{"id":143,"date":"2015-09-08T14:33:29","date_gmt":"2015-09-08T19:33:14","guid":{"rendered":"https:\/\/uwm.edu\/geosciences\/?page_id=143"},"modified":"2024-09-06T11:54:48","modified_gmt":"2024-09-06T16:54:48","slug":"sedimentologysurficial-geology","status":"publish","type":"page","link":"https:\/\/uwm.edu\/geosciences\/research\/sedimentologysurficial-geology\/","title":{"rendered":"Sedimentology\/Surficial Geology Group"},"content":{"rendered":"\n

This rsearch group specializes in Clastic Sedimentology, Sequence Stratigraphy, Clastic Petrology, Glacial, Fluvial, and Tidal Deposits; Antarctic and Gondwana Geology. Current research projects focus on understanding environmental changes that occurred during critical intervals in Earth’s history, including the late Paleozoic Ice Age and the ensuing Permian-Triassic greenhouse and the transition from the Cretaceous to the Tertiary prior to and following the extinction event.<\/p>\n\n\n\n

\"John<\/figure>\n\n\n\n

Dr. John L. Isbell<\/h2>\n\n\n\n

Specializes in Clastic Sedimentology, Sequence Stratigraphy, Clastic Petrology, Glacial, Fluvial, and Tidal Deposits; Antarctic and Gondwana Geology.<\/p>\n\n\n\n

Research:<\/strong> Dr. Isbell is a clastic sedimentologist and sequence stratigrapher who works with glacial, glaciomarine, fluvial, deltaic, and shallow marine sediment and sedimentary rocks deposited in foreland, rift, piggyback, and cratonic basins. He currently works in Antarctica, Argentina, Australia, South Africa, the Falkland Islands, the western United States, the Appalachian Mountains, and in Wisconsin. His work focuses on understanding environmental changes that occurred during critical intervals in Earth History. These include (1) the late Paleozoic Ice Age (LPIA) and the ensuing Permian-Triassic greenhouse (359\u2013199 million years ago) and (2) the transition from the Cretaceous to the Tertiary prior to and following the extinction event (145\u201355 million years ago).<\/p>\n\n\n\n

The LPIA represents the last complete transition from an icehouse to a greenhouse Earth. Both the LPIA and the current Cenozoic Ice Age share several important features:<\/p>\n\n\n\n

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  1. both occurred during times of low atmospheric CO2<\/sub>,<\/li>\n\n\n\n
  2. both ice ages were bi-polar,<\/li>\n\n\n\n
  3. both were\/are represented by long duration glaciation, and<\/li>\n\n\n\n
  4. both occurred during times when complex ecosystems characterized Earth.<\/li>\n<\/ol>\n\n\n\n

    The LPIA is an important ancient analog for understanding future environmental changes. The transition between the Cretaceous and Tertiary (Paleogene) is another critical interval in Earth history that Dr. Isbell studies. During the Cretaceous, the ancestral Rocky Mountains were drained by numerous river systems that flowed eastward across an extensive alluvial plain before emptying into a vast shallow sea. A bolide impact, which ended the reign of the Dinosaurs, forever changed this landscape.<\/p>\n\n\n\n

    Dr. Isbell integrates graduate and undergraduate students into his research both in the field and by studying physical sedimentary processes using the department\u2019s flume research facility.<\/p>\n\n\n\n