Laurentia's Grenville Loop: Tracking Rodinia Across the Mesoproterozoic to Neoproterozoic Boundary

Explore new perspectives on Laurentia's Grenville Loop and its role in tracking Rodinia across the Mesoproterozoic to Neoproterozoic boundary in this 29-minute conference talk by Yiming Zhang from the University of California, Berkeley. Delve into the paleogeography of Laurentia during the Neoproterozoic, crucial for reconstructing global paleogeography due to its central position in the supercontinent Rodinia. Examine the development of a new paleomagnetic pole from the early Neoproterozoic Jacobsville Formation, now dated to approximately 990 Ma. Learn about high-resolution thermal demagnetization experiments that resolve detrital remanent magnetization and the intraclast conglomerate test that confirms the primary nature of the magnetization. Discover how the inclination-corrected mean pole paleomagnetic position for the Jacobsville Formation supports continued plate motion of Laurentia across the equator in the late Mesoproterozoic to early Neoproterozoic. Investigate the implications of Laurentia's slowed motion following the onset of the Grenvillian orogeny and the need to revise the ages of Grenville poles. Gain insights into quantitative estimates of cooling rates and magnetic remanence acquisition timing for the Adirondack Highlands of the Grenville Province using inverted cooling history models based on new apatite U-Pb ID-TIMS thermochronological data.

Intro
The well-dated Keweenawan Track mild post-emplacement thermal histories
Late Mesoproterozoic Laurentia paleogeography ~25 Myr of rifting and fast plate motion
No date, No rate
Previous age interpretation for the Jacobsville Formation
Field and radiometric constraints on Jacobsville deposition and deformation
Detrital zircon maximum deposition age constraints using CA-ID-TIMS
Age constraints on faulting from U-Pb dates on late kinematic fault breccia calcite
Field and geochronology constraints on Jacobsville deposition and deformation
Jacobsville paleomagnetism previous work
Siltstone and fine-grained sandstone beds in the Jacobsville Formation
Jacobsville paleomagnetism high resolution thermal demagnetization
Red bed paleomagnetism high-resolution thermal demagnetization
Positive Intraformational conglomerate test
Fold test provides age constraints
Inclination correction using the elongation/inclination method
Revisiting the Adirondack Highlands thermochronology
New geochronology data from the Adirondack Highlands
New thermochronology data from the Adirondack Highlands
Laurentia at the Center of Rodinia Supercontinent
Implication for the age of the Grenville Loop
Revisiting the Grenville poles Brown and McEnroe, 2012
Laurentia's slowdown after the onset of Grenvillian orogeny