Association of phosphate with rhyolite glass in marine Neogene tuffs from Patagonia, Argentina
The precipitation/replacement of Ca-phosphate is a complex process that commonly takes place during the early diagenesis in marine sediments. The unusual occurrence of shallow marine, early diagenetic phosphatic deposits associated with glassy tuffs in the Neogene Gaiman Formation, in the Chubut Pro...
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todo:paper_00370746_v60_n4_p1007_Rubinstein2023-10-03T14:48:07Z Association of phosphate with rhyolite glass in marine Neogene tuffs from Patagonia, Argentina Rubinstein, N. Fazio, A.M. Scasso, R.A. Carey, S. Gaiman Formation Phosphate Phosphogenesis Tuffs Volcanic glass Complex Processes Early diagenesis Gaiman Formation Glass dissolution Phosphogenesis Reactive surfaces Tuffs Volcanic glass Calcium Deposits Hydration Lasers Phosphate minerals Phosphates Sedimentology Submarine geology Volcanoes Glass calcium chemical alteration diagenesis dissolution enrichment marine sediment Neogene phosphate precipitation (chemistry) rhyolite tuff volcanic glass Argentina Patagonia The precipitation/replacement of Ca-phosphate is a complex process that commonly takes place during the early diagenesis in marine sediments. The unusual occurrence of shallow marine, early diagenetic phosphatic deposits associated with glassy tuffs in the Neogene Gaiman Formation, in the Chubut Province, Patagonia, Argentina, constitutes a good case example for the study of replacement and precipitation of Ca-phosphate on an unstable substrate. Isocon diagrams illustrate that chemical changes during glass diagenesis include gains in loss on ignition and Ca, and losses of K. These changes are the result of glass hydration during sea water-glass interaction, together with adsorption and diffusion of ions into the bulk shard; combined, these represent an incipient process of volcanic glass replacement by Ca-phosphate. Subsequent early diagenetic P enrichment in the pore solutions led to phosphate precipitation, associated with pitting on the glass shards and pumice. The associated development of a reactive surface promoted the incorporation of P and Ca into their margins. Lastly, precipitation of calcium phosphate filled the vesicles and other open cavities, inhibiting further glass dissolution. The high porosity and reactivity of the volcanic glass provided an appropriate substrate for phosphate precipitation, leading to the development of authigenic apatite concretions in the volcanic-glass bearing strata of the Gaiman Formation. This research is of significance for those concerned with marine phosphatic deposits and sheds light on the processes of early diagenetic phosphate precipitation by replacement of an atypical, unstable substrate like hydrated volcanic glass. © 2012 The Authors. Journal compilation © 2012 International Association of Sedimentologists. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00370746_v60_n4_p1007_Rubinstein |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Gaiman Formation Phosphate Phosphogenesis Tuffs Volcanic glass Complex Processes Early diagenesis Gaiman Formation Glass dissolution Phosphogenesis Reactive surfaces Tuffs Volcanic glass Calcium Deposits Hydration Lasers Phosphate minerals Phosphates Sedimentology Submarine geology Volcanoes Glass calcium chemical alteration diagenesis dissolution enrichment marine sediment Neogene phosphate precipitation (chemistry) rhyolite tuff volcanic glass Argentina Patagonia |
| spellingShingle |
Gaiman Formation Phosphate Phosphogenesis Tuffs Volcanic glass Complex Processes Early diagenesis Gaiman Formation Glass dissolution Phosphogenesis Reactive surfaces Tuffs Volcanic glass Calcium Deposits Hydration Lasers Phosphate minerals Phosphates Sedimentology Submarine geology Volcanoes Glass calcium chemical alteration diagenesis dissolution enrichment marine sediment Neogene phosphate precipitation (chemistry) rhyolite tuff volcanic glass Argentina Patagonia Rubinstein, N. Fazio, A.M. Scasso, R.A. Carey, S. Association of phosphate with rhyolite glass in marine Neogene tuffs from Patagonia, Argentina |
| topic_facet |
Gaiman Formation Phosphate Phosphogenesis Tuffs Volcanic glass Complex Processes Early diagenesis Gaiman Formation Glass dissolution Phosphogenesis Reactive surfaces Tuffs Volcanic glass Calcium Deposits Hydration Lasers Phosphate minerals Phosphates Sedimentology Submarine geology Volcanoes Glass calcium chemical alteration diagenesis dissolution enrichment marine sediment Neogene phosphate precipitation (chemistry) rhyolite tuff volcanic glass Argentina Patagonia |
| description |
The precipitation/replacement of Ca-phosphate is a complex process that commonly takes place during the early diagenesis in marine sediments. The unusual occurrence of shallow marine, early diagenetic phosphatic deposits associated with glassy tuffs in the Neogene Gaiman Formation, in the Chubut Province, Patagonia, Argentina, constitutes a good case example for the study of replacement and precipitation of Ca-phosphate on an unstable substrate. Isocon diagrams illustrate that chemical changes during glass diagenesis include gains in loss on ignition and Ca, and losses of K. These changes are the result of glass hydration during sea water-glass interaction, together with adsorption and diffusion of ions into the bulk shard; combined, these represent an incipient process of volcanic glass replacement by Ca-phosphate. Subsequent early diagenetic P enrichment in the pore solutions led to phosphate precipitation, associated with pitting on the glass shards and pumice. The associated development of a reactive surface promoted the incorporation of P and Ca into their margins. Lastly, precipitation of calcium phosphate filled the vesicles and other open cavities, inhibiting further glass dissolution. The high porosity and reactivity of the volcanic glass provided an appropriate substrate for phosphate precipitation, leading to the development of authigenic apatite concretions in the volcanic-glass bearing strata of the Gaiman Formation. This research is of significance for those concerned with marine phosphatic deposits and sheds light on the processes of early diagenetic phosphate precipitation by replacement of an atypical, unstable substrate like hydrated volcanic glass. © 2012 The Authors. Journal compilation © 2012 International Association of Sedimentologists. |
| format |
JOUR |
| author |
Rubinstein, N. Fazio, A.M. Scasso, R.A. Carey, S. |
| author_facet |
Rubinstein, N. Fazio, A.M. Scasso, R.A. Carey, S. |
| author_sort |
Rubinstein, N. |
| title |
Association of phosphate with rhyolite glass in marine Neogene tuffs from Patagonia, Argentina |
| title_short |
Association of phosphate with rhyolite glass in marine Neogene tuffs from Patagonia, Argentina |
| title_full |
Association of phosphate with rhyolite glass in marine Neogene tuffs from Patagonia, Argentina |
| title_fullStr |
Association of phosphate with rhyolite glass in marine Neogene tuffs from Patagonia, Argentina |
| title_full_unstemmed |
Association of phosphate with rhyolite glass in marine Neogene tuffs from Patagonia, Argentina |
| title_sort |
association of phosphate with rhyolite glass in marine neogene tuffs from patagonia, argentina |
| url |
http://hdl.handle.net/20.500.12110/paper_00370746_v60_n4_p1007_Rubinstein |
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1782029012610056192 |