Began with the break-up of Gondwana Rifting between India and Madgascar around 90 Ma (Marion Hotspot Volcanism) India s acceleration towards Asia began around 65 Ma with the eruption of the Deccan traps. India moved at velocities up to 20 cm/yr during it s journey to Asia
Uplift caused increases in weathering and sediment influx into the ocean. The mountains restricted moist airflow into Asia causing desert formation on the leeward side and intensification of the monsoon on the windward side. Global cooling due to increased CO2 consumption
Physiographic Provinces W. US Colorado Plateau Rio Grande Rift Basin & Range Province Both are Cenozoic rift events that are changing wester North America.
Sevier & Laramide Orogenies Sevier Orogeny: ~140 Ma due to compressional forces (Kula and Farallon subduction) -Bordered the Interior seaway to the west. -Load created many foreland basins -Thin-skinned thrusting. -Latter stages overlap with Laramide Laramide Orogeny: Late Cretaceous to Tertiary - Same regions as Sevier orogeny, but extended further east -Thick-skinned exposing basement core complexes -Rapid convergence of Farallon plate -Nacimiento Uplift formed during the Laramide
Rio Grande Rift Development: Cenozoic -Series of Asymmetrical grabens -Broad shallow depressions during the Oligocene (~30 Ma -Pulse 1: Between 30-18 Ma: Low angle normal faults, horst-graben structures and volcanism -Pulse 2: 9-3 Ma volcanism, large-scale faulting and stretching of the crust
Rio Grande Rift Basins of New Mexico-Colorado San Luis Basin: CO and NM: formed within the past 4.5 Ma Espanola Basin: formed between 5-3 Ma Albuquerque-Belen Basin: coeval with the Espanola basin ALL are still actively subsiding!
-The Jemez Mtns (volcanic field) is a volcanic edifice. -Two main calderas (Valles and Toledo) -Volcanism started ~13 Ma -Toledo Caldera 1.4 Ma -Valles Caldera 1.1 Ma
Basin and Range Series of Horsts Uplifted Blocks Grabens- Downthrown blocks
The province was created about 20 million years ago as the Earth's crust stretched, thinned, and then broke into some 400 mountain blocks that partly rotated from their originally horizontal positions. These mountains of late Precambrian and Paleozoic rock continue to erode and fill the intervening valleys with fresh sediment.
Opening of the Drake Passage Before ~40 Ma, the Antarctic continent was largely ice free and covered with Pine forests and a reasonably diverse ecosystem. After 40 Ma, Antarctica began to cool and eventually became the ice-covered continent we know and love. Speculation is that the opening of a seaway between the Pacific and Atlantic isolated Antarctica and created the Circumpolar Antarctic current. Warm waters were no longer available to Antarctica and it began to cool
Alpine Orogeny
Alpine Orogeny Began in the Cretaceous and then overlaps with the Himalayan Orogeny Many consider one to be a continuation of the other. Very Long linear belt of mountains that dominate much of southern Europe The Alpine resulted from the collision of Africa with Europe.