![The relationship between the Neoproterozoic Noonday Dolomite and the Ibex Formation: New observations and their bearing on 'snowball Earth' [An article from: Earth Science Reviews]](https://www.ebooknetworking.net/books/B00/0RR/bigB000RR761C.jpg)
The relationship between the Neoproterozoic Noonday Dolomite and the Ibex Formation: New observations and their bearing on 'snowball Earth' [An article from: Earth Science Reviews]
Book Details
Author(s)F.A. Corsetti, A.J. Kaufman
PublisherElsevier
ISBN / ASINB000RR761C
ISBN-13978B000RR7612
AvailabilityAvailable for download now
Sales Rank12,196,722
MarketplaceUnited States 🇺🇸
Description
This digital document is a journal article from Earth Science Reviews, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
The Neoproterozoic Ibex Formation (Death Valley region, California) is commonly interpreted as a coeval basinal facies to the Noonday Dolomite carbonate platform. However, in some areas (e.g., the Black Mountains, Death Valley), the Ibex Formation is found to rest on the eroded surface of the lower Noonday Dolomite and older units. Sediment-filled grikes root from the top of the eroded lower Noonday Dolomite, followed by the subsequent deposition of the Ibex Formation. Thus, the lower Noonday Dolomite is not considered coeval with all of the Ibex Formation as they are separated by a significant unconformity. At the type section in the Ibex Hills, the basal Ibex Formation commonly consists of polymict conglomerate and laminated mudstone; the upper surface of the mudstone is pierced by large angular clasts of underlying units, including distinctive lower Noonday Dolomite tubestone lithotypes. Here, a finely-laminated pink dolostone that records negative @d^1^3C values caps the basal Ibex conglomerate. Several interpretations of the new observations are possible. The erosional unconformity upon which the Ibex is deposited may be glacio-eustatic in origin, the basal conglomerate would represent glaciogenic ice rafted debris, and the overlying dolostone is a classic cap carbonate (noted atop many Neoproterozoic glacial deposits worldwide). Combined with the record from underlying units, the Death Valley succession would then unambiguously record three discrete Neoproterozoic ice ages with cap carbonates in a single succession. Alternatively, the sequence boundary could represent local tectonic activity rather than glacioeustacy. her than glacioeustacy.
Description:
The Neoproterozoic Ibex Formation (Death Valley region, California) is commonly interpreted as a coeval basinal facies to the Noonday Dolomite carbonate platform. However, in some areas (e.g., the Black Mountains, Death Valley), the Ibex Formation is found to rest on the eroded surface of the lower Noonday Dolomite and older units. Sediment-filled grikes root from the top of the eroded lower Noonday Dolomite, followed by the subsequent deposition of the Ibex Formation. Thus, the lower Noonday Dolomite is not considered coeval with all of the Ibex Formation as they are separated by a significant unconformity. At the type section in the Ibex Hills, the basal Ibex Formation commonly consists of polymict conglomerate and laminated mudstone; the upper surface of the mudstone is pierced by large angular clasts of underlying units, including distinctive lower Noonday Dolomite tubestone lithotypes. Here, a finely-laminated pink dolostone that records negative @d^1^3C values caps the basal Ibex conglomerate. Several interpretations of the new observations are possible. The erosional unconformity upon which the Ibex is deposited may be glacio-eustatic in origin, the basal conglomerate would represent glaciogenic ice rafted debris, and the overlying dolostone is a classic cap carbonate (noted atop many Neoproterozoic glacial deposits worldwide). Combined with the record from underlying units, the Death Valley succession would then unambiguously record three discrete Neoproterozoic ice ages with cap carbonates in a single succession. Alternatively, the sequence boundary could represent local tectonic activity rather than glacioeustacy. her than glacioeustacy.
