Holar Sepp
University of Tartu
13 Papers
37 Citations
Holar Sepp is an academic researcher from University of Tartu. The author has contributed to research in topics: Anoxic waters & Chemistry. The author has an hindex of 5, co-authored 9 publications.
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Papers
Hydrothermal dedolomitisation of carbonate rocks of the Paleoproterozoic Zaonega Formation, NW Russia — Implications for the preservation of primary C isotope signals
Timmu Kreitsmann,Marian Külaviir,Aivo Lepland,Kärt Paiste,Päärn Paiste,Anthony R. Prave,Holar Sepp,Alexander E. Romashkin,Dmitry V. Rychanchik,Kalle Kirsimäe +9 more
TL;DR: In this article, the authors focused on a key interval of carbonate rocks in the upper part of the Zaonega Formation to obtain new high-resolution carbon, oxygen and strontium isotope data complemented by detailed petrography and mineralogical characterisation and showed in greater detail how magmatic hydrothermal fluids induced dedolomitisation and altered geochemical signals.
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Oxygenated conditions in the aftermath of the Lomagundi-Jatuli Event: The carbon isotope and rare earth element signatures of the Paleoproterozoic Zaonega Formation, Russia
Timmu Kreitsmann,Aivo Lepland,Michael Bau,Anthony R. Prave,Kärt Paiste,Kaarel Mänd,Kaarel Mänd,Holar Sepp,Tõnu Martma,A.E. Romashkin,Kalle Kirsimäe +10 more
TL;DR: In this paper, a multiproxy study of the Zaonega Formation of the Onega Basin (NW Russia) has been conducted to understand what led to the initial rise (great Oxidation Event, GOE) and postulated fall in free atmospheric oxygen and associated high-amplitude carbon cycle excursions, the Lomagundi-Jatuli Event (LJE and subsequent Shunga Event during Paleoproterozoic time.
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Redox zonation and organic matter oxidation in palaeogroundwater of glacial origin from the Baltic Artesian Basin
Joonas Pärn,Stéphane Affolter,Jüri Ivask,SC Johnson,SC Johnson,Kalle Kirsimäe,Markus Leuenberger,Tõnu Martma,Valle Raidla,Stefan Schloemer,Holar Sepp,Rein Vaikmäe,Kristine Walraevens +12 more
TL;DR: The distribution of redox zones in the anoxic O-Cm aquifer system is unusual as discussed by the authors, and strong reducing conditions are found near the modern recharge area characterized by low concentrations of sulphate.
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Hydrothermal fracture mineralization in the stable cratonic northern part of the Baltic Paleobasin: sphalerite fluid inclusion evidence
TL;DR: In this paper, calcite-sphalerite-bearing veins in a Silurian carbonate sequence in the Kalana quarry, central Estonia were studied to characterize the properties of the mineralizing fluids in the northern Baltic Paleobasin.
10
Constraining the conditions of phosphogenesis: Stable isotope and trace element systematics of Recent Namibian phosphatic sediments
Kaarel Lumiste,Kaarel Mänd,Kaarel Mänd,Jake V. Bailey,Eva E. Stüeken,Kärt Paiste,Kärt Paiste,Liisa Lang,Holar Sepp,Aivo Lepland,Kalle Kirsimäe +10 more
TL;DR: In this article, the trace element and stable isotope composition of Recent in-situ phosphatic sediments off the coast of Namibia was investigated, showing a shift from sulfidic to sub-oxic conditions, coinciding with the maximum in solid calcium phosphate mineral concentration, and unidirectional changes in Mo and Re enrichments and TOC abundance.
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