Permafrost palaeoclimate of Permian palaeosols in the Gerringong volcanic facies of New South Wales
Titel:
Permafrost palaeoclimate of Permian palaeosols in the Gerringong volcanic facies of New South Wales
Auteur:
Retallack, G. J.
Verschenen in:
Australian journal of earth sciences
Paginering:
Jaargang 46 (1999) nr. 1 pagina's 11-22
Jaar:
1999-02
Inhoud:
Late Permian (early Tatarian, 258 Ma) palaeosols exposed near Kiama and Dapto on the south coast of New South Wales can be recognised from their red colour, clayey and massive texture, and clay-filled root traces. Harvey pedotype palaeosols are within the upper Jamberoo Sandstone Member of the Broughton Formation. Loveleigh pedotype palaeosols are within the basal Kiama Sandstone overlying columnar jointed flows of the Blow Hole Latite Member of the Broughton Formation. Both kinds of palaeosols are strongly ferruginised with little relict bedding, yet they are little weathered and have surprisingly high amounts of feldspar and pyroxene. Both also show deformation of subsurface layers comparable to the active layer of permafrosted soils. Root traces in these palaeosols are sparse and comparable to those of woody gymnosperms, not chambered like the known roots of Glossopteris. Plausible components of the taiga woodland represented by the palaeosols include Gangamopteris, cordaites, seed ferns, and equisetaleans. Frigid palaeoclimatic indications from the palaeosols are compatible with a palaeomagnetically determined palaeolatitude of 57-85°S, and thus indicate an equator-pole climatic gradient in the Late Permian generally similar to that of today.
Tijdschrift beschrijving